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Return of banner repeaters to on (and PRIs to blank)

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Return of banner repeaters to on (and PRIs to blank)

Unread postby John Prytherch » Fri Mar 10, 2017 12:25 am

I have noticed that some modern LED type banner repeaters restore to "On" as soon as the train has begun to pass them, whereas others remain off until the signal itself has gone back.

This is noticeable at Manchester Deansgate where the new, gantry mounted, banner repeater for up signal MC 458 restores to "on" as soon as the train has passed it; the signal does not of course go back until the train has passed it, often after a station stop.

But on the down, the new banner repeater for MC 461, and the preliminary route indicator arrow, remain respectively "off" and illuminated until the signal itself has restored to "on" after the passage of the train. So they are giving clear indications behind the train while it makes its Deansgate station stop. I know this is not in the least dangerous, because everything is protected by signal 455. But just out of curiosity, I wonder why there seem to be different standards about the time at which these things restore.

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Re: Return of banner repeaters to on (and PRIs to blank)

Unread postby Mike Hodgson » Fri Mar 10, 2017 10:00 am

This does not sound to me like a difference in standards so much as a difference in the track circuiting arrangements in particular locations and the perpetuation of traditional practice.

Mechanical banners generally stayed off until the signal repeated was restored - being worked by the same lever and wires.
When electrical banners were used, that created (for free) the ability to restore after the train had passed them provided there happened to be separate track circuits before and after the banner. If banners are so restored, doing so improves safety marginally by effectively showing a more restrictive aspect in the event of another train following improperly. But that advantage is so marginal it would not justify the cost of putting in an additional TC just to achieve it.
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Re: Return of banner repeaters to on (and PRIs to blank)

Unread postby MRFS » Fri Mar 10, 2017 10:33 am

I noticed the same (well, I *think* I noticed the same) at Rochester New station the other night. I shall be going over to ring at the other cathedral again soon, so I shall have a look out.
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Re: Return of banner repeaters to on (and PRIs to blank)

Unread postby DY444 » Sat Mar 11, 2017 12:07 pm

Iirc there was an issue at Basingstoke after resignalling with a platform mounted banner being restored when the train passed it giving the impression to the guard that the platform signal (which the guard couldn't see) was at Danger. I think it was subsequently changed so that the banner was only restored when the signal went back to danger.
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Re: Return of banner repeaters to on (and PRIs to blank)

Unread postby Bob Davies » Sat Mar 11, 2017 6:21 pm

DY444 wrote:Iirc there was an issue at Basingstoke after resignalling with a platform mounted banner being restored when the train passed it giving the impression to the guard that the platform signal (which the guard couldn't see) was at Danger. I think it was subsequently changed so that the banner was only restored when the signal went back to danger.

The same applied to one at East Croydon Platform 3 when it was put on to Three Bridges but we spotted that during the commissioning weekend and changed it before anyone complained.
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Re: Return of banner repeaters to on (and PRIs to blank)

Unread postby RobMorel » Sun Mar 12, 2017 11:49 am

Up slow platform at St Albans (city) has a banner repeater WH268 BR tht does the same, with block joint visible ahead on outside rail
This gives the appearance to other trains on the up fast or platform dispatch staff working on approach to signal dealing with 12 car trains that the up slow service is 'starting against a red signal when actually WH268 is displaying a proceed aspect but the banner has returned to 'on' the moment the leading end of the movement has passed it......
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Re: Return of banner repeaters to on (and PRIs to blank)

Unread postby scarpa » Mon Mar 13, 2017 12:13 am

A decade or two ago on resignalling schemes in order to economise on track circuits and controls Banners and Distants were sometimes directly controlled through the stop signal ahead. I believe on recent schemes track circuit control is favoured so there is no confusion and I wonder if designers consider what if a train SPADS the signal in rear a traindriver would see a banner Off or a Green aspect.What would also be misleading if a train failed between Distant and Home the Distant or banner would still be showing an Off aspect. An assisting train in the rear although proceeding at caution would see Off aspects.
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Re: Return of banner repeaters to on (and PRIs to blank)

Unread postby John Webb » Mon Mar 13, 2017 9:14 am

RobMorel wrote:Up slow platform at St Albans (city) has a banner repeater WH268 BR tht does the same, with block joint visible ahead on outside rail
This gives the appearance to other trains on the up fast or platform dispatch staff working on approach to signal dealing with 12 car trains that the up slow service is 'starting against a red signal when actually WH268 is displaying a proceed aspect but the banner has returned to 'on' the moment the leading end of the movement has passed it......

Don't the dispatch staff also have 'OFF' indicators? (It's been a while since I travelled from St A City, I have to admit!)
I assume WH268BR is so sited for the benefit of ECS leaving the turnback siding?
On the Down lines at St A City the two BRs, sited just before the start of the platforms, revert to ON after about 4 coaches have passed them.
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Re: Return of banner repeaters to on (and PRIs to blank)

Unread postby RobMorel » Mon Mar 13, 2017 7:03 pm

Correct, central 'CD - RA' dispatch position has illuminated WH268 ' off ' light (under Victoria Road Bridge) but it is a strange sight seeing 12 car dispatcher towards Bedford end of platform raise dispatch bat when Banner is On
http://bed-pan.homestead.com/377319turnbacks.JPG
and just to confuse things here is an up train moving in down direction and down train moving in up direction!, Banner can be seen on left before footbridge.
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Re: Return of banner repeaters to on (and PRIs to blank)

Unread postby John Prytherch » Tue Mar 14, 2017 11:32 pm

I recall writing something in this forum about two years ago, after the Stalybridge resignalling, where on the Down Huddersfield at the end of Platform 4 there is a very prominent banner repeater for SE 7043 which returns to "on" as soon as the front of the train has passed it. But there is also a platform "off" indicator which remains illuminated until the actual signal restores, some time later. I re-thank the member of this forum who kindly taught me that an "off" indicator is not a signal!

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Re: Return of banner repeaters to on (and PRIs to blank)

Unread postby JG Morgan » Sun Mar 19, 2017 8:28 pm

It always strikes me as odd to see the "banner repeater" mid-way along Ebbsfleet platform 5 (up Gravesend line) showing ON when there's a train in the platform and the platform-end up signal is OFF. (There's a good view of both from the car pick-up / drop-off area).
Many readers of this Forum will remember the collisions / near-misses in the 1970s / 80s when the guard or platform staff gave the "Right Away" and the driver proceeded, without checking the platform starter signal. I suppose with the introduction of TPWS, any such error would result in the train being stopped before a point of conflict, so the risk is considered negligible.
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Re: Return of banner repeaters to on (and PRIs to blank)

Unread postby StevieG » Sun Mar 26, 2017 12:24 am

Regarding platform Banner repeaters versus 'OFF' indicators, various persons' opinions over many years left the distinct impression that, where needed because of sighting problems, Banners are intended for Drivers, and 'OFF's are for train despatch staff (guards, platform staff, etc. : Hence, in some locations, the provision of both), though I couldn't say whether modern standards might have introduced some degree of flexibility between which are used in what circumstances, and that some situations may have resulted in the provision of one informally becoming relied on as if the other.

One modern demonstration of the 'principle' in some modern times, is where, at terminal platforms with suitably divided track circuits, and where the starting signal is visible from neither driving cab positions of short trains, nor from some platform dispatch staff points (typically where CD / RA indicator operation equipment is located), and so both Banner and 'OFF's are provided, that if the front of a long train stands beyond such a Banner before even moving, the Banner remains at 'ON' throughout, but the 'OFF' indicator(s) still illuminate while the main starting signal is 'Off'.

JG Morgan wrote: " .... Many readers of this Forum will remember the collisions / near-misses in the 1970s / 80s when the guard or platform staff gave the "Right Away" and the driver proceeded, without checking the platform starter signal. I suppose with the introduction of TPWS, any such error would result in the train being stopped before a point of conflict, so the risk is considered negligible. "
AFAIR, the first measure to combat 'ding ding and away's was a Rule change requiring (in addition to Drivers observing platform starting signals), that dispatch staff (guard and/or platform staff) should also check signals before giving 'right away'.
On TPWS, just to clarify that, although TPWS TSS fitment is usually required at signals protecting points of convergence, crossing, or opposing direction moves, it is unlikely at signals protecting uni-directional plain line, and so a train starting past a red signal and entering a plain-line section still occupied by a preceding train may well not have TPWS present to stop it.
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