incident site. These are carried out by people who often, but not
always, have some form of equipment to work with. It could for
example concern fire fighting where one or more firemen uses a
hose and nozzle to shoot water into a blaze or to protect them-
selves against the fire. It could also concern a water supply me-
asure in which a firefighter uses a pump connect ed to a supply
of water (a water tank, fire hydrant or a combination of these) in
order to provide for a hose system. Or it may concern taking care
of victims in various ways. On the other hand it may also be so-
mething of a more general nature such as gaining information forA tank lorry full of petrol has tipped over on a main trunk road that
passes through Allmänsta municipality. The lorry is lying in its side
on the bank at the side of the road. The casualties have been attended
to and taken to hospital. The fire brigade is pumping the contents
of the tank lorry over to another tank lorry standing on the road.
Suddenly the tipped lorry starts to move and rolls down to the field
at the bottom of the bank. The firefighters working on the pumping
managed to get out of the way just in time and escaped, luckily,
with nothing more serious than a lesson learned. During the course
of emptying the tank, the vehicle’s centre of gravity moved. It was
lowered until eventually the potential energy in the vehicle was
converted into kinetic energy.
Example 15