“With this option, the cab has been given not a facelift but a rooflift. The roof has been raised by 350 mm, providing a number of benefits including better entry and exit to and from the cab, markedly improved upward vision with the optional roof window installed, better storage facilities in the cab for items such as safety helmet, safety package, gloves, lunch box, and more room for the driver,” Henri Jacobs, technical manager terminals at Terberg Benschop, explains. Standing headroom in the cab is now 1.84m and the spacious interior enables the driver to carry out his work in greater comfort, which results in improved safety.

As Mr Jacobs explains, the ZF-AS Tronic mid model is ideally suited to the torque requirements involved in terminal tractor applications with its high allowable engine torque of 1600Nm. By eliminating the torque converter ZF has been able to reduce weight significantly and, it claims, the transmission is also quieter, more fuel efficient and delivers more power to the drive wheels.

The new transmission is not only a gearbox, however, and also 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. Power shift transmissions with torque converters usually have four,five or six gears,but the ZF-AS Tronic mid has 12 forward speeds and two speeds in reverse. To simplify operation for the operator, and to prevent any driver-errors, Terberg has chosen to keep the shifting fully automatic.This means that, for instance, a tractor without a trailer will take off in seventh gear, whereas a tractor with a trailer connected will start in fourth gear.Any up/downshift is performed automatically by the transmission according to the installed ‘driving strategy’ program, which means that transmission life is maximised.

The main benefit of keeping the engine operating in the optimum range is reduced fuel consumption, which, depending on the application, can be reduced by circa 15% (actual savings depend on several factors including the engine, terminal topography and the time spent idling). As Mr Jacobs also explains, fuel consumption when idling is considerably lower with the AS Tronic Mid, which is particularly useful in a port application where terminal tractors spend a significant amount of time idling waiting in line for cranes.

Terberg installed the first AS Tronic Mid transmission in combination with a Cummins Tier 3 engine in October 2006 and has since completed extensive testing with the ZF AS-Tronic Mid transmission with several customers that prove the anticipated fuel savings, and the transmission is now being offered as an option on the YT182 and YT222 model. The higher purchase cost of the ZF AS Tronic Mid will be amortised “very quickly”by reduced fuel consumption, claims the company.