Rolling road tests lift-and-reach trucks

A tailor-made, 28-tonne rolling road has been designed and installed to test six aspects lift-and-reach trucks operation.

Cirrus Technologies of Redditch, England, has designed, installed and commissioned a tailor-made, 28-tonne rolling road for lift-and-reach trucks (telescopic handlers or telehandlers, with side-mounted engines) for Caterpillar (UK) at Desford, Leicestershire, a site which proudly holds the highest attainable, 6 Sigma manufacturing quality standard.

For more than 75 years, Caterpillar has been building the World's infrastructure and, in partnership with its worldwide dealer network, is driving positive and sustainable change on every continent.

With 2002 sales and revenues of $20.15 billion, Caterpillar is a technology leader and the World's principal manufacturer of construction and mining equipment, diesel and natural gas engines and industrial gas turbines.

Caterpillar products and components are produced in 50 US facilities and in 65 other locations in 23 countries around the globe (see www.cat.com).

In the UK, the Building Construction Products Division manufactures building construction equipment typically for building sites and farms everywhere and is located at Desford (tel: 01455 826 826), whilst the Diversified Products Division at Peterlee, Durham, specialises in larger machines for the mining, quarrying and civil engineering sectors.

The Cirrus rolltest equipment tests Caterpillar's telehandlers, a range that runs from 5 up to 15 tonnes.

The rolltest system accommodates different models and specifications of telehandler with maximum flexibility.

The rolling roads tests six aspects of each telehandler :- * Run-out speeds in each gear.

* Parking brake.

* Service (foot) brake.

* Differential lock.

* Dynamic run-out (i.e simulation of load carried).

* Uphill driving simulation.

Cirrus' front-end interface talks to the resident control system, which is the "Test Manager" from Vehicle Monitor Corporation (VMC) of Canada, the preferred supplier of test equipment software for Caterpillar plants around the globe.

"Total data capture" enables all data and reports generated by the VMC system on individual vehicles to be archived and accessed.

At the heart of the engineering are four 1.5m diameter rollers (with one Siemens AC motor and one drive system to each roller) and five hydraulic cylinders.

There are one such cylinder per axle (two total) for vehicle centralizing and lateral restraint, one cylinder each for fore and aft vehicle restraints (two total), plus another which positions the wheelbase.

The new rolling road has a unique restraint system, which is far stronger than that on a typical rolltest rig for automobiles.

Lateral restraint is controlled from the inside of the vehicle track: it is accomplished by means of the hydraulic cylinders which centralize the vehicle during set-up and restrain it before and during test.

Innovative Cirrus thinking also solved a particular problem: when changing gear or braking, the test vehicle will rock, so Cirrus devised and implemented a new principle.

They designed a solution which allows the restraint rollers to move 3mm - 4mm with the vehicle, and this "active damping" provides all the cushioning needed.

What is more, a remote link via modem between the Cirrus HQ at Redditch and the programmable logic controller (plc) of the rolling road at Caterpillar reports on the status of the system in real time and is proving effective in tracking down the source of any problem that may arise and in eradicating it.

Other important and interesting features technically are :- * An environmentally friendly, regenerative, power-saving system.

* The safe and secure booth enclosing the rolling road.

* A 2.2m deep pit which houses the workings of the rolling road and is easy to access at either end by ladder for scheduled maintenance.

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