The Anonymous Widower

Station Stop Performance Of The Intercity Tri-Mode Battery Train

Hitachi have stated that the their Intercity Tri-Mode Battery Trains will not use their diesel engines in stations and to leave the station.

The first Intercity Tri-Mode Battery Trains will be conversions of Class 802 trains.

This page on the Eversholt Rail web site, has a data sheet for a Class 802 train.

The data sheet shows the following for a five-car Class 802 train.

  • It can accelerate to 120 kph/75 mph in 100 seconds in electric mode.
  • It can accelerate to 160 kph/100 mph in 160 seconds in electric mode.
  • It can accelerate to 120 kph/75 mph in 140 seconds in diesel mode.
  • It can decelerate from 120 kph/75 mph in 50 seconds in electric mode.

Note.

  1. 75 mph is the operating speed of the Cornish Main Line and possibly the Highland Main Line.
  2. 100 mph is the operating speed for a lot of routes in the UK.
  3. It would appear that trains accelerate to 75 mph forty second faster in electric mode, compared to diesel mode.
  4. In diesel mode acceleration slows markedly once 100 kph is attained.

Can we assume that performance in battery mode, will be the same as in electric mode?

I am always being told by drivers of electric cars, trains and buses, that they have sparkling performance and my experience of riding in battery electric trains, indicates to me, that if the battery packs are well-engineered, then it is likely that performance in battery mode could be similar to electric mode, although acceleration and operating speed my be reduced to enable a longer range.

If this is the case, then the following times for a station call with a 75 mph operating speed are possible.

  • Electric mode – 50 + 60 + 100  = 210 seconds
  • Diesel mode – 50 + 60 + 140  = 250 seconds
  • Battery mode – 50 + 60 + 100  = 210 seconds

Note.

  1. The three figures for each mode are deceleration time, station dwell time and acceleration time.
  2. Times are measured from the start of deceleration from 75 mph, until the train accelerates back to 75 mph.
  3. I have assumed the train is in the station for one minute.

I suspect with a stop from 100 mph, that there are greater savings to be made than the forty seconds at 75 mph, due to the reduced acceleration in diesel mode past 100 kph.

Savings Between London Paddington And Penzance

There are fifteen stops between London Paddington and Penzance, which could mean over ten minutes could be saved on the journey.

This may not seem that significant, but it should be born in mind, that the fastest journey times between London and Penzance are between five hours and eight minutes and five hours and fourteen minutes.

So these small savings could bring a London Paddington and Penzance journey much closer to five hours.

Savings Between London Kings Cross And Inverness

There are probably not as great savings to be made on this route.

  • The electrification runs as far as Stirling.
  • There are only five intermediate stops between Stirling and Inverness
  • Stirling and Inverness are 151 miles apart.

On the other hand, the route has a lot of gradients, which may give opportunities to use the batteries to boost power on climbs and save fuel and emissions.

Conclusion

Replacing one or more of the diesel engines on a Class 800, 802, 805 or 810 train, on a route, where the full complement of diesel engines is not required, may well result in time savings on the journey, simply by reducing the time taken to accelerate back to operating speed.

I have indicated two routes, where savings can be made, but there may be other routes, where savings are possible.

December 20, 2020 - Posted by | Transport | , , , , , , ,

2 Comments »

  1. If battery is big enough it will provide oomph to match externally sourced power but i can’t see the diesel packs being able to recharge the batteries quickly enough between stops. Also there will need to be a balance struck between discharge/recharge cycles to avoid premature battery degradation. All interesting stuff though and the govt need to strike a deal with Hitachi to get a demonstrator built or take one the ones being built on spec for the East Coast Privateer.

    Comment by Nicholas Lewis | January 2, 2021 | Reply

  2. If the battery is the same weight as a diesel generator, it could be around 500 kWh.

    The energy of a train going at 100 mph would be just 75 kWh.

    I believe with regenerative braking at all stops and arriving into Penzance with no juice in the battery could be an efficient way to run the service.

    Comment by AnonW | January 2, 2021 | Reply


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