By the yard

The swing of the downturn took many port vehicle manufacturers by surprise, but the face of the decline has not been even, favouring some more than others, even where the ubiquitous yard tractors – the workhorses of the port world – are concerned.

For example, MAFI has just landed an follow-up order for 65 units (type MT 30 YT) for South Africa’s Transnet Port and Terminals – 53 of them destined for the Cape Town container terminal, six for the multipurpose terminal there and the rest going to the Durban multipurpose facility – all of which are in the process of an upgrade.

The company’s Peter Schäfer explains that the strength of the unit’s chassis had already been proven on site. However, he adds there are sometimes requirements “behind the scenes”. “Some SA ports have very large yards and remote areas,” he says, and despite the official H&S rules, he believes that the unit’s spacious cabin and ability to fit another rider onboard alongside the computer equipment was what finally tipped the order in Mafi’s direction.

So, much of it hinges on getting it right for the individual client. Some manufacturers are going all out for ‘added value’, bringing together machine packages that are, or can be, tailored to meet very specific needs.

Terberg for instance has worked on an extensive range of customisations – one example being upping the number of wheels and axles to spread the load over any ‘difficult’ surfaces.

In order to make them both greener and cheaper to run, the units feature a ZF AS-Tronic mid transmission system which, when in automatic mode keeps the engine in the optimum range – cutting fuel intake by about 15% and reducing wear, too.

Another development is the integrated lock-up clutch especially for tractors with torque converters, a fluid coupling that performs a clutch-like function. “You manoeuvre using the torque converter, and then when your speed has levelled out, the lock-up clutch cuts in and bypasses the torque converter giving a purely mechanical link – which makes for a much more efficient operation” explains Henry Jacobs of Terberg, giving a fuel saving of 5% to 20%.

Efficiency is definitely the name of the game and Allison Transmission is helping the cause by working with manufacturers by, for example, ensuring that the transmission is paired correctly with the rear axle ratio.

But as Lawrence Love of Allison explains, it depends on what the operators themselves want to get out of their tractors.

“The rise in fuel prices recently meant we saw port operators trying to squeeze the last drop of fuel out of their machines. It became obvious to ask, ‘what if we don’t need to keep the performance so high and, instead, take the tractors toward fuel savings?'” From this there have been a couple of important innovations. One has been the Reduced Engine Load at Stop – or RELS – which means the transmission goes into a mode best described as ‘partial neutral’, so taking some of the load off the engine.

Another is something called Load Based Shift Schedules (LBSS), a intelligent bit of kit that is incorporated into the transmission itself. “This runs software that allows the transmission to shift depending on how much load there is on the vehicle. In other words, it allows an automatic shift between ‘economy’ and ‘performance’ running,” explains Mr Love. “For those customers who want maximum fuel economy – there is a solution,” he adds.

But it is not necessarily that easy to incorporate all the goodies into one unit, explains Timo Matikainen, director of Kalmar’s Heavy Terminal Tractors division, who says that the design “has to optimise the whole powertrain”.

This means that engine, torque converter, transmission, axle ratios and even the tyre sizes have to be designed to work with each other – getting the optimum traction, acceleration and driving speed, both when driving empty or loaded. “As you can imagine, with so many variants and components, and also the huge amount of different applications where tractors are used, this really creates quite a puzzle in fitting it all together,” he adds.

So, Kalmar has recently released the modular TT616i, which can be customised to very specific operations. It has at its heart a very sturdy frame, on which different modules can be put together under a full CAN-BUS control system.

Mr Matikainen explains how the units can be tailored: “The standard engine supplied is the Cummins 173hp, but for customers continuously operating with heavy loads, we recommend choosing the more powerful Cummins 220hp engine, as well as fitting an elevating lift boom with a 36 tonne capacity.”

Besides five different lift booms, the choice of axle means you can combine the right kind of acceleration with sufficient speed. Among the variations is a silent drive option, (recommended for minimising night time noise levels) and an eco-drive.

But although this TT616i keeps to the EU Stage 3a/Tier 3 emission standards, there are other developments on the horizon.

Kalmar has been awarded a contract to supply three new hybrid terminal tractors for technology trials being carried out by the Port of Long Beach, CA, USA.

The three hybrid terminal tractors will be based on Kalmar’s well established Ottawa 4 X 2 terminal tractor. They will be fitted with a Parallel Hybrid Drive which converts power from on-board batteries. These will have been charged by the OEM diesel engine or regenerative braking system, and will push power to an electric motor for propulsion through the rear axle.

The hope is that the trials, due to start in about a year, will prove not only that it works but that used terminal tractors can be modified to hybrid power – gaining fuel savings of up to 30%.