Safety and performance drive transmission choice for high-level prison transport


High security prison trucks are specified with Allison fully automatic transmissions to ensure the highest levels of safety and control.

LONDON, UK – Thirteen prison trucks used to transport the UK’s highest category level prisoners have been specified with an Allison fully automatic transmission. The DAF LF trucks, fitted with 330 hp Cummins engines, use Allison 3000 Series gearboxes to ensure that the truck can be operated safely not just in congested London traffic, but also on longer motorway runs to other UK facilities. The difficulties of safely controlling vehicles with close police escorts and the subsequently higher clutch repair costs of manuals led Ministry of Justice engineers to use Allison’s proven fully automatic technology.

“Our vehicles transport the highest category prisoners on two main duty cycles,” explained the Ministry of Justice’s Technical Services Manager, Mike Sanchez. “The first is the ‘non blue light’ transport of prisoners to and from courts and the second is under ‘blue lights,’ where the vehicle is very closely surrounded by police cars and motorcycle outriders. The latter requires precision driving from our professional drivers to maintain the exact distance between the police vehicles over a range of speeds and traffic conditions.”

The need for precise control, rapid acceleration and safe braking led to prematurely high clutch and gearbox wear with legacy manual transmissions. “Keeping up with traffic and the police escort was challenging with manual boxes and necessitated clutch slipping, leading to higher wear and more time and cost in the workshop,” added Sanchez.

Allison’s fully automatic transmission with integrated torque converter offered the vehicle specifiers a gearbox that would cushion the driveline from wear and tear. With performance being equally crucial, a transmission able to maximise available engine power and deliver full-power shifting for rapid acceleration was ideal for this critical application.

“In some circumstances we are limited only by the speed rating of the tyres,” added Senior Fleet Engineer, John Kerr. “It is vital that the vehicle can be driven safely and in control to protect the occupants and public at large.”

Allison’s two pedal set up means drivers can keep both hands on the wheel at all times and enables the driver to focus on driving the truck. “Not having to shift is one less thing to worry about in tense situations,” said Kerr. “We want to ensure safety is paramount in these challenging environments.”

Allison worked closely with the Ministry of Justice’s engineering team to safely extract maximum performance from the drivetrain. “We can adjust transmission calibration parameters to deliver the necessary requirements for any application,” said Riccardo Sardelli, Area Manager for Allison Transmission in the UK. “After discussion with the specifiers, drivers and engineers, we focused on performance in this case. However, our latest generation software package is so flexible that we can also look at enhancing economy where appropriate in the drive cycle.” Allison cites the example of offering a ‘high performance’ calibration, which is only available when blue lights are functioning.

Feedback suggests that in addition to lower operating costs, switching to Allison automatics has also lowered driver frustration levels. “The drivers are delighted with the ease of operation and the safety improvements the fully automatic transmission provides in both the inner city environment and on longer cruising runs. They can concentrate and be much more aware of their environment, which has positive implications for everyone,” concluded Kerr.

Sep 03, 2012

About Allison Transmission

Allison Transmission (NYSE: ALSN) is the world’s largest manufacturer of fully automatic transmissions for medium- and heavy-duty commercial vehicles and is a leader in hybrid-propulsion systems for city buses. Allison transmissions are used in a variety of applications including refuse, construction, fire, distribution, bus, motorhomes, defense and energy. Founded in 1915, the company is headquartered in Indianapolis, Indiana, USA and employs approximately 2,600 people worldwide. With a market presence in more than 80 countries, Allison has regional headquarters in the Netherlands, China and Brazil with manufacturing facilities in the U.S., Hungary and India. Allison also has approximately 1,400 independent distributor and dealer locations worldwide. For more information, visit allisontransmission.com.