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Tunnel signals and gongs

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Tunnel signals and gongs

Unread postby colin1501 » Thu Dec 28, 2017 5:19 pm

I have been reading about tunnel signals and gongs on a couple of old threads on this forum (specifically in connection with the up outer distant at Blea Moor, and the down home at Dainton Tunnel), and had a couple of questions about gongs. For example, did the gongs sound continuously when the relevant signal was on, or were they 'approach controlled' in some way by the train, perhaps by activation of a treadle?

Also, I wondered just how audible gongs were, given that noise levels on a steam locomotive footplate in a tunnel must have been significant.

Grateful for any information.

Colin
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Re: Tunnel signals and gongs

Unread postby Chris Osment » Thu Dec 28, 2017 7:21 pm

colin1501 wrote:For example, did the gongs sound continuously when the relevant signal was on....


I would doubt that, otherwise - assuming that the signals would normally be 'on' - they would be sounding about 95% of the time :-)
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Re: Tunnel signals and gongs

Unread postby Ashley Hill » Thu Dec 28, 2017 8:01 pm

We have a gong of unknown origin in store on the SDR. It's a single stroke gong. Pulling the lever would pull the wire which lifts a spring loaded latch with the hammer attached. At the end of its stroke the latch releases and sounds the gong. A returning spring returns the latch. It's about 8" in diameter and to be honest not that loud. Probably more of a shunting gong if anything.
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Re: Tunnel signals and gongs

Unread postby RDNA » Thu Dec 28, 2017 10:12 pm

colin1501 wrote:I have been reading about tunnel signals and gongs on a couple of old threads on this forum (specifically in connection with the up outer distant at Blea Moor, and the down home at Dainton Tunnel), and had a couple of questions about gongs. For example, did the gongs sound continuously when the relevant signal was on, or were they 'approach controlled' in some way by the train, perhaps by activation of a treadle?

Also, I wondered just how audible gongs were, given that noise levels on a steam locomotive footplate in a tunnel must have been significant.

Grateful for any information.

Colin


I've extracted this from the 1960 LMR Midland Lines sectional appendix -

"GONGS IN TUNNELS
Gongs are fixed in the undermentioned tunnels for the purpose of warning Drivers that they are approaching the distant signal. If a Driver does not hear the gong sound, he must give information of the failure at his first stopping place, and the Station Master there must immediately wire the station nearest the gong. An examination of the gong must at once be made, and if there is any failure of the apparatus, the Signal Engineer's Department must be wired.

Totley - Down - 30 yards before reaching outer distant signal for Grindleford Station box.
St. John's Wood - Down - 75 yards before reaching Signal D.23.
Catesby - Up - 100 yards before reaching outer distant signal for Charwelton.
Victoria Street - Up - 100 yards before reaching home signals for Weekday Cross Jn.
Victoria Street - Down - 100 yards before reaching home signal for Nottingham Victoria South.
Mansfield Road - Up - 100 yards before reaching home signal for Nottingham Victoria North."

So far as I know these gongs were normally mechanically operated by treadle, regardless of the signal position/aspect.

They were to guard against drivers losing awareness of their location in possibly smoke filled tunnels.

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Re: Tunnel signals and gongs

Unread postby colin1501 » Thu Dec 28, 2017 10:23 pm

Thanks Dave - that all makes complete sense to me.

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Re: Tunnel signals and gongs

Unread postby StevieG » Thu Dec 28, 2017 11:05 pm

In case of interest colin1501, I think there was a mechanical 'gong' such as RDNA describes (which therefore must have sounded as each wheel passed over the treadle, so being audible to everyone in passenger trains as they passed) in Birmingham - I believe on the GW's Down, 'at' the exit of Snow Hill tunnel, I think to alert of the approach to the SH South box, Down Home (which must've been just inside or immediately outside the tunnel? - Others will know more I'm sure).
I believe it was alternatively well known as the 'Snow Hill clapper'.

Also, about the railway use of the term 'gong' (but not specifically relating to tunnels), aside from 'gong' block bells in signal boxes, and what sounds like the type of gong which Ashley Hill describes*, there have also been examples of what may have been called in some areas, trembler gongs (also known as trembler bells); - electric plunger-operated from SBs, to alert staff on/controlling regular set back shunt moves where the controlling signal was difficult to see for any of several reasons; and, where covered by local instruction, would be used by signalmen to give audible confirmation of either that the signal(s) for the move is 'Off', or additionally, authorise the movement to commence.
Similar bells (or, 'gongs') were also used, track circuit-operated, as automatic train approach warnings for track staff working between trains where approach views were poor.

* - [of which I have known examples on station platforms and at ground frames, and worked from SB lever frames by lever, often one coloured green, (one pull of which produces one 'clang': Also in SBs for return communication from GFs). Another use of same has been on some signals left 'off' for continual shunting, where replacement of said signal to Danger caused the gong to sound once, to hopefully alert shunting staff/drivers that the signalman had put the signal back.]
BZOH

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Re: Tunnel signals and gongs

Unread postby John Hinson » Fri Dec 29, 2017 6:26 am

colin1501 wrote:I have been reading about tunnel signals and gongs on a couple of old threads on this forum (specifically in connection with the up outer distant at Blea Moor, and the down home at Dainton Tunnel), and had a couple of questions about gongs. For example, did the gongs sound continuously when the relevant signal was on, or were they 'approach controlled' in some way by the train, perhaps by activation of a treadle?

Also, I wondered just how audible gongs were, given that noise levels on a steam locomotive footplate in a tunnel must have been significant.

I think the gong at Blea Moor sounded whether the signal was on or off, as a marker for the ground-mounted colour-light signal. Perhaps it wasn't very satisfactory as the signal and gong were later removed and replaced by a banner distant repeater at the entrance to the tunnel.

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Re: Tunnel signals and gongs

Unread postby scarpa » Fri Dec 29, 2017 6:13 pm

Goods and Mineral Junction operated an electric bell in the Down Goods Copenhagen tunnel by means of a plunger on the block shelf to indicate to the driver when the signal was off outside the tunnel.
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Re: Tunnel signals and gongs

Unread postby left » Sat Dec 30, 2017 4:44 am

As for audibility, in a steam locomotive, even in the loudest moments, you can “easily” hear each other if you scream. So I guess that a loud gong could be perfectly audible. Even more if, as it has been said, each axle operated the gong.
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Re: Tunnel signals and gongs

Unread postby colin1501 » Sun Dec 31, 2017 8:44 am

Thanks to all for the helpful responses on this - I now understand it all clearly. Essentially the purpose of the gong was to alert locomotive crews to their location, so that they would not (or should not) miss sighting the signal.

Colin
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Re: Tunnel signals and gongs

Unread postby JRB » Sat Jan 6, 2018 9:49 pm

The Snow Hill mechanical gong achieved fame when a well known (name?) performer did railway imitations on a popular 10" 78 rpm record and included it. He didn't explain it other than as a noise heard on that move.
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Re: Tunnel signals and gongs

Unread postby StevieG » Sun Jan 7, 2018 6:20 pm

JRB wrote:The Snow Hill mechanical gong achieved fame when a well known (name?) performer did railway imitations on a popular 10" 78 rpm record and included it. He didn't explain it other than as a noise heard on that move.
Reginald Gardiner ?
BZOH

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Re: Tunnel signals and gongs

Unread postby JRB » Mon Jan 8, 2018 3:53 pm

Very probably.
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Re: Tunnel signals and gongs

Unread postby Ashley Hill » Tue Jan 9, 2018 2:06 am

https://youtu.be/WJAzJdsWa3E

Could this be the Mr Reginald Gardiner of which you speak?
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Re: Tunnel signals and gongs

Unread postby JRB » Tue Jan 9, 2018 9:02 am

Yes, that's it.
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