Terberg Benschop News

Terberg and ZF launch ZF AS-Tronic MID in Terminal Tractor

Thursday, September 11th 2008

* This has been presented at the ZF FachPresseKonferenz 2008 at the Nürnburgring at 8 and 9 July.
Terberg Benschop B.V. and Germany’s ZF Friedrichshafen AG have introduced a new transmission for use in terminal tractors that cuts fuel consumption by ±15%. It is called the ZF AS-Tronic Mid.

Terberg and ZF have a lot of experience in supplying the ports sector with the well proven and well known ZF WG powershift-transmissions in heavy duty 4x2 and 4x4 Terminal and RoRo applications.

The company that has introduced the ZF WG201 powershift transmissions in the heavy duty 4x4 RoRo units has been Terberg back in 1994. Terberg installs since that time in all their 4x4 models the ZF powershift transmissions and has it as an option in the 4x2 models. Present installed ZF Ergopower transmissions at Terberg include the 3WG161, 6WG191, 6WG211 and the 6WG260 model.

However in the lighter duty 4x2 tractors, the conventional automatic transmission currently dominates due to their good performance and lower pricing.
ZF is now targeting this application with its ZF AS-Tronic technology which features a countershaft transmission with a dry clutch instead of a torque converter.

The ZF AS-Tronic concept was originally developed for heavy duty commercial applications but more recently ZF developed lighter weight versions aimed at applications such as distribution vehicles in urban environments where there is a lot of stop start work.
The ZF AS-Tronic mid model is perfectly suited to the torque requirements in terminal tractor applications with its high allowed engine torque of 1200Nm. By eliminating the torque converter ZF has been able to reduce weight significantly and, it claims, the transmission runs quieter, more fuel efficient and delivers more power to the drive wheels.

The new transmission is not only a gearbox, but includes a harness, shift lever and a display. Gears can be selected manually but in automatic mode the transmission is controlled by software that manages shifting to keep the engine in the optimum operating range. Sophisticated software governs the shifting and the operation of the clutch to maintain driver comfort and respond appropriately to shift-up, shift-down conditions and whether the vehicle is coasting or pulling.

The gearbox also selects the appropriate gear and time to change gears. While power shift transmissions with torque converters have 4, 5 or 6 gears the ZF AS-Tronic mid has 12 speeds in forward and 2 speeds in reverse. To simplify the operation for the operator and to prevent any driver-errors Terberg has chosen to keep the shifting fully automatic. This means a tractor without a trailer will take off in gear 6, whereas a tractor with a trailer connected will start in gear 4. Any up-/downshift is performed automatically by the transmission according to the installed “driving strategy” program. This means all shifts will be consistent which gives maximum possible transmission life and provides optimum operator comfort.

The main benefit of keeping the engine operating in the optimum range is reduced fuel consumption and depending on the application, fuel consumption can be reduced by ±15%.  Actual savings depend off course on several factors including the engine, the terminal topography and the time spent idling. Terberg says fuel consumption when idling is considerably lower with the AS-Tronic because of its reduced drag torque as the transmission has only a small oil pump and no converter. This is particularly useful in a port application where terminal tractors spend a significant amount of time idling waiting in line for cranes.

Another cost advantage is that the oil change interval is longer than with automatic or powershift transmissions. Terberg says the recommended oil change interval for a terminal tractor application is 3 years, using ZF Ecofluid M. The oil change volume is “only around 8.7 liter”.

Terberg has installed the first AS-Tronic Mid transmission in combination with a Cummins Tier 3 engine in October 2006 and has since done extensive testing with the ZF AS-Tronic Mid transmission with several customers. These tests have shown in realistic, real life operation fuel consumption benefits of up to 15%. The transmission is now being offered as an option on the YT182 and YT222 model. Terberg states the higher initial purchase cost of the ZF AS-Tronic Mid will be amortized very quickly by the reduced fuel consumption.

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