Siemens powers trucks like trams with overhead wires

[whole diary]

[NickF]

http://www.wired.co.uk/news/archive/2014-08/11/siemens-ehighway-tests

[trainer]

I think the trolley bus is a nearer comparison for overhead electric power for a road vehicle.  The catenary looks very heavy-weight and not at all like the less obtrusive power lines used for trams and trollies.  Can't see it catching on in narrow, historically sensitive streets.

Thanks for an interesting link, Nick.

[stuving]

Can't see it catching on in narrow, historically sensitive streets.

Surely that's not the idea? I think it's aimed at motorways, as part of a "what do we do if there's no oil left" plan B.

What is neat is to make use of in-road (presumably) guidance to keep the truck under the wires, so you no longer need to hook a "trolley" onto a wire.  A modest supercapacitor/battery allows you to change lanes or park. You could also make the supply three phase, if you wanted (e.g. you are Swiss).

[eightf48544]

I presumme the heavy weight wires and pans are to be able to pass the necessary Watts to a number of trucks simultaneously.

Was there any mention of the voltage?

Agree it's more like a trolley bus than a tram but it's funny how things keep getting reinvented.

Wonder if you can fit regen brakes?

[stuving]

Was there any mention of the voltage?

650V DC^▸ (Direct Current)

Wonder if you can fit regen brakes?

Yes.

As well as being a Siemens project, it has been part of a German government research project called ENUBA, followed by ENUBA-2. However, most of the material available (and almost all that is in English) is from Siemens.

They don't actually mention guidance, but do go on about clever adaptive pantographs. So I guess at this stage if you drive off line the pan drops - which you'd need to do anyway, even guided, and it saves coupling it to another research project.

[Rhydgaled]

Can't see it catching on in narrow, historically sensitive streets.

Surely that's not the idea? I think it's aimed at motorways, as part of a "what do we do if there's no oil left" plan B.

What is neat is to make use of in-road (presumably) guidance to keep the truck under the wires, so you no longer need to hook a "trolley" onto a wire.  A modest supercapacitor/battery allows you to change lanes or park. You could also make the supply three phase, if you wanted (e.g. you are Swiss).

Of course one of the advantages of rail electrification is the weight reduction from not having to carry self-power equipment (a benifit which is thrown away by the likes of the class 800/801) and hence a reduction in the amount of energy needed to shift the thing.

[stuving]

Of course one of the advantages of rail electrification is the weight reduction from not having to carry self-power equipment (a benifit which is thrown away by the likes of the class 800/801) and hence a reduction in the amount of energy needed to shift the thing.

Not only is the current demo system a hybrid, but there is no visible plan to drop the diesel engine. I think the reason is obvious - you will need it until the wires cover the great majority of point-point truck runs. That could be a very long wait...

The choice of 650V DC^▸ (Direct Current) is, I would guess, to avoid excess weight in transformers etc.

[Rhydgaled]

Of course one of the advantages of rail electrification is the weight reduction from not having to carry self-power equipment (a benifit which is thrown away by the likes of the class 800/801) and hence a reduction in the amount of energy needed to shift the thing.

Not only is the current demo system a hybrid, but there is no visible plan to drop the diesel engine. I think the reason is obvious - you will need it until the wires cover the great majority of point-point truck runs. That could be a very long wait...

The choice of 650V DC^▸ (Direct Current) is, I would guess, to avoid excess weight in transformers etc.

Of course you could detatch the trailer/container from the diesel power unit and put it behind an electric 'locomotive'.

[JayMac]

So a potential two power units for each trailer? And associated additional cost for marshaling yards/staff/time to effect the switch over.

Or stick with the designed single unit hybrid solution.

[broadgage]

Electrically powering a rubber tyred vehicle is inherently more complex than a tram or electric train.
A rubber tyred vehicle needs TWO overhead wires and TWO pantographs, unlike a rail vehicle or tram that needs only one, with return via the rails.
Having gone to expense of installing the infrastructure, then of course a trolley bus service on the same route might be viable.

[stuving]

Do remember this is research. They seem to be proposing the pictured system, as tried out on a test track in Germany, for the demo in California. However, I'd guess it might change a bit as it is further developed for that.

And I'm sure they have looked a lot of other possibilities, which may become preferable in the many years before any large-scale adoption. Once the truck knows where it is in the road, and has a battery or other energy store to take it even a few tens of metres, and the pantograph is moderately clever, all sorts of things are feasible.

For example, you simply stop the overhead supply at junction and rely on that energy store. Then you could put the two conductors side by side and clasp it with two collectors on a single arm. Or all sorts of other alternatives.

[Oxonhutch]

Many open pit metal mines use these vehicles for rock haulage out of the (often quite deep) mines using electric on the incline and switching over to conventional diesel on the level pieces - both in and out of the pit.

Click here for an article on such vehicles.  From personal observation (on the job), as soon as these trucks hit the electric juice, they speed up tremendously.  Very impressive in their scale too - the tyre height alone towers above a man.  Then there is the wheel hub, the top of the tyre and then the rest of the truck.  Hybrid monsters indeed.

[stuving]

Siemens have been busy on this project in the years since the earlier news items posted above, and have had two trucks doing trials in Sweden for a year, on a 2km stretch of public road. They just announced a bigger trial in Germany:

Siemens has been commissioned by the German state of Hesse to build an overhead contact line for electrified freight transport on a ten-kilometer stretch of autobahn. The line will supply electricity for the electric drive of a hybrid truck. Siemens originally presented its innovative "eHighway" concept in 2012. The system will be installed on the A5 federal autobahn between the Zeppelinheim/Cargo City Süd interchange at the Frankfurt Airport and the Darmstadt/Weiterstadt interchange.

The words all refer to the trucks as being hybrids, with diesel power as the other source not batteries. And as to what's happened to the proposed trial in California; I can still only see it mentioned in the future tense.

[Bmblbzzz]

Interesting idea.

Clearly it's more similar to a trolleybus than a tram but it has a railway-like pantograph. Presumably this is to allow overtaking, as the article says, and I'd imagine it also makes the connectors less likely to lose contact going over bumps and potholes.

I think it could be a useful step on the way to electric HGVs, which are going to be much more difficult than electric (or fuel cell!) cars due to the longer distances and greater unpredictability of refuelling spots. Though of course a regular port run involves one known recharging spot every time; but still there would be the downtime cost of recharging, unless it can be included in driver's rest. OTOH^▸ (On The Other Hand) it could turn out to be a great white elephant due to cost of OHLE.

[broadgage]

This idea has its merits but is not so new as may be supposed. Electric road vehicles powered from an overhead were used about 100 years ago.
IIRC^▸ (if I recall/remember/read correctly) the goods were placed in standard wagons primarily intended for horse hauling, but were hauled electrically up hills in particular.
I cant find the link but it was on a site about old technology.

Electrically powered canal boats were also tried.