DY444

I think the 50s are a text book example of how not to design a locomotive and a real world example of Roger Ford's Informed Sources law about any changes made from the prototype will be for the worse. Everyone talks about the electronics but there was far more to it than that - the oil throwing engine, the air filtration system, the flimsy main generator, the change away from a previously proven traction motor commutator design and so on. The oil throwing in particular made some of the other issues (eg the electronics) worse than they might otherwise have been. Wrt train heating it also suffered the same problem as earlier BR diesels built with eth in that it didn't anticipate the future demands that air con stock would impose. The eth generator was thus somewhat under nourished for air con rakes and there is an argument that the eth index for the class probably should have been lower than 61. Indeed in recognition of this there were special procedures laid down for managing the eth supply in the winter months when supplying a rake of stock with an eth index of over 48 if the stock had been standing with no supply for more than a specified period.

The eth on the sleeper 92s is set to 1500V.

Yes I see what you mean.

I have absolutely no idea but will take a wild guess and say it *might* be Sprague stock on the Paris Metro

which has been answered

I didn't mean you personally believed it. You said "Class 30/31 appear to be Type 3's which of course is wrong" Perhaps this would suit you better: They only appear to be Type 3s to someone who believes the first digit of the class number gives you the type. Class 50s, Westerns and Falcon rather blew that theory up.

Only if you believe the first digit of the class number gives you the type. Class 50s, Westerns and Falcon rather blew that theory up.

The original conversions were done to provide a locomotive capable of preconditioning a full rake of air con stock whilst working ecs into London termini. For that purpose they were absolutely fine.

OT. The really weird thing to me about D&P is that they did actually try to make it look like rural Yorkshire in the first few series with believable country locations, country-centric story lines and Wetherton being portrayed as a typical provincial market town. Then in later series it totally changed and Wetherton became an industrial city with a high rise skyline and urban decay etc and featuring a lot of Birmingham area locations (often replete with shop fronts bearing Birmingham area phone numbers!)

.. and multiple sequences filmed at Longsight in one episode, other episodes featured MkIVs at Leeds and Kings Cross, an HST at Wakefield Westgate, a scene filmed on the Scarborough platforms at York, and another featuring a DMU and class 25 on the KWVR

Ahem. The last time I checked Barnham was east of Chichester 😉

I don't think I'd fancy anyone's chances in the leading car of a 170 if it derailed and hit a bridge parapet above a ravine at 70+ mph but the RAIB seem to think otherwise. Quite what good a crumple zone will do in an accident involving orders of magnitude more energy than it was designed to cope with is anyone's guess but ASLEF have decided HSTs are dangerous in high energy collisions whereas every other flimsy DMU apparently isn't and so the future of HST is in doubt.

Kind of depends on the time frame, area and scope of the question. For instance on the SR it was very common for the simple reason that all the indigenous main line locomotives had eth (except the 3 "Hornby's" when they were still around). Same on the WCML in the early days when the LMR tried to use electric locomotives wherever possible. In general for diesels, I would say it was less common in the 1970s than it became later as eth locomotives were in high demand for passenger trains.

My perception as a distant dispassionate observer is that TfN operated rather too far towards the crayons and fantasy end of the spectrum and not enough towards the art of the possible end. And unlike TfL, which broadly pulls in the same direction most of the time, the geographical distribution and different aspirations of different areas make it less easy to gain a consensus. If you satisfy say Leeds and Manchester then you upset Bradford and Sheffield kind of thing. Throw in a number of occasions when it was clear TfN didn't really understand railways and them being sidelined didn't come as a great shock. As for local representatives deciding how to play things, yes that often works well, sometimes however it does not. Merseyside is experiencing that now with the class 777s where you have the Mayor playing political games by simultaneously backing Mersey Travel's operational plan and the RMT which opposes it. Result equals delay in service entry, dozens of new trains standing idle, and the need to thrash out a new operating model which will cost far more than the original one and result in higher fares or higher council taxes or both.

However there is a big mismatch on individual corridors even in the peak. LB-East Croydon is mainly 5 cars all day which is ok off peak but not for peak. LB-Epsom is 10 car all day which is too much even in the peak, Vic-Horsham is mainly 4 car which is not enough etc etc. The whole lot needs to be rebalanced because atm it looks like what it is; ie thrown together at the last minute as cascade plans fall apart. Meanwhile in a sane world, the class 379s currently sitting in sidings, would feature in some plan to sort this out. GWR put a tender out for some emus for an as yet undisclosed reason and 379s are rumoured to be in the frame with some GWR 387s released to somebody rumoured to be the plan. I wouldn't hold your breath though.

Flip side is there are several 8 and 10 car circuits running around South London off peak on weekdays that are virtually empty. Seems to me a reorganisation of the unit diagrams is needed to better match the available stock to demand.

The D6XX in Murder She Said is D603 Conquest

They used to do Exeter SD to Central ok (well most of the time anyway!)

... and a number of the summer ones were booked workings rather than "this is all we've got" last minute depot chuckouts. One of the more celebrated being the booked day out to the south coast every summer Saturday for one of Healey Mill's Knottingley based MGR 47s but there were loads of other examples.

Styal was 25kV only. Colchester-Clacton/Walton was fitted with two temporary neutral sections close together near Alresford. The short section between them could be configured as either 25kV or 6.25kV and was used for basic functional testing of the changeover mechanism on trains as required. When specific changeover testing was not in progress the section was left configured at 25kV.

OT but for the record. I'm not sure whether this is just badly worded and you are trying to say something else but the train supply on a class 47 did not come from the main generator. On 47401-420 it came from a separate eth generator (hence 47401-420 being nicknamed generators) and on the rest it came from a 3 phase alternator.

Re/332s. I think the depot thing was a sort of bonus (albeit at the cost of extra running to/from Reading) but they'd reached the point where they could switch on GW-ATP on the branch and operate 332s/360s, or switch on ETCS and operate 345s but they couldn't find a way to have both 332s and 345s so something had to give. The 332s were supposedly not in a great state and would have required ETCS and TPWS to continue if 345s were to run to Heathrow. So I think the compatibility issue was the primary reason Re/Not invented here. Agree. There was also Portsmouth, another Siemens pre-Westinghouse effort which was arguably a bigger foul up than the others. Then the whole Traffic Management fiasco where they fell over backwards to avoid using home grown products, which, when they did finally try one, proved to be very successful. Roger Ford of Modern Railways has a series of what he calls Informed Sources Laws which apply to railways. The 7th law states ‘The attractiveness of technology is directly proportional to the square of the distance of its factory of origin from London’.

TPWS was not fitted to the Heathrow tunnels nor to the Class 332s. That's not my recollection. I don't believe there was ever an intention to fit GW-ATP to class 345. My recollection is that ETCS was fitted to the Heathrow branch alongside GW-ATP which was to be retained until such time as the 332s were either fitted with ETCS or replaced. However when the ETCS was commissioned it was discovered that it and GW-ATP would not work together in the Heathrow tunnels and this forced a change of plan which resulted in the removal of GW-ATP from the branch and the replacement of 332s with 387s.

The Crossrail point can't be right as it doesn't save anything. The only difference having ETCS from Paddington to Airport Jn makes to Crossrail is that it saves a signalling system transition from TPWS to ETCS at Airport Jn, with the trains going straight from CBTC to ETCS at Westbourne Park. It makes no difference to the trains themselves as they still need the 3 signalling systems they already have. As for the Wherry lines scheme, I'm not sure how that helps. The interlockings may have compatibility with ETCS but you've already spent the money on lineside signals and associated gubbins. By the time that lot needs replacing again so will the interlockings!

As I see it savings totally depend on the scheme. I don't know what the current plans are given the need for cost savings but originally subsequent phases of the ECML (eg north of Grantham) were being talked about as retaining lineside signals. No doubt that would involve replacement of all the lineside signals with new ones in the areas concerned with a consequent substantial increase in cost over doing a traditional like for like or just ETCS with no signals as you are effectively resignalling it twice in terms of lineside equipment. Then you have schemes where ETCS appears to be being considered for reasons other than life expiry such as Paddington to Airport Jn. The signalling equipment there is barely half the age of most of that in say the Doncaster PSB area. No doubt there are sound reasons for doing that stretch but if the decision was based solely on asset condition it seems improbable to me it would be near the top of the list. Or put another way a cost is being incurred which otherwise wouldn't be for another decade at least. If the answer is the age of GW-ATP then my response would be that it will still be there from Airport Jn to Bristol and the whole line from West Drayton to Bristol and South Wales has been resignalled in the last decade. Actually GW-ATP is a good example of the tangle the railway gets itself into. It's now considered indispensable and potentially worthy of otherwise unnecessary large capital expenditure to retain an equivalent capability despite its limited coverage, its absence from every other line running at over 110mph and only one class of train being fitted with it. I am fully aware of the history and sensitivity of Southall et al but it does rather seem to be an albatross around the necks of those making investment decisions.