The Anonymous Widower

Roger Ford On Bombardier’s Aventra Problems

It has been well-publicised that Bombardier are having problems getting their new Class 710 trains working reliably for service on the Gospel Oak to Barking Lines.

In the February 2019 Edition of Modern Railways, there is an article written by the well-respected Roger Ford, which is entitled Train Makers Face ‘Year Of Truth’.

Roger makes a succession of important points about Bombardier and Aventras in particular.

Class 345 Trains

Roger says this.

While reliability continues to be poor, software issues have been largely down to signalling interfaces at the western end of Crossrail.

Production appears to have been paused at 57, with perhaps 37 accepted.

Class 345 Trains And Class 710 Trains Use Different Software

Roger says this.

For the Class 345s, Transport for London specified an evolution of the Class 378 ‘last generation’ software. However the units for London Overground and Greater Anglia, and the other Aventra contracts for delivery beyond 2019, are true next generation trains with a new ‘family tree’ of software.

So it would appear that Class 345 and Class 710 software problems could be unrelated!

My experience of putting together large complicated software systems over forty years, leads me to add these two statements.

  • If the base hardware has been thoroughly tested and put together in a professional manner, it will be very rare for the software to not work on one set of hardware and work perfectly on several dozen other sets.
  • You can’t do too much testing; both of the hardware and the software, both on test systems and in real-life scenarios.

I don’t know anything of the computer hardware structure and its connectivity on Aventras, but I wouldn’t be surprised if a lot has been lifted straight out of the aerospace industry, in which Bombardier has a substantial presence. Borrowing proven techniques and hardware will hopefully reduce the risk.

The major risk will be the software that is totally new and unique to the Aventra.

So to me, it is not surprising that the complicated signalling on Crossrail, has been the major trouble on the Class 345 trains.

In this article on Rail Magazine, which is entitled Gospel Oak-Barking Fleet Plan Remains Unclear, this is a paragraph.

London Overground was due to put new Bombardier Class 710 electric multiple units into traffic on the route from March 2018, with a full rollout by May. However, problems with the Train Control Management System (TCMS) has so far prevented this.

I suspect that the TCMS is totally new and unique and has a level of complexity much higher than what is used in the Class 345 train.

  • It will have the ability to test all the trains sub-systems on a continuous basis.
  • The TCMS  will be an important part of the train testing process, which is why I have listed it first.
  • The TCMS will control 25 KVAC overhead and 750 VDC third rail power collection.
  • It will control the energy storage, that is reputedly fitted to the train.
  • It will handle regenerative braking using the energy storage.
  • Electricity usage will be optimised.
  • It will control all the displays and systems throughout the train.
  • It will interface to the signalling system.
  • It will communicate train status and faults back to the depot.

I also suspect that every Aventra will have the same TCMS, which will probably be compatible with the proposed 125 mph bi-mode Aventra.

This is not a new concept, as in the 1980s, Boeing 757 and 767 aircraft had identical cockpits, flight control systems and a common rating for pilots.

The Aventra has been described as a computer-on-wheels. Could it also be described as an aircraft-on-rails?

When I was growing up, all new trains, aircraft and vehicles were generally fully described with detailed cutaway drawing in a comic called Eagle.

Bombardier have seemed to be very reluctant to give details about what lies under the skin of an Aventra. Could it be very different to all other trains?

There is one big disadvantage about having a common TCMS, in that, it requires a very high quality of software design, programming and testing and that any lateness in the software delays the whole project.

Class 710 Trains For The Gospel Oak To Barking

Roger says this about the delayed Class 710 trains for the Gospel Oak to Barking Line.

According to,Bombardier, delivery of the Class 710 fleet is now due to be completed by the end of 2019. Given that the original date was September 2018, this is 15 months late. But with large numbers of Class 710 vehicles in storage, it also seems unduly pessimistic.

Roger does not have a reputation for looking on the bright side of life, so when he says that the schedule is unduly pessimistic, I give that a high chance of being right.

Surely, when the final approved version of the TCMS software is delivered, all of those trains in storage can be woken up, tested by the TCMS software then go through a pre-delivery check with the appropriate level of trouble-free running.

It’s a bit like having a new PC on your desk. You can’t really use it, until the software you need to do your job is installed. But as the software will be designed for your PC and has already been fully tested, it is unlikely to be a traumatic operation.

It appears to me, that the more comprehensive the TCMS software, the quicker it will be to take a train from manufacture to ready for service.

Class 720 Trains For Greater Anglia

Bombardier are already building the Class 720 trains for Greater Anglia.

Are these just being checked and tested before being put into store?

As with the Class 710 trains, will they be woken up using the same final fully tested version of the TCMS software?

I would be very surprised if the software on the two trains used different versions of the software.

When I was writing Artemis, we had two versions; one for single users and another for multiple users.

The software for both was identical and it worked on two different operating systems.

That is one of the advantages you get with well-written software.

Hence my belief that all Aventras have a common TCMS software.

Building Aventras

The article says that Bombardier are gearing up to have six Aventra production lines in Derby, which would mean they can turn out 24 vehicles a week.

That is a high production rate, which would mean that the 222 vehicles for the London Overground could be built in under ten weeks.

Bombardier must be expecting a lot of orders!

 

 

January 27, 2019 - Posted by | Transport/Travel | , , , ,

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