## How Much Power Is Needed To Run A Train At 125 mph?

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, which is not very challenging.

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

Can I get any other figures for running at 125 mph, that agree or disagree with these figures?

**Class 801 Train**

I have found this on this page on the RailUKForums web site.

A 130m Electric IEP Unit on a journey from Kings Cross to Newcastle under the conditions defined in Annex B shall consume no more than 4600kWh.

This is a Class 801 train.

- It has five cars.
- Kings Cross to Newcastle is 268.6 miles.
- Most of this journey will be at 125 mph.
- The trains have regenerative braking.
- I don’t know how many stops are included

This gives a usage figure of 3.42 kWh per vehicle mile.

**InterCity 125**

Note that the Class 43 power cars of the InterCity 125 (HST) put 1,300 kW to the rail and have a 1,700 kW engine. Two of these powerful beasts giving out a total of 3,400 kW,, can sustain a ten-car train (two power cars and eight passenger cars) at 125 mph.

In the roughly thirty seconds, it would take to cover a mile, an HST could use 3400/120 kWh or 28.3 kWh.

Counting the locomotives as a car and dividing by ten gives 2.83 kWh per vehicle mile.

This is actually a maximum figure, as the driver could throttle-back if required.

This figure is not out of line with the 3.42 kWh per vehicle mile for a Class 801 train, that I stated earlier.

The force was with Terry Miller and his team.

**Class 222 Train**

The Class 222 trains have one 580 kW engine in each car.

In the thirty seconds, it would take to cover a mile, a Class 222 train would use 580/120 or 4.83 kWh per vehicle mile.

Again this must be a maximum figure.

**Class 170 Train**

The Class 170 train is a 100 mph train with a 315 kW engine in each car.

In the thirty-six seconds, it would take to cover a mile at 100 mph, a Class 170 train would use 315/100 or 3.15 kWh per vehicle.mile.

Again this must be a maximum figure.

**Conclusions**

I know this was a rather rough and ready calculation, but I can draw two conclusions.

- Trains running at 125 mph seem to need between three and five kWh per vehicle mile.
- The forty year old InterCity 125 has an efficient energy use, even if the engines are working flat out to maintain full speed.

The only explanation for the latter is that Terry Miller and his team, got the aerodynamics, dynamics and structures of the InterCity 125 almost perfect. And this was all before computer-aided-design became commonplace.

In future for the energy use of a train running at 125 mph, I shall use a figure of three kWh per vehicle mile.

It is also probably a good starting point for a 100 mph train.

After all, if a forty-year-old diesel-electric train built from steel can achieve that figure, surely a modern electric train built from aluminium can do better!

[…] How Much Power Is Needed To Run A Train At 125 mph?, I showed that to run at 125 mph, a train needs around three kWh per vehicle […]

Pingback by Tender Set To Be Issued For East West Rail Rolling Stock « The Anonymous Widower | July 13, 2019 |

[…] investigated this question in How Much Power Is Needed To Run A Train At 125 mph? and came to the conclusion, that 3 kWh per vehicle mile is a sensible […]

Pingback by Is Bombardier’s 125 mph Bi-Mode Aventra With Batteries, A 125 mph Battery-Electric Aventra With Added Diesel Power To Extend The Range? « The Anonymous Widower | July 13, 2019 |

[…] How Much Power Is Needed To Run A Train At 125 mph?, I calculated the figure for some high-speed […]

Pingback by Bombardier Doesn’t Seem Too Disappointed On Missing Out On The Abellio East Midlands Railway Order « The Anonymous Widower | August 1, 2019 |

[…] How Much Power Is Needed To Run A Train At 125 mph?, I answered the question in the title of the […]

Pingback by My First Rides In A Class 755 Train « The Anonymous Widower | August 6, 2019 |

[…] I use a figure of three kWh per vehicle mile for the energy consumption of an electric multiple unit running on a typical route. My reasoning for this figure is given in How Much Power Is Needed To Run A Train At 125 mph?. […]

Pingback by Around The Fife Circle Line « The Anonymous Widower | September 2, 2019 |

[…] How Much Power Is Needed To Run A Train At 125 mph?, I calculated that to overcome air resistance and keep a high speed train at 125 mph needs around […]

Pingback by West Ealing Station – 2nd September 2019 « The Anonymous Widower | September 2, 2019 |

[…] How Much Power Is Needed To Run A Train At 125 mph?, I calculated […]

Pingback by New Railway Station Between Hinckley And Nuneaton Receives Backing « The Anonymous Widower | September 16, 2019 |

[…] How Much Power Is Needed To Run A Train At 125 mph?, I estimated that using 3 kWh per vehicle mile is not a bad estimate for the energy use of an […]

Pingback by Merseyrail’s Battery Intentions « The Anonymous Widower | September 17, 2019 |

[…] that the train uses 3 kWh per vehicle mile (SeeHow Much Power Is Needed To Run A Train At 125 mph?) , this would […]

Pingback by Battery Power Lined Up For ‘755s’ « The Anonymous Widower | September 25, 2019 |

[…] How Much Power Is Needed To Run A Train At 125 mph?, I estimates that an electric Class 801 train needs 3.42 kWh per vehicle mile to maintain 125 […]

Pingback by Bombardier And Hitachi Come Up With Similar Car Lengths « The Anonymous Widower | September 27, 2019 |

[…] How Much Power Is Needed To Run A Train At 125 mph?, I said […]

Pingback by HS2 Way Out In Front In Tunnel Design For High-Speed Rail « The Anonymous Widower | October 5, 2019 |

[…] How Much Power Is Needed To Run A Train At 125 mph?, I did a simple calculation using these […]

Pingback by A Selection Of Train Noses « The Anonymous Widower | October 14, 2019 |

[…] In How Much Power Is Needed To Run A Train At 125 mph?, I calculated that a five-car Class 801 train needs 3.42 kWh per vehicle mile to cruise on electricity at 125 mph. […]

Pingback by What Would Be The Range Of A Tri-Mode Class 802 Train? « The Anonymous Widower | November 17, 2019 |