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| Infrastructure | Bridge Technology |
Table of Contents
Appendix A
Appendix B
Appendix C
Appendix D
Bibliography
| NAME | OPERATOR/CONTACT | LENGTH (FT) |
LANES | TUBE | TRAFFIC 103/day |
| Wallace (Mobile) |
Alabama Highway Dept. 1701 Beltline Hwy. North Mobile, Alabama 36618 Gordon Prescott (205) 470-8280 |
3109 | 1 1 |
2 2 |
10 |
| Caldecott (Oakland) |
Cal. Division of Highways P.O. Box 559 Orinda, California 94563 E. R. Mayo (415) 848-3482 |
3610 3610 3371 |
1 1 1 |
2 2 2 |
100 |
| Posey/Webster (Oakland) |
same as above | 3545 3350 |
1 1 |
2 2 |
24.5 |
| Eisenhower (Loveland Pass) |
Colo. Dept. of Highways 4201 East Arkansas Denver, Colorado 80222 Phillip McOllough (303)623-4678 |
8941 | 1 1 |
2 2 |
20 |
| I-95 Mall (Wash. D.C.) |
D.C. Dept. of Transportation Division of Bridge Const. & Maintenance 4701 Shephard Parkway SW Washington, D.C. 20032 Daniel O'Donnell (202) 767-8528 |
3400 | 1 1 |
4 4 |
58 |
| 9th Street (Wash. D.C.) |
same as above | 1610 | 1 | 3 | 14 |
| 12th Street (Wash. D.C.) |
same as above | 729 | 1 | 3 | 22 |
| Baltimore Hbr. (Baltimore) |
Md. Transportations Authority Toll Facilities Administration P.O. Box 3432 Baltimore, Maryland 21225 B. W. Jedrowicz (301) 355-3500 |
7650 | 1 1 |
2 2 |
65.5 |
| Dewey Square (Boston) |
Mass. Dept. of Public Works 100 Nashua St. Boston, Massachusetts 02114 Louis DeFranzo (617) 727-5010 |
2400 | 1 1 |
3 2 |
125 |
| Callahan | Mass. Turnpike Authority 145 Havre Street Boston, Massachusetts 02128 William Crowther (617) 569-2106 |
5070 | 1 | 2 | 65 |
| Summer (Boston) |
same as above | 5657 | 1 | 2 | 65 |
| Prudential Center (Boston) |
same as above | 604 | 1 1 |
4 4 |
|
| Detroit-Windsor (Detroit) |
Detroit-Canada Corp. 100 East Jefferson Detroit, Michigan 48226 Ronald Delaney (313)567-4222 |
5130 | 1 | 2 | 18 |
| Lowry Hill (Minneapolis) |
Minn. Dept. of Highways 2055 North Lilac Dr. Minneapolis, Minnesota 55422 Edward Schanus (612)545-3741 |
1496 | 1 1 |
3 3 |
32 |
| Brooklyn- Battery (NYC) |
Triborough Bridge & Tunnel Authority P.O. Box 35 New York, New York 10035 Robert Martin (212) 360-3000 |
9117 | 1 1 |
2 2 |
40 |
| Queens-Midtown (NYC) |
same as above | 6272 6414 |
1 1 |
2 2 |
60 |
| Holland Tunnel (NYC) |
Port!Authority of NY &NJ Holland Tunnel 13th & Provost Jersey City, New York 07302 Frank Smyth (201) 963-5511 |
8558 8371 |
1 1 |
2 2 |
60 |
| Lincoln (NYC) |
Lincoln Tunnel 500 JFK Boulevard, East Weehawken, New Jersey 07087 Edward Bennet (201) 867-9095 |
8216 7482 8006 |
1 1 1 |
2 2 2 |
95 |
| Fort Pitt (Pittsburgh) |
Pa. Dept. of Transportation Fort Pitt Tunnels District 11-3 Pittsburgh, Pennsylvania 15220 M. A. Schrauder (412)381-1775 |
3600 | 1 1 |
2 2 |
78 |
| Liberty (Pittsburgh) |
same as above | 5690 | 1 1 |
2 2 |
50 |
| Squirrel Hill (Pittsburgh) |
same as above | 4225 | 1 1 |
2 2 |
83 |
| Allegheny (Somerset Co.) |
Pa. Turnpike Commission P.O. Box 8531 Harrisburg, Pennsylvania Kenneth Krotz (717) 939-9551 |
6070 | 1 1 |
2 2 |
20 |
| Blue Mountain (Franklin Co.) |
same as above | 4339 | 1 1 |
2 2 |
12 |
| Lehigh (Lehigh Co.) |
same as above | 4380 | 1 | 2 | 12 |
| Kittatinny (Franklin Co.) |
same as above | 4727 | 1 1 |
2 2 |
12 |
| Tuscarora (Franklin Co.) |
same as above | 5326 | 1 1 |
2 2 |
12 |
| Big Walker (Wytheville) |
Va. Dept. of Highways and Transportation Wytheville, Virginia 24382 James Smith (703) 228-5571 |
4230 | 1 1 |
2 2 |
6 |
| East River Mt. (I-77 @ W.Va border) |
East River Mountain Tunnel Star Route Box 5A1 Rocky Gap, Virginia 24366 Charles Fore (703) 928-1994 |
5400 | 1 1 |
2 2 |
6 |
| Hampton Rds (Norfolk) |
Va. Dept. of Highways and Transportation P.O. Box 3447 Hampton, Virginia 23663-0447 Raleigh Yeatts (804) 723-0761 |
7479 | 1 1 |
2 2 |
55 |
| Downtown (Norfolk) |
same as above | 3350 | 1 | 2 | 25 |
| Midtown (Norfolk) |
same as above | 4194 | 1 | 2 | 16 |
| Baltimore Channel (Bay Bridge/Tunnel) |
Chesapeake Bay Bridge and Tunnel District P.O. Box 111 Cape Charles, Virginia 23310 James Brookshire (804) 331-2960 |
5450 | 1 | 2 | 4 |
| Thimble Shoal (Bay Bridge/ Tunnel) |
same as above | 5738 | 1 | 2 | 4 |
| Deas Island (Vancouver B.C.) |
Provincial Ministry for Trans. and Highways
|
2165 | 1 1 |
2 2 |
72 |
| Memorial (Beckley WVa) |
West Va. Turnpike Authority P.O. Box 1469 Charleston, West Virginia 25325 George McIntyre (304) 348-3740 |
2600 | 1 | 2 | 9.5 |
| Tape | Contents |
| A side 1 | I-64 Hampton Rds |
| A side 2 | I-64 Hampton Rds |
| A side 3 | I-64 Hampton Rds |
| A side 4 | I-64 Hampton Rds |
| A side 5 | I-64 Hampton Rds |
| A side 6 | I-64 Hampton Rds |
| B side 1 | Baltimore Harbor |
| B side 2 | Baltimore Harbor |
| B side 3 | Baltimore Harbor; Norfolk end; Chesapeake start |
| B side 4 | Norfolk Elizabeth River start |
| B side 5 | Chesapeake Bridge/Tunnel |
| B side 6 | Chesapeake Bridge/Tunnel |
| C side 1 | I-95 Mall Tunnel |
| C side 2 | I-95 Mall Tunnel; Holland Tunnel |
| D side 1 | Lincoln Tunnel |
| D side 2 | Lincoln Tunnel |
| D side 3 | Lincoln Tunnel |
| E side 1 | Queens-Midtown |
| E side 2 | Queens-Midtown; Boston Callahan |
| E side 3 | Boston Callahan |
| E side 4 | Boston Callahan; Dewey Square |
| F side 1 | Dewey Square; Blue Mt. (PA Turnpike) |
| F side 2 | Blue Mt. (PA Turnpike) |
| G side 1 | Pittsburgh |
| G side 2 | Pittsburgh |
| K side 1 | East River Mt. and Big Walker Tunnels, VA |
| K side 2 | Lowry Hill Tunnel, Minneapolis, MN |
| L side 1 | Wallace Tunnel, Mobile, AL |
| L side 2 | Deas Island, Vancouver, BC |
| M side 1 | Eisenhower Tunnel, CO |
| M side 2 | Eisenhower Tunnel, CO |
| M side 3 | Eisenhower Tunnel, CO |
| M side 4 | Eisenhower Tunnel, CO |
| N side 1 | Caldecott Tunnel, Oakland |
| N side 2 | Caldecott Tunnel, Oakland |
| N side 3 | Unintelligible Caldecott |
| N side 4 | Caldecott Tunnel; CHiPs Sacramento |
| N side 5 | CHiPs Sacramento |
| N side 6 | CHiPs Sacramento |
APPENDIX
C Monday 29 Nov 82 7200 ft long, straight, runs north-south but ends are designated east-west to
match long-range direction. No shoulders, 2 lanes uni-directional, sidewalk,
power for lighting, standby emergency generator with limited capacity (won't run
ventilation system) dual power, no double loss in + 5 years. Serious fire would
deactivate lighting probably. Key to fire prevention: keep flammable materials
out of the tunnel. Fire extinguishers in niches @ 3-400 ft O.C.; theft no
problem; shoulders probably no impact on this. Fire main with hydrants. Direct
line to Hampton Rds FD. Four wreckers, patrol wagons, etc., ample vehicles.
Sound powered telephone system, two-way radios for tunnel comm. TV
surveillance. 16 supply, 16 exhaust fans. One ventilation section = ½ tunnel
length. Assessment of suitability: hard to answer, no experience with adverse
conditions. No real escape routes except ventilation spaces. Adequacy of
drainage and storage? Large spill would be a problem. How about pumps and sumps?
Would large spill be a problem? "I suspect so." Biggest problem would
be disposal. Basic philosophy: prohibit hazardous materials. Reputable firms
cooperative; not-so-reputable sneaking through real problem. No
"significant" fires in Mr. Yeatts' tenure. FD has been called on
occasion to assist.
Opinions on procedures allowing hazardous vehicles through tunnel: opposed to
any use. Bridge + ferry OK in Hampton Rds with some flack. Grudging acceptance
general. Maybe transit in early AM with escorts. Never during high-volume
traffic times. Possible design changes: (reluctantly put forward) safety
shoulder, expensive but perhaps useful. Preferred direction of response: with
traffic. Sometimes against. Note tunnel has no cross-tube communication.
Wreckers can be turned in tunnel. May take 2-3 hours to route traffic through
one tunnel. This is longer than effort!to clear tunnel normally takes. No system
in place to double direction in tunnel. Traffic patterns typical: balanced as to
direction except at extremes of weekends with beach traffic going to Va Beach:
Friday afternoons and Sunday evenings. Automatic traffic counting. Deluge system
to reduce temp., probably won't stop a fire. Fans will probably suffer but
should be kept running, even to destruction. Expense of high temp. fans probably
not justified.
Mr. Calvin Moxley, I-64 Hampton Rds Tunnel:
Several original vehicle fires (autos); none that spread beyond vehicle of
origin. Regular practices and drills with local fire dept's. Tunnel hose outlets
compatible with local FD equipment. Inspection stations busy checking cargoes,.
View on licensing or permit system: If only way across, might do it. Could not
afford to stop traffic even in middle of the night. Both tunnels now at
saturation point.
Emergency ventilation plans exist to sectionalize tunnel exhaust and supply
in case of fire. Ventilation ducts contain water spray nozzles to cool fumes
prior to fan. Drainage and sump system not designed to handle flammable liquid
spills. Dumping of flammable liquids into river always a problem in Hampton
Roads. Recommendations: explosion proofing of equipment subject to flammable
vapors. Restricting equipment from areas subject to fumes. Dampers could be
installed but would never have been used in either Hampton Rd tunnel. Controls
and actuators would have to be fireproof.
Against sprinkler system. "Described Seattle system too sophisticated
for us, still don't like it. Cost would outweigh benefit. Maybe OK for mountain
tunnel, but water would stay in underwater tunnel until pumped out." I-64
was suppose to have AM radio override for comm. between tunnel operators and
drivers. Did not materialize.
Jim Harrison I-64:
Suggest closed circuit TV, AM-FM radio override (not foolproof yet), loud
speakers, improvements to fire hydrant freeze protection. Wrecker with
self-contained, non-aqueous firefighting equipment to save time and waste-water
at fire scene. Emergency procedure training of operators may be large problem.
No complete ops manual; word-of-mouth training only. Procedures designed to
deliver fresh air to stalled motorists. Cars, then, may block firefighters from
entering in direction of traffic; fumes may prevent them from entering wrong
way. Test combined with training session may be good idea. Tunnel often
unmanned. Officers seldom have opportunity to fight fire. Motorists normally get
niche fire extinguisher and fighting fire when officials arrive. Maintenance of
extinguishers sometimes a problem. CO2 normally supplied. Cutting off
pumps in event flammable liquid enters drain system desired but very difficult
now (impacts dumping flaming liquid into river). Drains often blocked by dirt
and sand. Drains on both sides.
AM rebroadcast too weak to adequately communicate. New systems also have
power problems; only one system broadcasts emergency on normal AM station bands.
Lighting in new tunnel would probably fail in big fire. Old tunnel lighting
wiring embedded in concrete; would probably survive. Loudspeakers may be
beneficial; need test or evaluations from existing system. Speakers would have
to be maybe 100 ft o.c. Roof sectional dampers sounds like good idea.
Mr. Hatch I-64:
Has been with tunnel since open: No "significant" fires. Several
"consequential" fires that were confined. Only one that burned up in
tunnel. No flares in tunnel! Gasoline from accident almost reached flares set by
trooper in tunnel. Sand used to soak up flammables, but this and asphalt still
flammable. Proximity of local fire department a big factor; use personnel to
direct traffic and create access for FD equipment. Hydrants OK.
Exterior inspection of passing vehicles and halting before portal very
effective. Brake fires most common. Direct line to FD important, "life
saver". Immediate response, also check on false alarms. Everybody has
radio, so much dependence on that. Local fire chief concerned about tunnel
fires; has good training program concerning tunnel and its operation. Stress
total approach to prevention, not initial design (I think this is his point) as
best solution to safety problem. Motorist attitudes seem neutral when taken
together: some more careful, some less, some phobic, some manic. Trucks in only
one lane necessary for later cleanup and access during fire.
Drainage system may be problem, since it automatically dumps to river. Toxic
material (PCB's etc.) would be gone before it could be stopped. On other hand,
holding volatile substances for later disposal is dangerous. Also, blocking
traffic for any purpose is dangerous, causes accidents. Ventilation system
seemed to work OK during fires experienced to date. Elimination of smoke
important factor in retaining ability of trapped motorists to respond to
directions in a rational and cooperative manner.
Three important things: communications, surveillance, reaction. Communication
most important. Instructions to motorists in tunnel very important; should be
combined with contingency plans, training, and practice. Fire extinguishers
should be readily available since experience shows enough clear heads are often
available to assist or anticipate officials in fighting and containing fires.
Placement on both sides of roadway important, and at roadway level, not catwalk
level. Catwalk cars needed. Gasoline or electric power still problem. Need some
form of non-roadway transport!for delivery of monitors and for rapid response to
emergencies. Traffic control system allows rapid response to in-tunnel
stoppages. Goes with communication above. Heat sensitivity of materials
important: aluminum, brass, etc. will melt at normal fire temperatures.
Monday December 6, 1982 Tunnel open Nov 1957. One major fire March '78. Outside east portal. Oil
truck rammed by Coca-Cola truck: Coke truck fuel spilled, started fire in Coke
truck, oil truck, and load of creosoted railroad ties. Fire contained by prompt
response of local fire department. Fires inside tunnel (engine fires) contained
by force in tunnel. External inspection important, surveillance prior to portal,
suspect vehicles pulled over. Signs warning against hazardous materials. LPG,
even on recreation vehicles, prohibited.
Tunnel police trained in firefighting. Fire stations very close to each
portal, summoned by direct line. Close relationship, frequent-visits, etc.
maintained. Three governments involved: Baltimore City, Baltimore County, Anne
Arundel County. Policemen stationed 800 yds apart in tunnel. Firefighting equip
in tunnel: fire ext. also fire valves. Ext. in niche, CO2. Fire ext.
in tunnel effective; recommended. Police usually use, but motorists often help.
Truckers good, usually have own fire ext. Access to tunnel against traffic,
officer on scene diverts, slows, or stops traffic using traffic signals. 8"
fire main through tunnel, valves 300 ft o.c. 500 gpm from city main, with
booster pump. Firefighting equipment on wreckers, not sure if foam capability.
Under-curb scupper. Felt adequate in event of fuel spill. Gutters cleaned
every week (not completely maybe). Sumps adequate; performed so far as expected.
Need explosion-proof pump motor. Midtunnel sump goes to portal sump for
environmental reasons. Recommends direct discharge with filtering.
No TV surveillance; coming within year. Considered necessary in emergencies,
allows better communication. Can be used to reduce need for tunnel monitoring by
policemen. Have fire plans, exercises, training. Contingency plans include
recommended operation of ventilation system for several fire scenarios. Study of
possible automatic system underway. Sensors now automatically control fan speed.
System has been effective during minor fires experienced to date. Ceiling
dampers sound reasonable. Fans are designed for +1,000°F; on established PM
program. At full capacity can produce 50 mph wind in tunnel. Tunnel radio used
to communicate with motorists; AM only, radio must be on. Response time of
police and FD important.
Drivers may be more careful in tunnels, but about 100 summons issued each
month for lane changing (illegal) in the tunnel. Still, natural tendency for
care in tunnel helps, except at night. Extra lanes or even tubes would be
helpful. Sprinkler system considered, deleted from fear truck exhaust would set
off sprinklers, cause panic because motorists would think tunnel had failed,
i.e., was letting river in. Sprinkler system has good and bad points. Water may
spread oil fire; would have no effect on engine fire. May knock down fire and
reduce heat but would make lots of steam. Would cause accidents if activated
without warning. Road would be extremely slick from road residue, which is never
rinsed off in tunnel. Sprinklers more dangerous than helpful.
Lighting might fail during major fire. Luminaries exposed to flames and
mechanical damage. Lighting on series patterns; whole tunnel not affected.
Serious fire would require supplemental lighting, but this is standard on fire
equipment. Hazardous materials excluded from tunnel; alternate routes available,
no pressing need to accept risk of materials in tunnel.
Design of tunnels seems to be optimized as to level of risk, proximity and
cooperation of local fire department of primary importance. Computerized vent
control system desirable to assist operators in making proper decisions in event
of emergencies. Satisfied ventilation required; cool fresh air in at bottom, hot
exhaust out at top.
Six between-tube passages; could be important as survival feature if combined
with proper signs and prewarning systems, such as radio. Radio system is
installed; get many comments from motorists stating how comforting information
messages over radio are in event of stoppages. Have signs saying "AM radios
broadcast in tunnels". Equipment cost $60,000. System modified to provide
pre-recorded information messages twice during transit. Believes best
ventilation arrangement during fire to be full exhaust, curtailed supply. No
sprinklers.
Mall Tunnel, Washington D.C. (includes 3 tunnels):
Only one fire: engine wiring. Quickly extinguished without fire department
response. No fire extinguishers in tunnel; no towing or emergency vehicles. Fire
hydrants only. No manning. Emergency phones in mall; no phones, no nothin' in
9th and 12th street tunnels. Depend on passing motorists.
Water supply perhaps adequate. Drainage?: OK if working; cleaning a big
problem. Clogging attributed to inlet design and holding basin. Could or should
be much bigger. Emergency ventilation plan in "manual" (no enthusiasm
matching I-64 or Baltimore Harbor). Control room manned 24 hrs. Smoke detectors
of fan outlets only. None in tunnel; cleaning water and diesel exhaust setting
them off or damaging them would be problem. High speed fan test produced dust
cloud, elicited response from fire department. Has not been repeated. No
operating procedures to prevent dust accumulation followed.
No emergency exits except portals. No communication system, depend on fire
department. One tween tube connecting door; normally locked. Radio rebroadcast
not working from beginning. No plans to repair or replace. Tunnel too wide for
effective system, maybe. No traffic figures made recently. Lose lighting?
Possibly partially. Temperature resistance of stacks? No thought given. Fans
wouldn't stand heat. No deluge system to keep fan cool on Mall Tunnel. Signs
posted "Hazardous Cargo Prohibited"; no enforcement, no inspection. TV
surveillance system disconnected (funding); system worked OK. Incident: empty
gas truck hit wall, broke light fixtures. Full truck would have been disaster.
No way to locate fire using general public phones which are now only source of
info to operators. (Don't think much of complex Seattle sprinkler system.)
Aren't sure the kinds of fans installed. No effective lane control; lights are
ignored. No effective traffic control short of police barriers set up manually
after the fact.
Wednesday 8 December 1982, Lincoln Tunnel Admin. N.J. Holland Tunnel incident, May 13, 1949. See report. No "significant"
fires since then. Manned post at entrance to tunnel surveys vehicles, excludes
those showing evidence of hazardous materials. Checks manifests of suspect
trucks. Additional police officers assigned as vehicle inspectors during rush
hours. Exclusion program backed up by 1) cooperation with other agencies to
develop regulations and guidelines, 2) education of carriers and promulgation of
requlations and guidelines, and 3) pursuit of violators through court and
punitive action. Always policeman at entrance. Facility Operation Agents (FOA)
in tunnel. TV cameras. Traffic detection loops in tubes.
Partial shutdowns at night for maintenance. Fire extinguishers in niches on
both sides of roadway. Usually in place. 90% of fires extinguished by operators
using in-place fire extinguishers. Some CO2, some dry chemical.
Extensive training for familiarization with equipment and operating in smoky
tunnel. Expect to handle fire with tunnel equipment and personnel; would call
local FD only upon indication that fire was too large to handle at first or if
it grew beyond crew's ability to suppress. Sprinkler supply adequate. May accept
redesign of scupper drainage system for new tunnel.
Tunnel ventilation system recommended for smoke removal. Ceiling dampers
would be maintenance headache; suggest consumable ceiling panels. Fan
construction or cooling should be such that operation during fire would be
adequate to protect lives; undamaged survival of the fan should be secondary.
Communications systems should deal with motorists both inside and outside
tunnels. Motorists entering dangerous conditions despite warning signs or
instructional messages seem to be the norm. Radio rebroadcast systems cannot
incorporate the FM band.
Concerning Caldecott operation: tunnel is wider than others, with walkway at
road level. Passing is permitted, contrary to most other tunnels. Speed limit is
high (50 mph); most other tunnels have speed limits substantially lower than
open roads. These factors tend to alleviate the normal apprehension of
transiting motorists which has contributed to remarkable safety record of
tunnels. Quantification of psychological effect of these factors impossible, but
this appears significant despite its counter-intuitive thrust. Catwalk cars give
valued mobility to operators in tunnel. (Vulnerability of tunnels to terrorist
activities might change cost/benefit balance of study says Scanlon.)
Bob Martin, Triborough Bridge/Tunnel Authority, Brooklyn Flammable and hazardous materials prohibited; no checks. Personnel at portals
stop obvious violators. No shoulders; no lane changes allowed. Heavy traffic
contributes to greater accident rate; traffic backs up through tunnel from toll
booth, causing accidents, despite warning signs. Sharp curve on entry. Many
rear-enders from interface between stopped and moving vehicles. Fires have never
resulted from this condition.
Emergency vehicles are short wheel-based; normally approach emergency against
traffic. TV monitoring. Telephone used for crew communication; no radio. Signal
control stations supplement voice. Fire warning automatically activates traffic
signals; traffic stopped at portal by attendant. Vehicle has fire extinguisher
and hose. Hose never has been used to fight fire; cleanup only. Fire
extinguishers 150 ft o.c. in niches. ABC powder preferred for better control of
all fires.
From smoke bomb tests, best results achieved using all fans at high speed
(exhaust) to remove smoke and fumes. Damage to ducts and fans accepted.
Ventilation system expected to allow access to fire site, removal of motorists,
and reduction of heat. Tunnel manned 0600-2400. No automatic fire detectors,
smoke detectors, or automatic sprinklers. Water supply unlimited. Sumps
sufficient to take liquids dumped in tunnel. Disposal into river frowned on.
Stairway exit to Governors' Island for Brooklyn Battery; to ventilation
buildings at quarter points for Queens Midtown. Crossovers at mid tube and at
ventilation buildings.
Escorted transit of tunnel may be possible. Direct link to NYFD. Fussible
link panels? No thought; no fires. Fire extinguishers placed on bridges lost to
theft. Sprinkler system not recommended: have no effect on major fire, such as
Caldecott. Fan systems, especially V-belts and motors inside fan ducts, not
expected to survive, or maybe even operate for long, during fire.
Friday 10 December 1982 No "significant" fires in Boston area tunnels in plus 50 years.
Several single-vehicle fires. Fuel fires seem to be a result of tunnel upgrade
(4%). Float of carburetor sticks in open position allowing fuel to overflow and
spill onto engine exhaust manifold. May spread to rest of engine compartment and
perhaps to rest of vehicle. Unleaded gas seems to provide no natural lubrication
to carburetor parts; this compounds problem. Grade not excessive, but backup
delays are contributory, since still vehicle and idle engine speed mean more
sticking and high spill volume. Magnesium engines also factor.
ABC extinguishers 85 ft o.c. Personnel in tunnel at all times; trained to
fight fires. Could not extinguish magnesium fire! Wheels burn also. Magnesium
oxide smoke foul-smelling and dense (white). Hazardous materials prohibited,
even hay for race horses and building materials. Warning system: 28 phones 100
ft o.c.; available to guards or motorists. Well-marked and instruction placard
included. No TV surveillance. No heat or smoke detectors; No traffic flow
detectors. No such systems contemplated based on safety record of existing
system and cost of new ones. Fire stations close by; their cooperation important
factor.
Fire plan worked out 15 or 20 years ago; subject of annual meeting to review
and update, retrain new personnel, etc. Local fire stations approx. one-fourth
mile from portals. Motorists using fire extinguishers primary fire fighters;
usually react quickly and effectively. Commuter tunnel with many repeat
customers familiar with conditions and procedures. Fire extinguishers (ABC) in
use recommended by fire underwriting firm. Towtruck at portal; does not respond
to fire, experience indicates tow truck, because it responds with traffic
while opposite number switches ends, cannot respond to fire with traffic, so
lets fire departments respond against traffic and stays put. Fire
departments send equipment to both ends of both tubes. Fire alarm to department
has no other information other than location, i.e., no phone, etc. 4" wet
fire line, hose connections 100 ft o.c., no hoses.
Lines drained in winter; can be re-activated by FD. Procedures all in plan.
Line has never been used. Confident that dangerous amount of flammable liquid
could not settle in drainage system because of entry restrictions on all bulk
liquid carriers. Exhaust fans increased to maximum and supply fan shut down in
half of tube with fire; portion without fire not adjusted. No smoke-test, but
interviewee impressed with this procedure's effectiveness on several occasions,
despite initial doubts. Motorists encouraged to remain with vehicle in event of
fire (note: only small fires expected, not hazardous material fires). Callahan
tunnel fans chain drive, Sumner direct drive. Both exposed to possible
combustion products.
Emergency procedure training of all tunnel personnel imperative. Personnel
participate in live-fire drills run by Logan airport. Places little faith in
complex automatic systems. Concerning communication, bullhorns don't work:
acoustics in tunnel atrocious. Will have radio system to rebroadcast all local
AM stations with capability to override with emergency messages. No FM
capability seems to be possible; AM capability viewed as useful and popular. No
cross-tube connections in place or possible. Radio communication capability
demands systems, personnel, and procedures able to gather information, make
timely and sound decisions, and give accurate and helpful instructions.
Irresponsible use worse than nothing.
Fire would disable entire tunnel lighting, requiring firefighters to provide
own artificial lights. Sprinklers not considered an effective additional fire
protection system. People more careful inside tunnel, but certain people
inclined to caution or fearful on normal highways may get dangerously phobic
when inside tunnels. Congested traffic often brings motorists unwilling to enter
tunnels to portals. Minimum and maximum speed limits and
"stay-in-lane" regulations enforces and violators cited. Exploiting
tunnel phobia not considered effective safety ploy.
Prudential Tunnel is becoming longer (1800 to 3000 feet) through air rights
enclosure. Existing tunnel has longitudinal ventilation with supply fan only;
piston effect depended upon now to provide major portion. New part will have
axial exhaust fans in unknown arrangement. Traffic patterns and control similar
to I-95 Mall in DC: normal urban arterial traffic in multilane cut and cover
enclosed roadway.
Dewey Square Tunnel, Boston 10 December 1982 Tunnel part of downtown Boston's arterial system. No significant fires since
opening in 1958. Some minor vehicular fires. No hazardous materials allowed in
tunnel. No personnel in tunnel; have TV, also telephones. Large Boston FD
station within 1000 feet of portal. Dry stand pipe through tunnel activated by
gate valves outside tunnel. Type ABC fire extinguishers in niches about 300 ft.
o.c., two units per niche. Regularly inspected. Believe public is aware of
extinguishers because many are stolen. No shoulders, walkway only. Axial exhaust
fans under control of tunnel monitors. System is old. Probably would not survive
exposure to combustion products.
Radio system covering all AM bands has been installed in tunnel. Can be
overridden to provide messages to motorists. Loudspeakers installed but not used
for long time; now out of repair. Worked OK when kept up. (If so, why radio
system?) Traffic pattern and control similar to I-95 Mall as portion of covered
freeway. Tunnel has no assigned vehicles; depends on local law enforcement and
fire prevention resources. No pedestrian exitways; have to leave at portals or
at several mid-tunnel exit ramps.
Protruding fire hydrants subject to damage; recommend recess as standard
feature. Recommend fireproof roof structure. Fully transverse ventilation may be
too expensive, considering length. Sump and pumping system adequate but
conditions hard on components. Long lead time for replacement. Major fuel spill
would be a serious problem; sump won't hold it. Retrofit of sprinkler system
rejected because of clearance problems. (No discussion of their fire prevention
role.) TV components subject to high failure rate because of corrosive
atmosphere in tunnel. Qualified security firms reluctant to work in tunnel
environment. Trucking industry highly cooperative with tunnel authorities.
Monday 13 December 82 One Accident in 1965-66: Tractor-trailer loaded with fish oil caught fire.
(Responses and details unintelligible.) No automatic warning or communication
equipment. Expect wrecker and fire truck to fight fire; no local FD. Fire truck
has powder, foam concentrate, hoses. No water on truck; uses tunnel water from
hydrants. Fire extinguishers in tunnel. Respondent has no recall of a fire in
tunnel during his tenure (post '66). CO2 extinguishers, 6" fire
main. 35,000 gallons of water on hand for fire fighting.
Only supply fans, no exhaust. Tunnels are self-ventilating as far as CO
concentration is concerned. Four people monitor tunnel. Gasoline trucks
delivering to turnpike stations only allowed through, and then only with traffic
stopped. Other hazardous materials and other circumstances prohibited. No
organized preportal surveillance. No lane changing in tunnel. Drivers more
careful in tunnel; more alert. Sprinklers? Unintelligible response. Traffic
lights supplemented by attendants arrival at portals depended upon to stop
traffic. Smoke from fish oil fire exited tunnel successfully without mechanical
help.
Tuesday 14 Dec 82 One Fire: Deliberately set and car abandoned in empty Squirrel Hill tunnel
about 2 a.m. City fire department summoned; fire extinguished. Minor engine
fires put out with fire extinguishers in tunnel. Squirrel Hill has alarm
buttons; Fort Pitt fire alarm system being rehabilitated after several years'
out of commission. Tunnel crews respond to fire on wrecker trucks; quick
thinking motorists often fight fire with tunnel fire extinguishers. ABC powder.
Additional help summoned by radio. Crews concentrate on emptying tunnel,
stopping traffic at portals.
Ventilation system; each end of Fort Pitt has three supply fans for supply;
no constant exhaust. Large exhaust fan activated to exhaust air through supply
duct in case of emergency. Liberty has no fire main; other two have hydrants,
but dependence placed on fire extinguishers. No meetings or training sessions
with local fire departments. Recent reorganization has disrupted tunnel crew
training. No flammable liquids allowed through tunnels. No mention of active
surveillance. Cross-tube doors are not marked during present rehab.
Pittsburgh FD has requested reinstallation of old alarm and standpipe systems
in tunnels; will be too expensive, although alarm systems have been refurbished.
Manager feels he's caught between tight budget restraints on one hand and
non-quantified safety recommendations on the other. Would like to see quantified
cost/benefit analyses of safety impact of tunnel design choices. 86,000
cars/day. Prefers another method to sprinkler system, considering sub-freezing
winter temperatures. Tunnels require clearance for catwalks, cameras, signs,
etc. Catwalk in Fort Pitt has railing removed.
30 November 82 Single tube, 2-way traffic. No sprinklers. No fire detection system, no TV.
Tunnel manned by at least one person. 6" fire main; hydrants 300 ft. o.c.,
no hoses. Fully transverse ventilation. Wrecker/ fire truck has 500 gallons
water with foam, CO2 fire extinguishers, hoses. Dry chem. fire
extinguishers 100 ft o.c. Wreckers stationed at on-shore sides of islands so
both sides of one fire can be served.
One fire; truck blew tire, continued to drive, overturned, caught fire.
Supply turned off, exhaust on full. Wrecker put out fire before fire department
arrived. Ventilation system effective enough to allow firefighting without
breathing apparatus. No damage to ventilation equipment greater than soot
deposits. Chesapeake Beach fire department normally called (breakdown fence
access to highway available in emergencies); is professional FD at south end of
Bridge/Tunnel. Regular familiarization tours scheduled at least annually. Can
call FD dispatcher via radio link. Ocean Beach FD normal backup to Chesapeake
Beach. No fire extinguishers stolen; are beneficial during initial response to
fire.
CO2 vs ABC powder. Powder messy but more effective on more
different kinds of fires. Prohibition of hazardous cargo major factor in
preventing major fires. Restrictions may impose hardships, but protecting
structure given primary consideration. How about permit or escorted transit at
low traffic times? Would depend on frequency and amount of disruption of normal
service. Do restricted space and traffic controls encourage greater care on the
part of drivers? Believe they do, but this greater care may not offset the
actual problems caused by lack of space. Knowledge that vehicles will be checked
causes many potentially dangerous vehicles to avoid the bridge/tunnel. Shoulders
in tunnel might encourage vehicles with problems to pull off and stop, creating
a much more dangerous situation than continuing out portal. Might also provide
sleeping area for transiting motorists. Thus safety feature would be turned into
a dangerous condition by public using it as a convenience feature.
Automatic sprinkler system not deemed beneficial for Bay Tunnels. Tunnel not
constantly manned; some blind spots at ends from station. Depend on motorists
calls from telephones, all of which are well-marked, with instructions for use,
and location-coded for pin-pointing origin of call. Heat from truck exhaust may
set off sprinklers. 150,000 gallon water supply; fire hydrant adequate.
Compatible with all local fire department equipment. No idea of temperature of
air in exhaust fan during 1979 truck fire. No damage to fan. Suggest no
communication system will effectively communicate with all motorists: AM radios
may be missing or off; loudspeakers cannot overcome traffic noise. Also, man
giving instructions must be knowledgeable and wise enough to give effective
instructions. Can only be helpful if combined with TV surveillance system.
30 November 82 No "significant" fires; small vehicle fires only. No resulting
damage to tunnel fabric. Never had vehicle completely burn. Downtown 3300;
midtown 4400 ft. Midtown tunnel has CO2; downtown has ABC powder.
Like CO2 better: doesn't create mess, extinguishes more fire, leaves
cars in better condition. 300 ft o.c. Both tunnels have automatic sprinklers:
Gainwell Deluge systems. Designed only to cool air entering exhaust system. One
tunnel has only fan-room sprinklered. Automatic heat detectors activate deluge
systems.
Standpipe in tunnel with booster pump for 1000 gpm flow. Ventilation is
exhaust only (one tunnel). Expect to increase exhaust in event of fire. Both
tunnels manned. Manning may be dropped when incorporated into Interstate system.
Personnel at portals would stop traffic. Fire stations are within one half mile
of each portal. No direct lines; must call by telephone. Tunnel vehicles have
fire hoses, fire extinguishers, foam applicators. Emergency response plan worked
up by city.
Hazardous materials prohibited. Inspection stations at each portal. Easy
alternate routes available between Norfolk and Portsmouth. Belt-drive
centrifugal at downtown; Joy Axial at Midtown. (portion of interview missing)
Tunnel equipment has self-contained breathing apparatus on board.
21 February 83 Is a commuter tunnel. About a year ago had head-on in two-lane tube resulting
in fire. Sprinkler system under construction and not used. Fire extinguished by
fire depart-men. Other small fires in past; old sprinkler system Operators
monitor traffic with TV cameras; detect fires visually. No telephones operative;
no pull-boxes in tunnels. No automatic traffic counters or movement indicators.
Two fire stations available; one at each end. Lane lights indicate closed lanes,
but reliance placed on personnel or RCMP highway patrol to actually stop
traffic. Wrecker has self-contained fire extinguishing equipment, dry chemical
extinguishers every 70 ft in tubes. Effective in putting out small fires.
Tubes have connecting doorways, but no real room for people to stand in other
tunnel, since there's no walkway. Ventillating fans are 2-speed reversible; fire
department will direct use of fans. During head-on just inside south end, north
fan put on exhaust. Did not clear fumes from burning fires. Fire department
standpipes outside each end and at every third door; supplied from municipal
water system. System is dry; needs about 4 minutes to charge standpipe/
sprinkler system inside tunnel. New system has not been used as yet. Hazardous
materials prohibited. Drainage system not fireproof. Believes motorists drive
more slowly and carefully in tube, but special entry conditions at portals
congest entering traffic, which opens up as motorists accelerate through tunnel.
17 February 1983 Tunnel not manned. 25 cameras in tunnel; two men monitor in central control
room. Surveillance includes approach interchanges. Supply ducts under roadways,
290,000 CFM normal, 700,000 CFM max. 2½" hoses in tunnel; expect
professionals to extinguish fire, not motorists. Pull boxes in tunnel but depend
on TV monitors.
One vehicle fire, recreational van's fuel pump hose ruptured, raw fuel caught
fire. Lots of smoke. Van burned completely because smoke prevented firemen's
access. Firemen recommended minimum ventilation during fire; Mr. Prescott
believes full ventilation may have facilitated access and allowed extinguishing
of fire before burnout. Occurred about 2:00 a.m. No other cars entered tunnel;
light traffic was stopped by personnel. Reports motorists do not heed lit
warning signs.
Linen fire hoses no good; prefer poly-ethylene. Fire extinguishers in tunnel
not used on real fire yet. Occasionally stolen. Commercial wrecker used to
remove breakdowns. No lane changing restrictions. Foam capability in low-point
sump. Hazardous materials prohibited by signs; spot-check enforcement only.
Another commuter tunnel. High-volume traffic produces piston effect. No
sprinkler systems.
Would advocate manual actuation if sprinklers were present. Believe
sprinklers would be helpful but full of problems. Hazardous material transit
with permit? Would be opposed even with escort, for legal liability reasons, not
safety reasons. Reasonable alternate routes available.
24 February 83 No flammable or explosive materials (20 lb LP tanks on campers okay). No
inspection or enforcement by tunnel operators. Tunnel not manned; TV camera
surveillance. No "significant" fires. One was result of collision.
Ceramic tiles spalled from heat. City FD responded to fire and extinguished with
dry chemical. Call phones in tunnel. Believe TV detected fire. Five
extinguishers in each barrel 20 lb dry chem. in niches. Several have been
discharged or stolen. No shoulders, but tunnel is in densely populated area with
light traffic in early morning, allowing mischievous drivers access and
opportunity.
Dry fire line needs to be charged from convenient hydrant above ground. Only
two outlets per tube; no sprinklers. Feel no need for additional fire prevention
systems in tunnel. Motorists generally familiar with tunnel and show no signs of
greater care.
Four 150 Hp fans; one runs at low RPM 24 hours. Auto CO2 system
controls additional fans. Fans supply through 2 louvers in ceiling. Cannot judge
effect ventilation had on fire. Efficacy of ventilation for smoke removal would
depend on position of fire. Drains often fouled by debris and tracked-in dirt,
especially in winter. No cross-tunnel doors; only escape out portals. Believes
officials necessary to halt traffic; signs usually ineffective.
Big Walker Tunnel, Virginia No "significant" fires. Telephones in tunnel; "fire" and
"help" buttons 100 ft. o.c. Portal traffic control lights. Tunnel fire
truck, pumper, with foam capability. Volunteer fire departments about 6 miles
away; would be called by phone. Fire extinguishers in niches; would expect
motorists to use effectively. No standpipe. In event of fire would shut down all
supply fans, activate exhaust fans full speed. Some hazardous materials
restricted (gasoline but not fuel oil prohibited). Fans are chain-driven
centrifugal.
18 February 83 No "significant" fires; one truck brake fire. Apparently observed
entering tunnel; immediate response. Telephones and fire/help buttons to control
room. Same fire truck as at Big Walker. No stand pipe. Exhaust fans activated
for truck fire; effective in removing smoke. 6-7000 vehicles/day. 5654 ft. Fire
extinguishers in tunnel; none stolen. Drainage system often stopped up with soda
and beer cans, styrofoam cups. Treatment plant serves tunnel drainage, provides
water for washing. Believes supply fans could serve ventilation needs of tunnel;
doesn't think any ventilation system would help in major hazardous material
fire. Solid state fan and lighting control system reliable but impossible to fix
on site upon breakdown. Highly susceptible to lightning transients.
Eisenhower Tunnel 9 March 83 No "significant" fires; all minor mechanical or cargo fires. Fuel
tank fell off auto, dragged out of portal, burst into flame. All fires
extinguished very quickly (within minutes). Tunnels tend to be safer because
curves are gentle and intersections or transition points are generally missing.
Hazardous loads rerouted over passes weather permitting. Amounts of flammable
liquids controlled depending on packaging. When pass closed, tunnel cleared to
run all hazardous material trucks at 750-1000 foot intervals through, hourly.
Portal guards inspect trucks; expect cooperation from truckers and get it. Fires
detected through TV surveillance, tunnel phones, people in pulpits or on
catwalks, frequent work crews. Tunnel not normally manned. 11 traffic control
stations (800 ft. l.c.) with loop detectors. Computer sets speed limits; warns
of stoppages.
Crews on combination wrecker/fire truck (Holland Tunnel Design) respond.
Rescue truck at east portal with large dry chemical extinguisher. Goes in with
traffic normally. Fire extinguishers in niches, fire hydrants 250 ft o.c.;
120,000 gallons storage. Stand pipe has not been used for fire fighting.
Ventilation system can draw out blue smoke from supercharged failures, but after
very long lag. Vehicular movement through long tunnel sets up piston effect in
direction of travel. Residual flow would carry combustion products away from
traffic for some period after fire, creating safe area in front of fire until
firefighters arrive.
Cross-adits 200 ft o.c. identified over doorways as "Fire Exit".
Tunnels drain east; waste treatment plant at east portals. Flammable liquids
would gather in sedimentation tanks, which overflow to underground holding
tanks. All equipment is explosion proof; all entries gas-tight. Plan to manage
spill promulgated. Valves positioned manually. Some volunteer fire departments
within 10 miles can be summoned. Professional units at Idaho Springs 18 miles
east. No special training in fighting "tunnel fires"; compatibility of
equipment has been checked. Departments summoned by phone only.
Believe exhaust necessary for safety of tunnel occupants during fire, provide
access for firefighters. Dearth of fire history leaves lack of definitive
answers to design problems, need well-thought-out test program. Cross-adits with
signs and location lights highly recommended; could have saved lives at
Caldecott. Stand pipe never yet used to fight fire. Presence re-assuring, can be
used to clean up afterwards, but assumed ineffective on flammable-liquid fires.
Remote tunnel should have 500 gpm (two fire hoses) minimum flow capability with
150,000 gallon minimum storage if 500 qpm source is unavailable.
Colorado Highway Department performs accident rate analyses on segments of
highways to identify high-risk areas and the features making them so.
Cost/benefit analyses are performed on improvements to alleviate these features.
Use $170,000 per fatality in addition to actual medical costs and property
damage. Has similar-studies for tunnels. Believes adequate lighting to be a
cost-effective safety benefit. Backup condition develops at short tunnels east
of Idaho Springs when skiers return to Denver Sunday evenings producing many
rear-end collisions at entrances to poorly lit tunnels.
Westbound traffic experiences 3000 ft rise up to and through tunnel (high
point is at west portal) whereas eastbound traffic has only 1000 ft rise to west
portal and downgrade through tunnel. Significantly more failures in westbound
tube vs. eastbound as a consequence.
Caldecott Tunnel, Oakland, California 7 April 82 only "significant" fire; about 10 single-vehicle fires
or fires involving two vehicles in collision annually. Hazardous material
prohibited from 3-5 pm; tunnel operators have no enforcement responsibilities or
authority. No portal inspection. California automobile inspection requirements
more stringent than other states.
Fire alarm boxes and telephones only detection systems; no manning, no TV in
tunnel; only approaches monitored. Use to have "fire" and
"help" buttons, but usually both were pushed. "Fire" button
has been eliminated. Must call fire departments; approximately 7 minute response
time. Fire extinguishers (10 lb dry) 120 ft o.c. in tubes. Fire department
vehicles usually beat state wrecker to accident site, so no extensive fire
fighting equipment is on wrecker. (Description of fire department response:
"Orinda enters against traffic" reveals typical incident occurs in
eastbound (upgrade) tubes similar to Eisenhower.)
Stand pipes with hydrants 250 ft o.c.; connected to city water. Has capacity
in excess of 500 gpm. Drainage system can divert hazardous liquid to holding
tank. Ventilation system only needed in old bores; new westbound tube is
self-ventilating from traffic flow. Old (middle) tube still needs supplemental
ventilation even with westbound traffic. Natural flow from bay inland not as
effective in old tubes as in new; slower upgrade traffic doesn't induce flow as
readily as faster down-grade traffic.
Ventilation automatically activated by CO monitors at early stage of 7 April
fire; soon shut off because CO level fell below actuation point. Fire department
did not want exhaust fans reactivated by override. Fire department considered
knowledgeable and responsible agents in this. Do not believe exhaust system
would have had any effect. West portal placement of fans means combustion
products would have had to be pulled from far side of fire. No formal training
or exercises with fire departments, but 8-10 small fires per year keeps them in
practice.
Sprinkler system would have had no effect. Foam would have impeded traffic.
Sprinklers would have no controlling effect on commonly occurring under-hood or
inside-passenger compartment automobile fires. Hydrant system positive benefit.
Alternate routes available for hazardous materials but only along long
stretches of roadway less suitable than US 24. Believe accidents rate inversely
proportional to lane width; don't know of any studies supporting narrower lane
widths for safety. Don't believe bus driver would have been deterred from
passing gas truck by narrower tunnel on 7 April. 2-lane segment of San Mateo
bridge has far more rear-end accidents than 3-lane segment with shoulder. Tunnel
has 4 cross-adits. Not marked as emergency exits; not recommended as refuges
during fire: not ventilated; no place at other end to avoid traffic. No
provisions for handicapped access.
Posey-Webster (same crew as Caldecott):
One small vehicle fire; fire department turned fully trans-verse ventilation
system full on, went to fire and extinguished it.
California Highway Patrol Office CHiPs report!did not address post accident conditions. Would not hazard guess
as to tunnel roadway features contributing to accident or fire. Re foam:
ex-firefighter interviewed says foam would impede motorists trying to leave area
of a fire (Russ Meyer says foam is no slicker than wet pavement) tunnel full of
foam bubbles would be disconcerting at best.
APPENDIX D 1. Autostrada Tunnels Near Genoa, Italy
The following information was obtained during a visit to the Azienda
Natzionale Autonoma delle Strada (ANAS), Genoa, Italy, on September 7, 1983. Mr.
Neonnio Paolucci, chief engineer of ANAS, was in charge of the group that
conferred with the investigator and accompanied him on an inspection tour of
some of the tunnels. The ANAS office is at Via Savona 3, Genoa, Italy, telephone
(010)594485.
The tunnels visited are on the main autostrada (or super-highway) which runs
from Pisa along the Mediterranean coast passing through LaSpezia, Rapollo,
Nervi, Genoa, Savona, Albenga, Imperia, San Remo, and Ventimiglia to the French
border. There are similar tunnels on three autostrades leaving Genoa and Savona
for Turino and Milano.
Autostrades in Italy were built on a competitive basis by private companies
bidding to design, build, finance, operate, and maintain a section until the
debt is retired by collected tolls, when the entire highway becomes the property
of the Italian state.
The autostrades have over 500 kilometers of roadway in tunnels along these
routes. There are approximately 90 tunnels, from less than 100 meters to as long
as 3,000 meters. Most are between 100 and 600 meters. The tunnels are lined with
reinforced concrete in a circular arch design. In some cases, the lining seems
to be of stone or concrete blocks. Most of these highways are now dual-divided
with either four lanes, two in each direction, or six lanes, three in each
direction. Initially, sections of this autostrada were constructed with only two
lanes, half of the roadway which exists today, with one tube carrying two-way
traffic.
The roadway is approximately 12 feet wide. Two-lane bores have a sidewalk
about 2 feet wide on either side; between the edge of the sidewalk and the
tunnel wall there is an 8-or 10-inch gutter which carries away water seeping
down the wall. Each tunnel has a proper name appearing on a sign on either side,
as do the bridges. The length in meters is usually given.
These tunnels have no tile or other reflective surface on either the walls or
a ceiling, nor the high quality lighting system which we see in the United
States and in some of the longer mountain tunnels between Italy, France, and
Switzerland. Tunnels are never washed.
Tunnels under 1,500 meters (5,000 ft) have no ventilation system, no
emergency call (SOS) boxes within the tunnels, no fire hydrants with fire mains,
and no niches with fire extinguishers. Ventilation is induced by the piston
effect of the moving traffic; only tunnels longer than 1,500 meters (or about
5,000 feet) have mechanical ventilation, fire protection, or user safety
systems. These are equipped as follows:
ANAS engineers demonstrated a new type of CO monitoring system. Located in
the passageway between the two bores of one of the longer tunnels, the sampler
consisted of a single infrared analyzer which compares the tunnel air to
standard gas from a bottle mounted in the unit. Six points in the tunnel were
sampled in sequence.
There is no traffic signal system in any of the tunnels.
There are no laws in this part of Italy restricting any kind of hazardous
cargo from using the autostrada or any of its tunnels. This investigator
observed many gasoline and fuel oil tank trucks which appeared to be in the
8,000- or 9,000-gallon range. Propane, liquid petroleum, and trucks carrying
pressurized gases were also numerous.
There are no heat, fire, or smoke detectors installed anywhere in these
tunnels. A fire would be reported only by a user talking to the central control
room, which typically supervises an entire length of autostrada under the
jurisdiction of one company.
Local fire departments are depended upon to control fires in these tunnels.
The control room must call the appropriate fire department through the
commercial telephone system; there are no direct lines. Training and practice
sessions are conducted on a semi-annual basis to familiarize the firemen and the
autostrada personnel with the problems associated with tunnel fires. Obviously,
there are many fire jurisdictions involved.
The lighting in the tunnels varies considerably. Fluorescent and low-pressure
sodium are the most common fixtures, with low pressure sodium in the entrance
and exit zones to boost the lighting level there. In some instances,
high-pressure sodium lights have been used in the entrance transition zones.
This investigator felt the lighting to be adequate. (Some of the driving was
done during bright daylight on a sunny day.)
The shorter tunnels (less than 1,500 meters) seem to be adequately ventilated
by the piston effect. When traffic stops, this effect is lost. There are signs
in-between tunnels requesting stopped motorists to turn off their motors until
they can proceed. Thus is this problem dealt with on Italian autostrada. This
investigator walked through several of the tunnels while inspecting various
features. The piston effect is extremely strong; large amounts of air moved
through the tunnel by the moving traffic.
The Italians have taken a very practical approach to the tunnel design and
construction here. Given the number and length of tunnels, economics dictated
minimum expenditures on construction, operation, and maintenance of these
tunnels, except for the longer ones. A lighting system is the most common
refinement; everything else apparently has been ruled out as too costly.
Over the years of heavy traffic, the walls and arches of these tunnels have
become flat black, the poorest reflective surface. Although the lighting is
adequate under the circumstances, one cannot help wonder if these dirty walls
and obscured, high level lighting are truly economic on a total life cycle cost
basis. The Italians say that, on a total life cycle cost basis, this approach,
dark walls and no washing, is the least expensive.
The Italians invented jet-fan piston-effect ventilation to keep costs
manageable. ANAS engineers indicated that jet-fan ventilation design has
advanced beyond that installed in the longer tunnels near Genoa. Current
thinking, based on tests and modeling, places fans in the ceiling only near the
entrance and exit of a tunnel, with no fans in-between. Two fans are installed
side by side--the number of such sets of fans at the entrance would vary with
tunnel length. Fan motor, conduit, automatic control, and maintenance would cost
less with this new approach, they said.
There are serious drawbacks to the approach the Italians have taken, but
these disadvantages surface only during emergency conditions, during accident or
fire. The Italians apparently accept these potential hazards, believing any
additional sophistication in these directions would be prohibitively expensive,
considering the total length of tunnel on these highways, making the project
economically infeasible.
2. Celle Ligure, Italy, Tunnel Fire
Mr. Paolucci and his staff at ANAS thought this investigation concerned
tunnel ventilation, not fire prevention and control. Consequently, they were not
prepared to discuss the fire which occurred on May 21, 1983 in the Pecorila
Galleria, near Celle Ligure. We went to the tunnel, however, and walked its
entire length, inspecting the point where the fire seemed to be the worst and
where the pavement in the roadway was rough with holes.
Mr. Paolucci told me that the accident and fire was in litigation, so he and
his staff were prohibited from providing any detailed information regarding the
fire or its consequences. He did state, however, that the accident was a result
of a minor accident which occurred near the exit portal of this 662-meter-long,
two-lane, uni-directional tunnel. As a result, traffic backed up within the
tunnel. A truck owned by a Spanish firm carrying fish and allegedly speeding was
unable to stop and collided with the stopped vehicles inside the tunnel. The
driver chose to drive in the middle of the road, that is, between the two lines
of vehicles, thereby smashing cars in both lanes. As the result of the
collisions (exact number unknown at this time), there was a fire caused by the
ignition of gasoline and other fuels from ruptured tanks. Nine persons burned to
death, but apparently only because they could not leave vehicles distorted by
the collisions. There were some 20 other persons injured in the accident and
fire. The truck driver lived, but was badly injured. He is in the hospital and
under guard because he will be jailed until a verdict is rendered in his trial.
He may have been drunk, but that is not certain.
Help was summoned to the scene by witnesses using a portal SOS box. Details
concerning how the fire was fought, how long it burned, and a host of related
questions will have to await the end of litigation. A copy of the report!will be
obtained with the aid of Mr. Paolucci and the American Counsel in Genoa as soon
as it is available.
As was stated, this tunnel is 662 meters long, almost 2,200 feet. Since the
walls of these tunnels are flat black from the years of use, it was impossible
to ascertain from the smoke patterns on the wall and ceiling which way the smoke
went from the fire scene. The only real evidence of the fire are the ruts in the
pavement about half-way through the tunnel and the obvious damage to the
lighting fixtures no longer functioning. A temporary string of mercury vapor
bulbs has been installed high on one wall to provide lighting until the damage
to the lighting system and pavement can be repaired. Mr. Paolucci said that,
because of the heavy traffic and the hazards of putting two-way traffic in the
companion bore for the time it would take to repair the tunnel, repairs had been
indefinitely delayed.
3. St. Gotthard Tunnel
The St. Gotthard Tunnel is the longest road tunnel in the world, 16.3
kilometers, portal to portal or slightly over ten miles. The tunnel lies
completely within Switzerland and passes between the Swiss Cantons of Ticino on
the south and Uri on the north. Tunnel construction started in 1969 and opened
to traffic in 1980. The connecting roads north and south of the tunnel each have
four lanes of traffic; the tunnel has only two lanes.
The tunnel was designed by Electrowatt in Zurich. The tunnel has two bores;
the larger, which handles the traffic, is a typical mountain tunnel with an
arched ceiling. The traffic lanes are 7.8 meters wide and the ceiling 4½ meters
high. Fresh air and exhaust air ducts are placed in the arch above the ceiling.
The second bore is a safety or service tunnel, built to the east of the main
tunnel and positioned to be the start of a second traffic bore if and when such
a bore is ever constructed. The safety tunnel has a 7½ meter square
cross-section (which is sufficient to accommodate a small jeep) and is equipped
with supply ventilation entirely separate from that in the traffic bore.
The main traffic tunnel has enlargements at both sides of the tunnel every
750 meters to provide a parking space for cars. It has sheltered rooms every 250
meters for the safety of persons in the tunnel. These sheltered rooms are
between the main and safety tunnels. A stainless steel, 24-hour-rated, fire door
separates the main tunnel from the safety space. There is an SOS box in the
safety space with two fire extinguishers and an intercom to the control rooms at
either end of the tunnel. Another fire door leads to the safety tunnel. Escapees
can travel by jeep or on foot to a portal.
There are four vertical or inclined shafts to the surface along the tunnel.
These shafts were bored by machine. They are partitioned to form two ducts, one
for fresh air and one for exhaust. Fan rooms are located above the tunnel where
shaft and tunnel meet.
The roadway is 1,081 meters above sea level at the north portal and 1,145
meters at the south portal. These low-altitude access roads make this tunnel
safe and convenient year-round because snow removal is not as difficult at these
altitudes as in high-altitude mountain passes.
The tunnel bores have been lined with reinforced concrete. A poured ceiling
forms the duct space above the roadway. Traffic bore sidewalls have a void space
behind for handling seepage. Each side of the roadway has a slightly elevated
sidewalk .7 meters wide. Underneath are cable ducts and a fire main connected to
fire hydrants spaced at intervals along one side. The wall lining panels are
light tan epoxy.
The tunnel ventilation is a fully transverse system divided into nine
sections. The total capacity is 2,150 cubic meters per second, enough to
accommodate a calculated 1,800 vehicles per hour per lane (3,600 vehicles per
hour both lanes). There are six fan rooms: one at each portal and one under each
of the four vertical shafts. Each duct, whether supply or exhaust, has just one
fan, an axial flow with controllable pitch blades and two-speed motors. The fans
are 3.42 meters in diameter, although some smaller systems have smaller fans.
Motors are installed in the hub, and are cooled by a separate fan and duct. The
fans are placed above the roadway ceiling; a removable panel provides access
underneath the fan. The fan supports are designed to allow fan removal through
the ceiling opening by a special truck that lowers the fan and carries it out of
the tunnel.
There is space above each fan to open and remove the upper half of its
housing tube, exposing the motor, blades, bearings, and hydraulic pitch
controlling mechanism for service. All of these components can be changed with
the fan in place.
Each fan has heavy-duty multiblade dampers between fan and air shaft and
between fan and duct. Damper and duct arrangements bypass the fans so that stack
effect ventilation can be used when traffic and atmospheric conditions permit.
Switchgear, batteries, and transformers serving the lighting and ventilating
fans for that section of tunnel are installed in auxiliary spaces in each fan
room. Air conditioning units keep these rooms at a comfortable temperature
year-round. Each fan room has a control panel for the systems in its tunnel
section. Each section has a carbon monoxide (CO) analyzer in the fan room to
operate the fans and stack effect ventilation bypass. It controls through the
computer, by a separate automatic fan control system independent of the computer
system, and can be manually overridden from the central control rooms or
locally.
The total connected load for the ventilation system is 23,000 kilowatts. The
longest ventilation sections are approximately 2,500 meters, under the highest
mountain peaks. The fresh and exhaust air ducts above the ceiling vary in cross
section area depending upon the length of the particular ventilation section
being served. Generally speaking, in the north sector, where there are more
frequent shafts to the surface, the fresh air duct is 7.3 square meters and the
exhaust 5.7 square meters. In the south sector, where the ventilation sections
are longer, the fresh air duct is 13.5 square meters and the exhaust 10.5 square
meters. Note that the fresh air ducts are larger than the exhaust air ducts in
both cases. The system is fully transverse: small ducts behind the sidewalls
serve outlets above the sidewalk on one side of the tunnel. Exhaust air ports
are spaced every 25 meters along the roadway ceiling.
At the most-centrally-located fan room, there is a separate ventilation
system supplying fresh air to the safety tunnel. There are three fans: one for
normal ventilation, one spare, and a larger one for emergency conditions. Safety
tunnel air is supplied at a pressure higher than the traffic tunnels .
The lighting system was designed to provide obstacle identification day and
night at the limits of the stopping distance. A continuous, single-lamp strip of
40-watt fluorescent lamps is installed in the eastern lateral corner of the
tunnel section. The road-level illumination meets international and U.S. DOT
recommendations. The output of each lamp can be regulated in steps to adjust
illumination to the traffic volume.
Every tenth lamp is fed permanently through a static inverter connected to a
220-volt battery system, retaining one-tenth of the illumination in a power
failure. In addition to this normal tunnel lighting system, there is an
incandescent emergency lighting system on the tunnel east wall about 50
centimeters above the sidewalk at 50-meter intervals. These lamps are connected
directly to the battery system and, upon notification of an emergency, come on
automatically to provide lighting lower than the normal lighting at the corner
of the ceiling above. Additional high-pressure sodium fixtures installed near
the portals are automatically adjusted to outdoor illumination.
The illumination level of the tunnel can be controlled manually from the
control room. Some statistics: the number of fixtures, 14,000; the installed
lamp load, 1,000 kW; and annual energy consumption, 4,000,000 kilowatt hours.
All tunnel systems can be controlled by a Seimens computer located in the
south administration building using software specific to St. Gotthard. Each
system can also be operated either by its own separate automatic system or
manually from the north or the south control rooms and from panels in the fan
rooms.
In terms of fire prevention, this tunnel is covered under European Common
Market regulations which prohibit vehicles carrying any cargo classified as
hazardous in a published list. These regulations also require that vehicles
carrying these cargoes have placards depicting the hazardous material and the
best fire control method, i.e., foam, water, or powder. The St. Gotthard Tunnel
is not a toll facility and does not cross an international border, so there are
no custom inspections at the portals. Most Swiss and Europeans are law-abiding
in regards to this particular law, however, and the tunnel personnel believe
hazardous cargoes transit the tunnel seldom, if at all.
The tunnel has three fire detection systems. The first is a series of
detectors installed on the ceiling at 25-meter intervals. These detectors are
manufactured by Cerberus, a subsidiary of Electrowatt. They have two stages; the
first stage more sensitive than the second. Upon sensing a fire, the following
occurs: The supervising personnel in the control room are alerted by optical and
acoustical signals; the position of the detected fire is shown on a special
panel-display in the control room; the TV system is switched on; the tunnel
illumination rises to maximum level; the emergency lighting is turned on; and
the ventilation system is switched over to "Fire Program". When the
less-sensitive second stage of a fire detector is activated, the fire department
is summoned.
The second means of detection, SOS cabinets, allow a person calling the
control room to hear and speak despite noise in the tunnel. These cabinets also
have two dry powder fire extinguishers. If a fire extinguisher is removed from
the cabinet, an alarm sounds in the control room and tunnel systems respond as
they do when the first stage of a fire detector is triggered. If the control
room decides that help is needed, a message appears on a screen in the box
indicating in several languages that help is on the way.
The third means of detection, traffic loops, are embedded in the roadway and
tie into the computer, which keeps track of the traffic flow. The system is
sensitive enough to detect a single vehicle stopping. An alarm is sounded and
the monitor automatically shows the view from the nearest TV camera. Traffic
signals turn red or flash yellow behind the vehicle involved on both roadways to
warn motorists that there are problems up ahead.
There is an emergency fire station near each portal, each equipped with three
fire engines. All three can attach to the fire line hydrants in the tunnel and
have ample hoses for fighting fires. One is equipped with foam and the others
with dry powder; all are equipped with first aid kit, resuscitators, and all
other normal emergency equipment. They also serve as tow trucks, with equipment
necessary to free people from damaged vehicles, perform minor repairs, and tow
the vehicles from the tunnel. Each is equipped with a two-way radio which
transmits in the tunnel through a relay system.
When a vehicle enters one of the tunnel turnout spaces, detection loops in
the pavement alert the control room and television monitors cover the area. Each
safety room is equipped with fire detectors tied into the computer, a first aid
kit, and battery-powered emergency lighting.
Each of these interacting systems is described in more detail below.
Traffic Control System. Traffic signals are placed on both tunnel
sidewalls every 250 meters. They are normally off, but can be switched on
manually by police personnel if needed. In case of fire or excessive
concentration of carbon monoxide, they are automatically switched on as
described above.
SOS Stations. Alarm boxes installed inside the tunnel allow the road
tunnel patron to summon help in case of need. They are placed every 125 meters
on the west side and every 250 meters on the east. Each box contains a telephone
direct to the control room, a single alarm button in case the telephone is not
operating or cannot be used, and two portable fire extinguishers. The alarm
boxes are marked by an illuminated signs. Lifting the telephone receiver or
removing a fire extinguisher prompts the traffic lights to interrupt traffic
flow and activates the TV system.
Television System. 83 television cameras are placed every 250 meters
or so, affording the control room staff a view of any situation along the tunnel
through ten monitors. The cause of a disturbance can be identified and
appropriate countermeasures initiated without delay. The TV system does not
operate continuously; it is automatically activated under circumstances
described above, but it can be switched on manually if required.
Radio and Broadcast Facilities. Overhead cables connect to a repeater
system and allow reception and transmission of all eight frequencies used by the
police and maintenance organizations of both Cantons. According to the Swiss,
communication from the control rooms to service vehicles is vitally important in
an emergency. The radio system is arranged so service is not disrupted, even if
several cables are damaged. The same aerial cable also transmits FM broadcasts
from both Cantons for reception by standard car radios. Important messages
relevant to the safety of the travelers may be passed to drivers tuned to these
frequencies, interrupting the FM broadcast program. The same equipment permits
national car telephone service-equipped vehicles to call anywhere in the world.
Electrical Power Supply. Electrical power comes from two different
networks, with a line voltage of 50 kV. If one supply networks fails, the other
can take over 75% of the total tunnel load, corresponding to 1,500 vehicles per
hour in each direction. Emergency power supplies are installed in each fan room
and control room. They consist of static converters connected to 220-volt
batteries. The overall load of the tunnel is distributed as follows: 86% for
ventilation, 4% for illumination, and 10% for auxiliary equipment.
Control. The whole tunnel installation is supervised and operated from
two control rooms, one on each end of the tunnel, under the auspices of the
particular Canton involved. Signals from both the supervisory and control
instruments, as well as calls from the SOS boxes, are directed to these control
rooms. Each end controls the tunnel for three weeks in turn. About 4,000 signals
are transmitted to the control room from 11 remote stations in the tunnel. These
display the traffic situation and plant status on panels and print statistics in
Germany and Italian. The control rooms are quite striking. They are loosely
divided into two areas: the police and safety functions supervised by the
police, and operations supervised by technical personnel. The police service is
manned continuously. Its major functions are supervising the traffic flow on
access roads and inside the tunnel; operating the communication installation,
SOS, telephone, and Telex; and organizing emergency services. The major
functions of the operators are supervising all mechanical and electrical
systems, maintaining the facilities, and assisting in case of accidents or
shutdown.
There is no doubt that a tunnel of this great length presented the Swiss
design engineers with unique traffic control, safety, fire, and other emergency
problems which far exceed those encountered in shorter tunnels. The solutions
developed for this tunnel are apt; apparently little has been spared to make
this tunnel as safe as possible.
The Swiss should be commended for this tunnel's design and construction.
Design, materials, equipment, and workmanship are absolutely first class and
extremely high quality. Although the tunnel is three years old, it appears brand
new. The equipment rooms are extremely well maintained. Paint looks new and
everything is extremely clean. The only fire protection system missing is an
automatic sprinkler system. Electrowatt engineers said they had considered the
possibility of installing a sprinkler system during preliminary design, but had
rejected the idea because of the danger of superheated steam being produced,
explosive reignition of fumes, and possible destruction of stratification where
hot air and smoke is high and fresh air low.
Electrowatt indicated that the fire detectors were now working well.
Initially, the first stage was a little too sensitive and they had many false
alarms triggered by passing diesels. This has been corrected now. With a tunnel
of this length, it is important that a fire be detected early and its location
be clearly defined, so the Swiss depend on the fire detectors as their primary
fire prevention weapon. This first defense is backed up by the SOS boxes and the
traffic control loops. With the safety tunnel and the safety rooms, patrons have
a safe haven and escape route near at hand.
The ventilation system has no spare fans installed. If a fan fails,
ventilation is boosted in adjoining sections to supplement the lost ventilation.
Fans can be replaced quickly, however, and several spare fans are on hand.
Electrowatt indicated that a fan could be changed in 4 to 6 hours. This involves
shutting down one lane, usually during the early hours of the morning when
traffic is lightest.
Electrowatt acknowledged severe problems with the computer software. It is
still not functioning after three years, and the operators now prefer the manual
or the automatic backup systems. If and when the software is functional,
Electrowatt anticipates additional problems getting operating personnel to use
it after having satisfactorily operated the tunnel without software for so long.
4. Seelisberg Road Tunnel
The Seelisberg Tunnel is a twin-bore, 9.25-kilometer-long tunnel on the Swiss
National N-2 motorway connecting Basel and Chiasso. It is the longest twin-bore
tunnel in the world. The St. Gotthard, Mont Blanc, and Frejus tunnels are
longer, but they have only a single bore with opposing traffic. The Seelisberg
Tunnel is 35 kilometers from the St. Gotthard tunnel on the same route. It
bypasses a steeply sloped mountainous point which juts into Lac Lucerne, where a
shoreline highway would be very costly and longer than the tunnel.
There are two ventilation shafts from the tunnel to the surface, with fan
rooms at each intersection, creating six ventilation sections along the 9.25
kilometers of tunnel. The portals are at an altitude of 485 meters, or about
1,500 feet above sea level. The roadway grades are very slight, .45 percent at
the northern section and .6 percent in the south. Two normal cross-sections have
been used. Near the portals a conventionally-driven, full horseshoe section was
adopted. In the middle areas, a mechanically-driven circular section was used.
In the horseshoe section, ducts for exhaust and fresh air are above a ceiling,
with a partition separating the two ducts. In the circular section the exhaust
air is above the ceiling and fresh air below the roadway. The roadway inside the
tunnel is 7.5-meters wide with .8-meter-wide walkways on both sides. In both
tunnel cross-sections, the fresh air is introduced on one side just above the
sidewalk and the exhaust air leaves through openings in the ceiling. Two fan
rooms are at the portals and two are in the tunnel. One shaft is 275 meters tall
and the other runs horizontally 640 meters to the surface. The shafts are
circular with a partition to form two ducts, one for fresh air and one for
exhaust air. The walls of both tunnel sections have a curved panel mounted free
of the structural lining to provide a space for seepage. Most of the conduits
and cable ducts are under the sidewalks with the fire line and culverts for
drainage.
Ventilation for both bores has been calculated for a maximum load of 3,600
cars per hour, or 1,800 cars per lane hour. At maximum ventilation the system
can deliver 3,540 cubic meters per second of air to the tunnel. Both bores are
divided into six ventilation sections and each section is equipped with intake
and exhaust ducts similar to the St. Gotthard installation. Fresh air flues
blowing air into the roadway are installed every 8 meters. Exhaust ports are
installed in the ceiling on 16-meter centers. Fans are West German-manufactured
TLT with two-speed motors in the hub and controllable pitch blades. Dampers are
provided in the same manner as described in the St. Gotthard tunnel. Engineers
of the Canton involved insisted that fan removal and replacement be accomplished
not from the main traffic lanes but from the large cross passages between the
two bores at the fan rooms.
Continuous fluorescent strip lighting with several degrees of intensity to
adjust for day- and night-traffic are installed in one upper corner of each
traffic bore. Lighting is augmented with high pressure sodium fixtures at the
entry portals. Emergency lighting is provided as described for the St. Gotthard
tunnel.
The general installations of fire safety and traffic controls in the
Seelisberg Tunnel are similar to those in the St. Gotthard Tunnel, except there
is no safety tunnel. The safety rooms are in cross-passages between the two
tunnels and are equipped similar to those at St. Gotthard. Fire detectors, with
single-level sensitivity unlike those at St. Gotthard, are spaced 30 meters
along both ceilings. This type has been a problem, since hot diesel truck
exhaust often set them off.
TV cameras are installed every 30 meters for traffic control. The SOS boxes
are identical to St. Gotthard's, with two manual fire extinguishers, an alarm
button, intercom, and warning lamps.
Three-color traffic control lights are installed in each lane at each
cross-tunnel. These can be manually or automatically operated. Magnetic roadway
loops are tied to a computer similar to the St. Gotthard installation.
Carbon monoxide and visibility-level detectors are similar to St. Gotthard.
This facility has a control room at each portal. Differences of opinion between
Cantons have prompted certain compromises in control room design.
The fire station, some distance from the south portal, is equipped with three
impressive Mercedes Benz fire engines that look somewhat like American soda and
beer delivery trucks, with corrugated roller doors on each side. One truck is
equipped with foam, the other two with dry powder. All trucks have hoses
compatible with the fire hydrants in the tunnel. The trucks can tow a vehicle,
extricate any people trapped in a distorted vehicle, and render first aid. All
the firemen are trained to give emergency medical aid, although an ambulance is
on hand. Police cars regularly transit both bores of the tunnel every hour or
so.
In the three or so years that Seelisberg and St. Gotthard have been open to
traffic there have been no serious fire incidents. There have, however, been
numerous small fires involving the same problems which we experience in the
United States, that is, motor, upholstery, brake, and tire fires. These are
detected by the several methods described under St. Gotthard. The fires have
been extinguished by dry powder fire extinguishers from the SOS boxes or by fire
equipment. There have been no injuries and no reported problems with ventilation
or system operation.
This facility is not under computer control even after three years in
operation, a matter of great concern to Electrowatt. This is being diligently
worked on, however, and they expect the computer control system will soon be
functioning normally.
Fire tests were conducted in the Seelisberg tunnel in 1980 using simulations
of credible incidents. Three simulations were performed.
The Swiss were satisfied by the response to these test emergencies and felt
they learned much about the functioning of the fire emergency systems and
personnel.
5. Frejus Road Tunnel
The Frejus Tunnel lies between Lyon, France, and Turino, Italy, and is the
shortest route between Brest, Paris, and Lyon in France and Turino, Milano, and
Rome in Italy. There is a railroad tunnel at the same location through which the
fastest trains between Paris and Rome pass.
The tunnel is about 13-1/2 kilometers or 8.4 miles long, making it one of the
longest road tunnels in the world. The grades in the tunnel are gentle, about
1/2 percent. Both portals are roughly l,000-meters (3,000-feet) high.
The tunnel has a single bore constructed in the typical mountain tunnel
horseshoe configuration. It is lined with reinforced concrete; the fresh air and
exhaust ducts are located above a false, reinforced-concrete ceiling. A vertical
partition divides the fresh air from the exhaust. Ventilation is fully
transverse, with flues from the fresh air duct carried down the side walls to
introduce air just above the sidewalk. The exhaust air leaves the tunnel through
ceiling ports and the exhaust duct above, the same system used in the St.
Gotthard, Seelisberg, and other mountain tunnels in Europe.
The 9 meter roadways are wider in this tunnel than in others, providing
15-foot traffic lanes. There is a .9-meter-wide, elevated sidewalk at curb
height at each side, with space for cable ducts and the water main for fire
hydrants below. The tunnel is enlarged every 2.1 km into an emergency car park,
with a safety area opposite.
Shafts connect with the surface 4.2 kilometers from the Italian portal and
5.8 kilometers from the French portal. These shafts provide exhaust and fresh
air to fan rooms located at the bottom of each shaft beside the main tunnel.
Because this tunnel crosses a border, it is a cooperative endeavor between
Italy and France. There were some philosophical differences in ventilation and
other construction, design, and operating features of the tunnel: the air shafts
located on the French side have a single shaft with a partition to separate
fresh and exhaust ducts; on the Italian side there are two smaller shafts, one
for fresh and one for exhaust air.
The highways leading to this tunnel are not yet complete. Coming from Turino,
the road is winding and difficult to drive. A new highway from the portal
10-kilometers south will provide more convenient access. It is complete and will
be open in about 60 days. A superhighway from this point to the autostrada near
Turino is being planned and should be complete in about 4 years. Similar
conditions exist on the French side.
The traffic during this investigator's visit was very light. None of the
ventilation system fans were operating. Our escort noted that there were times
when heavier traffic required the fans to operate.
There are control rooms on each end of the tunnel. They are not as elaborate
as those in the Swiss tunnels, but they were none-the-less effective and
practical.
The ventilation is fully transverse. There are four fan rooms, one at each
portal and one at each shaft. There are two fans on each duct, four in each
portal fan room and eight in each of the others, for a total of 24. The
ventilation system has been designed for an upper limit of 1,800 vehicles per
lane hour, or a total of 3,600 vehicles in both directions per hour. Maximum
capacity is 1,580 cubic meters per second of fresh air and 1,300 cubic meters
per second of exhaust air.
There are carbon monoxide (CO) and smoke-level sensing systems, one set of
sensors in each section. The system maintains 100 parts per million CO, allowing
a maximum excursion to 150 parts per million. Atmospheric clarity is 15% to 30%.
This design differs from the Swiss one, with two fans on each duct. The fans are
axial flow with two-speed motors (1,000 and 1,500 rpm) located in the hub, with
18 hydraulically-controlled fan blades.
The internal fan rooms are at the side of the main tunnel between the roadway
bore and the shafts to the surface. Each internal fan room consists of a large
gallery excavated between the main bore and a shaft. This gallery is equipped
with an overhead crane. On each side of the gallery there are two exhaust fans
and two supply fans for the ducts serving both directions of the roadway on that
side. The crane can lift a fan and drop it on a truck where it can be carried to
the roadway and of the tunnel. Fans can also be serviced in position: the upper
half of the circular fan housing is removable for access to the blades, the
blade control mechanism, the motor, and the bearings. Each fan is supplied with
an automatically-controlled, heavy-duty, multiblade damper between the fan
outlet and the tunnel ducts. If a fan is to be removed, a heavy plate is bolted
on the shaft access to isolate the open fan section from the supply or exhaust
shaft. Each fan room contains transformers and switchgear for the fans,
lighting, and other systems in its section. The french supply 20 kv and the
Italians 16 kv, increased by transformers to 20 kv to match the French
potential.
Steps had been taken at the portal buildings to prevent recirculation of
exhaust or vitiated air. This was presumably the case at the shaft outlets also.
The Frejus Tunnel has lighting fixtures on both sides of the roadway in the
corner between wall and ceiling. The fixtures are not continuous. Design
illumination is 50 lux (lumen per square meter). Each fixture is a combination
of fluorescent and low-pressure sodium. With both tubes mounted behind a glass
or plastic clear lens. Entry zone lighting is augmented by more low-pressure
sodium fixtures on the walls and ceiling. Intensity can be varied according to
outside conditions.
This tunnel has niches on both sides of the roadway; one side contains a fire
hydrant and an SOS box, the other side an SOS box only. The SOS boxes contain
fire extinguishers which, if removed, sound an alarm and automatically shift the
system into the fire mode, a pushbutton for fire or emergency and a telephone.
The telephones require one to place his head between two lobes containing loud
speakers. There are signal lights spaced every 600 meters on both sides of the
tunnel which normally burn green. In case of fire, lights turn red or
flashing-yellow behind the point of emergency and green ahead.
The presence of magnetic loops was not determined.
The tunnel has 83 television cameras and two monitors in the control rooms at
each end of the tunnel. These monitors can tune to one camera each, or can pass
from camera to camera to follow a vehicle through the tunnel.
Tunnel wall panels are free of the wall to allow seepage to flow into
drainage below. On the French side these are fire-retardant, impregnated wood
panels with a painted surface of some kind. On the Italian side they are
concrete and look unfinish. The tunnel is washed at least twice per year.
The French and Italian emergency ventilation modes differ in a fire. The
Italians select full supply air and use exhaust only when smoke becomes a
problem. (The Italian engineer conducting the tour was unable to explain the
French method.)
Outside each portal is a fire station, equipped with three fire engines.
These fire engines are very similar to Seelisberg's. One engine is equipped with
foam and the other two with powder. All have hoses compatible with the fire
hydrants in the tunnel, which have nozzles with both French and Italian threads.
Fire trucks also double as tow trucks, and have dollies, jacks, equipment for
removing people from damaged vehicles, first aid kits, and stretchers.
The Frejus Tunnel has been well-designed and well-constructed. Tunnel
authorities depend upon a patron's call from an SOS box or removal of a fire
extinguisher to notify the control room of a problem. These do pinpoint the
location, however, so TV cameras can observe the problem area, the computer can
automatically place the particular ventilation sections and the tunnel
ventilation system in the fire mode, signal lights are adjusted as previously
described, fire fighters are alerted, and the engines dispatched. The fire mains
are pressurized year-round. The fire main is buried in the concrete beneath the
roadway and the fire hydrants are the regular street-type that do not freeze.
The safety areas in this tunnel exist only at 2.1 kilometer intervals; there
is no safety tunnel as in St. Gotthard. There are fire doors at the fan rooms,
however, with separate ventilation available to protect these potential refuges.
Hazardous cargoes are prohibited per European Common Market hazardous cargo
regulations.
About three months ago, a truck carrying plastic burst into flame for some
unknown reason. The truck driver used an SOS box to call for help, and the fire
was expeditiously extinguished. The tunnel roadway was damaged and the walls and
ceiling blackened, but no one was injured or killed. Here again, litigation is
involved and tunnel personnel will not discuss this matter in any detail.
6. The Great St. Bernard Tunnel
The investigator only drove through this tunnel late one afternoon; there was
no formal visit. The tunnel lies on a highway connecting Aosta, Italy, and
Montreux, Switzerland. It is 5.8-kilometers long, shorter than the other tunnels
visited on this trip, and also higher. The road leaving Aosta to the tunnel is
narrow and two-lane; and it winds up the mountain with many switchbacks. A toll
(about $10 for small car and driver) is collected at a small town some distance
from the tunnel. The tunnel highway climbs from this town to the tunnel covered
by avalanche sheds most of the way. There is no portal because the
snow-shed-covered highway leads directly to an underground area resembling a
large parking garage. Here are immigration and customs facilities for both Italy
and Switzerland and a parking area, gas stations, restaurants, stores, and
restrooms.
The tunnel appears similar to the other mountain tunnels: roadways,
sidewalks, and walls have similar dimensions. The ceiling on the Italian side
seems to be constructed of Q-deck. On the Swiss side it appears to be reinforced
concrete. From the placement of fresh air and exhaust-air flues and ports it
seems that there are three air ducts above the ceiling. Two fresh air ducts on
either side with flues coming down to supply air openings just above the
sidewalk and a centrally located exhaust duct with exhaust ports located in the
middle of the tunnel ceiling. There are SOS boxes spaced frequently along both
sides of the tunnel roadway. Pictures clearly indicate a fire hydrant, fire
extinguishers, an alarm button, and an intercom to talk with the control room.
There are signal lights on both sides spaced about 500 or 600 meters apart.
These have three lights, red, yellow, and green; the green lights were
illuminated in both directions. Every 500 or 600 meters there is an enlargement
in the tunnel to provide a parking area. Some places were much wider with doors
suggesting fan room at this point.
The walls and roadway seem to be more rough than the other tunnels seen on
this trip. The walls are very dirty, almost flat black, and show water staining
in some areas.
7. The Mont Blanc Tunnel
The Mont Blanc Tunnel opened in 1965. It is 11.6-kilometers long and passes
under the Alps near the highest mountain in Europe, Mt. Blanc. Because of its
location, it has become a very heavily traveled route between France and Italy.
Truck traffic is particularly heavy.
The tunnel has two lanes of opposing traffic. The cross section is the
typical horseshoe, but the air ducts are underneath the roadway, so it has the
arched circular ceiling typical of the tunnels seen around Genoa. The walls are
reinforced concrete with textures depending upon the lining. Years of heavy
diesel traffic have made these walls flat black
Initially, lighting and ventilation were designed for 600 vehicles per hour,
of which 10% were to be trucks. In two years of operation this 600-vehicle limit
was exceeded many times. In heavier traffic the atmosphere in the tunnel becomes
extremely smoky, which made the illumination appear inadequate and visibility a
problem.
After two years the lighting and ventilation systems were improved and the
tunnel now operates with satisfactory carbon monoxide levels. Visibility
continues to be a problem, however, but the brighter lighting has helped to keep
it at satisfactory levels. There is talk of a second bore at Mont Blanc, which
would help the situation considerably, since the traffic would be two lanes in
one direction, adding piston effect ventilation to the mechanical.
Since the mountain range above this tunnel is extremely high, (2,480 meters
of rock above the tunnel at one point, a minimum of 1,000 meters) intermediate
shafts to the surface for ventilation were considered economically unfeasible.
Consequently, all ventilation had to come from the portals. In order to provide
the large ducts necessary, they were constructed under the roadway. The initial
system had four fresh air ducts and one exhaust duct. Since the tunnel is
11.6-kilometers long, the ducts serving each tunnel half from each portal fan
room would be 5.8-km, or 18,900-feet long. Design engineers felt that a single
fresh air duct would be too long to assure even distribution to the roadway, so
the total length was divided into four ventilation sections, each 4,700 long.
Each 4,700-foot section has its own supply duct and fan in the fan house. Fresh
air flues discharge air just above the sidewalk on one side of the tunnel.
Initially, the fifth duct was for exhaust, and its capacity was approximately
1/3 the total supply capacity. Ducts high on the sidewall at rather large
intervals carry the exhaust air down to the exhaust duct below the roadway. The
other 2/3 was exhausted out the portals. This ventilation system was classified
as a semi-semi-transverse system. The improvements made after the traffic
increased beyond the initial design level converted the single exhaust duct into
a supply duct on the theory that more fresh air was needed to dilute the smoke.
All of the exhaust leaves through the portals. The velocity in the roadway at
maximum ventilation is about 17 miles per hour.
Each duct is equipped with two large bottom-horizontal discharge, centrifugal
fans in the ventilation building. Each fan has inlet boxes and shafts extend out
each side of the fan to a large motor on one side and a small motor on the
other. These two-speed motors, driving the fan through reduction gear boxes,
produce fan speeds of 1/4, 1/2, 3/4 and full.
The inlet boxes prevent air movement within the fan room. Each fan has multi
blade dampers at inlet and outlet for isolation. Fans are of French manufacture;
motors Italian. Fans, motors, and components can be removed by an overhead crane
to an area under a hatch where a truck crane can lift to the surface. The fan
rooms contain switch gear for the fans and lighting and were very neat, well
painted, and clean.
There are carbon monoxide (CO) and opacity sensing systems in the tunnel
periodically spaced along its length. These sensors relay information to a panel
in each control room, where CO and smoke levels are recorded on strip charts.
There is one set of sensors for each ventilation section, or five in one control
room, a total of ten for the entire tunnel.
NOTES FROM TUNNEL FIRE STUDY INTERVIEWS
Admin Off. Mr. Yeatts, I-64 Hampton Rds Tunnel, Va.:
Baltimore Harbor Tunnel, Mr. Jedrowicz, Associate Administrator:
Edward Bennett, Manager, Lincoln Tunnel
Frank Smyth, Manager, Holland Tunnel
Ray Scanlon, Port!Authority Hazardous Cargo Expert:
Battery and Queens Midtown tunnel:
Sumner and Callahan Tunnels in Boston, MA, Mr. William
Crowther:
Dept. of Public Works (Highway Dept.) for Massachusetts
Mr. Louis DeFranzo:
Blue Mt. Tunnels Control Room, Pa. Turnpike
Mr. Krotz:
Fort Pitt Tunnel, Pittsburgh
Mr. M. A. Schrauder, Manager of Pittsburgh Tunnels
Mr. Francis Mies, Manager of Pittsburgh Tunnels:
Chesapeake Bay Bridge Tunnel
Mr. Brookshire
Mr. James Barkroft, Chief of Police, Gene Barry, Supt. of
Maintenance:
Norfolk, Elizabeth River Midtown and Downtown
Mr. Yeatts:
Deas Island Vancouver B.C. 2,165 ft long 72,000 AT
Provincial Ministry of Transportation and Highways
Frank Blunder, Disty. Hwy. Manager
Sydney Watson, Chief Operator
Mike Moore, National Inst. LTD, Contractor (expected; no show):
Wallace Tunnel Mobile AL
Gordon Prescott Manager I-10 Tunnel
also involved with Bankhead I-10 4,251 ft:
Lowry Hill Tunnel, Minneapolis, MN
Edward Schanus:
18 February 1983
Mr. Jim Smith:
East River Mountain Tunnel, West Virginia
Mr. Charles Fore:
District 1 Office, Colorado Highway Dept.
Mr. Phil McOllough, District Engineer and Manager of Eisenhower Tunnel
Mr. Dick Johnson:
10 March 83:
Sacramento. California 11 March 83:
OBSERVATIONS OF EUROPEAN TUNNELS