The Mont-Blanc Tunnel refurbishment The Mont-Blanc Tunnel

Owner’s
Representative
Road
Infrastructures
the mont blanc tunnel
refurbishment and modernisation
france
civil engineering
underground structures
safety equipment
project management
works’ commissioning
equipments’ commissioning
The challenge
In the wake of the fire on 24 March 1999 which gutted the Mont
Blanc tunnel and led to it being closed to all traffic, administrative
and technical inquiries were held in France and Italy.
Following these investigations, a Franco-Italian report set out 41
recommendations to improve safety in 4 main areas:
upgrading safety systems,
reinforcing rescue facilities,
establishing a sole operating entity,
introducing new traffic rules.
civil engineering
The civil engineering works consisted in constructing:
a central safety control room,
116 smoke extraction flues,
37 shelters,
116 safety recesses,
78 fire prevention recesses,
4 fire hydrant reservoirs.
safety equipment
Central Technical Control of safety installations (CTC)
This computerised system for information gathering and processing allows the appropriate operating procedures for any incident
which is detected to be implemented automatically in a matter of
seconds (electronic display panels, lighting, ventilation, emergency response / triggering of automatic safety procedures).
The central safety control room
Located at the entrance on the French side of the tunnel, this
room controls allthe installations. It is backed up by an identical
safety control room located on the Italian side.
Traffic control and user information
Speed is limited to 70km/h and the distance between each vehicle must be a minimum of 150 m. Special devices check for any
infringement of these rules and provide real-time information to
tunnel users on traffic conditions and what to do in case of an
incident (electronic display panels, flashing red lights, FM radio
messages).
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Automatic Incident Detection (AID)
By analysing images from 20 cameras AID enables any traffic
anomalies to be detected in seconds so that safety and signalling
systems can be alerted via the CTC system.
Thermal imaging system
A Fire Detection system (FDS) alerts the CTC in the event of an
abnormal increase in temperature anywhere in the tunnel.
Fire-fighting equipment
The difference in atmospheric pressure between the two entrances to the tunnel creates a draught along the tunnel. In the event
of a fire, controlling this draught is vital to avoid a rapid build-up
in the tunnel and to ensure that the smoke rises to the roof of
the tunnel from where it can be evacuated.
The airflow is controlled by 76 ventilation impellers located in
the roof. The CTC automatically calculates the impeller operation
speed required.
The smoke extraction flues extract exhaust fumes during periods of operation and smoke in the event of fire. Fitted with remote-controlled doors, they are linked to the foul air duct.
The capacity for smoke extraction is 150 m3 over 600 m everywhere in the tunnel.
Safety equipment for tunnel users
Safety recesses are situated every 100 m on alternate sides of
the tunnel. Each one is equipped with an emergency telephone,
2 fire extinguishers and an alarm button.
Shelters are situated at 300-metre intervals along the tunnel.
They are completely isolated from the atmosphere in the tunnel
the mont blanc tunnel
refurbishment and modernisation
france
and provide a safe place for users. Each shelter is equipped with
an airlock with 2 fire doors. There is a videophone for contacting
the control room.
The shelters are linked to an evacuation gallery, situated beneath
the roadway, in which two electric vehicles can circulate to evacuate the injured.
Binational organisation of emergency procedures
Emergency first aid is provided by 10 firefighters based in three
emergency posts (one at each entrance and one in the middle
of the tunnel). Each team has two vehicles, one of which has a
twin cab (the Janus).
SYSTRA’s role
SYSTRA’s role consisted of:
day-to-day management and organisation:
• budget control of estimates and costs drawn up by the project manager,
• checking the timetable for the different phases of the project:
preliminary designs and project design, drawing up the tender
• documents, consulting contracting companies and organising
tenders, engineering works, operations relating to the commissioning and operational implementation of the tunnel,
• attending meetings organised by the owner or the project
manager,
• taking part in ATMB’s communications activities,
• co-ordination with the owner of the Italian part of the tunnel,
• drawing up the documents for tenders launched directly by
ATMB for the external inspection of the works.
specific responsibilities:
• technical inspection of preliminary and project plans, of the
tender documents and of documents relating to instructions
• for tunnel maintenance, operation and safety.
• commissioning of works and equipment
• auditing the work of the project manager
• providing expert advice and inspection as required.
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at a glance
caracteristics
of the tunnel
Length: 11.6 km
Width: 8.6 m
Height: 3.8 m
Altitude:
french entrance: 1,274 m
italian entrance : 1,381 m
highest point of the roadway:
1,395 m
Average traffic density: 5,600
vehicles per day
(of which 60% are passenger
vehicles)
companies involved
Owners: Société des Autoroutes
et Tunnel du Mont Blanc (ATMB),
Società Italiana del Traforo
del Monte Bianco (SITMB)
Assistance to the owner (ATMB):
SYSTRA
Assistance to the owner (SITMB):
SITEC Enginering
Project Manager: Franco-Italian
consortium SCETAUROUTE/SPEA
Health and Safety Coordination:
PRESENT
Operations following re-opening
of the tunnel: GEIE TMB (subsidiary
of the two concession-holder
companies)
cost
Total (2002): € 350 million,
of which:
civil engineering: 40%
safety equipment: 60%
financing
ATMB + SITMB
European subsidy for design
and safety equipment:
€ 22.5 million
key dates
24 march 1999: fire in the tunnel
February 2000: disposal
of installations and restoration
of power supply networks
April/july 2000: cleaning
and decontamination work
August 2000: start of civil
engineering works on the Italian
side
October 2000: start of civil
engineering works on the French
side
March 2001: installation
of equipment starts
September 2001: testing prior
to operation
9 march 2002: tunnel comes into
operation for light vehicles
25 june 2002: tunnel opens
to vehicles over 3.5 tonnes
(alternating traffic)
march 2013
In May 1999 SYSTRA was chosen by ATMB following a European
tender to provide assistance to the owner for the refurbishment
and modernisation work on the Mont Blanc tunnel.