Electrification to Exeter, then carry own electricity to Plymouth?

[whole diary]

[grahame]

Rather that diesel and elecric bimodes, why not run electric all the way to Plymouth, carrying own electric supply west of Exeter where the salty seawall may be an overhead issue?

http://www.guardian.co.uk/uk/2013/feb/03/battery-powered-intercity-trains-possible-study

[eightf48544]

It would be an awfully big battery to store 3Mw for an hour.

What's wrong worth changing engines at the end of the wires. You could have league tables of the quickest. Might need a bit of track alterations but probably less expensive than carting diesel engines around under the wires for 30 years.

[Worcester_Passenger]

It would be an awfully big battery to store 3Mw for an hour.

What's wrong worth changing engines at the end of the wires. You could have league tables of the quickest. Might need a bit of track alterations but probably less expensive than carting diesel engines around under the wires for 30 years.

Agree completely.

The French are quite happy about attaching a diesel on the front of a TGV^▸ (Train a Grande Vitesse) where they haven't got wires.

[JayMac]

The French are quite happy about attaching a diesel on the front of a TGV^▸ (Train a Grande Vitesse) where they haven't got wires.

Does this routinely happen day-in, day out, on timetabled services?

TGV Atlantique services used to be diesel hauled between Nantes and Les Sables d'Olonne on the Atlantic coast, with just three diesels specially converted to provide the service. The line from Nantes has now been electrified however.

[broadgage]

Railway traction from battery power is entirely doable, and I suggested just that on another thread.
The size and cost of the battery is unlikely to be economic for 600 mile ranges, just because it is possible in theory that does not mean that it is sensible in practice.

I can certainly see battery powered trains being of use on branch or secondary routes for relatively modest speeds and distances.
Possibly also useful for mainlines that are electrified ALMOST throughout, but that have short problematic sections.
Charging by physical removal/swopping the battery for another is most unlikely to be viable, too much to go wrong ! Coupling and uncoupling  multiple units seems to result in enough problems.

In the case of a non electrified branch or secondary route, then charging whilst on the electrified main line and whilst stopped at the terminus should suffice.

[stebbo]

I've said this before elswhere on the IEP^▸ (Intercity Express Program / Project.) debate but I believe that using a diesel engine to haul an electric train over non-electrified sections makes sense.

I can't see batteries being effective for inter-cities on the Bristol/Exeter/Portsmouth/Penzance or Oxford/Worcester/Hereford or Swindon/Gloucester/Cheltenham routes. Nor do I personally see it as particularly effective to lug unused diesel plants around for chunks of the journey.

Of course if there was more spending on electrification (and less on HS2^▸ (The next High Speed line(s)).......)

[broadgage]

I cant forsee batteries being sensible for long or fast intercity routes, despite it being possible in theory.
I can certainly forsee battery power being used for bits of a generally electrified area that cant be economicly electrified, including,
Particularly scenic or historic locations
Tunels with tight headroom
Where waves would be a problem
In depots and sidings
To permit of through running from an electrified line on to a private or heritage line
For diversionery routes that are not electrified
And for when the OHLE fails.

If only limited operation on battery power is required then a relatively small battery is needed.
A reasonable specification might be to run for say 30 miles at 60 MPH or furthur at slower speeds. That would be a much more modest battery than that needed to run 600 miles at line speed.

[Western Enterprise]

This reminds me of the time when many industrial plants around the place had fire-less locomotives, they would charge up with steam from the boiler house and then shunt around the site with just a boiler full of pressurised steam.
This was usually in places where sparks may have been a fire problem.
Of course, if the steam ran out, you were just left with a no-good lump of metal. It would be just the same with batteries, if for what ever reason they died out, you would be left with a service going nowhere in short order.

[paul7575]

Battery power just isn't feasible for something with the mass of a train is it?  Surely if it was at all practical they wouldn't be proposing adding small diesel engines to the EMUs^▸ (Electric Multiple Unit) for rescue purposes would they?

Paul

[Kernow Otter]

Rather that diesel and elecric bimodes, why not run electric all the way to Plymouth, carrying own electric supply west of Exeter where the salty seawall may be an overhead issue?

http://www.guardian.co.uk/uk/2013/feb/03/battery-powered-intercity-trains-possible-study

Or, radically, distribute some of the many billions being invested and proposed for investment in rail, somewhat more fairly and less politically and run wires to Penzance.....

[onthecushions]

The problem with all batteries is the low energy density (qv).

The graph in

 http://en.wikipedia.org/wiki/File:Energy_density.svg

 may help explain this.

They are used on rail for shunting (such as the Southern MLV's or the two industrials at the Coventry Electric Railway Museum) and for an experimental bemu (SC79998/9). I believe that a 125 power car was considered for a "hybrid" conversion, where batteries are used to assist in acceleration and climbing but are recharged on braking and level running, giving higher peak power and less cycling of the diesel.

OTC

[broadgage]

The energy density of batteries has recently improved significantly, though it remains far less than the energy density of diesel or other common fuels.

One advantage though is that no heavy diesel engine is needed, the extra weight being ONLY that of the battery. The power from the battery may be applied to the same traction motors that utilise power from the OHLE when available.

Electric cars are available with ranges of 200 miles and more, and a train should be able to better that on account of the lower friction.

Another advantage of battery power is that regenerative braking is easily achieved without the complications of returning power to an external supply.

Also trains need batteries in any case, relatively small ones for control and auxillary purposes and emergency lighting. If a traction battery was installed, a small proportion of its capacity could be utilised for other purposes thus saving the space and weight taken up.

Batteries give warning of running down by the voltage reducing, they dont suddenly become empty unlike fuel tanks. There is therefore very little risk of becoming stranded.

[Tim]

...fuel tanks don't suddenly become empty either.  Not unless they get a hole in them.

[broadgage]

...fuel tanks don't suddenly become empty either.  Not unless they get a hole in them.

Well no, but they do unexpectedly become empty ! I have been on a train that ran out of fuel.

[Electric train]

In earlier threads about IEP^▸ (Intercity Express Program / Project.)'s being bi-mode and what a waste of energy it would be to cart a dead diesel around that pales into insignificance compare to carting around several tonnes of batteries indeed an engine would be lighter.

I did mention to one of our Overhead Line Engineers about wiring the line through Dawlish ............. would be an interesting challenge was his reply although he could not think of a solution off the top of his head he felt sure one could be found ........ at a cost