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Edwin_m

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    Modelling N gauge contemporary NW England.

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  1. One of the principles of the Midland's re-miling was that a branch with a "trailing" junction in the direction of increasing mileage had its mileage starting from a zero at the junction ("facing" branches continued the mileage at the junction). The longest such branch was from Derby all the way to Bristol and Bath which was a single mileage series. The current passenger services deviate from the measured distance using the cut-off at Kingsbury (built after the re-mileing) and the diversion via New Street (not continuous as the main mileage takes the shorter route via Camp Hill). Thanks for clearing this up. Saved me spending ages wading through Five Mile Diagrams!
  2. We were staying in the area at the time and my father took us to see the loco in the field. By that time there was a security guard, who was happy to let us look but explained that there had been thefts. I recall the loco as being uncovered but don't remember any temporary road having been started at the time of our visit.
  3. Coming from the Trent Valley the ELR changes from LEC2 to LEC3 at Trent Valley Junction No1. The mileage is continuous so probably post-dates the original Grand Junction. The Quail map doesn't show bridge numbers but they may well run on from the Birmingham direction as you suggest. The change from LEC3 to LEC4 just north of Stafford station as well, again with no mileage change. If I get time I'll see if I can work out what the bridge numbers are doing in this area. Going by how the mileposts relate to route histories, some companies appear to have set up or revised their mileposts after the lines were first built. The Stafford case above appears to be one example, and the Midland re-miled its entire network in about 1907. But in recent history the tendency has been to keep the mileposts the same even if they are extremely illogical, because so many records and drawings rely on them. The same is probably true of bridge numbers.
  4. The "steering" effect described above, where the conicity of the wheel avoids flange contact except on tighter curves, relies on the wheels on each side rotating at the same speed. If that doesn't happen then there is a risk the bogie starts "crabbing", or running along at an angle with the flanges on diagonally opposite wheels in contact with the rail even on straight track. There are ways round this but they introduce more complication, for example Talgo trains have a linkage from the body sections to the two-wheeled "bogies" which keeps the axis of the wheels midway between that of the two body sections above, and therefore parallel to the track. However a system is now being tested that has independent wheels with a motor in each wheel hub and some sort of active steering of the "axle" (which connects the wheels but doesn't rotate). Details are commercially sensitive but it appears to be measuring the curvature and using this to steer the axle to the correct angle and also to adjust the relative rotation of the two wheels so flange contact is avoided even on tight curves.
  5. But for the same radius curve the difference in running distance between the two wheels would be greater for a wider track gauge. So to avoid flange contact, the coning angle would have to be steeper or the wheel would have to be thicker.
  6. Saw something about this on a high-numbered Freeview channel a few months ago (assuming your're referring to "three-metre gauge" not three separate metre-gauge lines...). They mentioned that engineers had said (probably not to Adolf himself) it was totally impossible, but didn't explain why. Any suggestions?
  7. But where's the demand for connections? Anyone going north from Oxford or Bicester or MK will find the direct services to Birmingham from those places quicker than making a connection at Calvert, despite the speed of the HS2 leg. The same applies from beyond Oxford, perhaps less so from beyond MK given the connection would have to be at Bletchley instead so probably onto a slower train. But the further east you get, the fewer people will want to make the journey in the first place and the more likely any that do want to will have a more direct route to their northern destinations. That just leaves Winslow and Islip, plus any new EWR stations in the area resulting from new development - who would probably access any HS2 station by other means given the shorter distance.
  8. I think you're barking up the wrong tree. HS2 is a main plank of government policy.
  9. And EWR to MK or Oxford are alternatives (although slower) for those that do want to head north.
  10. Narrower gauges were and are clearly more at risk of overturning, particularly in a strong sidewind. But even in this cases I'd expect the permitted speed to have been grossly exceeded and the passengers to have been thrown about.
  11. I don't think Sharnbrook to Clay Cross would ever have qualified by most people's rules. There have never been more than two tracks between north of Kettering and the southern approaches to Leicester, except for various short loops, and the alternative via Corby is certainly a separate route. Leicester area to Clay Cross (and a bit further to north of Chesterfield) was four-track throughout up until sometime in the 1980s, provided you allow the short separation around Trent, but now has three or two south of Syston and from around Trowell to Clay Cross. I'd be inclined to set a rule that a route should be regarded as four-track if the land between the tracks remains within the operational railway boundary, plus parallel viaducts and tunnels where this is true at both ends. For the MML this would allow the divergence at Bedford but not Sharnbrook or the one at Trent, where there are houses between the high level lines and the other tracks. I think SPC is St Pancras to Chesterfield as it ends just north of there. I believe the GWR or Western Region originated the ELR system so they got all the plum abbreviations such as MLN for their main line. ELRs are allowed to continue through junctions so usually only one curve of a triangle will have its own ELR. The main restriction is that posted mileage must not repeat within the same ELR (so ELR plus mileage uniquely identifies a location on the network) and many ELRs have a digit after the three letters to ensure this.
  12. Indeed. The limit on railway speed is more about aerodynamics than anything to do with track gauge. The curving speed is limited on the grounds of safety and comfort of passengers on the train, as this limit is reached long before there is any risk of overturning. Looking at the chimney on Rocket, I think the Stephensons probably were contemplating a bigger loading gauge than what they ended up with.
  13. However the fast and slow pair do separate over Sharnbrook, to the extent that the slows go through a tunnel and the fasts don't, so its status as a continuous four-track is a bit dubious. If we allowed this then would we allow the Northampton Loop, the GN&GE Joint, etc - where do you draw the line?
  14. HS2 did look at the only credible surface route, the "New North Main Line" from Old Oak to Northolt, which hasn't really had a purpose since Paddington-Birmingham services ended. But they found it was cheaper to tunnel underneath it than to upgrade it to high speed standards which would have involved disruption by raising bridges etc. And it now looks likely that the line will be used to run a Chiltern service into the Old Oak interchange, allowing passengers from that line to connect easily to HS2 but probably more importantly to the Thames Valley and Heathrow.
  15. I was going by crow-flies distances from a mapping site, mainly because my Quail map is at home and I'm not!
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