Becasue all self-sufficent Armies need a fire service on site incase of a fire in the munitions dump. Or the barracks. Or the canteen. Or somewhere else on site that we don't hear about much.
(Usung Flickr as a the hosting site, as the MOCpages picture system sucks and messes everything up)
LTC, Lego Truck Company, felt it was time to update the Desert Commando's main truck. The TR-14, they decided, would be used only to transport supplies out in the fields and over rough ground, where they excelled.
Turning to the drawing board, LTC decided to create a truck to be used on the roads in the towns and cities occupied by the DC. It need to be able to haul supplies the long distances between cities, be strong, easily adaptable and easy to maintain and fix. They decided to try a new approach on this new truck, and make it a long-nose cab, instead of an over-engine cab.
The tests went well, and the TA-19 was created. A few months later, a TA-19 was turned into a fire truck, and thus it became the standard fire-fighting vehicle of the Desert Commando Army.