The Anonymous Widower

The Future Of Diesel Trains

Many feel that diesel trains have no future in the modern world, because of all those carbon and particulate emissions.

However, this article in Rail Technology News, which is entitled ScotRail To Trial Hydraulic Tech To Cut Of Carbon Emissions.

This is the first paragraph.

A new hydraulic pump could reduce Scotland’s carbon emissions by 4,000 tonnes of carbon dioxide per year.

This sounds impressive, but how is it done?

Many modern diesel muiltiple units, like the Class 170 trains, used in the ScotRail trial have hydraulic transmissions, where a pump fitted to the engine creates hydraulic power, which then drives a hydraulic motor to power the train.

But modern trains also need to have electricity in each car for lighting, air-conditioning and other services.

So typically, a hydraulic unit in each car is used to generate the electricity required.

It is this hydraulic unit, that has been replaced by a much more efficient digitally-controlled hydraulic unit.

That sort of hydraulic unit has one Scottish company’s stamp all over it; Artemis Intelligent Power, which started as a spin-off from Edinburgh University.

Artemis Intelligent Power has a page about Rail applications on their web-site.

This is the introductory paragraphs to their work.

Whilst electrification has enabled the de-carbonisation of much of the UK’s rail sector, the high capital costs in electrifying new lines means that much of Britain (and the world’s) railways will continue to rely on diesel.

In 2010, Artemis completed a study with First ScotRail which showed that between 64 and 73 percent of a train’s energy is lost through braking and transmission.

In response to this, Artemis began a number of initiatives to demonstrate the significant benefits which digital hydraulics can bring to diesel powered rail vehicles.

Two projects are detailed.

The first is the fitting of a more efficient hydraulic unit, that is described in the Rail Technology Magazine article.

Under a heading of Faster Acceleration, Reduced Consumption, there is a technical drawing with a caption of The Artemis Railcar.

This is said.

We are also working with JCB and Chiltern Railways on a project funded by the RSSB to reduce fuel consumption and improve engine performance by combining highly efficient hydraulic transmission with on board energy storage in the form of hydraulic accumulators, which store energy during braking for reuse during acceleration.


  1. The use of hydraulic accumulators to provide regenerative braking.
  2. The involvement of JCB, whose construction equipment features a lot of hydraulics.
  3. The involvement of Chiltern Railways, who like their parent company, Deutsche Bahn, have a lot of diesel-hydraulic multiple units and locomotives.

The article goes on to detail, how a test railcar will be running before the end of 2017.

This technology could have tremendous potential in the UK.

The Benefit Of Regenerative Braking

In the Wikipedia entry for Regenerative Brake, this is said.

Savings of 17%, and less wear on friction braking components, are claimed for Virgin Trains Pendolinos. The Delhi Metro reduced the amount of carbon dioxide (CO2) released into the atmosphere by around 90,000 tons by regenerating 112,500 megawatt hours of electricity through the use of regenerative braking systems between 2004 and 2007.

The entry also says that some London Underground trains save twenty percent.

It would be a large benefit to the train operating companies, if they could just have a similar saving on the cost of diesel fuel.

Could Existing Trains Be Converted?

In England, Wales and Scotland,currently there are around two hundred modern Turbostar diesel multiple units. of which thirty are used by Chiltern Railways.

Whether these can be converted, depends on the engineers and the result of the current trial, but the economic benefits of a successful conversion route could be very beneficial.


This is technology to watch!



December 30, 2017 - Posted by | Energy Storage, Transport | ,

1 Comment »

  1. […] In The Future Of Diesel Trains, I talked about work being done in Edinburgh, by a company called Artemis Intelligent Power, to improve the efficiency of diesel-hydraulic trains. […]

    Pingback by Class 158/159 Bi-Modes? « The Anonymous Widower | February 27, 2018 | Reply

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