The Anonymous Widower

Could A Battery- Or Hydrogen-Powered Freight Locomotive Borrow A Feature Of A Steam Locomotive?

Look at these pictures of the steam locomotive; Oliver Cromwell at Kings Cross station.

Unlike a diesel or electric locomotive, most powerful steam locomotives have a tender behind, to carry all the coal and water.

The Hydrogen Tank Problem

One of the problems with hydrogen trains for the UK’s small loading gauge is that it is difficult to find a place for the hydrogen tank.

The picture is a visualisation of the proposed Alstom Breeze conversion of a Class 321 train.

  • There is a large hydrogen tank between the driving compartment and the passengers.
  • The passenger capacity has been substantially reduced.
  • The train will have a range of several hundred miles on a full load of hydrogen.

The Alstom Breeze may or may not be a success, but it does illustrate the problem of where to put the large hydrogen tank needed.

In fact the problem is worse than the location and size of the hydrogen tank, as the hydrogen fuel cells and the batteries are also sizeable components.

An Ideal Freight Locomotive

The Class 88 locomotive, which has recently been introduced into the UK, is a successful modern locomotive with these power sources.

  • 4 MW using overhead 25 KVAC overhead electrication.
  • 0.7 MW using an onboard diesel engine.

Stadler are now developing the Class 93 locomotive, which adds batteries to the power mix.

The ubiquitous Class 66 locomotive has a power of  nearly 2.5 MW.

But as everybody knows, Class 66 locomotives come with a lot of noise, pollution, smell and a substantial carbon footprint.

To my mind, an ideal locomotive must be able to handle these freight tasks.

  • An intermodal freight train between Felixstowe and Manchester.
  • An intermodal freight train between Southampton and Leeds.
  • A work train for Network Rail
  • A stone train between the Mendips and London.

The latter is probably the most challenging, as West of Newbury, there is no electrification.

I also think, that locomotives must be able to run for two hours or perhaps three,  on an independent power source.

  • Independent power sources could be battery, diesel, hydrogen, or a hybrid design
  • This would enable bridging the many significant electrification gaps on major freight routes.

I feel that an ideal locomotive would need to meet the following.

  • 4 MW when running on a line electrified with either 25 KVAC overhead or 750 VDC third-rail.
  • 4 MW for two hours, when running on an independent power source.
  • Ability to change from electric to independent power source at speed.
  • 110 mph operating speed.

This would preferably be without diesel.

Electric-Only Version

Even running without the independent power source, this locomotive should be able to haul a heavy intermodal freight train between London and Glasgow on the fully-electrified West Coast Main Line.

I regularly see freight trains pass along the North London Line, that could be electric-hauled, but there is a polluting Class 66 on the front.

Is this because there is a shortage of quality electric locomotives? Or electric locomotives with a Last Mile capability, that can handle the routes that need it?

If we have to use pairs of fifty-year-old Class 86 locomotives, then I suspect there are not enough electric freight locomotives.

Batteries For Last Mile Operation

Stadler have shown, in the design of the Class 88 locomotive, that in a 4 MW electric locomotive, there is still space to fit a heavy diesel engine.

I wonder how much  battery capacity could be installed in a UK-sized 4 MW electric locomotive, based on Stadler’s UK Light design.

Would it be enough to give the locomotive a useful Last Mile capability?

In Thoughts On A Battery Electric Class 88 Locomotive On TransPennine Routes, I estimated that a Class 88 locomotive could replace the diesel engine with a battery with a battery capacity of between 700 kWh and 1 MWh.

This would give about fifteen minutes at full power.

Would this be a useful range?

Probably not for heavy freight services, if you consider that a freight train leaving the Port of Felixstowe takes half-an-hour to reach the electrification at Ipswich.

But it would certainly be enough power to bring the heaviest freight train out of Felixstowe Port to Trimley.

If the Felixstowe Branch Line were to be at least partially electrified, then I’m sure a Class 88 locomotive with a battery instead of the diesel engine could bring the heaviest train to the Great Eastern Main Line.

  • Electrifying between Trimley and the Great Eastern Main Line should be reasonably easy, as much of the route has recently been rebuilt.
  • Electrifying Felixstowe Port would be very disruptive to the operation of the port.
  • Cranes and overhead wires don’t mix!

I wonder how many services to and from Felixstowe could be handled by an electric locomotive with a Last Five Miles-capability, if the Great Eastern Main Line electrification was extended a few miles along the Felixstowe Branch Line.

As an aside here, how many of the ports and freight interchanges are accessible to within perhaps five miles by electric haulage?

I believe that if we are going to decarbonise UK railways by 2040, then we should create electrified routes to within a few miles of all ports and freight interchanges.

Batteries For Traction

If batteries are to provide 4 MW power for two hours, they will need to have a capacity of 8 MWh.

In Thoughts On A Battery Electric Class 88 Locomotive On TransPennine Routes, I said this.

Traction batteries seem to have an energy/weight ratio of about 0.1kWh/Kg, which is increasing with time, as battery technology improves.

This means that a one tonne battery holds about 100 kWh.

So to hold 8 MWh or 8,000 kWh, there would be a need to be an 80 tonne battery using today’s technology.

A Stadler Class 88 locomotive weighs 86 tonnes and has a 21.5 tonne axle load, so the battery would almost double the weight of the locomotive.

So to carry this amount of battery power, the batteries must be carried in a second vehicle, just like some steam locomotives have a tender.

But suppose Stadler developed another version of their UK Light locomotive, which was a four-axle locomotive that held the largest battery possible in the standard body.

  • It would effectively be a large battery locomotive.
  • It would share a lot of components with the Class 88 locomotive or preferably the faster Class 93 locomotive, which is capable of 110 mph.
  • It would have cabs on both  ends.
  • It might have a traction power of perhaps 2-2.5 MW on the battery.
  • It would have a pantograph for charging the battery if required and running under electrification.
  • It might be fitted with third rail equipment.

It could work independently or electrically-connected to the proposed 4 MW electric locomotive.

I obviously don’t know all the practicalities and economics of designing such a pair of locomotives, but I do believe that the mathematics say  that a 4 MW electric locomotive can be paired with a locomotive that has a large  battery.

  • It would have 4 MW, when running on electrified lines.
  • It would have up to 4 MW, when running on battery power for at least an hour.
  • ,It could use battery-power to bridge the gaps in the UK’s electrification network and for Last Mile operation.

A  very formidable zero-carbon locomotive-pair could be possible.

The battery locomotive could also work independently as a 2 MW battery-electric locomotive.

Hydrogen Power

I don’t see why a 4 MW electric locomotive , probably with up to 1,000 kWh of batteries couldn’t be paired with a second vehicle, that contained a hydrogen tank, a hydrogen fuel-cell.and some more batteries.

It’s all a question of design and mathematics.

It should also be noted, that over time the following will happen.

  • Hydrogen tanks will be able to store hydrogen at a greater pressure.
  • Fuel cells will have a higher power to weight ratio.
  • Batteries will have a higher power storage density.

These improvements will all help to make a viable hydrogen-powered generator or locomotive possible.

I also feel that the same hydrogen technology could be used to create a hydrogen-powered locomotive with this specfication.

  • Ability to use 25 KVAC overhead or 750 VDC third-rail electrification.
  • 2 MW on electrification.
  • 1.5 MW on hydrogen/battery power.
  • 100 mph capability.
  • Regenerative braking to batteries.
  • Ability to pull a rake of five or six coaches.

This could be a very useful lower-powered locomotive.

What About The Extra Length?

A Class 66 locomotive is 21.4 metres long and a Class 68 locomotive is 20.3 metres long. Network Rail is moving towards a maximum freight train length of 775 metres, so it would appear that another twenty metre long vehicle wouldn’t be large in the grand scheme of things.

Conclusion

My instinct says to be that it would be possible to design a family of locomotives or an electric locomotive with a second vehicle containing batteries or a hydrogen-powered electricity generator, that could haul freight trains on some of the partially-electrified routes in the UK.

 

 

 

July 28, 2019 - Posted by | Transport | , , , , , ,

1 Comment »

  1. […] this feeling, that running two different locomotives as a pair might be more efficient and I wrote Could A Battery- Or Hydrogen-Powered Freight Locomotive Borrow A Feature Of A Steam Locomotive?, where I examined the […]

    Pingback by BNSF And Wabtec Prepare To test Battery-Electric Locomotive « The Anonymous Widower | July 8, 2020 | Reply


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