Loop and siding lengths

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Loop and siding lengths 01/05/2015 at 05:09 #71566
maxand
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http://www.SimSig.co.uk/dokuwiki/doku.php?id=simulations:derby:lengths

I am mystified by the acronyms PP, PP-C and PF in the Notes column. As usual, nothing in the manual or glossary to help me here. Also DY and the numbers after it - signal number ranges? What do they mean? Does P stand for Permissive?

TIA.

Last edited: 01/05/2015 at 05:37 by maxand
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Loop and siding lengths 01/05/2015 at 07:54 #71571
kaiwhara
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" said:
http://www.SimSig.co.uk/dokuwiki/doku.php?id=simulations:derby:lengths

I am mystified by the acronyms PP, PP-C and PF in the Notes column. As usual, nothing in the manual or glossary to help me here. Also DY and the numbers after it - signal number ranges? What do they mean? Does P stand for Permissive?

TIA.
You could do some research and look at the Sectional Appendix, which is freely available...

Sorry guys, I am in the business of making people wait!
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Loop and siding lengths 01/05/2015 at 07:58 #71572
kbarber
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DY definitely Derby - controlling box.

P is permissive working. Rules have changed rather a lot since my day (I remember doing permissive working in mechanical boxes... much more fun... especially if the regular men never bothered and had to be reminded they had the facility, but that's another story entirely...)

I suspect PF is 'Platform'. In the old Block Regs it meant permissive working for passenger trains (which in this case included light engines and ecs) but goods trains were required to be worked absolute block and would be written in the Sectional Appendix as P-PF. As opposed to P-P, which was 'Passenger' and meant permissive working for freight trains (but again, I think, including light engines and ecs) while passenger trains were required to be worked absolute. There was also P-F (or was it P-G) for designated goods lines, where passenger trains were never supposed to venture at all except under the authority of a block conversion ticket.

P and PF were designations of conveneience; before the 1985 resignalling a number of the lines through Crewe station were designated 'P & PF' in the Sectional Appendix; both platform and through lines were thus designated and the result was that permissive working was thereby permitted for absolutely everything.

This being all modern lights-on-poles stuff I can't really help with PP or PP-C.

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Loop and siding lengths 01/05/2015 at 09:04 #71578
maxand
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Kaiwhara wrote:
Quote:
You could do some research and look at the Sectional Appendix, which is freely available...
I did my research to the best of my ability, so don't criticize me for not finding something when I don't know where to begin looking.

However, your suggestion to look in the Sectional Appendix is appreciated and did lead me to the answer, so here it is for all the other newbies.

First, from our own glossary on Permissive Working:
Quote:
Most operation on passenger lines is block working, in that only one train is permitted in any section at one time. At certain locations, mainly stations, in is necessary to join trains, or allow more than one train into a platform at the same time.

Permissive working means that more than one train can be signalled into the same signal section at a time. Usually this is a station platform or a goods loop. This is only permitted as per the local instructions, and certain conditions have to be met.
From Network Rail's Sectional Appendix – General Instructions – National – Explanation of Table A terms and symbols
Quote:
To identify the type of Permissive Working that applies at a given location refer to the appropriate Sectional Appendix Table A for that location. If there is authority for Permissive Working, this will appear in the Signalling and Remarks. There are different authorities that depend upon the signalling and layout of the location. The following list identifies the types of Permissive Working that will appear in the Sectional Appendix.

Type Description
PP Permissive Working – full use for class 1, 2, 3 ECS, 5, 9 and 0 trains
PP – A Permissive Working – Attaching and Detaching use only for class 1, 2, 3 ECS, 5, 9 and 0 trains
PP – C Permissive Working – Contingency use only for class 1, 2, 3 ECS, 5, 9 and 0 trains
PP – S Permissive Working – Platform Sharing use only for class 1, 2, 3 ECS, 5, 9 and 0 trains
PF Permissive Working for class 3 to 8 and 0 trains
Quite possibly the F in PF stands for Freight.

I have added these explanations to the Platform, Siding and Loop Lengths page of the Derby manual.

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Loop and siding lengths 01/05/2015 at 11:25 #71585
Steamer
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" said:
I have added these explanations to the Platform, Siding and Loop Lengths page of the Derby manual.
I've moved it to the generic 'Permissive Working' page to avoid duplication and added links from the Derby page, as these codes are used in other manuals.

By the way- when deleting pages, please use the 'Backlinks' button and re-direct any links to another page. I've changed all the ones that pointed at 'permissive' to 'permissive_wrkg'.

"Don't stress/ relax/ let life roll off your backs./ Except for death and paying taxes/ everything in life.../ is only for now." (Avenue Q)
Last edited: 01/05/2015 at 11:39 by Steamer
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The following user said thank you: maxand