5 car works cost too much?

[snoggle]

Looks like TfL are having to go back and seek revised authority in respect of the 5 car works. Unfortunately the paper has scant detail (quelle surprise!) but given its tone it looks like the infrastructure works have proved more costly than expected.

content.tfl.gov.uk/fpc-160727-item06-locip-p1-final.pdf

[dazz285]

perhaps when they extended the platforms for 4 car they really should have made it 5... Very poor short-sightedness.

[stapler]

Or six-car, judging by the level of crowding on Camden Rd-Stratford.

[dazz285]

apparently class 378's can't be extended to 6 car anyway. The only option now is to increase the frequency. DC will be going to a 15 min service once all the class 710's have arrived then the class 378 will head upstairs to the NLL/WLL to increase their services.

[stapler]

Jul 27, 2016 8:12:05 GMT dazz285 said:

apparently class 378's can't be extended to 6 car anyway. The only option now is to increase the frequency. DC will be going to a 15 min service once all the class 710's have arrived then the class 378 will head upstairs to the NLL/WLL to increase their services.

Think I've heard that before, but why not?

[Chris M]

Jul 27, 2016 8:14:06 GMT stapler said:

Jul 27, 2016 8:12:05 GMT dazz285 said:

apparently class 378's can't be extended to 6 car anyway. The only option now is to increase the frequency. DC will be going to a 15 min service once all the class 710's have arrived then the class 378 will head upstairs to the NLL/WLL to increase their services.

Think I've heard that before, but why not?

The train software apparently cannot cope with more than 5 cars.

[stapler]

Train software? Surely software can be upgraded? (and frequently is, as systems change...)

[Chris M]

embedded systems are rather different to PC software as the whole design philosophy is around reliability rather than flexibility. A train system is designed to work only with the very specific hardware it is installed on, and the job each system does will do on day 10,000 exactly what they did on day 1. No new programs will have been installed, it doesn't need to do the equivalent of both word processing and spreadsheets for example. This way the number of bugs in the system will be far fewer and updates almost unneeded, etc.

[will]

I k ow this may highlight my train systems ignorance but wouldn't it be possible to wire to carriages together so that 2 carriages could be seen by the trains computer as 1 carriage?

[peterc]

I k ow this may highlight my train systems ignorance but wouldn't it be possible to wire to carriages together so that 2 carriages could be seen by the trains computer as 1 carriage?

It should be possible in theory but the train system only recognises a certain amount of kit in each carriage so your "virtual carriage" could only have two pairs of doors instead of four, etc etc

[jukes]

It is quite correct that the 378s cannot be extended to 6-car for all the reasons given above. The DC line frequency will remain at 3 tph with the arrival of the six new 710s which is the same number of units as 378s currently allocated - they will be cascaded to the NLL and ELL. In order to increase the DC frequency to 4 tph (i.e., every 15 minutes) you would need 8 units - and there is an option for 2 extra units (not yet exercised) in the contract for the 710s. Similarly to increase the GOB from 4 tph to 5 tph, you would need 2 extra 710s and here again there is an option in the contract (also not yet exercised). There are also contractual options for the additional units required for the Barking Riverside extension and possibly for Stratford-Angel Road (STAR) services.

[norbitonflyer]

Jul 27, 2016 15:50:43 GMT jukes said:

The DC line frequency will remain

Did a double take at that, as on DC the (electrical) line frequency is, by definition, zero!