Volvo has launched a new version of its I-Shift featuring crawler gears capable of starting from standstill with a load of 325 tonnes.

Volvo claims that the new gears,which are added to the automated transmission,provide exceptional startability for trucks carrying heavy loads in demanding situations. The system is entirely unique for series-produced heavy trucks.

The new version of Volvo’sI-Shift makes it possible to add up to two new crawler gears, which means,among other things, that the truck can move off with a gross combination weight (GCW)of up to 325 tonnes from standstill.

“I-Shift with crawler gears offers entirely new scope for heavy trucks with automated transmission to regulate their speed when crawling slowly and reversing. The driver can haul a heavy load without worrying about getting into situations that may lead to costly standstills,”says Peter Hardin, Product ManagerFM andFMX.

With the new crawler gears, the truck can drive at speeds as low as 0.5-2 km/h. This helps immensely during precision manoeuvres such as in construction and maintenance tasks.

“The vastly improved driveability and startability with the new crawler gears makes the driver’s job far easier when operating in difficult terrain on slippery surfaces with heavy loads, such as at construction sites, in mines orin forests. The heavier the transport operation and the poorer the surface or the terrain, the more the driver gains from a truck with crawler gears,” explains Peter Hardin.

For haulage firms carrying out heavy transport operations on demanding surfaces as well as regular highway driving, crawler gears also offer considerable flexibility and the possibility of improved fuel economy.

“I-Shift with crawler gears makes it possible to start off from standstill in extreme situations. Combining them with a suitable rear axle ratio that optimises engine revs at high speeds results in lower fuel consumption on the highway. This is a significant benefit to haulage firms doing this kind of work,”says Peter Hardin.

Depending on application area,I-Shift is available with one or two forward crawler gears, and with or without two reverse crawler gears. Reverse crawler gears make it possible to reverse extremely slowly, which is a major advantage when reversing manoeuvres require immense precision.

Volvo says that the I-Shift with crawler gears is a further development its I-Shift developed with startability and for driving at particularly low speeds in mind.

It can allow driving as slowly as 0.5-2 km/h and can handle starts from standstill with a gross combination weight of up to 325 tonnes, which is unique for series-produced trucks with automated gearboxes.

It is available as eitheradirect-driveoroverdrivegearboxwith oneortwo crawler ratios.It is also possibleto specifytworeversingcrawler ratios.

Thelow crawlergearsareintegrated into theI-Shift and in orderto handlethehigh loads involved, several components aremadeofhigh-strength materials. Thegearboxis 12 cm longerthan aconventionalI-Shift unit.

It is available forVolvo Trucks’13- and 16-litre engines in the Volvo FM, Volvo FMX,Volvo FH and VolvoFH16.

Inagearboxwith one crawlergeartheratio is 19:1 in adirect-drivegearbox, or

17:1 in an overdrivegearbox. (The ratio ofthelowest gearina regularI-Shift direct-drivegearboxis 15:1.)Inadirect-driveoran overdrivegearboxwith two crawlergears thelowestratio is 32:1. The ratio ofthelowest reversegearis 37:1 in adirect-drivegearbox.