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jim.snowdon

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Everything posted by jim.snowdon

  1. What the St Bees signaller is alleged to be doing is only possible if the section signals are not interlocked with getting a line clear for the section, and since that principle has been progressively built into signalling for many decades I am surprised that it hasn't spread to St Bees. Either way, what the signaller is doing is in conflict with the rules, even if it is a fudged form of one engine in steam working.
  2. That's just a hydraulic spring. The important feature of that arrangement is that the return stroke of the actuator can be damped so that the switches return to the normal position quite slowly. It saves wear and wear on the mechanism as otherwise it would return to normal between the bogies on each carriage.
  3. The fuel train is a regular working originating from the Isle of Grain and is a completely different flow to the pipelines which, from memory, originate from the Fawley refinery. It's a flow that has been going, possibly on and off, for some time. I was involved in a project to procure a fleet of tank cars for Q8 Petroleum around 1990 that was scuppered by the actions of one S Hussein.
  4. There is no hard and fast answer to this one, although left hand running in loops is a general convention. It all depends on how the layout is signalled, and any layout can be signalled in accordance with what the customer, ie the Operator, wants (and is prepared to fund). I don't recall the Board of Trade having any 'rules' on the subject either, although there was the common sense design principle that trains running in to a loop should have the straighter route, the presumption being that trains running out of the loop would normally be starting from rest or at a low speed and would not be inconvenienced by any speed restrictions through the reverse curves at the end of the loop.
  5. The lines between Euston and Watford were built as a joint exercise with Underground Electric Railways of London (UERL), the owners of the Bakerloo Line. That determined the use of 4-rail electrification from the beginning, and in technical terms, 4-rail avoided any arguments over stray current and interface arrangements with the Signal Engineers. At the time, c.1915, 4-rail electrification was effectively the London area at the time, with only the Central London and City & South London Railways being 3-rail (and the latter was actually a 3-wire DC system with +550V on one line and -550V on the other). The LSWR's 3-rail electrification was only just about to come on line at the time. With the Watford DC Lines committed to being 4-rail, it was an inevitability that the whole of the North London system would also be 4-rail, and there it stayed until BR decided to convert what was left of it to 3-rail in 1970 for reasons that I have never discovered.
  6. The L&YR's Southport Line may look like a four rail system at first sight, but the centre rail was only a reinforcement rail for the return circuit, bonded to both running rails and not in contact with anything on the train. In contrast, the Mersey Railway was electrified using positive and negative conductor rails, ie 4-rail, but the Wirral Railway, which connected with it, was electrified using the standard 3rd rail arrangement. Wirral Railway trains were equipped with centre negative shoegear and automatic contactors that changed the negative connection from running rail to the 4th rail at the changeover point at Birkenhead Park.
  7. The rivet pattern would also suggest side hinged 'cupboard' doors, as would the presence of a door hinge visible on the right hand side (as posted) at the top of the second stanchion. That, plus the generally welded construction, would indicate it as an ex-LNER loco coal wagon.
  8. I'm not aware of any British diesel electrics having anything but a direct connection between the engine and generator shafts. The common approach was for the generator to have only an outer end bearing, the inner end of its shaft being supported by the engine crankshaft. US practice, from what I have seen, tends towards making the generator mechanically independent of the engine, but still coupled directly.
  9. Narrower (9"?) corner plates were a feature of wartime built wagons, introduced as an economy measure compared to the traditional 12" plates.
  10. From a check on the OS 25" map for c.1928*, the only siding, and therefore lodging for any camping coaches, is on the landward side of the running line. Thus, they would, in this picture, be hiding behind the train. The absence of the pillbox that was built around the outcrop seen in the picture would also date the photograph to pre-1939. The same map also shows nothing in regard to the tea rooms that are in the background, so all that can be said, in my view, is that the picture was taken some time between 1928 and 1939. * https://maps.nls.uk/view/106020710
  11. Which will always prompt the question as to why 41 was unused, or what it was intended for.
  12. The only certainty will be that the No.1/A end will be the end where Forward on the controller sets up the Forward train line. But then, with two engines and, therefore two traction equipments, one will be in Forward, the other in Reverse. None of this will be obvious to the bystander however.....
  13. The insides of PO coal wagons (and railway owned examples, including the BR steel ones) were unpainted save for any metalwork on wood bodied wagons, which was generally given a 'black japanned' finish at construction. Open merchandise wagons were similarly unpainted when wooden bodied. The unknown is the pre-BR steel bodied coal wagons - BR adopted a policy of using a self-weathering grade of steel (Corten) but how widespread that practice was for pre-BR wagons is unknown to me.
  14. There is a view in circulation amongst railway modellers that it was a requirement, if not a BoT requirement, that vehicles carrying livestock, especially in freight trains, should be coupled immediately behind the locomotive so as to reduce shocks to the occupants. It certainly seems plausible, and would be consistent with many livestock wagons being equipped with screw couplings and vacuum brakes/through pipes. The question is was this ever set out in the railways rules or general appendices?
  15. Intriguing. My knowledge of Chippenham station dates from long after the branches had gone and the Calne branch bay is much the more obvious feature.
  16. And then there's Chippenham, which I recall as having the bay between the up and down lines, and not directly accessible from the latter.
  17. Yes you can - you follow the prototype signalling principles, just as the signal engineers had to when faced with a new track layout. Probably because it added operating interest, which is generally what model railway operation is all about. The bog-standard railway station with two platforms and a goods yard is pretty boring to operate.
  18. They were more 'strong recommendations' than actual Rules with legal force. They were essentially what the Railway Inspectorate expected to see and considered to be good practice. If you complied, then approval would normally be forthcoming. You could deviate from them, but you had to have convincing reasons why (a) compliance was not reasonably practicable and (b) that what you proposed was no less safe than a compliant arrangement. The only legal rules were those set out in the various Regulation of Railways Acts, which marked those relatively rare occasions when the Inspectorate's powers of persuasion had to be backed with force to deal with recalcitrant railway companies.
  19. I'm sure Heljan's pricing policy is the classic one of 'screw the customer for as much as they will pay', otherwise known as setting the highest price that the market will bear. The unfortunate part is that people make the comparison against what it would cost them to build one, or more likely, what it would cost to get one built, ignoring the fact that these RTR models are mass produced, with all the economies of scale that that brings.
  20. It is an ISO container, or more specifically an integral bodied tank with ISO length and width dimensions and twistlocks on the corners. Not that common, relative to the number of ISO tank containers that had the tank contained within a complete frame, as at the head end of that train.
  21. Marking the axlebox with the journal size is a normal, and necessary, practice. Bearing brasses come in a range of different sizes. If it's not on the cover, it will be somewhere else on the casting.
  22. But still fit in the RCH axleguard. That's governed by the adaptor housing in which the roller bearing fits.
  23. From my understanding of current signalling design, signal spacing is determined on the basis that the braking is initiated at the point of passing the signal, not the point at which it was sighted. That is a necessary worst case condition as the visibility of the signal in different weather conditions cannot be presumed. Early sighting is therefore a bonus. Sighting, in the context of being able to identify the signal aspect against the background, is an important consideration, particularly when it is a stop aspect. There is also the issue of being able to see the signal at all when the train is stopped at the expected stopping point. This has become more of an issue with the way modern stock no longer has side windows convenient to the driver. Gone are the days when the driver could poke his or her head out of the cab side window and look at the miniature aspects (the 'pig's ears') on the side of the signal head. The worst case elements are taken into account in the standards applicable to both signalling and rolling stock.
  24. I would agree, and in the days before wagon brakes became more of a standard fittting it quite possibly was practice to sprag a wagon's wheels on a down gradient. Where I suspect confusion starts to creep in is in distinguishing between a sprag, as a device to prevent an unbraked vehicle from moving, and a brake stick, used by shunters to obtain more leverage when pressing down the brake lever.
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