Shunting in electric token block areas

[DavidBird]

I think you may have a couple of things conflated here. I'll try to summarise:

 

You are shunting into section if you pass *either* the section signal *or* the outermost Home for approaching trains.

 

If the outermost Home is in advance of the Section Signal then there may well be a local instruction prohibiting shunting into section.

 

If there are no local instructions otherwise, there are three ways of shunting into section.

 

1) By shunting behind a departing train. In this instance no bells are exchanged unless the other Signalman knocks out whilst the Section is obstructed, in which case the 2-1 is answered by 3-3 which the other Signalman acknowledges.

 

2) By blocking back.

 

3) By releasing a token.

 

In cases 1 and 2, if the shunt has to pass the Section Signal and that signal is interlinked with the token instruments, then self-evidently the shunt must be authorised to pass that signal at Danger.

 

In case 1 here, if for example a train has left A for B, and shunting needs to be done at A, when would the token be replaced in the machine at B?

Would it be after B's 2-1 is answered by 3-3, or would the token be kept by the signalman at B and only replaced after he then gets 2-1 (Train out of section or Obstruction Removed) from A?

[Ray H]

In the hope that I don't confuse the issue I presume the token is returned to the machine before the TOOS signal is sent by B otherwise - and this is purely my logical mind saying this - the indicator on the machine might still show blocked even though the TOOS signal has been sent.

 

Another reason why the token may be returned to the machine is that the Blocking Back doesn't normally warrant the token being removed for the movement so why would it need to be kept out?

 

I freely admit that I may be thinking along the wrong . . . .

[RailWest]

Do not forget that GWR key token machines had only manual indicators. Also IIRC the same principles applied to electric tablet and electric staff working.

 

Unlike 3-position block instruments for double-line working, with token/staff/tablet machines you can't simply turn an indicator to 'Train in Section' in order to record a 'Block Back' as they don't work like that. This is where good booking practice in the Train Register comes into play :-)

[The Stationmaster]

I would disagree. Although there were a lot of loops on the GWR with traps, in general they tended to be either for speeding up the services (eg the Barnstaple and Minehead branches), or for safety reasons such as severe gradients etc (and then more as a protection against 'break aways' on unfitted goods trains).

 

The Stationmaster may have other views? :-)

 

Not entirely 'RailWest'  - the big advantage of adding a trap point in advance of the signal controlling the exit from the loop at a crossing station was that it speeded up the process of crossing trains.  Where there were no such traps the normal procedure of stopping both trains at their respective Home Signal if two were approaching at the same time applied and they would then be allowed into their respective loop one after the other.  However if the loop was trapped this restriction didn't apply and apart from being checked at the Home Signal approaching trains could be allowed into their respective loops without one having to wait for the other if they arrived at about the same time.

 

Thus for example when the DN& S single line sections were upgraded, and loops extended, in WWII all - judging by signalbox diagrams - of the crossing loops were also provided with trapping at the same time.  it didn't affect acceptance conditions but it did speed up the crossing process.

 

Kevin's ('Nearholmer') point about the provision of Starting Signal is an interesting one.  The Cornwall Railway was possibly not alone in following exactly that course and providing only Distant and Home Signal at crossing stations however the lack of a Starting Signal was found to be a principal cause of the head-on collision on the single line between Menheniot and St Germans in 1873 and thereafter Starting Signals were required at crossing stations.  And of course once they were there they also provided a very clear indication to a Signalman of the position of the Clearing Point plus affording much greater safety when crossing trains.

[ForestPines]

In case 1 here, if for example a train has left A for B, and shunting needs to be done at A, when would the token be replaced in the machine at B?

Would it be after B's 2-1 is answered by 3-3, or would the token be kept by the signalman at B and only replaced after he then gets 2-1 (Train out of section or Obstruction Removed) from A?

Ray H is right here - the Signalman (at B in this case) must always replace the token in the instrument before sending Train Out Of Section.

[RailWest]

Ray H is right here - the Signalman (at B in this case) must always replace the token in the instrument before sending Train Out Of Section.

Correct.

 

Regulation 1 specifies that the token must be replaced in the instrument before the signalman (at B) sends 2-1 to A. Regulation 7(a)(ii) requires the signalman at A to send 3-3 to B if the line is still occupied outside the Home signal after receiving that 2-1.

[The Stationmaster]

In case 1 here, if for example a train has left A for B, and shunting needs to be done at A, when would the token be replaced in the machine at B?

Would it be after B's 2-1 is answered by 3-3, or would the token be kept by the signalman at B and only replaced after he then gets 2-1 (Train out of section or Obstruction Removed) from A?

 

Not quite like that.

 

When the train proceeding in the right direction arrives at B, in clear of the single line from A, the Signalman at B would place the token in his machine for the section A -B and send the Train Out of Section (2-1) bell signal to A.

 

If the shunt move at A is still outside the Home Signal (i.e. on the single line) the Signalman there would send the Blocking Back bell signal (3-3) to B and the Signalman at B would acknowledge it.

 

When the shunt move at A has returned within the protection of the Home Signal and clear of the single line the Signalman at A would send the Obstruction Removed (2-1) bell signal to B, and B would acknowledge it.

 

It should be noted that this is in accordance with the 1960 and 1972 Regulations and earlier Regulations  might differ slightly - for example the GWR 1937 Regulations have much more to say about 'special shunting tokens' although the procedure where they were not in use was basically the same as the 1960 & 1972 Regulations.  The GWR 1920 Regulation was slightly different again in that it started off by presuming the availability of a shunting staff or token but subsequently gave the procedure to be used where such staff/token were not in use - and again basically no different from the 1960 etc Regulations.

[St Enodoc]

If there are advanced starting signals and outer home signals then all shunting will take place within station limits and not the block section.

 

For example there is no need to get a single line token out or worry about blocking back at Sheffield Park thanks to the installation of an advanced starter (15) and an outer home (19) with 740 yards between them.

 

If however a shunt move has to take place past the outer home then either it must be done after the departure of a northbound service or a single line token will need to be issued.

 

In pre-preservation (or indeed the first few decades of Bluebell ownership) things were far simpler signalling wise and there were no such things as an advanced starter or outer home to facilitate shunting.

That's right Phil. In the 1970s it was necessary to take a staff (ETS in those days) to run round. That was easy mid-week when only one train was running but not so easy with a two-train service if the other train was in the section. I think that this was one of the reasons why the "pull off" along the Newick spur was used instead of running round per se.

[Martin Shaw]

Hi St Enodoc

You and I probably know each other, I was often signalman at Sheffield Park at that time. I remember well bell codes 5-2, release staff for shunting, and 2-5 shunt withdrawn. This was I feel prior to the installation of the outer home and advance started at SP. No doubt If I ploughed through BNews for the time I could date the events. The pull off down the Newick spur was to retain some semblance of a timetable on summer sundays because you couldn't round via the single line. It was a long time ago.

Regards

Martin

[St Enodoc]

Hi St Enodoc

You and I probably know each other, I was often signalman at Sheffield Park at that time. I remember well bell codes 5-2, release staff for shunting, and 2-5 shunt withdrawn. This was I feel prior to the installation of the outer home and advance started at SP. No doubt If I ploughed through BNews for the time I could date the events. The pull off down the Newick spur was to retain some semblance of a timetable on summer sundays because you couldn't round via the single line. It was a long time ago.

Regards

Martin

Yes, it was definitely before the outer home and advanced starter were installed Martin - 1973/4 to be precise. I used to spend two weeks of the school holidays at the Bluebell and on mid-week days often carried out a number of jobs at once as there weren't enough people around. I thought the codes were 5-2 and 2-5 but couldn't be certain so I didn't mention them. After I left school I moved away from the South so my active participation stopped but I am still a BRPS member.

 

Remember the good old "no signalman" release for the staff at the Park? I would love to see those ETS instruments back in use one day. I think I could still manage that combined flick and roll of the wrist even after more than forty years.