The Anonymous Widower

How Much Energy Does A Crossrail Class 345 Train Use?

I will start with the Crossrail Rolling Stock Technical Fact Sheet, which dates from 2012.

The Class 345 trains were built to this specification.

This is said about the power required.

Energy efficiency of 24 KWh per train kilometre (equivalent of 55g CO2 per passenger kilometre)

So what does this mean now that trains are running and trains will have been designed and probably accepted to this specification.

Assuming, that trains will be nine-car when completed, 24 KWh per train per kiometre translates into 2.67 KWh per car per kiometre or 3.29 KWh per car per mile.

Ian Walmsley’s Train Energy Usage Figure

In an article in the October 2017 Edition of Modern Railways, which is entitled Celling England By The Pound, Ian Walmsley says this in relation to trains running on the Uckfield Branch.

A modern EMU needs between 3 and 5 kWh per vehicle mile for this sort of service.

My calculated value is in line with this figure, as the Uckfield Branch is not that different to some of the Crossrail branches.

What Is The Kinetic Energy Of A Crossrail Train?

I ask this question to show the energy values involved.

If I take a nine-car Class 345 train, this has a mass of less than 350 tonnes and a maximum speed of 145 kph.

1500 passengers at 80 kg each works out at another 120 tonnes.

So for this crude estimate I’ll use 450 tonnes for the mass of a loaded train.

This gives the train an energy of 365 megajoules or 101 KWh.

This amount of energy is only a couple of KWh larger than the largest battery size of a Tessla Model S car.

It leads to the conclusion, that batteries could be large enough to store the regenerative energy generated by the train, when it stops.

How Far Could A Crossrail Train Run On Batteries?

If the batteries were sized for the regenerative braking, then a battery of 100 KWh would probably be sufficient in most circumstances.

Using Crossrail’s figure of 24 KWh per train per kiometres, gives a convenient range of four kiometres, which is probably in excess of the largest distance between stations.

But Crossrail trains are effectively two half-trains with two pantographs.

So perhaps they will be fitted with two batteries!

The battery capacity would be arranged to give the desired amount of emergency power.

Conclusion

There’s a lot more to learn about these Crossrail trains.

 

November 16, 2017 - Posted by | Travel | , ,

1 Comment »

  1. The Class 345 is the first “deep tube” train with air conditioning. There are batteries fitted, but solely for the purpose of emergency auxiliary power.

    You’d be lucky to find any significant self-recovery capability with only two battery packs. I’ve seen the numbers.

    Comment by David | November 23, 2017 | Reply


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