The Anonymous Widower

Class 230 Trains On The Conwy Valley Line

I suspect to some people, the use of Class 230 trains, which are rebuilt London Underground D78 Stock on the Conwy Valley Line is a challenge to far.

Class 230 Trains

I wrote about these trains in First D-Train With Transport for Wales In March 2019, where I stated that the train formation will be.

  • DM – Driving Motor with battery
  • T – Trailer with four generators
  • DM – Driving Motor with battery

As the trains will have regenerative braking, this will be used to help charge the batteries.

Note that batteries and traction motors are only in the Driving Motor cars.

The Conwy Valley Line

The route of the single-track Conwy Valley Line can be summsarised as follows.

  • From Llandudno to Llanrwst it is a fairly level route alongside the River Conwy.
  • From Llanwrst the line climbs to a 240 metre summit in the Ffestiniog tunnel, with gradients as steep as 1-in-47.
  • From the summit, the train descends into Blaenau Ffestiniog with gradients as steep as 1-in-43.

It has some of the characteristics of a roller-coaster.

Class 230 Trains On The Conwy Valley Line

Provided the trains can handle the gradients either side of the summit, they can just roll down the other side. During the descent, the regenerative braking will charge the batteries.

This will have the following effects.

  • Trains on the downhill sections will not need to use their diesel engines.
  • Trains waiting in Blaenau Ffestiniog station, won’t need to use their diesel engines until they start back to Llandudno.
  • I suspect some Northbound services, trains would be able to reach Llandudno without using their diesel engines.

Gravity is being used as an energy store to create an efficient railway!

Energy Of A Class 230 Train On The Conwy Valley Line

I am curious to know how much energy is needed to get a fully-loaded train up the hill from Llandudno to Blaenau Ffestiniog.

Consider the following.

  • A D78 Driving Motor car weighs 27.5 tonnes
  • A D78 Trailer car weighs 19 tonnes
  • Wikipedia says “For the Country layout, each D-train unit is to be a three-car formation, which would accommodate 163 seats along with a total capacity of 291.”
  • I assume each passenger weighs 90 Kg with baggage, buggies and bicycles.
  • I think it is fair to say that each generator and battery weighs about a tonne.
  • The summit of the line in the Ffestiniog Tunnel is 240 metres above sea level.
  • I will assume that the coastal end of the route is at sea level.

This means that the empty train weighs eighty tonnes and a full load of passengers weighs twenty-six tonnes.

Using Omni’s Potential Energy Calculator, this gives a potential energy for the train of seventy kWh, at the summit with a full load of passengers.

This figure means that if two 55 kWh batteries from a New Routemaster bus were used on the train and they were fully-charged, then they could power the train to the summit and on to Blaenau Ffestiniog.

It should be noted that Vivarail talk about using 106 kWh battery rafts on the Class 230 train.

A Few Questions

I have these questions.

Are These Class 230 Trains Serial Hybrids?

I ask this question, as it could be key to making the operation of the trains more efficient on this line.

The train would always be powered directly from the batteries.

  • The diesel engines would cut in to charge the batteries, when the battery charge level got to a certain low level.
  • The diesel engines would cut out, when the battery charge level, got to a certain high level.

As the train has four generator sets, an appropriate number could be used as required.

A well-trained driver or an intelligent control system could make these trains very efficient.

In this article on RAIL Magazine, this is stated.

Shooter told RAIL that the trains will save around 20% on fuel consumption.

Adrian Shooter is Chairman of Vivarail, who are creating the Class 230 trains.

Possible Electrification Of The Ffestiniog Tunnel

The Class 230 trains are created from London Underground D78 Stock and I suspect it would be possible for the Class 230 trains to be powered by third-rail electrification.

The Ffestiniog Tunnel is the summit of the Conwy Valley Line.

  • It is a single-track.
  • It is 3.5 kilometres long.
  • One end of the tunnel is close to Blaenau Ffestiniog.

Would it be a sensible idea to electrify the tunnel either fully or partially, to top up the batteries?


  • The third-rail electrification would be no intrusion in the landscape.
  • The electrification could only be switched on when a train is present.
  • I don’t think supplying power would be difficult.
  • There could be less need to run on diesel.

The electrification could even be extended to wards Blaenau Ffestiniog station, so that trains leaving the station could have electrical power to climb to the summit.

Will The Class 230 Trains Attract Passengers?

I think that the Class 230 trains have several passenger-friendly features.

  • All new interiors.
  • Ten percent more seats and almost twice the capacity.
  • Lots of space for bicycles
  • Large windows
  • Wi-fi and power sockets
  • Accessible toilet

Hopefully, there will also be step-free access between train and platform.

This package of improvements should encourage more to travel.

I also suspect, that having a decent train with a novelty appeal that connects to the Ffestiniog Railway will tap a new market of travellers.


I have no doubt, that Class 230 trains will be able to provide a successful service on the Conwy Valley Line.





July 24, 2018 - Posted by | Transport/Travel | , , , , ,

1 Comment »

  1. […] I wrote about this in Class 230 Trains On The Conwy Valley Line. […]

    Pingback by A Day Out From Liverpool « The Anonymous Widower | July 25, 2018 | Reply

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