The Anonymous Widower

Could Hitachi’s Class 800 Trains Work The Cornish Main Line On Battery Power?

The distance between Plymouth and Penzance stations along the Cornish Main Line is just seventy-nine miles and thirty-eight chains. I’ll call it 79.5 miles.

Hitachi’s proposed train is described in this infographic.

The range on battery power of 90 km or 56 miles, will not be quite enough to get all the way between Plymouth and Penzance!

But note the phrase – Allows Discontinuous Electrification; at the top of the infographic.

Will Electrification Be Needed?

Obviously or the train could perhaps wait at Truro for ten minutes to charge the batteries.

But how customer-unfriendly and disruptive to good operating practice is that?

Could Bigger Batteries Be Fitted?

This obviously is a possibility, but surely an operator would prefer all of their trains to have the same battery range and updating them all for a longer distance might not be an economic proposition.

Could Intelligent Discontinuous Third-Rail Electrification Be Used?

Third-rail electrification, is hated by the Health & Safety Taliban, as it occasionally kills people trespassing or falling on the railway. But in the UK, we have around 1,500 miles of third-rail electrified line, that generally operates to a high level of safety.

Can my modern successors make third-rail electrification absolutely safe in new installations?

Third-Rail And Discontinuous Electrification Installations!

To connect to overhead electrification, the driver or an automatic system on the train, must raise the pantograph. It doesn’t often go wrong, but when it does, it can bring down the wires. This section on panotograph weaknesses from Wikipedia give more details.

With third-rail, the connection and disconnection is automatic, with far less to go wrong.

These pictures show a gap in the third-rail electrification at the Blackfriars station, which was rebuilt in 2012, so it must meet all modern regulations.

Note the gap in the third-rail, which carries the current.

  • The third-rail shoes on the train disconnect and connect automatically, as the train passes through.
  • The only rails with voltage are between the tracks for safety.
  • The high-tech shields appear to be real tree wood painted yellow.

As an Electrical Engineer, I actually suspect, that this gap in the conductor rail, is to isolate the North and South London electricity supplies from each other,, so that a catastrophic failure on one side doesn’t affect both halves of Thameslink.

Third-Rail Electrification In Stations

Most rail passengers in the UK, understand third-rail electrification, if they’ve ever used trains in the South of London or Merseyside.

Electrifying stations using third-rail equipment could enable battery trains to go further.

  • Stopping trains could top-up their batteries.
  • Passing trains, that were low on power could make a pit-stop.
  • All trains would connect automatically to the third-rail, when in the station.

The safety level would be raised by making sure that the third-rail was electrically-dead unless a train was over the top.

I am by training a Control Engineer and one of my first jobs in a dangerous factory as a fifteen-year-old,  was designing and building safety systems, that cut power to guillotines, when the operator put their hands somewhere they shouldn’t! I remember endlessly testing the system with an old broom, which survived unscathed.

I believe that only switching on the electrification, when a train completes the circuit, is a fairly simple operation for modern control switchgear. I can imagine an intelligent switch constantly monitoring the resistance  and only switching on power, when the resistance in the circuit looks like a train.

Third-Rail Electrification In Discrete Locations

Overhead electrification can receive complaints in scenic locations, but third-rail electrification can be invisible in tunnels and over bridges and viaducts.

The Cornish Main Line has four tunnels, two bridges, which include the Royal Albert Bridge, and no less than thirty-two viaducts.

How many of these could be used to hide electrification?

  • Any electrified sections could be intelligently controlled to increase safety.
  • Power for the electrification could come from local renewable sources, using techniques like Riding Sunbeams.

I can see engineers developing several techniques for discrete electrification.

Third-Rail And Charging Battery Trains

I like the Vivarail’s Fast Charge concept of using third-rail equipment to charge battery trains.

This press release from the company describes how they charge their battery electric Class 230 trains.

  • The system is patented.
  • The system uses a trickle-charged battery pack, by the side of the track to supply the power.
  • The first system worked with the London Underground 3rd and 4th rail electrification standard.

As the length of rails needed to be added at charging points is about a metre, installing a charging facility in a station, will not be the largest of projects.

Under How Does It Work?, the press release says this.

The concept is simple – at the terminus 4 short sections of 3rd and 4th rail are installed and connected to the electronic control unit and the battery bank. Whilst the train is in service the battery bank trickle charges itself from the national grid – the benefit of this is that there is a continuous low-level draw such as an EMU would use rather than a one-off huge demand for power.

The train pulls into the station as normal and the shoe-gear connects with the sections of charging rail. The driver need do nothing other than stop in the correct place as per normal and the rail is not live until the train is in place.

That’s it!

As an electrical engineer, I’m certain the concept could be adapted to charge the batteries of a conventional third-rail train.

Vivarail’s press release says this about modification to the trains.

The train’s shoe-gear is made of ceramic carbon so it is able to withstand the heat generated during the fast charge process.

That wouldn’t be a major problem to solve.

Hitachi And Third Rail

The picture shows a Hitachi Class 395 train at Gillingham station.

 

The silver-coloured  third-rail equipment is clearly visible, under the javelin logo.

These trains are cousins of all the new Hitachi trains in the UK, so I suspect fitting third-rail equipment to Class 80x trains, is just a matter of finding the appropriate documents on the computer and raiding the parts bin.

I suspect, as Hitachi will probably be building some more trains for Southeastern to start the Highspeed service between London St. Pancras and Hastings, that Hitachi are already working on the design of a third-rail high-speed train with batteries.

I doubt that Hitachi have any fears about fitting third-rail gear to their trains, as an optional extra.

Electrifying Between Plymouth And Penzance

Obviously, Plymouth and Penzance stations would have charging facilities, but now many would the trains handle the 79.5 miles in between?

There are three possibilities.

Limited-Third Rail Electrification

As I indicated earlier short lengths of intelligent third-rail electrification could be added at various places on the route.

A full battery would take the train fifty-six miles and as the Cornish Main Line is nearly eighty miles long, I suspect that the train would need almost a full charge halfway along the route.

  • Hitachi claim in the infographic, that a full-charge takes 10-15 minutes, when the train is static, so I will assume the largest figure of this range, as charging on the move might not be as efficient, with everything happening at 90 mph.
  • So I will assume a fifteen minute charge time.
  • Typically, a Class 80x takes two hours between Penzance and Plymouth, which is an average speed of just 40 mph.
  • In fifteen minutes, the train will go ten miles. So a rough estimate would say ten miles should be electrified.

As electrification in stations would allow trains to have a bigger sup, a scientifically-correct simulation would show the best philosophy.

The London Paddington and Penzance services call at the following stations, that are West of Plymouth.

Liskeard, Saltash, St. Germans, Bodmin Parkway, Lostwithiel, Par, St Austell, Truro, Redruth, Camborne, Hayle and St Erth

Note.

  1. Some smaller stations do get skipped.
  2. According to Real Time Trains, stops seem to take 1-2 minutes.
  3. Trains are usually nine- or ten-cars, but I feel that the proposed improvements between Bodmin General and Bodmin Parkway stations, that I wrote about in Increased Service Provision Bodmin General-Bodmin Parkway, may result in a large reorganisation of services between London and Cornwall.

Could it be that electrifying the major stations with third-rail electrification would enable enough power to be taken on board by a train running between London Paddington and Penzance, so that the journey could be completed?

Vivarail Fast Chargers

Vivarail’s Fast Chargers could be fitted at all or selected stations and trains could take a sip as and when they need.

A charger would also be needed at any Cornish terminal station, that would have services from battery electric trains.

A Mixture Of Third-Rail Electrification And Vivarail Fast Chargers

Both technologies are interchangeable and can be used with compatible battery electric trains.

I would expect an accurate mathematical model will indicate the best layout of electrification and Fast Chargers.

 

July 26, 2020 - Posted by | Transport | , , , , , , , , , ,

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