The U.S. Army in Germany recently added eight vehicles to their fire truck fleet comprising of Scania structural pumpers P410 B4x4HZ with the new CP 31 Crew Cab. The vehicles are powered by a 302 kW (410 hp) diesel engine combined with an Allison 4000 Series™ fully automatic transmission. The vehicles will be stationed at different locations across Germany.
The U.S. Army has been procuring this vehicle configuration for 10 years now. This is partly because of the advantages provided by a standardized operational fleet in terms of staff training and vehicle maintenance, but also due to the positive experience with Allison transmissions over the past three decades.
“So far, the transmissions have fulfilled all requirements of the U.S. Army with regards to performance, operation and maintenance,” said Sigurd Mack, Fire Protection Specialist at the U.S. Army Installation Management Command’s European Headquarters in Sembach near Kaiserslautern. “This also applies to the integrated hydraulic retarder and the Power Take-Off with the pump and roll function. It enables us to maneuver the vehicle safely and, at the same time, operate the water pump via the Power Take-Off – which is indispensable for efficient firefighting. For our operations and emergency responses good acceleration, easy handling and robustness are essential.”
According to the American NFPA (National Fire Protection Association) 1901 (Standard for Fire Apparatus) directive for firefighting vehicles, fully automatic transmissions are mandatory for heavy firefighting vehicles. In its solicitation, the U.S. Army has not only specified fully automatic transmissions, but also identified the specially designed transmission software for emergency vehicles. “A fully automatic transmission will only properly benefit the driver during operation if the shift pattern is tuned to the vehicle and the transmission works together effectively with the driver. It has to meet the specific mission for emergency response,” said Mack.
Allison fully automatic transmissions differ from other technologies. Among other things, their specially developed shift calibration programs for fire services which, combined with continuous powershifting, result in improved acceleration, higher average speed, and thus faster response times.
The fully automatic Allison transmission with its patented torque converter and Continuous Power Technology™ multiplies engine torque during vehicle start-up and acceleration. Gear changes are made without interruption, resulting in the smooth transfer of power to the drive wheels and maximum efficiency between engine and transmission.
“The transmissions shift smoothly at precisely the right moment, allowing the driver to concentrate fully on the road, which contributes significantly to accident prevention,” said Mack.
Allison fully automatic transmissions have demonstrated their outstanding reliability and durability under extremely difficult conditions, and are consequently used by numerous fire brigade fleets worldwide. There are currently about 70 Allison fully automated vehicles in the fire truck fleet of the U.S. Army in Germany.
The oldest Allison transmissions in the fire brigade of the U.S. Army in Germany have clocked up over 30 years of service. In 2007, the drivetrain components from twelve older Amertek 2500L trucks were removed and installed into twelve overhauled firefighting trucks, so called “glider kits.” The Detroit diesel engines and the Allison HT 750 DRD transmissions of the Amertek 2500L trucks, which at that time were already around 25 years old, were fitted to a new HME 1871 SFO chassis with a body made by Hensel.
“In the USA, general vehicle overhaul is a recognized procedure for vehicle maintenance and service life extension. The engines and transmissions, especially in fire trucks, are still in relatively good working condition and have proven to be very reliable, even after a long period of time. This contributed to the decision for a service life extension,” said Mack.
Compared to a new purchase, the “glider kits” helped to save approx. 80,000 – 100,000 USD per vehicle without compromising the functionality. The “glider kits” are used as multi-purpose vehicles for firefighting and for providing technical assistance.
