Road-rail first

Based near Horsham in the South of the UK, L&W Contracting is the preferred supplier for construction equipment rental in the counties of Kent and Sussex to Network Rail, the public body that owns all of the UK’s railway lines. Since winning the contract the company has invested UK£ 1,5 million (€ 2,2 million) on road rail excavators. The latest addition to its fleet is a New Holland MH2.6, and it is the first time this model has been converted to road- rail use in the UK.

The conversion was carried out by Rexquote, a company based in Taunton, in the South-west of the UK, which specialises in converting standard wheeled excavators to road/rail use. The key components of the system are two sets of guide wheels - front and back - which are the same gauge as the railway track.

Once the excavator has driven on to the railway, the guide wheels are lowered to locate them onto the tracks. They then lift the excavator off its pneumatic tyres. However, the Rexquote system still uses the excavator’s normal two-speed hydrostatic drive system to propel it along the tracks. In their final position the guide wheels bear on the excavator’s pneumatic tyres and are driven through friction with the rubber tyre.

The basic MH2.6 is a 10 tonne class wheeled excavator, but the addition of the rail guide wheels and other hardware associated with the conversion takes this up to 12 tonnes. The boom configuration chosen by L&W provides 8 m of horizontal reach, and this was one of the deciding factors for buying the machine.

L&W Contracting training manager Gary Jayes said, “The three-piece boom is better for work close to the excavator, and the offset allows us to dig alongside the tracks,” he said.

In addition to Rexquote’s road- rail equipment, L&W Contracting has fitted additional instrumentation in the shape of Prolec’s Liftwatch system. This load sensing system gives the operator a warning if the machine’s safe lifting capacity has been exceeded, and also includes an automatic shut-off function.

It is an important safety feature because the MH2.6’s 120° (60° either side) offset boom means the machine is capable of lifting loads over the side of its chassis. In such cases, the load is not opposite the machine’s fixed counterweight, so there is an increased risk of tipping the excavator over.

“The Prolec ensures the machine will lift a load in the safest possible way,” said Mr Jayes.

Despite being a preferred supplier L&T Contracting says the organisation’s “bureaucracy” makes it impossible to train operators on Network Rail-owned track. However, the company has an agreement with the Bluebell Railway, a restored steam railway in Sussex, whereby it is allowed to use parts of the track in return for carrying out maintenance work on the lines.