HomeInternationalSwiss towing Discovery

The rail industry has an access problem. While a few lines run alongside roads for part of their length, most are located away from public access, across fields and down cuttings or up on embankments.

So when work is needed, often the only way to get all the equipment and heavy plant to site is along the railway lines themselves. For this purpose, a wide range of conventional equipment has been modified with the addition of flanged rail wheels front and back. Some of these are purely for guidance – the vehicle is still supported, powered and braked through the normal rubber-tyred road wheels which run along the top of the rails, the flanged wheels just stop it from falling off.

The conversion of other vehicles is more complex. The rubber tyres, or even tracks, are jacked clear of the rail and the whole vehicle is now driven by the rail wheels, with hydrostatic drives and separate braking systems.

Many types of vehicle have been converted; excavators, bulldozers, people-carriers, trailers, lorries – even road rollers. All adapted, not necessarily to work on-track, but to at least get to the work site.


So those companies that convert equipment for use on the railway are used to being asked to work on something new. However, a recent phone call taken by James Platt, managing director of Aquarius Rail Technologies, the well-known specialist rail converter of Land Rover Defenders, took him by surprise.

Could he convert a mystery SUV for rail, to tow in excess of 100 tonnes on track. Unsurprisingly, he wondered whether the call was a prank. However, he agreed that it could be done and, once the confidentiality agreements were signed, it was revealed that the call was from Jaguar Land Rover and the SUV in question was a Land Rover Discovery Sport. It was to be used in a promotional film for the new model.

This request wasn’t as odd as it sounded. “In fact I was involved in the launch of the original Discovery in 1989, when it towed a series of train carriages,” James commented later. This was obviously going to be something similar.

Aquarius has been converting highway-based vehicles for the last 17 years including Land Rovers, Ford Rangers, Mitsubishi Canters and Kawasaki Mules for the rail industry, so if anyone was going to have the knowledge it would be James and his team.

1989 – the first Discovery train pull.

Is it possible?

One obvious snag was that the published towing capacity of the Discovery Sport is 2.5 tonnes, not 100. Could the sub 3.5-tonne compact SUV tow over 100 tonnes?

To see if the stunt was even possible, Aquarius conducted a test using the next best thing: an R2R4x4 Land Rover Defender. One damp spring morning an Aquarius
R2R4x4 was driven to the Ecclesbourne Valley Railway at Wirksworth in Derbyshire.

Under a cover story, the Defender was hitched to two 20-tonne brake vans and one 40-tonne carriage and driven up a 1:220 slope. That initial testing was a success, proving that the Defender model would be likely to meet the requirements.

The next stage was to carry out static pull tests at Aquarius headquarters with an R2R4x4 providing a benchmark against which to test the Discovery Sport. Surprisingly, the Discovery Sport produced 15 per cent more pull than the Defender – incredible given the compact SUV is 800kg lighter, at a tare weight of just 1,700kg.


Now confident in the theory that a 100-tonne train could be towed, a Discovery Sport with the latest 180PS Ingenium diesel engine was delivered to the Aquarius team, which set about fitting a modified rail guidance system to provide simple lightweight rail frames.

The conversion had to look discreet – no Rail Yellow RAL 1003 for this rail gear, which was powder coated black. An additional battery was added to power the rail gear, which was hidden, with the two rail gear pumps, in the boot. With its superior soundproofing, this rail guidance system was the quietest Aquarius has ever made.

Apart from the sight of small rail wheels, the Discovery Sport looked like a standard vehicle and the electro-hydraulic rail guidance system was controlled from the driver’s seat just like the Aquarius R2R4x4.

Once the road/rail conversion was complete it was time to test the functionality of the rail gear on a local historic track, this time at Wensleydale Railway, a short drive from Aquarius’ factory at Ripon, North Yorkshire. The test included pulling a Class 37 diesel locomotive up and down a 1:600 gradient. Communication between RRV and locomotive operators was paramount because the Discovery Sport was not visible from the loco’s cab.

The Discovery Sport was hidden from prying eyes throughout this period with no word to friends and family. Sworn to secrecy, the converted Discovery Sport travelled the country under canvas and was hidden from view in the workshop.

Off to Switzerland

Now ready for its starring role in Jaguar Land Rover’s promotional film, arrangements were made to ship the vehicle to Switzerland. It was going to tow a trio of carriages across the River Rhine on the dramatic Hemishofen bridge in northern Switzerland, a historic steel span measuring 935 feet long and soaring 85 feet above the river. The activity was designed to demonstrate Jaguar Land Rover’s cutting-edge 2.0-litre Ingenium diesel engine and the traction technologies and towing capability of the Land Rover Discovery Sport.

The three luxury train carriages had a combined weight of 108 tonnes. This is the equivalent to the weight of a Boeing-757 airplane, or 60 times the weight of the Land Rover.

James Platt was in Switzerland for the filming as the road/rail technical expert, and was in the passenger seat operating the rail gear throughout the stunt. Unlike on the earlier test of the first model Discovery in 1989, the Discovery Sport completed its impressive pull without the aid of low- range gears. Instead, the compact SUV’s state-of-the-art 9-speed automatic gearbox and Land Rover’s Terrain Response technology aided traction. At the press of a button, the All Terrain Progress Control (ATPC) system was even able to maintain a set speed, effectively working like a low speed cruise control from a standing start.

“What an experience!” exclaimed James afterwards. “This has been a great project for Aquarius; it has really allowed our team to shine. There has been problem solving throughout, from how to make the rail guidance system light enough and minimising disruption to the Discovery Sport chassis, to how to hide the cables for the electro-hydraulic system.

“The train pull really did demonstrate how remarkable the Discovery Sport’s semi-autonomous off-road driving system is.”

Karl Richards, lead engineer for stability control systems at Jaguar Land Rover, said: “Towing is in Land Rover’s DNA, and Discovery Sport is no exception. Over the years, we have introduced game-changing towing technologies to take the stress out of towing for our customers. I’ve spent most of my career travelling to the most punishing parts of the world to test Land Rovers in gruelling conditions, yet this is the most extreme towing test I’ve ever done.”

Following the successful filming, the Discovery went back to Jaguar Land Rover and James is now wondering what the next phone call will bring.

Rail Engineer is the leading independent quality monthly magazine for engineers, project managers, directors and leading rail executive decision makers. Head to www.railsubs.com to make a free subscription to RailEngineer magazine or one of its sister publications.


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