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Acle signal box

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Acle signal box

Unread postby Train approaching » Mon Jul 11, 2016 8:02 am

Someone has passed this to me to look at, but surely the "section signal" should be the advanced starter:

The box is equipped with a 20 lever Saxby and Farmer frame, of the same vintage as the building. There are distant, home, starter and section signals in each direction, all of them wire operated semaphores apart from the down distant.
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Re: Acle signal box

Unread postby John Hinson » Mon Jul 11, 2016 9:27 am

To my eyes, it is both. As I understand it a "section signal" is a generic name for the signal protecting the block section. Depending on the track layout, a home, starter or advanced starter could be the "section signal".

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Re: Acle signal box

Unread postby John Webb » Mon Jul 11, 2016 12:13 pm

Am I missing something? Only in Train Approaching's post, and in John H's reply, they seems to be referring to a picture which I can't see anything of!
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Re: Acle signal box

Unread postby Mike Hodgson » Mon Jul 11, 2016 3:21 pm

I thought that too John, but there's an old diagram here that might help.
http://signalbox.org/diagrams.php?id=328

To my mind the precise terminology only really matters within some context such as the rule book or perhaps a set of locking. For example the old black 1950 rule book said certain things about a Home Signal or a Starting Signal, and did not refer to section signals, nor did it define any of these terms, so application of a rule would depend on how a particular signal had been designated. I have always understood the most advanced running signal to be the section signal, but that isn't quite right where intermediate block section signals exist. I don't know whether the current rules define a section signal or in what context they make stipulations.

However in the case of the linked ACLE diagram I would have called 3 a starter and 4 an advanced starter, and I would expect both 3 and 4 to be locked if you have one coming the other way, and I would also expect the rules to ban clearing them even if the locking didn't. The Down direction signals don't match Trainapproaching's description of wire-operated semaphores so I assume the current layout differs from 1969.
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Re: Acle signal box

Unread postby John Hinson » Mon Jul 11, 2016 5:01 pm

I believe the auto signals have been dispensed with. I can't think of a single good reason to justify provision of an advanced starter in that direction. The only reason the other one was provided in the first place was to allow shunts in/out of the yard with the section occupied.

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Re: Acle signal box

Unread postby colin1501 » Mon Jul 11, 2016 6:25 pm

This (later?) diagram shows a down section signal/advanced starter, numbered 16. I have also seen and photographed this signal as recently as last year, so the description quoted by Train Approaching is accurate.

http://www.lymmobservatory.net/railways ... s/acle.jpg
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Re: Acle signal box

Unread postby davidwoodcock » Mon Jul 11, 2016 6:27 pm

I thought that advanced starters were provided at Acle to allow a train to wait acceptance from the next box at a position where it was clear of the clearance point, so that the following train (in the same direction) could be accepted as far as the home.

Remember the whole set up was designed to considerably increase line capacity while spending next to no money and I believe it was quite successful in that respect. It was in the nature of summer Saturday traffic that it was very heavy ex-Yarmouth in the morning and very heavy to Yarmouth in the afternoon, so significantly unbalanced for some hours on end.
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Re: Acle signal box

Unread postby John Hinson » Tue Jul 12, 2016 4:27 am

davidwoodcock wrote:I thought that advanced starters were provided at Acle to allow a train to wait acceptance from the next box at a position where it was clear of the clearance point, so that the following train (in the same direction) could be accepted as far as the home.

Remember the whole set up was designed to considerably increase line capacity while spending next to no money and I believe it was quite successful in that respect. It was in the nature of summer Saturday traffic that it was very heavy ex-Yarmouth in the morning and very heavy to Yarmouth in the afternoon, so significantly unbalanced for some hours on end.

I am surprised that summer Saturday traffic levels increased after the late 1960s to the extent that trains were held lengthy times waiting acceptance at advanced starters. "Considerably increasing capacity" is usually done in a way to stop traffic queueing like that. I believe the automatics were provided when Berney Arms was abolished, rather than in response to increased traffic. It is certainly interesting that an advanced starter was provided after that and then the automatics later abolished.

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Re: Acle signal box

Unread postby Roger Bell » Wed Jul 13, 2016 5:59 am

I have always believed rightly or wrongly that the extra signals were provided at Acle as a belt and braces precaution when direction lever working replaced tokens.The section signals were provided with detonators. The signals are only a short way from the starters with not enough room to stand a train on the single line. Another possibility could be to allow a very long train to draw forward to clear the points at the other end of the loop.
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Re: Acle signal box

Unread postby colin1501 » Sat Jul 16, 2016 7:44 am

Train approaching - your post above contains a direct quote from an article which I wrote (but which has not been published anywhere), and I'm obviously keen to know who has asked you to look at it. Apologies for posting this on the forum, but I've tried to private message you without success. Can you please PM me, so we can discuss.

Thanks, Colin
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Re: Acle signal box

Unread postby Mike Hodgson » Sat Jul 16, 2016 11:03 am

colin1501 wrote:This (later?) diagram shows a down section signal/advanced starter, numbered 16. I have also seen and photographed this signal as recently as last year, so the description quoted by Train Approaching is accurate.

http://www.lymmobservatory.net/railways ... s/acle.jpg


Although I am used to "Start/end of Token Working" signs, I haven't noticed the "Non token working ahead" signs of this diagram anywhere before. Is it a non-standard sign - perhaps I've missed it but I can't see this sign listed on the excellent Railsigns website. Having a sign is not at all unreasonable given the dire threats that have always been in rule books to drivers who enter a single line section without the proper token, but I thought route knowledge/sectional appendices covered whether or not a particular line used tokens - when/why were such signs introduced?

The sign itself seems a little odd from the driver's point of view, in that a train standing at the advanced starter is already on a single track line, although it doesn't have a token and has not yet reached the start of non-token working - implying perhaps that he ought to have a token? Is a driver expected to understand the concept that within station limits the signalman controls the area?
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Re: Acle signal box

Unread postby John Hinson » Sat Jul 16, 2016 11:24 am

Mike Hodgson wrote:The sign itself seems a little odd from the driver's point of view, in that a train standing at the advanced starter is already on a single track line, although it doesn't have a token and has not yet reached the start of non-token working - implying perhaps that he ought to have a token? Is a driver expected to understand the concept that within station limits the signalman controls the area?

Not really, the same applies at any advanced starting signal on a single line. You can proceed as far as that signal without a token although generally you would only do so to shunt, otherwise somebody has a long walk with the token.

I have been racking my brains as to the reason for the signal being provided and still cannot think of one. It did not exist when the line was converted to TCB so the theory it was provided as "belt and braces" for the lack of token doesn't really hold. Nor does the one about accepting a train with another standing at it, as it has been mentioned that there wouldn't be enough room to do so. The best offering is crossing trains where one is too long for the loop, although the existing advanced starter would have coped with that. Intriguing indeed . . .

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Re: Acle signal box

Unread postby steve thompson » Sat Jul 16, 2016 6:42 pm

You can see signals 4 and 16 on youtube taken last year, just put in "Acle station", there is a white notice below each signal but you cannot read them.
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Re: Acle signal box

Unread postby beast66606 » Sun Jul 17, 2016 8:31 am

The plates on signals 4 and 16 read "NON-TOKEN working ahead" - I photographed them last week
Better to be thought a fool than to type a response that confirms it.

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Re: Acle signal box

Unread postby Roger Bell » Tue Jul 19, 2016 3:33 pm

Is it common to use detonators on semaphore advance starters on single lines or is this another feature that makes Acle unusual if not unique?
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