Is there any reason for pumped water rather than a flange greaser? I've never heard of one of those before.Used to have a pumped water lubrication system but long term out of use
Is there any reason for pumped water rather than a flange greaser? I've never heard of one of those before.Used to have a pumped water lubrication system but long term out of use
I just checked and for anyone wanting to experience it, I think the only service to use it is the 09:12 to Meadowhall on a Sunday, starting at Retford Platform 2.The curve from Retford high level down to the Worksop line is pretty sharp, made the Pacer I was on last time I experienced it squeal!
Yes thats the one !!I think you mean at Earlestown station. The south-to-east and south-to-west curves there are both extremely tight, with the former being perhaps a bit tighter, to judge from the OS 1:25k map.
There's a couple of early morning and late evening weekday trips too...I just checked and for anyone wanting to experience it, I think the only service to use it is the 09:12 to Meadowhall on a Sunday, starting at Retford Platform 2.
They are both 25 mphI just watched a cab ride of it and it said 25 eastbound. Westbound is a tighter curve so might be slower.
I believe that's the Caxton Curve, the sharpest on the entire Underground system, according to this link on Wayback MachineLeaving Shepherd's Bush LU westbound is the sharpest I've personally seen.
TfL Central line factsheet (dated Sep 2012) said:To avoid paying compensation to property owners, the line was constructed as far as possible underneath existing roads, hence the twists and turns in the Bank area. But the sharpest curve on the Central line, and indeed the entire London Underground system, is actually the Caxton Curve, between Shepherds Bush and White City.
Much of the tube was constructed under roads to avoid wayleave payments. Victoria Line broke that tradition. So thats why there are many curves underground.I believe that's the Caxton Curve, the sharpest on the entire Underground system, according to this link on Wayback Machine
The relevant extract is:-
It's a 60 m (200 ft) radius, but hard to appreciate being totally underground.
I was walking underneath the bridge there one time when a pacer passed through. Its was very noisy!Yes, out of Carnforth heading for Skipton on a Pacer! You needed to have your fingers in your ears
I was just going to post the same. 20mph speed restrictionLeeds - Harrogate line, Crimple Curve sub 200m radius.
About 220m radius, according to Google Earth.I don't know the radius, but Stourbridge North Junction where the line to Birmingham curves away has check rails, a 15 mph limit and is on an upward slope towards Stourbridge from Lye, so trains in that direction are climbing around a sharp curve, just to add to the fun.
About 180m radius.In Cambridge, the curve away from Coldhams Lane Junction towards Newmarket is 20 mph (or possibly lower at the level crossing point) with a check rail.
No definitive source unfortunately, but I've read, possibly in these forums, that for new UK construction, an absolute minimum for passenger curves today is 150m radius. Might be in TSIs? There are equations for curve speed clearly which also depends on the degree of cant used and the acceptable cant deficiency. Here's one cited in handy mixed UK units, with a bonus graph!I'm finding it interesting that there are so many 'contenders'. Are there no definitive figures? I woild have imagined it might be a factor in deciding what lengths of train or vehicle might be permitted and also a factor in matters of speed limits? I guess it's also a factor in determining wheel profile design?
Appendix C: Calculation of rail line speed as a function of track curvature
We have adopted the following limit for curve radius as a function of line speed:
Thank you for that. I'm trying to picture the research carried out to determine the formula- trains wizzing round bends of declining radius until they fall off or over.No definitive source unfortunately, but I've read, possibly in these forums, that for new UK construction, an absolute minimum for passenger curves today is 150m radius. Might be in TSIs? There are equations for curve speed clearly which also depends on the degree of cant used and the acceptable cant deficiency. Here's one cited in handy mixed UK units, with a bonus graph!
I'm sure it's all calculated theoretically initially by boffins, but I suppose you could confirm it with an ever-tightening spiral. You send the test train in fully sensored up from the outside at a set speed and see at what radius it starts to tip alarmingly, hoping you can then brake sufficiently before it actually turns over!Thank you for that. I'm trying to picture the research carried out to determine the formula- trains wizzing round bends of declining radius until they fall off or over.
That’s 20mph though, and it doesn’t look, from a drivers point of view at least, that tight. Same goes for Earlstown as suggested by @frodshamfella whilst this is probably the tightest curve on a platform, it’s not the tightest curve.Having travelled from Liverpool to Frodsham last Sunday via Halton Curve, that was rather screechy !