The Anonymous Widower

Class 158/159 Bi-Modes?

In the March 2018 Edition of Modern Railways, there is a short news item, which is entitled Bi-Mode Study For SWR DMUs.

The Class 158 and Class 159 diesel multiple units used by South Western Railway are diesel-hydraulic units.

Under their franchise aggreement, South Western Railway, agreed to perform a study, to see if the multiple units could be converted from diesel-hydraulic to diesel-electric transmission.

If this is successful, then the plan would be to fit a third-rail capability to the trains, so they could use the electrification between Basingstoke and Waterloo on services to Salisbury and Exeter.

Could the conversion also raise the operating speed of the trains from their current 90 mph to a more timetable-friendly 100 mph?

It looks like it could be a feasible , especially as the article states they might re-use redundant modern traction equipment from Class 455 trains, which are due for replacement.

Disruptive Innovation From Edinburgh

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.

This is an extract from the original post.

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.

Note.

  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.

I wonder if Artemis Intelligent Power have ideas for improving the efficiency and creating bi-modes of Class 158 and Class 159 trains?

Could they for instance produce a highly-efficient electrically-driven hydraulic pump, that could be powered by the third-rail electrification, where it is available?

If they can, the advantages of this approach include.

  • The ability to swap from diesel to electric power as required.
  • Regenerative braking could be made available.
  • The trains would still use diesel-hydraulic transmission.

It must surely, be at a lower cost.

February 27, 2018 - Posted by | Travel | , , , ,

1 Comment »

  1. […] The problem of this route might be solved by converting the Class 158/159 trains in bi-modes, as I wrote about in Class 158/159 Bi-Modes? […]

    Pingback by Midland Mark 4 « The Anonymous Widower | February 27, 2018 | Reply


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