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Definition of Station Limits

Unread postPosted: Tue Dec 5, 2017 7:23 pm
by Chris Osment
My understanding is that 'station limits' for a signal-box on a double-track line would normally be from the outermost home to the 'section signal' in each direction. But what happened in those situations (certainly not uncommon on the L&SWR) where there was a crossover or trailing in advance of the section signal - where was the end of station limits in such a case?

If an engine had to pass the section signal in order to shunt in/out of the siding or go across the crossover, then presumably it was regarded as going into the block section, so how might such movements usually be dealt with on the block? Was it common for 'shunting into forward section' to be authorised at such places?

Re: Definition of Station Limits

Unread postPosted: Wed Dec 6, 2017 1:02 am
by Mike Hodgson
That's the definition I have always undertood to be correct.
I dont think Shunting into Forward Section was even in the Block Regs in LSWR days, I think it was introduced about the time the green books came in (1960}.
Wouldn't you have had a Shunt Ahead signal, in such situations authorsing you to go no farther than necessary to shunt?

Re: Definition of Station Limits

Unread postPosted: Wed Dec 6, 2017 7:26 am
by John Hinson
Chris Osment wrote:My understanding is that 'station limits' for a signal-box on a double-track line would normally be from the outermost home to the 'section signal' in each direction. But what happened in those situations (certainly not uncommon on the L&SWR) where there was a crossover or trailing in advance of the section signal - where was the end of station limits in such a case?

If an engine had to pass the section signal in order to shunt in/out of the siding or go across the crossover, then presumably it was regarded as going into the block section, so how might such movements usually be dealt with on the block? Was it common for 'shunting into forward section' to be authorised at such places?

Station Limits relate to signal locations, as you say, so the position of the points is irrelevant.

If a train needs to go into the section, for whatever purpose, it needs to be signalled on the block.

John

Re: Definition of Station Limits

Unread postPosted: Wed Dec 6, 2017 1:10 pm
by Chris Osment
Mike Hodgson wrote:Wouldn't you have had a Shunt Ahead signal, in such situations authorising you to go no farther than necessary to shunt?


I can think of a number of locations where either nothing like that existed, or else there was just a ground signal leading out from a siding. But even with a specific SA signal, surely you would still have to put the movement on the block anyway - the SA would just be an indication that it was for a short movement only rather than all the way through the section?

John Hinson wrote:If a train needs to go into the section, for whatever purpose, it needs to be signalled on the block.


That confirms my assumption. So - assuming that 'Shunting into Forward Section' either did not exist at the time or else was not authorised at that location - then I presume that you offered the train forward and then Cancelled when the shunt had been withdrawn? If so, then (assuming an engine and some ECS or a few wagons) what would it be offered as please?

Re: Definition of Station Limits

Unread postPosted: Wed Dec 6, 2017 3:37 pm
by John Hinson
Chris Osment wrote:That confirms my assumption. So - assuming that 'Shunting into Forward Section' either did not exist at the time or else was not authorised at that location - then I presume that you offered the train forward and then Cancelled when the shunt had been withdrawn? If so, then (assuming an engine and some ECS or a few wagons) what would it be offered as please?

Mr Osment - have you lost your marbles? You would offer it as whatever it was of course.

John

Re: Definition of Station Limits

Unread postPosted: Wed Dec 6, 2017 4:20 pm
by Chris Osment
John Hinson wrote:Mr Osment - have you lost your marbles? You would offer it as whatever it was of course.


They fell off the train register desk and rolled away......:-)

Thanks for the confirmation!

Re: Definition of Station Limits

Unread postPosted: Wed Dec 6, 2017 9:46 pm
by Chris Osment
Looking further into this, I note that in the 1930 SR Block Regulations there are two Regs (apparently 34 and 35, but the numbers are obscured on my page) for “Shunting between Signal Boxes within Station Limits, in the Right Direction” and “...ditto..., in the Wrong Direction” respectively, with a number of additional special bell-codes. Only the latter is marked as “where authorised”, so presumably the former was freely available.

The phrase “signal boxes within station limits” would suggest to me that, in a case (say) with a box at each end of a physical station, then in each direction there was one ‘station limits’ only from the outermost home of one box to the section signal of the other box, rather than one set for each box separated by the block section between them.

My interest in this has arisen as a result of a discussion elsewhere specifically about the North and South boxes at Evercreech Junction, though that is complicated by the fact that apparently the S&DJR used the LMS Block Regs at one time !

Re: Definition of Station Limits

Unread postPosted: Wed Dec 6, 2017 11:55 pm
by Mike Hodgson
Chris Osment wrote:My interest in this has arisen as a result of a discussion elsewhere specifically about the North and South boxes at Evercreech Junction, though that is complicated by the fact that apparently the S&DJR used the LMS Block Regs at one time !


Ah well, in that case, yes you should have sent Shunting into Foward Section - because it was in the LMS regulations (1934 and 1947) - but it wasn't in the Midland's 1917 regs

Re: Definition of Station Limits

Unread postPosted: Thu Dec 7, 2017 5:01 pm
by Is Line Clear
Chris Osment wrote:Looking further into this, I note that in the 1930 SR Block Regulations there are two Regs (apparently 34 and 35, but the numbers are obscured on my page) for “Shunting between Signal Boxes within Station Limits, in the Right Direction” and “...ditto..., in the Wrong Direction” respectively, with a number of additional special bell-codes. Only the latter is marked as “where authorised”, so presumably the former was freely available.

The phrase “signal boxes within station limits” would suggest to me that, in a case (say) with a box at each end of a physical station, then in each direction there was one ‘station limits’ only from the outermost home of one box to the section signal of the other box, rather than one set for each box separated by the block section between them.

My interest in this has arisen as a result of a discussion elsewhere specifically about the North and South boxes at Evercreech Junction, though that is complicated by the fact that apparently the S&DJR used the LMS Block Regs at one time !


Page 28 of the 1930 SR book. Regs are numbered 34A and 34B in my copy.

Re: Definition of Station Limits

Unread postPosted: Thu Dec 7, 2017 5:06 pm
by Chris Osment
Is Line Clear wrote:Page 28 of the 1930 SR book. Regs are numbered 34A and 34B in my copy.


Thanks for the info. There is an amendment page for something else pasted on that page in my copy and it covers the Reg Nos.

Re: Definition of Station Limits

Unread postPosted: Thu Dec 7, 2017 9:32 pm
by alancolq
Hello all - an interesting discussion. Just to add some Scottish region oddities, shunt into forward section was authorised on the Down Main from Dalmeny Junction towards Dalmeny Station as the former's trailing crossover was in advance of the down starter. There was no shunt signal so the starter would typically be pulled slowly as the train approached and (sometimes at any rate!) the signalman would stand at the window holding up his crossed arms to indicate to the driver that he would be going "through the road".

Interestingly, if Dalmeny Station was switched out, shunt into forward section was initially not authorised towards Forth Bridge North so the train would be offered on as normal, train entering section sent and then the cancelling signal sent when the shunt was withdrawn. When Edinburgh-Glasgow diversions became more common, with trains reversing at Dalmeny Junction, the powers that be decided to authorise the shunt bell signal to Forth Bridge North box as well. Rumour went that this was due to the introduction of push-pull services and their special 4-4 bell code causing some confusion at Forth Bridge North!

Re: Definition of Station Limits

Unread postPosted: Fri Dec 8, 2017 2:40 am
by John Hinson
Chris Osment wrote:The phrase “signal boxes within station limits” would suggest to me that, in a case (say) with a box at each end of a physical station, then in each direction there was one ‘station limits’ only from the outermost home of one box to the section signal of the other box, rather than one set for each box separated by the block section between them.

It certainly sounds like something of that sort - one would need to see said company's Rules/Regulations to see how they define "station limits".

John

Re: Definition of Station Limits

Unread postPosted: Tue Dec 12, 2017 3:55 pm
by Chris Rideout
There was a case at Southampton Central where an Up Main Shunt Ahead was provided but taken away when TC block was introduced. Shunting Past the Up Main Advanced Starting (no 11) into the tunnel was a strange affair because there was an automatic distant arm underneath no 11 and this would clear as well. Setting back from inside the tunnel was not easy because the driver needed to see the ground signal at 58B (no 59). Yes, the bell codes 3-3-2 and 8 consecutively were used.