Fire-fighting in railway vehicles
In a modern-day society, increasing use is being made
of railway vehicles to perform infrastructural tasks in the
area of: passenger transport. Particularly stringent fire
protection requirements have, of course, to be laid down
for the relevant passenger trains. Hitherto, this has been
reflected in stringent requirements for the material and
equipment used in the trains. Corresponding standards and
other requirements relating to the design of trains and to
their construction and to the materials and equipment
selected constitute not inconsiderable restrictions on the
makers and operators of train when new projects are being
carried out. When vehicles belonging to old rolling stock
arc being brought up to a fit state, it is only with
difficulty, or not at all, that the conditions imposed by
the authorities can be met.
It can be expected that, in the next few years too,
rail systems are increasingly going to be laid wholly or
partly underground. Because of the particular problems that
fire protection poses in tunnels, there will therefore
continue to be a steady rise in the requirements that
railway vehicles have to meet.
Added to this is the fact that it is only the way in
which the rolling stock itself behaves in fires that can be
influenced by the design of the vehicles and by the
materials and equipment selected. There is on the other
hand no way in which the fire loads such as clothing and
luggage which the passengers take on with them can be
influenced. Even the taking on of incendiary materials by
arsonists is almost impossible to prevent.

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The fire-fighting systems for the spaces occupied by
passengers which have hitherto been installed in railway
vehicles, which has only happened anyway in exceptional
cases, have mostly been of the "open system" or "wet
system" types.
In the first case, it is necessary in addition for a
fire detection and alarm system to be installed which will
detect fires and will then give the fire-fighting system an
activating signal for the area affected. To keep down the
system costs in terms of valves controlling the area, the
particular devices for dispensing extinguishing agent are
not activated individually but, regularly, in groups. The
result of this is that the amount of extinguishing agent
used is greater than it would be in the case of selective
individual activation. This in turn means that the supply
of extinguishing agent, and hence the weight which has to
be carried, turns out to be higher.
In the wet system, the devices for dispensing
extinguishing agent are activated by thermal triggering
elements in the individual devices. This gives individual
activation. However, the entire pipe network out as far as
the devices for dispensing the extinguishing agent has to
be pre-filled with extinguishing agent in this case. This
is not without its problems, because in certain
circumstances the vibration typical of railway vehicles
might causes leaks of greater or lesser severity in the
network of piping, allowing the extinguishing agent to
escape, as a result of which not inconsiderable damage
might be done even though the amounts were very small.
The above-mentioned measures for improving fire
protection are what are called passive measures. As
described, they are a considerable restriction on makers
and operators. There are significant imposed tasks which

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cannot be performed at all by passive fire protection
measures.
It is therefore an object of the invention to reduce
these problems or at least to considerably moderate them.
The scheme which is described here makes provision for
the pipes which connect the supply container for
extinguishing agent (or the pump) to the devices for
dispensing the extinguishing agent to be filled with a gas,
or air, under pressure.
One aspect of the invention is a railway vehicle
according to Claim 1. Another aspect is a fire-fighting
arrangement according to Claim 12.
If one of the devices for dispensing extinguishing
agent opens as a result of being acted on thermally, the
pressure in the system of pipes drops and, via a suitable
arrangement, the mechanism which cuts off the pipe from the
extinguishing agent is opened. Following this, the network
of piping is filled with extinguishing agent, whereupon the
latter can emerge from the device or devices for dispensing
extinguishing agent which have been activated previously.
If however gas/air escapes not as a result of a device
for dispensing extinguishing agent being activated but
because of a (fairly small) leak, the network of piping is
not filled with extinguishing agent but further gas/air is
fed in until the usual test pressure has been reached again
in the network of piping.
It would be particularly advantageous if the pipe
system were full of air when in the "standby" mode and if
this air were to originate from the vehicle's compressed-
air system. In this way, the carrying of additional
pressurised containers could be dispensed with.
A particular further embodiment of the system would be
one in which the compressed air from the vehicle was also

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used to drive extinguishing agent out of a container for
extinguishing agent and into the network of piping.
A further embodiment of the system would make
provision in addition for (simple) fire alarms. Only if
there were a fire signal from the fire alarms and, at the
same time, a significant drop in pressure would the network
of piping be filled with extinguishing agent. If only the
"pressure drop" signal occurs, it acts as an alarm message
for a leak. It is important for the network of piping to be.
monitored continuously for leaks so that the ability to
operate is ensured in emergency cases. The option of simply
leaving the network of piping unfilled and without any
gas/air applied in the standby mode thus is removed.
Fig. 1 shows a railway vehicle 2 having a fire-
fighting system. A compressed-air supply 6 is provided in a
wagon 4. The compressed-air supply 6 may be provided both
in the wagon 4 and in the motive unit. Pneumatically
operated functional facilities of the railway vehicle 2 are
driven by means of the compressed-air supply 6. These may
for example be the brakes. As well as the compressed-air
supply 6, what are also provided in the wagon 4 are a
pressure-generating means 8 and a supply container 10 for
extinguishing agent. For fire-fighting purposes, there is a
system of pipes 12 coupled to the supply container 10 for
extinguishing agent. Arranged' on the system of pipes 12- are
fog nozzles 14a, 14b. The arrangement described operates as
follows:
in the quiescent state, compressed air is fed from the
compressed-air supply 6 into the pressure-generating means
8 via the pipe 7. With the help of the compressed air taken
from the compressed-air supply 6, a quiescent pressure is
generated in the system of pipes 12 by means of the
pressure-generating means 8. For this purpose, there is a

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connection 11 between the system of pipes 12 and the
pressure-generating means 8. The quiescent pressure may be
a few bars. Leaks in the system of pipes 12 cause slight
pressure drops in the mbar range, the pressure drops being
sluggish, i.e. taking place over a long period. Such
pressure drops are detected in the pressure-generating
means 8 via the connection 11. The quiescent pressure is
corrected by means of compressed air taken from the
compressed-air supply 6. What is achieved by this means is
that a constant quiescent pressure prevails in the system
of pipes 12.
In the event of a fire, the fire can be detected by
means of burst-actuated pistons in the fog nozzles 14. This
happens as a result of the fact that the burst-actuated
pistons shatter due to the increase in temperature and the
compressed air in the system of pipes 12 is able to escape.
Other means of detection are also possible. The compressed
air 12 can be used for fire detection, meaning that in the
event of a fire, and in particular as a result of the
increase in temperature, the system of pipes 12 is opened
and the compressed air is able to escape. As well as this,
a separate fire alarm (not shown) may be provided by means
of which a fire can be indicated manually.
It is now proposed .that, in the event of a fire, i.e.
if there is at least a pressure drop in the system of pipes
12, but preferably if there is both a pressure drop in the
system of pipes 12 and also a report of fire made by the
fire alarm, compressed air from the pressure-generating
means 8 is driven via the connection 9 into the supply
container 10 for extinguishing agent. The compressed air
causes extinguishing fluid to flow out of the supply
container 10 for extinguishing agent and into the system of
pipes 12 and, after a short time, to be applied to the fog

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nozzles 14. It Is preferable for the pressure-generating
means 8 to generate a high pressure, such for example as 80
to 200 bars. What is achieved by this means is that an
extinguishing fog is produced at the fog nozzles 14.
If a fire is detected, which can be done in the
pressure-generating means 8, via the connection 11, as a
result of a pressure drop in the system of pipes 12, then
high pressure is generated in the supply container 10 for
extinguishing agent. This is able to cause a connection,
initially closed, to be opened between the supply container
10 for extinguishing agent and the system of pipes 12. This
connection may be closed off by means of, for example, a
burst disc which bursts at an increased pressure and also
by means of a valve. In the event of a fire, the connection
11 to the system of pipes 12 is shut off in the pressure-
generating means 8 and the air pressure is taken into the
supply container 10 for extinguishing agent via the
connection 9.
As well as air, any other gas may also be used to
generate the high pressure in the system of pipes 12.
As a result of the coupling according to the invention
between the compressed-air supply 6 and- the pressure-
generating means 8, pumps which are already present in the
wagons 4 may be given over to a further use. The cost and
effort of installing a fire-fighting system for railway
vehicles is reduced. The capital investment costs remain
low and the cost and effort of maintenance can ~ be
minimised.

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Claims
for filing
1. Fire-fighting system for a railway vehicle comprising:
- a supply container for extinguishing agent,
- a system of pipes,
- means for dispensing extinguishing agent, and
- a pressure-generating means, wherein
- the pressure-generating means is coupled to a
compressed-air supply belonging to the railway
vehicle,
- a quiescent pressure can be generated in the system
of pipes with the help of the pressure-generating
means,
- the system of pipes is filled with gas at a
quiescent pressure, and
- a case of fire can be detected by means of a
pressure drop in the system of pipes.
?.. Fire-fighting system of claim 1, wherein in the event
of a fire the means for dispensing extinguishing agent
generate a pressure drop.
3. Fire-fighting system of claim 1, wherein the pressure
drop in the event of a fire is greater than a pressure
drop due to leaks in the system of pipes.
4. Fire-fighting system of claim 1, wherein a case of
fire can be detected by means of a burst-actuated
piston in the means for dispensing extinguishing
agent.

5. Fire-fighting system of claim 1, wherein a case of
fire can be detected by means of a fire alarm.
6. Fire-fighting system of claim 1, wherein in the event
of a pressure drop, a fluid connection is established
between the supply container for extinguishing agent
and the system of pipes.
7. Fire-fighting system of claim 6, wherein a bursting
disc or a valve established the fluid connection.
8. Fire-fighting system of claim 1, wherein in the event
of a fire, the compressed-air supply belonging'to the
railway vehicle drives the extinguishing fluid by air
pressure.
9. Fire-fighting system of claim 1, wherein in the event
of a fire, the extinguishing fluid can be dispensed
from the means for dispensing extinguishing agent at a
high pressure of between 80 and 200 bars.
10. Fire-fighting system of claim 1, wherein in the event
of a fi,re, the means for dispensing extinguishing
agent produce an extinguishing fog.
11. Fire-fighting system of claim 1, wherein the means for
dispensing extinguishing agent have at least one fog
nozzle.
12. Railway vehicle comprising a fire-fighting system of
claim 1.

The invention relates to a railway Vehicle comprising a fire-fighting
system having a supply container for extinguishing
agent, a system of pipes, means for dispensing extinguishing
agent, and a pressure-generating means. To improve the
reliability of this system, it is proposed that the pressure-gencrating
means be coupled to a compressed-air supply
belonging to the railway vehicle, that a quiescent pressure
can be generated in the system of pipes with the help of the
pressure-generating means, and that a case of fire can be
detected by means of a pressure drop in the system of pipes.