-
Our booking engine at tickets.railforums.co.uk (powered by TrainSplit) helps support the running of the forum with every ticket purchase! Find out more and ask any questions/give us feedback in this thread!
Viaduct Guard Rails
- Thread starter MOONY
- Start date
- Status
Sponsor Post - registered members do not see these adverts; click here to register, or click here to log in
R
RailUK Forums
furnessvale
Established Member
- Joined
- 14 Jul 2015
- Messages
- 4,576
Until a better answer comes along, it could be a relic of 10ft wheelbase wagons and their desire to derail at the magic speed of 49mph, hence the speed limit of 45mph imposed on them. A single axle could derail and be dragged for miles before finding a suitable crossover etc. to pile up on.
Incidentally, I always considered part of the problem to be NOT telling drivers the true nature of the dynamics involved. By being limited to 45mph, I am sure some drivers, when running late thought "another 5mph won't hurt", but that put them right on the dangerous harmonics. Pull the train through to 55mph and things settled down again. I have confirmed this with several drivers.
Edit to add. I didn't answer the original question. Perhaps the guard rails are on the line where the speed of 45+ mph could be achieved, ie downhill side.
Last edited:
Ploughman
Established Member
On the same route but outside the area stated.
Bell Busk viaduct has Guard Rails in both lines.
Bell Busk viaduct has Guard Rails in both lines.
Supercoss
Member
- Joined
- 5 Jun 2016
- Messages
- 299
These are installed To keep any derailed vehicle from striking parapet based on line speed .
Last edited:
I imagine the OP knows that, the question is why on one track and not the other.
furnessvale
Established Member
- Joined
- 14 Jul 2015
- Messages
- 4,576
Correct, but the original posed question was why are they only fitted on the down line and not the up?
Randomer
Member
- Joined
- 31 Jul 2017
- Messages
- 317
A guess but going back to the original posters question could it be something to do with the dynamic behaviour of loaded and unloaded wagons?
Didn't Settle-Carlisle previously had loaded freight flows primarily in one direction?
furnessvale
Established Member
- Joined
- 14 Jul 2015
- Messages
- 4,576
Not during the 10ft wheelbase "upending" saga. Most 45mph freights were diverts off the WCML while we got on with extensive renewals. One or two heavy freights were loaded south, empty north, like the Long Meg anhydrite, but that was a law unto itself and restricted to 35mph!
At one Christmas party for the Preston district civil engineers, the lads wrote a song to the tune of "Much binding in the Marsh", one line of which was "The hopper train from Long Meg's been upended", such was its propensity for hitting the deck!
Dent Head Viaduct has guard rails on both roads whereas a little further north, Arten Gill Viaduct is an example of many that have them on the down only.
Moony
Ploughman
Established Member
Bell Busk Guard rails mentined earlier were installed after a renewal.
CAnnot recall if there was a set in place pre renewal.
CAnnot recall if there was a set in place pre renewal.
pdeaves
Established Member
Are the viaducts curved? If so, could it be to do with which way a train would tend to try and fall? (If not, it will be some other reason!)
NI 271
Member
There aren't any on either road over Dent Head viaduct.
There are six viaducts between Settle and Carlisle with them on both lines (it could possibly be argued seven if you include the single line over Batty Moss viaduct, also the bridge over the A66 just north of Appleby has them on both roads), and five that have them on the down only. I've no idea why those five have them only on the down.
CEN60
Member
- Joined
- 17 Dec 2018
- Messages
- 267
Re the structures that only have them on one road - are the guard rails on the "outside" of the curve in the direction of "normal" running?
I think the question was if the guard rails were on the track that is on the "outside" of the curve. The thinking being that a if a train on the inside of the curve derailed, the other track would be a natural barrier.
Ploughman
Established Member
The gathering rails or Butterflys will need to be in the 6ft and cesses
All viaducts with guard rails
Bell Busk - both directions
Marshgate - both directions
Church - down only but on a straight
Ribble - both directions
Little - both directions
Ribblehead
Arten Gill - down only outside curve
Lunds - both directions
Ais Gill - both directions
Crosby Garrett - down only inside curve?
Griseburn - down only on a straight
Ormside - both directions
Bell Busk - both directions
Marshgate - both directions
Church - down only but on a straight
Ribble - both directions
Little - both directions
Ribblehead
Arten Gill - down only outside curve
Lunds - both directions
Ais Gill - both directions
Crosby Garrett - down only inside curve?
Griseburn - down only on a straight
Ormside - both directions
CEN60
Member
- Joined
- 17 Dec 2018
- Messages
- 267
Yes - sorry that's what I was getting at - I am well aware of where they go and the intricacies of the gathering / flare panels - having had to detail them at various times - it's not uncommon to see them fitted to the "outside" curve only - as you note if the train on the inside comes off - the opposite sixfoot rail acts a bit like a guard rail. The original observation of only one guard set of rails might also be influenced by track gradient - ie fitted to the curve at the bottom of a gradient. Having said that - any that I have detailed recently on 2 track railway - both tracks have had them fitted. The final say on if they should be fitted is decided by the Network Rail Route Asset Manager (RAM - Track) - at least that is what the standard currently says.
Also consideration of the topography, embankments etc should be taken into account when deciding whether to fit.
- Status