I would've thought they'd modify the 67s with a TDM to work with the DVTs.
The DVT's have been converted to work with the Class 67. The modification involves a bank of relays which are driven by the controls in the cab of the DVT and send appropriate signals down a multi-core cable to the locomotive at the other end of the train. The logic for doing it that way round was actually EWS's when they converted the company train but reflecting on our experience it was the correct approach. The TDM was notouriously unreliable on the West Coast, and problems still occurr with the NXEA fleet. This is due to the complex nature of the signal that is sent down the train using the lighting control cables. It was and is not at all uncommon for the TDM to "de-configure". In essence this means that the two TDM devices on the Loco and the DVT could not be sure that they were receiving the correct signal from the other and hence would shut down to prevent in-correct signals causing the train to do things it should not!
On the other hand the Class 67's already had the AAR system as fitted to all the GM loco's in this country. This uses a 27-way multiple jumper and each cable is for one signal thus making it simpler in operation than the TDM. With the exception of a cable being ripped out by something on the track this has proved to be faultless.
It is relatively easy to modify the coach with the modifcation taking less than 8 hours and not being hugely expensive. The most expensive part is the multiway plug and socket on each end of the coach.
The DVT's retain the ability to work with a TDM equipped locomotive.
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Yeah, the modernisation and transformation of the Chiltern line was initiated by Network Southeast. They had plans to build a fleet of Class 168s (albeit very similar in outward appearance to the 165/6s) for usage on Birmingham services.
Chiltern have a very easy franchise compared to some TOCs, so it's no wonder they've done well.
The initial Route Modernisation in the late 80's and very early 90's was instigated by Network South East under BR. This included the replacement of all the signalling as far north as Aynho Junction controlled from a new signalling centre at Marylebone and the purchase of the Class 165's (although 165001 to 007 were moved to Thames very quickly).
Chiltern Railways as it is now really started in April 1994 when Chiltern was separated from Thames and Chiltern and became an entity in its own right. At that time Adrian Shooter was installed as MD and with the exception of 5 or 6 managers he installed his own management team.
All the developments and upgrades since that time have been driven by Adrian and his team. They formally took over the running of the company as a private franchise in July 1996.
The Class 168's were developed by this team with Bombardier (then ADtranz) to the Chiltern spec. Porterbrook won the tender to finance the Class 168's and then went on to market them with Adtranz/Bombardier as the Class 170. The only significant technical difference being the electrical configuration of the front coupler. Chiltern were even offered the new 170 style front end on the initial 168's but declined the offer as it would have delayed delivery by up to 6 months.
All the infrastructure developments since 1994 have been developed in house with the co-operation of RT and then NR and that continues to this day with a DB Regio UK project team leading the development of the current Evergreen 3 project.
Exciting times continue! It is fair to say that the late 80's route modernisation set a good foundation for what has followed, but wrong to say that anything like the majority of the investment and development was even dreamt of by BR/Network South East.
