The vehicle has to enter the United Utilities site at Knutsford, Cheshire, via a narrow tunnel under a railway line.
Warning signs at the tunnel entrance say it is 2.4m wide (actual width is 3m), but it is only 1.9m at the narrowest point – with a concrete kerb both sides further reducing the space.
The operator worked with Volvo Trucks and dealer Thomas Hardie Commercials for several months, with CAD drawings and a site visit with the model cab to ensure the truck could pass through the tunnel.
The result is the Volvo FM-460, which features Volvo Dynamic Steering to ensure precision manoeuvring, and it replaces a 2009-plate, FL-280 powered, four-axle drawbar tanker outfit.
The vehicle is plated for operation at 32 tonnes gtw and specified with air suspension on all axles. The front axle air suspension can be lowered by up to 50mm. The low height ‘car transporter’ sleeper version of the FM cab reduces overall height, as does running on low profile 355/50R22.5 tyres on the front axle and 295/60R22.5 tyres on the drive axle. The tyre choice helps the 5.2m wheelbase FM-460 to achieve a nominal chassis height of just 850mm.
The complete truck is 3.07m high to the top of the Crossland tanker body on the prime mover. FMX-style mirrors are mounted on arms positioned close in to the cab and without cowls to minimise the overall width.
United Utilities transport co-ordinator Dale Savage says the truck spec took about a year to finalise. “We have also done some work on widening the approach to the tunnel so the driver can straighten the drawbar up before he enters it. We needed to retain the existing entrance to the site as it wasn’t possible to gain permission from the local landowner to build a new road in, and rebuilding the railway bridge wasn’t an option due to cost and disruption. “We looked at replacing the FL like for like, but decided to go with the FM with its extra power giving improved productivity and range.”