Tokenless Block

DerekC

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Can anyone tell me which sections of NR single line infrastructure are still operated on "Tokenless Block" principles? For those interested and who don't know what that is, there is good article here; (I have copied the important bit below)


The BR(WR) Tokenless Block instrument consists of a single-needle indicator with 3 positions (labelled 'Normal', 'Train In Section' and 'Train Accepted'), a 2-position rotary 'acceptance' switch ('Normal' and 'Accept') and two push-button switches ('Offer' and 'Train Arrived'). The block instrument betrays its BR(WR) origins, as the wooden case is similar to that used for the 'single-deck' version of their standard commutator block instrument (often used for 'permissive' instruments), and it may well be that the instruments were converted from redundant items. Block-bells are not provided with this system, as the method of operation does not require them, although in practice the signalmen tended to use the bells of the box-to-box telephones.
It should be noted that the 'Normal' indication is given by the needle pointing to the left, rather than being vertical in the centre as is usual with most 3-position indicators. The reason is that in this tokenless block system, unlike most 3-position block systems, there is a continual flow of electric current through the line wires to hold the indicator over to the 'Normal' position. In the event of an electrical failure, then gravity causes the needle to fall to the central 'Train In Section' position and provides a 'fail-safe' indication (this situation can be seen in the photograph, where the instrument has been disconnected). Some of the instruments were manufactured with the central legend on the indicator reading 'Line Blocked', but this has been covered by a sticky label bearing the 'Train In Section' legend.

Basic Operation​

To describe the basic operation of the system, let us assume that the signalman at box 'A' wishes to send a train to his colleague at 'B'. If the instruments are normal (and all else is in order in accordance with the Regulations) then A pushes his 'offer' button - provided that B turns his acceptance switch to 'Accept' (or has done so already), then the indicators on both instruments will go to 'Train Accepted' and the lock on the section signal at A will be released. When the train passes the section signal it will occupy a track-circuit, which causes the section signal to change to a red aspect and both block indicators to go to 'Train In Section'. When the train arrives at B and passes beyond the home signal it will operate a treadle, and occupy and then clear two track-circuits in succession - upon completion of this process a 'train arrived' condition will be registered within the system. When the signalman at B has seen the train arrive clear of the single-line complete with tail-lamp he returns his acceptance switch to 'Normal' and presses his 'Train Arrived' button - if the 'train arrived' condition has been proved then both indicators will return to 'Normal' and the block is clear.

It must be emphasised that, when A presses his 'Offer' button, there is no visual or audible indication at B that a train is being offered. The design assumption with this system was that trains would run according to the timetable, and so B would have placed his switch to 'Accept' already in anticipation. (It is possible for both signalmen to keep their switches at 'Accept', so that the first one to 'offer' gains the section.) This 'pre-acceptance' feature means that B does not have to be present in his signal-box in order for A to offer or despatch the train. If B should find it necessary subsequently to stop the train leaving A then, provided that the block is still in the 'Train Accepted' condition, he has merely to return his switch to 'Normal' - the indicators will return to 'Normal' and the release on the section signal at A will be cancelled. The section signal is normally a colour-light, so cancellation of the release causes the signal to change automatically to a red aspect, even if signalman A is not present in the signal-box to replace the signal lever. (It is permitted to have a semaphore section signal, in which case the cancellation causes a warning buzzer to sound continuously until the signal lever is returned to normal.) Conversely A can cancel his 'offer' by turning his own switch to 'Accept' temporarily, whereupon both block indicators will revert to 'Normal'.
 
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Gloster

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A bit of googling suggests that there is some on the Knaresborough-York line and also Barrow-Park South Junction. I am not sure about the situation around Dullingham and there may still be some around the fringes of the Grampians. Nor am I sure about the set-ups between Wilton and Tisbury, and Maiden Newton and Dorchester West.
 

dk1

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There’s one error on here. It shows tokenless block between Honiton and what appears to be Seaton Jct. This is now on Basingstoke ROC.
Also isn’t Reedham-Yarmouth now TCB. Saxmundham-Leiston surely isn’t RETB either.
 

Legolash2o

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There’s one error on here. It shows tokenless block between Honiton and what appears to be Seaton Jct. This is now on Basingstoke ROC.

The NESA, the Table A diagram has it tagged as TB but I do remember struggling to map the data in that area.

Also isn’t Reedham-Yarmouth now TCB. Saxmundham-Leiston surely isn’t RETB either.
NESA didn't show the signalling for Reedham - Yarmouth but I found an article showing a recent signalling scheme and on next publish should be seen as TCB.

Saxmundham shows as OTS on NESA.

Thanks both for spotting the potential errors, appreciated!
 

Efini92

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This is a superb resource! Clearly a lot of work has gone into this!

One minor issue I've found, is for NW6015 (WKL2). Between Rainford and Kirkby, including the freight stub to at Dale Lane, is ETB and not as shown NTS.
What’s NTS?
 
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Whoops. Auto correct prefers Non-technical Skills (NTS) over No Signaller Token (NST).
Probably best to read before submitting, next time :oops:
 

Efini92

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Whoops. Auto correct prefers Non-technical Skills (NTS) over No Signaller Token (NST).
Probably best to read before submitting, next time :oops:
Is it not token working into Knowsley freight terminal and one train working with staff to rainford?
 

matchmaker

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A few errors on Perth - Inverness. It should be:

Stanley Junction - Dunkeld & Birnam is Tokenless Block ("Token Block" doesn't sound right)

Dunkeld & Birnam - Pitlochry and Pitlochry - Blair Athol is Track Circuit Block (Pitlochry is now remotely controlled from a panel in Stanley Junction)

Blair Athol - Dalwhinnie is Absolute Block

Dalwhinnie - Kingussie is Tokenless Block

Kingussie - Inverness is Track Circuit Block
 

Legolash2o

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This is a superb resource! Clearly a lot of work has gone into this!

One minor issue I've found, is for NW6015 (WKL2). Between Rainford and Kirkby, including the freight stub to at Dale Lane, is ETB and not as shown NTS.

Thanks!

This is where NESA annoys me as it says NST. Seems to be increasingly wrong, which is worrying as it's the official published information :'(

A few errors on Perth - Inverness. It should be:

Stanley Junction - Dunkeld & Birnam is Tokenless Block ("Token Block" doesn't sound right)

Dunkeld & Birnam - Pitlochry and Pitlochry - Blair Athol is Track Circuit Block (Pitlochry is now remotely controlled from a panel in Stanley Junction)

Blair Athol - Dalwhinnie is Absolute Block

Dalwhinnie - Kingussie is Tokenless Block

Kingussie - Inverness is Track Circuit Block
Thanks for these and I will investigate in the morning.

P.S. I've also fixed the legend to say 'Tokenless Block'
 

Railsigns

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A few errors on Perth - Inverness. It should be:

Stanley Junction - Dunkeld & Birnam is Tokenless Block ("Token Block" doesn't sound right)

Dunkeld & Birnam - Pitlochry and Pitlochry - Blair Athol [Atholl] is Track Circuit Block (Pitlochry is now remotely controlled from a panel in Stanley Junction)

Blair Athol [Atholl] - Dalwhinnie is Absolute Block

Dalwhinnie - Kingussie is Tokenless Block

Kingussie - Inverness is Track Circuit Block

Which is what the map currently shows.

The only problem I see on that line is the transition between Absolute Block and Tokenless Block at Dalwhinnie being shown too far to the south.
 

Legolash2o

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I've moved the transition at Dalwhinnie to be just north of the station at 53m 58ch (Signal Box). It will be visible at next publish.

Does anyone know what TBSC is please? I treat it the same as Tokenless Block.
1654016953685.png
 
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Is it not token working into Knowsley freight terminal and one train working with staff to rainford?
Rainford signal box has a single token machine for both Knowsley and Kirkby.

Trains to Kirkby collect the token from the signaller at Rainford and return it on the way back. There's an auxiliary token machine at Dale Lane for trains to Knowsley, so that they can lock-in, and allow the passenger trains access to the single line.

It has in the past been shown as OT(S) in the section appendix, but is now shown as NST. Talking to a colleague who works the box at Rainford, he assures me he definitely exists and operates the line under ETB regulations. :lol:

I've informed the relevant department with NR about this discrepancy.
This is where NESA annoys me as it says NST. Seems to be increasingly wrong, which is worrying as it's the official published information :'(
I have to agree with you on that one. Some data is superbly accurate, but unfortunately, other datasets less so. :'(
 

Efini92

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Rainford signal box has a single token machine for both Knowsley and Kirkby.

Trains to Kirkby collect the token from the signaller at Rainford and return it on the way back. There's an auxiliary token machine at Dale Lane for trains to Knowsley, so that they can lock-in, and allow the passenger trains access to the single line.

It has in the past been shown as OT(S) in the section appendix, but is now shown as NST. Talking to a colleague who works the box at Rainford, he assures me he definitely exists and operates the line under ETB regulations. :lol:

I've informed the relevant department with NR about this discrepancy.

I have to agree with you on that one. Some data is superbly accurate, but unfortunately, other datasets less so. :'(
If it runs on ETB regulations, am I right in thinking the signaller can authorise a train to pass the signal at danger and enter the single line for shunting purposes?
 

MarkyT

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Scottish Tokenless Block.
Tokenless Block (Scottish) according to the signalling record society glossary.
Various regions of BR had their own standard varieties of Tokenless Block. At Reading signalling drawing office, we had a WR standard arrangement detailed in the E10K circuit book. Functionally they were all very similar, but the detailed design of the instruments and circuitry differed and may have been minor operational variations. There was also a BR standard system developed eventually, supposed to bring together the best features of all. I don't know why the Scottish Region specifically identified their particular type in the SA, but maybe there were some lines north of the border with different TB types that needed to be identified.
 
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If it runs on ETB regulations, am I right in thinking the signaller can authorise a train to pass the signal at danger and enter the single line for shunting purposes?
At the risk of going a bit over 'rulesy', here's how I understand it.

Rulebook module S5 outlines all the occasions when a train can pass a signal at danger. It specifically mentions passing a signal at danger for shunting purposes, but only where there is no signal provided for the movement.

Module TS4 specifically relates to ETB regulations. Under section 3.7 - 'occupying the single line for shunting purposes', it states that a token must be withdrawn for a shunting move, and where provided the signal cleared.

In the case of Rainford, I can't think of an occasion where a signal would need to be passed at danger, with the exception of a signal failure, but happy to be corrected.
 

Railsigns

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Various regions of BR had their own standard varieties of Tokenless Block. Functionally they were all very similar
No, they were not. The Scottish Tokenless Block is fundamentally and radically different from the others. The WR and BRB systems were designed to allow automatic acceptance, whereas the ScR system wasn't. A unique feature of the Scottish system is the 'shunting key', which is given to a driver to permit shunting into the single line. The Scottish system allows a signal box to switch out immediately after two trains have crossed in the loop, in effect putting them both in the same section but heading away from each other.
 

Efini92

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At the risk of going a bit over 'rulesy', here's how I understand it.

Rulebook module S5 outlines all the occasions when a train can pass a signal at danger. It specifically mentions passing a signal at danger for shunting purposes, but only where there is no signal provided for the movement.

Module TS4 specifically relates to ETB regulations. Under section 3.7 - 'occupying the single line for shunting purposes', it states that a token must be withdrawn for a shunting move, and where provided the signal cleared.

In the case of Rainford, I can't think of an occasion where a signal would need to be passed at danger, with the exception of a signal failure, but happy to be corrected.
It’s more hypothetically. As I understand it (happy to be corrected) under token working trains can be authorised to pass a signal at danger for shunting purposes but with staff working they cant.
I thought that’s why it’s one train working with staff to Kirkby. Once the train is onto the single line the signaller has no control over when the train will return, therefore they cannot have another train on the single line.
 

MarkyT

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No, they were not. The Scottish Tokenless Block is fundamentally and radically different from the others. The WR and BRB systems were designed to allow automatic acceptance, whereas the ScR system wasn't. A unique feature of the Scottish system is the 'shunting key', which is given to a driver to permit shunting into the single line. The Scottish system allows a signal box to switch out immediately after two trains have crossed in the loop, in effect putting them both in the same section but heading away from each other.
Thank you for the clarification. I have no personal experience of the Scottish variety at all. The switch-out feature with two in section heading away is clever. Is there any 'non-Scottish' TB in Scotland, identified differently in the SA?
 

Class 170101

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The Channel Tunnel is wrong. its showing 186mph for passenger and lower for Freight. I thought the speed was nearer 87mph (100kph)?
 

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