Reality-Based Training For Fire Brigades In Tunnels – First

Experience Report

Volker Wetzig

VSH VersuchsStollen Hagerbach AG, CH 7320 Sargans

ABSTRACT

This report is concerned with a comprehensive integrated training programme for the fire brigades
covering the Westerschelde tunnel. All fire brigades which could potentially be called upon to respond
to an emergency in the Westerschelde tunnel were included in this programme. This is the first time
that all response units have undergone special training before the opening of a tunnel.

The participants were introduced to emergency situations and the arising dangers and risks through
various exercise scenarios. To start with they were trained in basic procedures, such as communication
whilst in tunnels and reconnaissance of emergency scenes involving unspecified - possibly even toxic
- substances, whilst in artificially smoky tunnels.

With real fires under controlled conditions, the response units were introduced to dealing with rising
temperatures and an increase in smoke in the tunnel. To this end realistic tunnel accidents were created
in the 200m fire test gallery of VSH Hagerbach Test Gallery Ltd. The exercises carried out clearly
demonstrated the necessity of such courses, since even firefighters behave differently working under
stress in a tunnel environment, than in the open. By the same token, questions which above ground do
not arise in the same way take on added significance. Examples of this are communications,
reconnaissance of the accident site and saving people at a great operational depth.

1. INTRODUCTION

Underground construction has been on the increase across the world – there is huge demand for good
quality transport infrastructure, both road and rail, and it can often only be met with extensive
subterranean construction: in heavily populated areas the only remaining room for infrastructure is
underground. In many new industrializing countries, new infrastructures can only be achieved through
tunnels or underground galleries on account of the topographic circumstances.

Along with the technical challenges of construction, the demands on emergency services are
constantly growing: the infrastructure and the electro-mechanical equipment involved in underground
travel routes are becoming ever more complex, and the decision-making processes are increasingly
supported by electronic aids (eg control structures). The expectations of society and road users for
speedy and optimally successful rescue operations are growing rapidly, and this places emergency
services under additional pressure.

Despite all of the technical advances made in recent years, the empirical component still plays a major
role in rescue operations. Nor will this change in the future: the interpretation of events, their
development, and the introduction of special rescue and protection measures not only requires solid
theoretical knowledge, but also a good measure of experience – a quality which can only be acquired

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through practice. It is impossible to imagine rescue services in underground construction without
practical experience.

This practical experience demands that the training process must at a given point involve real fires.
Only in this way can the rescue forces expose themselves to the special demands and properties of
underground fires, and learn how to deal with them.

The majority of events in tunnels which require the presence of rescue and response forces is
fortunately not connected with fire. The training for such occurrences under real conditions is thus at
least as vital as the basic fire brigade training, and that means there is also an increasing necessity for
training and education in crisis management.

Before the opening of the 6.6 km long Westerschelde tunnel, which passes below the Schelde in the
Netherlands a few kilometres away from its estuary with the North Sea at a depth of up to 60m below
sea level, the fire brigade response forces were trained in practical tunnel work. The fire brigade’s
command decided after a detailed survey to have the training of the response forces for the new
operational area done at the VSH Hagerbach Test Gallery in Flums, SG (Switzerland). This is the only
site in Europe which offers realistic training facilities for underground operations. The following
report is based on the experiences of the fire services of the Westerschelde tunnel.

When considering the training of rescue forces for tunnel operations, it must always be borne in mind
that the rescue operation represents the last link in a chain of protective measures which must be taken
to prevent an accident or to minimise the effects of one. In the following we will not concentrate any
further on the protective measures based on construction and organisation.

2. ICST –INTERNATIONAL CENTRE FOR SAFETY IN TUNNELS

All activities at VSH Hagerbach Test Gallery which contribute to the improvement of safety in tunnels
come under the project name ICST. The facility which today exists for this purpose, with a length of
around 400m, was created step-by-step according to current needs. The cavities mined into the solid
rock allow training and experiments using any amount of fire without endangering their solidity.

At the centre of the facility is the 200m long fire tunnel with the cross-section of a two-lane road
tunnel, and a parallel tunnel. The two tunnels are connected by cross-connections. There are also
tunnel sections with smaller cross-sections, which also open onto stair shafts. These parts of the
installation allow the practice of situations as they arise in works tunnels under carriage ways, in
support areas or in the narrow and winding access ways to metro stations. (Figure 1)

There are plans to extend the facility so that it offers yet more comprehensive possibilities for training
and education of fire brigades.

3. TRAINING CONCEPT

Rescue forces’ operations in a tunnel probably constitute some of the most demanding tasks with
which fire brigades are confronted. The great difficulties result from the special circumstances of the
tunnel environment such as
- the distance to the combat zone
- the duration of the operation
- high temperatures, since the heat cannot escape freely
- intensive smoke and reduced vision
- unknown freight on the vehicles
- restricted communication

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Figure 1 Site map of the gallery

This makes the training for tunnel operations specialist training which builds on basic extensive fire
brigade skills. The training is focussed on the response team as a whole, not on the individual
members, as the only way to deal with a tunnel operation efficiently and safely is by means of
seamless cooperation.

With this as a given, it is advisable to fit the training programmes to the needs of each response
situation. These are, for example:

- the tunnel system (single or double line)

The points above should already be taken into account in the planning and design phase of a tunnel, so
that the construction and any rescue operations complement each other.

Temperatures of 1000°C and above, as set out in the specifications for the fire protection in
construction, are not bearable for humans and also for firefighters. Should such temperatures arise in
the centre of a fire, the site must be cooled from the sidelines, so that the response forces can work
their way to the source of the fire through temperature of no more than 300 °C.

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4. TRAINING PROGRAMME

During training the participant is led through the problems of tunnel operations in several steps, and
develops the correct behaviour patterns.

A first module deals with the identification and assessment of the accident scene. In an accident
scenario involving a delivery vehicle, the composition of the contents must be judged in order to
ascertain what further rescue measures are appropriate. It is particularly important to assess whether
poison or any other noxious substances which would place the rescue teams in danger are present.

This reconnaissance proceeds through a preliminary control, which is carried out immediately after the
alarm is raised. Already at this stage the safety of the response forces is to be guaranteed by way of
appropriate protective measures, such as taking along an extinguisher. As with all other operations,
communication with operation command is to be constantly maintained. This can be an additional
problem just by going through a transversal tunnel if the tunnel’s radio communication system has
been damaged in the accident.

People in the accident zone must be rescued while at the same time ensuring the safety of response
staff and patients.

In a further module people at great operational depths and in smoky areas are to be rescued. In this
situation orientation and communication pose the greatest problems. The performance of the response
forces can be significantly improved with the help of a thermal imaging camera. If the picture from the
camera is directly transmitted to the response unit’s command, the latter can respond quicker to the
evolving situation. There are however limits to the use of thermal imaging cameras, if parts of the
room are invisible due to structural features, or if the room is all at the same temperature so that no
contrasts can be seen.

Operational exercises in sections of tunnel artificially filled with smoke serve to help recognise the
difficulties of tunnel operations and to teach the correct response. The confined conditions of a tunnel
system, with cross-connections and secondary areas such as ventilation and transformer stations, etc.
make communication considerably more difficult. Radio contact can be maintained no more than two
branches into the tunnel system at best, and must be maintained by means of appropriate measures
such as relay posts. Once the significance of the communication problem in underground facilities is
recognised, it is basically possible to bring about improvements by installing appropriate equipment.

With air supply restricted to breathing equipment the range of movement of the fire services is greatly
reduced. Even if every 250m in the tunnel there are cross-connections which give access to the other
tunnels, there can in a worst case scenario be an operating depth of 250m, which is very difficult to
cope with. The exercises in saving individuals whilst using breathing protection in real tunnel sections
with artificial smoke made all participants very aware of this problem.

Simulated vehicle fires with real heat and smoke introduce course participants to the ancillary
conditions of a fire in the tunnel. Unlike outside, most of the heat cannot disappear upwards. The heat
is reflected by the roof and walls of the tunnel generating intense heat in the driving area. If the tunnel
structure is not protected by a fire protection system, the response forces additionally have to reckon
with concrete potentially cracking, massively damaging the structure of the tunnel. In extreme cases
this can lead to the collapse of structural components.

In the final exercises the contents of all of the other exercises are combined and the response teams are
confronted with a staged event which must be dealt with on their own, whilst under the supervision of
the instructors. The crisis must be mastered in small teams and within a very confined space. The
teams must simultaneously save individuals, fight fire, cool the structure and if needs be prevent
noxious substances escaping. (Figure 2)

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Figure 2 Firefighting operational exercise

The response techniques depend on the capabilities of each fire brigade. Thus foam and water
extinguisher systems are used, but also special systems such as CAFS (Compressed Air Foam
System). Only in practical use do the advantages and disadvantages of the different systems become
evident. The decisive factors are:

- transport investment
- time required to get the equipment ready
- effectiveness in extinguishing
- cooling effect

Although these are “only“ exercises, the response forces are pushed to the limits of their mental and
physical capacities. Experiencing the limits of their own tolerance in a realistic environment allows
participants to be sure that they do not overstretch themselves in an emergency, putting themselves
and their colleagues in unnecessary danger.

Briefings after each course lead to a discussion on the experience gained and how the fire fighting
forces can optimise their approach.

5. CONCLUSIONS DRAWN FROM THE TRAINING COURSES TO DATE

The experience gained from the different operational exercises under ground have shown that it is vital
for response forces to train under circumstances which are as realistic as possible. Working with
breathing equipment always poses an additional difficulty. The smoke and heat conditions in tunnels
are difficult to compare with experiences above ground, where operating depths are usually very

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limited. Only those who have known ”in peacetime“ what it means to maintain communication lines,
to recognise their physical and mental limits, to use their equipment quickly and efficiently under
difficult circumstances, will be successful in a crisis.

Exercises show participants the possibilities and the limits of firefighting in tunnels and more often
than not take the firefighters to their personal limits. The personal experience gained from these
realistic exercises is of significant importance to the firefighters. It allows them to put the knowledge
gained from their training into practice in a real emergency and bring it quickly under control.

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