A few years ago network rail purchase at huge cost at least 1 track renual trains as used by most other railways including many in the third world.
Never hear of them mentioned. Do they still use them or another white elephant?
K
2 are out tonight. I’m not saying where. They are out almost every night somewhere. You don’t hear fo them mentioned, as no news is good news. Similarly, I don’t suppose you hear much about the three new grinding trains either (although you would if you were stood next to one).
If installed as part of a resignalling or recontrol scheme adding bi directional signalling will add very little to the overall project cost as the hardware is relatively cheap, even adding additional crossovers is likely to add less than 5% to the costs.
Modern LED signals require very little maintenance and that which is required can easily be done in the standard possessions overnight.
Not sure what simplified system you think exists and how it enables "trains around stoppages" or "around the edges of possessions" but bi directional signalling would allow the high output kit to start work earlier and stop later by running the last/first few services on the unaffected line before the service builds up to a level needing a 2 track railway.
I’m not sure what recent experience you have in estimating railway resignalling projects, but take it from me that if full bi-Di is installed on a full resignalling it increases costs by around 50-70% depending on scale. And that’s just the signalling. If you are adding new crossovers... well these start at around £2m each. For example a £70m simple resignalling being specified as full bi di with four new sets of crossovers can easily become a £125m resignalling.
A recontrol project rarely alters anything out on the ground or in the interlocking, so trying to install new bi di then is effectively turning it into a full resignalling at many multiples the cost.
Incidentally, when commissioning bi-di it usually more than doubles the amount of testing that has to be done (as it is not only twice the number of routes, but every route now has a potential conflicting move, and these need extra tests). This more than doubles the testing time. On most routes, the extra possession time required for the installation, testing and commissioning of the extra kit is more than would ever be saved over 30 years of slighly different overnight access. Hence why bi-di is only usually installed on the busiest and highest value routes.
