Siemens tests "eHighway of the Future" vision with tram-like overhead cables


May 23, 2012

Siemens is currently testing its eHighway of the Future concept in Germany - where commercial vehicles retro-fitted with a diesel/electric power train receive electric power from overhead cables via a new pantograph system

Siemens is currently testing its eHighway of the Future concept in Germany - where commercial vehicles retro-fitted with a diesel/electric power train receive electric power from overhead cables via a new pantograph system

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With most major auto manufacturers now actively developing electric vehicles, the drive towards a zero emission personal electric transportation future seems very much on the horizon. Road pollution doesn't just come from cars of course, freight vehicles are also major players in choking our highways and byways. Siemens is currently testing a possible solution in Germany that's based on proven railway and tram technology but has been adapted for trucks on roads. Heavy goods vehicles have been fitted with a newly-developed pantograph that can automatically raise to meet overhead cables and transfer electric power to hybrid diesel/electric power trains. Energy recovered from regenerative braking can also be fed back into the system for re-use by other vehicles.

The Siemens eHighway concept announced at the 26th Annual Electric Vehicle Symposium in Los Angeles recently is a two part system. The first involves the rollout of a two pole catenary system along one or more lanes on freight transport routes that caters for two-way electricity transmission and ensures a reliable power supply by feeding the overhead wire via container substations. The substations used in the current test project feature a medium-voltage DC switching system, a power transformer, a rectifier 12-diode array and a controlled inverter (for the feedback of the electric energy generated by regenerative braking).

Heavy goods vehicles have been fitted with a brand new pantograph - the second part of the concept - with an intelligent control system that can either automatically connect to an overhead wire upon detection by a built-in scanner or be manually controlled by the driver. Installed above the driver's cabin, the system is said to be capable of detecting the relative position of the overhead contact wire to the pantograph and counterbalances any lateral movements of the truck via active horizontal adjustment.

The test vehicles have also been retro-fitted with diesel-electric power trains, where they are always powered by an efficient electric motor but when in diesel mode, the vehicle's engine powers a generator, which in turn drives a downstream motor and turns the cardan shaft. When traveling under eHighway electric power, the vehicle is driven by the electric motor only. Siemens says that the driver is not aware of the transitions between different drive modes.

The field trial in Germany is reported to have confirmed full performance potential, independent of weather, conditions and load. The concept proved to be at least as flexible as existing fuel-based road freight transport solutions thanks to the maneuverability of the mobile pantographs, with reduction in carbon dioxide, nitrogen oxide, soot and noise pollution and added fuel efficiency benefits. Keeping up with the flow of traffic doesn't appear to have been a problem either, with speeds of up to 90 km/h (55 mph) being reached without difficulty under direct transmission of electric power.

Moving beyond the proof of concept test phase, schemes for the electrification of ports and cargo centers are already being considered but the solution has great potential for expansion to inner city roads in much the same way as streetcars/trams, and of course onto major transport routes. Naturally, such an infrastructure could also readily support the electric power needs of pure battery electrics, vehicles with range extenders, or those fitted out for compressed natural gas.

Source: Siemens

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Paul Ridden While Paul is loath to reveal his age, he will admit to cutting his IT teeth on a TRS-80 (although he won't say which version). An obsessive fascination with computer technology blossomed from hobby into career before the desire for sunnier climes saw him wave a fond farewell to his native Blighty in favor of Bordeaux, France. He's now a dedicated newshound pursuing the latest bleeding edge tech for Gizmag. All articles by Paul Ridden

I guess it's one of the solutions, but I don't think it should be the only one. What if there's a malfunction? Everything will just stop? Maybe they should create extra lanes for electric transportation. I don't know.


I love the idea. What I wonder is, is there not a better alternative than overhead cables? With overhead cables only large vehicles can benefit, and really large vehicles like special transports cannot pass at all. If it was on the side or even better on the ground, private vehicles could use it too and recharge their batteries on the fly.

Vinni Vince

What an attractive solution.

Mark A

because it is an intelligent pantograph and the vehicles will be hybrid they can overtake normally and the driver will be unaware of the diesel electric transition during overtaking manoeuvres

Panayis Zambellis

I guess what's old is new again. Los Angeles used to be at the forefront of public transportation technology, hard to believe as that may be. In the 1920's there was a "trackless electric trolley" that ran up Laurel Canyon to Bungalow Land. Sort of a dreamy utopian world in LA in the 20's that I wish I could have seen... quite different from today's LA. You can see photos at the link below. The project failed because the roads weren't yet paved (!) and because the systems weren't efficient enough to make the system worthwhile.


@Railwaymen, I suppose that the trucks retain their conventional powertrains and can use them if the electricity is down, but save on diesel costs 99.9% when it is working. They would have to retain diesel engines to deliver goods beyond the coverage of the electric infrastructure. I would like to see wireless electricity through the roads, but that technology is probably a long way off.

Alex Stelling

correction, that trackless trolley in LA was 1910 - 1912. 100 years ago! Amazing.


And as always, everyone knows that electric cars are NOT really zero-emission... they should be called "remote emission". Most often, the electricity is generated by a coal plant hundreds of miles away, which creates more pollution than modern gas-powered cars. If the electricity is generated by hydroelectric or nuclear power, then the atmospheric emissions are reduced, but you end up destroying habitats or making nuclear waste. Solar still isn't economical and has a huge carbon footprint just to create the solar cells. Wind or tidal power are probably as close as we can get, but there aren't enough of either type of generators to meet current demands.


i think i like the trolley better,i mean 10 cents for a cab. if they could just get it down to one whip antenna type conductor.


This has inspired me to a new idea. Rather than spending all that time and effort building a cable system like this one, why not use a tesla style system for wireless power transmission? Just over highways... You could retrofit streetlights to step up current to a high potential, broadcast it, and have that current picked up by vehicles..... Just thinkin


Way to go Siemens!.. I hope it won't be vapour..

I too, love the idea, and @railwayman, first I had a sudden, "oh, sh…t he's right!" reaction but then relief came:) thanks to other commentators. But you're right, it's one of the many solutions, not the only. Only THE is the electrification.

Though, if I was the engineer in charge, I would forget ICE motor all together and throw some batteries in there. I don't know when we are going to accept the fact that burning something to move is not the way to go. It's not efficient, it's not healthy, it's not economical,… it's almost criminal to insist. But hey, 7 out of 10 most influential companies in the world we're talking about.


@MRing, wish I had of thought of that in my post! Seriously if that does become available, and I hope it does, better to do it through the road. I think roads of the 21st century should charge electric cards, and painted lines should be replaced with LEDs and de-icing.

@Warhead, that's a myth. As internal combustion engines are not very efficient, a dirty coal power station powering every electric car would be better than every car having its own engine. Clean coal would be significantly cleaner again.

Alex Stelling

I wonder what cost structure this would use, and how you could get individual (professional) drivers to drive in ways that save fuel, since a lot of efficiency is about aerodynamics and driving habits.

Gas engines have pretty terrible efficiency, but a well driven diesel engine can easily blow away a hybrid in mpg - but then there are refinery costs etc. to worry about if you are comparing straight across to electrics. Electric power probably is more efficient, even if it's made using coal and, if this is charged back to the companies that use electricity, it is reasonable that there could be peak rates and off-peak rates.

MRing: Tesla was a cool guy, but there are several really good reasons we don't have large-scale wireless power transmission, including effects on health, danger of creating plasma, inefficiency of power transmission through multiple interfaces (types of material), and messing up signals used for research and communication. Even large (the kind that would provide power to move a car) magnetic fields are probably not good if you are traveling through them every day.

Charles Bosse

I remember transit buses that used overhead conductors.It worked okay in summer,but in the winter,ice fog would freeze on the overhead cables,and the bus driver would have to frequently stop and position the pickup arms back on the cables,as they were thrown off the cable in spots where the ice was extra thick.


Do the lines include a pit stop or do you park on the road and walk?


This looks like crap, and would cost a ton. I think electric cehicles are the future...but this isn't the method we will use. It will be better batteries (longer range), and faster charge times. Period.

Derek Howe

I have been working on this for 15 years...guess I am just too slow.


3871 x 2592 pixel jpeg original:

Brisbane '1963 TRAM 545 & TROLLEY BUS 35', looking towards Woolloongabba. While the trams stayed firmly on buried tracks (and passengers crossed roadsurface to board or exit), the trolley busses would swing into the kerb so passengers boarded from footpath. The Trolleypoles (paired for return current) swiveled to maintain current flow.

More here:

"The bus does not need to travel directly below the wires as does a tram but can move quite a distance to either side. For example on the Story Bridge in Brisbane which has 3 traffic lanes in each direction, the trolley wires were mounted over the centre lane and the trolleybuses could travel in any of the lanes because the booms would swivel and still reach the wires."


@ Warhead - the payback in energy or carbon production (whatever floats your boat) is between 1.5 to 3 years depending on the solar panel type and producer. Considering most panels are warrented to provide 80%+ of their rated output for 25 years (and will continue for many more years after) that's pretty fair. It's a very old debunked myth that solar panels take more power to produce than they will ever generate.

Marc 1

Why only supply power? If you're going to have overhead lines anyway, this would be the logical short to medium-term solution for an intelligent roadway, where autonomous vehicles could drive themselves just by following the hardwired lines. Unlike the wireless ultimate solution of the distant future, they wouldn't need to rely on not yet completely accurate GPS for location determination, and would be able to have tremendous connectivity between networked vehicles to create an intelligent road system.


cables are ugly.

Evan Webb Stuart

@Evan, @donwine,

Highways are ugly, so who cares if you add some cables.


To continue the thought from mizage, railroads are ugly too. But they seem to work quite well, especially for moving freight. Transferring the railroad technology that is so familiar in Europe to heavy-duty trucking is a logical step. Making that step in an industrial environment will be much easier than for personal transport. A targeted approach for heavy freight may be the best of both worlds for that segment; efficient electric propulsion on the major freeways, efficient (and versatile) diesel/electric hybrid off the grid.

Bruce H. Anderson

Not one person has addressed the obvious ..why go to the effort of creating such a system that will inevitably seek to replace the driver, why do this in this stage ,,,simply make the truck be guided along the tram lines via a controller station.


Many European cities (Edinburgh, Manchester, Marsailles) have endured enormous disruption and ruinous expense to install tram systems. These require overhead cables AND tram tracks. The tram tracks are the bit which causes the the disruption, digging up the roads, and -as they require the rerouting of lots of underground services- the ruinous expense. If you use an over head wire system like the one above, then you don't need the tracks. lots of cities still have excellent trolley bus systems in operation, and clean air as a result. Unlike trams, trolley buses can use batteries to go off route for a while e.g. into schools and hospital car parks. Better batteries means that this is now a much more extensive option than it used to be and is good enough for trucks to go many kilometres away from the wires too. New materials and smart electronics for metering power make this old tech a modern winner.

Dirk Scott
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