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Detonator placers

You are here: Home > Forum > Miscellaneous > The real thing (signalling) > Detonator placers

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Detonator placers 17/09/2019 at 18:53 #120453
Steamer
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Are there any Network Rail boxes which still have working detonator placers? The question occurred to me when I was at Garsdale last week- from what I could see through the window, there were two levers that were painted that way, but I couldn't see any on the track, and there didn't appear to be any rodding associated with them.

On the subject of detonator placers, were there any general rules requiring their use, other than in an emergency? I know there were local instructions (Exeter West being a case in point) mandating their use in specific circumstances, but were there any general requirements for using them? Or did signallers tend to use them regularly to protect moves, even if it wasn't a requirement?

For anyone unaware, detonator placers are worked from a lever in a mechanical box, and are used to place and remove detonators (small explosives placed on the rail to alert drivers to danger ahead) at a specific point. The levers are painted white with black chevrons.

"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)
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Detonator placers 17/09/2019 at 18:57 #120455
TUT
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Steamer in post 120453 said:
On the subject of detonator placers, were there any general rules requiring their use, other than in an emergency? I know there were local instructions (Exeter West being a case in point) mandating their use in specific circumstances, but were there any general requirements for using them? Or did signallers tend to use them regularly to protect moves, even if it wasn't a requirement?
One thing that might be of interest:

Number 20 lever in Banbury North signal box stated on its lever lead

"Crossing & detonator Dn. Bay & Dn. Main"

With 20 lever reverse the points would be set for a train to exit the Down Bay onto the Down Main and the dets would be lifted. When 20 points were returned to the normal position, the detonators were placed on the track simultaneously.

Or that's what I gather from the diagram and lever lead anyway,

Last edited: 17/09/2019 at 18:57 by TUT
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Detonator placers 17/09/2019 at 20:44 #120456
Stephen Fulcher
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That's correct. There wasnt room for conventional trap points there so the detonators were installed. 17 at the South was the same.

There was also a conventional detonator placer on one line until the North Box closed

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Detonator placers 17/09/2019 at 21:48 #120459
bugsy
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For those who don't know what they are (I didn't until I looked it up)
.......


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My goodness, that was difficult, but I managed it.
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Detonator placers 18/09/2019 at 09:19 #120463
kbarber
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I believe (but not quite sure where the information comes from, one of the many bits I've picked up, so some caution may be in order) that 'normal' det placers were abolished some years ago, perhaps even before I left the railway (1994). (In support of that, the motorised det placers at Stratford had been abolished by the early '90s.)

In situations like those at Banbury, it may be that det placers continue to be required. How many of those remain I really do not know, but it can't be many and may be none at all.

As far as I recall, there were never specific instructions beyond the requirement that they should be used as one possible means of stopping a train in emergency.

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Detonator placers 18/09/2019 at 10:25 #120464
Andrew G
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I've seen them required by the Signal Box Special Instructions at Corkickle No 1, Corkickle No 2 and St Bees when the respective single lines were worked by Acceptance Lever.

Corkickle No 2

St Bees

Returning to the Banbury reference here is a view of Banbury North's diagram which shows Detonators 20 normal position on the running line.

Banbury North Diagram

Last edited: 18/09/2019 at 10:26 by Andrew G
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Detonator placers 18/09/2019 at 12:53 #120471
clive
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kbarber in post 120463 said:
I believe (but not quite sure where the information comes from, one of the many bits I've picked up, so some caution may be in order) that 'normal' det placers were abolished some years ago, perhaps even before I left the railway (1994).
I'm sure I saw them at Selby later than that. I don't recall if they were still there when I was there a couple of years ago. Has the area been resignalled recently? That might be when it went.

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Detonator placers 18/09/2019 at 15:15 #120473
Giantray
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London Bridge ASC had detonator placers at several Signals up until just before the new century. They were used because overlaps ahead of the signal they were at, had very short overlaps (less that 50 yards). Locations I remember where Platform starter london end of Platform 6 at London Bridge and the Platform starter on the platfom on No 1 Down at New Cross. Obviously with the advent of TPWS train stop and overspeed sensors, where fitted there is really no need for a detonator placer for any scenario.
Professional Railwayman since 1981. Railway Historian (SER, LCDR)
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Detonator placers 18/09/2019 at 15:31 #120474
Ron_J
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There are none left on NR infrastructure in Scotland. Incidentally RSSB have just completed the testing phase of a major study into the audibility and effectiveness of detonators, with the initial results indicating they're more or less useless for their intended purpose these days. For those who have an account you'll find it on SPARK.
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Detonator placers 18/09/2019 at 17:45 #120477
jc92
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Giantray in post 120473 said:
London Bridge ASC had detonator placers at several Signals up until just before the new century. They were used because overlaps ahead of the signal they were at, had very short overlaps (less that 50 yards). Locations I remember where Platform starter london end of Platform 6 at London Bridge and the Platform starter on the platfom on No 1 Down at New Cross. Obviously with the advent of TPWS train stop and overspeed sensors, where fitted there is really no need for a detonator placer for any scenario.
I never knew panels had detonators available at all.

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Detonator placers 18/09/2019 at 18:11 #120478
Stephen Fulcher
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Ron_J in post 120474 said:
There are none left on NR infrastructure in Scotland. Incidentally RSSB have just completed the testing phase of a major study into the audibility and effectiveness of detonators, with the initial results indicating they're more or less useless for their intended purpose these days. For those who have an account you'll find it on SPARK.
A lot of preserved railways have abolished them on safety grounds.

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Detonator placers 19/09/2019 at 09:30 #120495
Giantray
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I find it hilarious that a safety device is abolished on safety grounds. When I was on the Permanant Way in the early 1980s, we used to have to provide a man to place detonators on the approach to a Warning Board for an Emergency Speed Restriction until it was published to train crews, two detonators. Wasn't a problem if the Warning Board was out, but before the boards were out you had to stand a short distance from the detonators displaying a yellow flag! Flags aren't used for Speed Restrictions now and Emergency Speed Restrictions have Emergency Speed Indicators prior to the Warning Boards and the addition of portable AWS Magnets at both which didn't exist back in the early 1980s.
Professional Railwayman since 1981. Railway Historian (SER, LCDR)
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Detonator placers 19/09/2019 at 16:19 #120504
Ron_J
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The issue is that they aren’t audible in modern train cabs, quite apart from the fact that we as an industry are still regularly killing staff who are placing protection.
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Detonator placers 19/09/2019 at 17:05 #120505
TUT
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I agree that once is too many, but I think you would have to admit that people are not being 'regularly' killed placing protection by any meaningful definition of the word 'regularly'.

I could be wrong, but I got the impression that one of the incidents (if not the incident) that prompted this review was the tragic incident at Stoats Nest Junction?

The poor gentleman who lost his life on that occasion was not killed placing protection. He was killed wandering onto an open line after placing protection

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Detonator placers 26/09/2019 at 04:42 #120620
Giantray
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It is very lucky that more have not been killed in placing detonator protection for Engineer's Possessions. Lost track of the number of times I have had trains on running lines run over detonators placed on open lines instead of the blocked lines, very lucky after the detonators were placed and not whilst the blockman is on the line placing the detonators!

My colleague was killed by a shunting movement due to complacency. A Possession had been taken every night from the same set of points, but on the last night it moved 40 chain further down the line to a signal to allow a shunt movement in the morning. Unfortunately my colleague placed his detonators at the same place they had been all week and when retrieving them in the morning didn't hear the shunt move propelling towards him. This was in 1990. I have no idea how many lives have been lost or near misses there have been since then, but they are all one too many. Detonators are an old 19th Century invention that really needs replacing with some 21 st Century method.

Professional Railwayman since 1981. Railway Historian (SER, LCDR)
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