Spectacular road/rail application for Mercedes-Benz Unimog
at Métro Lausanne-Ouchy S.A.
A world first in every respect – the new metro line for the IOC city enters the Guinness Book of Records
Unimog general distributor in Switzerland, Robert Aebi AG, Regensdorf/ZH and Unimog implement partners Zwiehoff (Rosenheim) and Zagro (Bad Rappenau) pioneer twin traction with rail guidance system
Right from the start of construction several years ago, the Unimog vehicles have proven their merit as reliable workhorses on rails
Wörth am Rhein / Lausanne – When the “m2”, the new line run by Métro Lausanne-Ouchy S.A., comes on stream in summer 2008 as Switzerland’s first metro line, there will be another two entries ripe for the Guinness Book of Records. No other metro anywhere in the world has to cope with an altitude difference of 338 m and gradients of up to 12% along a 5.9-kilometre stretch. And what’s more, the new “m2” as successor to the old “Ficelle”, which ran from Ouchy on Lake Genevato Lausanne-Flon, was built in a record-breaking time of just under four years. This project is an absolute first in underground railway construction in many respects and in terms of railway technology can easily hold its own with what remains Switzerland’s most important north-south railway link inaugurated 125 years ago, the Gotthard line. The “m2” metro tackles the 5.9-kilometre stretch with gradients of up to 12% and a height difference of 338 m (!) with no aids such as a cogwheel mechanism or a traction cable. The new fully automatic metro line with Alstom rubber-tyred vehicles will link the Lausannedistrict of Ouchy on Lake Genevawith the northern reaches of the city, which has a population of 250,000 and is home to the headquarters of the International Olympic Committee (IOC) and the “Biopôle” science park in the north of the city. The total investment runs to 590 million Swiss francs.
The rescue unit operating for the "m2" consists of two twin-traction Mercedes-Benz Unimog U 400 vehicles with a Hiab XS055 crane and swappable rear attachment and is a world first for rail-guided vehicles. Philippe Goy from Lausanne, responsible for all the electromechanical systems and the various applications covered by the two Mercedes-Benz Unimog U 400 vehicles with their Zwiehoff-Zagro rail guidance system in the “m2” project, is a railway engineer to the core. He recalls the tender phase for these vehicles: “Of the various manufacturers in Switzerlandand the neighbouring European countries, only three suppliers were able to offer series-production vehicles. Some thought they could secure the contract with their own purpose-built vehicles. But we were looking for vehicles with a proven volume-production track record. The test runs on wet rails, which had also been treated with soap, hauling heavy loads of up to 2 x 12 t gross vehicle weight on the old cogwheel line from Ouchy to the former Lausanne-Flon terminus in the city centre, convinced us and the experts from HTL Yverdon involved in the project of the Mercedes-Benz Unimog’s credentials.” The good friction coefficient of rubber on steel once again proved an advantage, a crucial factor in the good test results. The official operating permit for the Unimog vehicles on the metro line run by the Swiss Transportation Office was obtained at the end of June this year.
The Mercedes-Benz Unimog vehicles proved to be the most cost-effective solution for the envisaged application in all the commercial and technical comparisons. None of the rival tenders could offer better value for money. And on top of all these sound benefits was the globally acknowledged reputation of this tried-and-trusted vehicle. “The decision was easy for us”, underlines Philippe Goy, adding emphatically: “another important factor was that we couldn’t have had a better service partner set-up than with Robert Aebi AG (headquartered in Regensdorf/ZH), the Unimog general distributor in Switzerland, who has a sales and service outlet literally just down the road in Morges on Lake Geneva.”
Master and slave: Unimog with twin traction
Once the testing and decision-making process was complete, a start was made on implementing the rescue and service vehicles project. The test runs confirmed that two vehicles with twin traction were required for safety reasons and to cope with the towing load of up to 54 t which an empty metro train represents, along with gradients of up to 12%. The first vehicle in the convoy, dubbed the ‘master’, in which the driver sits, is connected via a drawbar to the second – driverless – vehicle, the ‘slave’. The electronics and all the driving systems are controlled synchronously. To achieve this, a groundbreaking control system for rail-guided vehicles had to be developed which could also cope with the towing requirements.
The Rosenheim-based (Upper Bavaria) company G. Zwiehoff GmbH, a specialist in marketing and designing road/rail vehicles, consummately rose to the task. Zagro in Bad Rappenau near Heilbronnbuilt the rail guidance system. Philippe Goy confirms: “The cooperation among our team with Aebi, Zwiehoff and Zagro was excellent. As engineers we were always on the same wavelength when we had to come up with a solution for the task in hand. And thanks to this cooperation we could also run all the tests locally using a realistic configuration. This fact ultimately also helped us pull off the remarkable overall result we have today.”
Métro Lausanne-Ouchy S.A. is therefore excellently equipped should the worst occur, say a train breaks down or a power outage occurs, with the Unimog vehicles on hand to come to the rescue in an emergency. The vehicles will be asked to do far more than just tow stricken trains, though. Future operations include service work on the entire line as well as washing and vacuuming the tunnel sections. The crane plus an additional generator for each unit are needed for daily line maintenance, which must be carried out between 1.00 and 5.00 a.m.when the metro line is out of service.
The “m2” project team also realised that railways are worlds apart from their road transport counterparts. When the two Mercedes-Benz Unimog vehicles were delivered, they sat waiting idly on the track in the municipal yard. But it wasn’t long before material was needed somewhere on the new stretch of line. And then those in charge realised the value of their two “diamonds”. Throughout the construction phase, now already well into its third year, the Unimog vehicles were deployed some 12 to 16 hours a day in three shifts. Such a punishing schedule had not been planned but the Unimog vehicles rose to the challenge superbly and the construction managers realised straightaway what these vehicles could actually do. And so they were used for every conceivable task during the construction phase, even those tasks for which they were never intended.