Why are the fire engines at airports a different shape then other fire engines?

Question

Why are the fire engines at airports a different shape then other fire engines?

Answer 1

They are different because their design requirements are different than your average fire truck.

The airport fire trucks are primarily designed to fight large jet fuel based fires. They must bring whatever fire suppressant with them as their are no hydrants readily available near the runways or taxiways. They can be larger than normal because they are based on an airport and their are very wide open areas to drive on.

The average fire truck has to drive on normal width roads, fight all kinds of fires and can usually have access to a supply of water nearby.

Answer 2

They have large tires due to the possibility of going off road between the runways and taxi ways.  Many of them have a nozzle called a penetrator that is used to punch a hole in the body of the aircraft to get AFFF inside to put out a fire.

The carry large water and AFFF tanks because there may not be a water supply on parts of the airport.

AFFF  stands for Aqueous film forming foam.

Some of the large trucks can exceed 60mph.

Answer 3

They have large tires to reduce ground pressure for driving across the field. They are very large to contain the water and chemical suppressant tanks and pumps. They can spray water or foam. Some even have a boom arm and a pointed nozzle they can use to punch through the skin of the aircraft to spray the inside. They are highly specialized vehicles for fighting fires at the airport. They have to deal with fuel fires, burning metal and have no hydrant network to hook up to.

Answer 4

The first part is they are absolutely massive. much larger than standard fire trucks. They aren't limited by the width of a road and typically they are wider than an average lane. Some can be short to fit under wings, but that is not typical. There is no more dangerous place to be then under the wing of a burning airplane, that is where the fuel is...

It is true that they spray foam, but they also spray water, they have large tanks to hold enough fire suppressant to put out most any fire they will come across. Unlike normal fire trucks, they can't hook up to a fire hydrant.

They usually sit 3 people across, with the driver being in the middle. There are remote nozzle operators along with more traditional firemen who have easy access to the doors.

Another important part of their design is their speed. Its amazing how quickly they can move, especially considering their weight. Not only are they fast, but they do well off road also, as often times the fastest way to a burning airplane will be through a grass field between taxiways.

  

Answer 5

1 they need to be low to get under wings

2 they spray foam not water

Answer 6

Other fire engines rely on being able to hook up to a fire hydrant for water.  Crash trucks have to carry all the water with them as there is little time to stop and hook up.  So they have to be big to carry a lot of water.

Also crash truck may be involved in a fire themselves or a massive explosion.  So they carry their crews inside where they can remotely run the water cannon.

Lastly,  they sometimes have to push one plane away from another.  For example,  if one is on fire and the other is not.  So they are massive with lots of power so they can move in and actually move a plane.