Mystery apparatus at Radstock

John Palmer
Posts: 575
Joined: Fri Jul 15, 2011 11:09 pm

Mystery apparatus at Radstock

Postby John Palmer » Thu Mar 07, 2019 11:22 am

Having been delighted by the discovery that 223 of Ron Toop's S&D photographs have been put online at https://www.flickr.com/photos/midsomer-norton-south-station/sets/72157629882634822/page1, I've been poring over a particular favourite shot of mine taken from Tyning's Incline at Radstock, and noticed a mystery artefact the purpose of which I should be pleased to see explained. Here is an extract from the photograph which I have annotated to identify the artefact in question, and its position relative to various railway features.
Mystery apparatus at Radstock East.jpg

The location is immediately adjacent to Tyning Colliery batch (spoil heap) and thus well within North Somerset Coalfield territory. I mention this due to the possibility that the apparatus is related to coal mining activity in the area, but I think it is more likely that it forms part of the signalling installation. Two such possible applications occur to me, but I'll keep them to myself for the moment in the hope that some erudite contributor can state authoritatively what this apparatus is.

User avatar
Rod Cameron
Posts: 654
Joined: Fri Jul 25, 2008 12:01 pm

Re: Mystery apparatus at Radstock

Postby Rod Cameron » Thu Mar 07, 2019 1:10 pm

Ivo Peters' tripod?
Rod

User avatar
BryanJohnson
Posts: 97
Joined: Wed Jul 23, 2008 7:45 pm

Re: Mystery apparatus at Radstock

Postby BryanJohnson » Sat Mar 09, 2019 8:11 pm

I passed this query on to to a friend with an interest in the S&D, who in turn circulated it around an S&D group. I offer the following response from a retired S&T engineer in that group.

"It is a Gainstroke Lever, used where there is an excessive pull of wire to a remote signal. It is usually employed on a Distant signal which can be up to a mile away from the box.
They are usually installed mid-way between the box and signal. I have known this to vary where there is sometimes curvature of the line. A case in point is one on the Crewe Shrewsbury line at Wem on the Distant signal reading towards the Crewe direction from Salop.

It works on the basis of a very long vertical crank, the wire from the box direction is terminated at this point higher up the crank. A new wire is made off lower down the crank and continues to the signal. The difference between the two terminations gives extra stroke or travel hence its name of Gainstroke. Because of the weight and length of the wire a weight is usually added to the other end of the crank arm to take up the slack in the wire."

RedDragon
Posts: 68
Joined: Tue Apr 28, 2009 7:17 pm

Re: Mystery apparatus at Radstock

Postby RedDragon » Sat Mar 09, 2019 9:24 pm

There does not seem to be any connection between the point rodding run that seems to be unbroken between the rodding stools either side of the outlined device. Enlarging the image shows no evidence of a cable run operating the device and connected at different points to the device providing the additional leverage force ?

User avatar
Will L
Posts: 1665
Joined: Sun Jul 20, 2008 3:54 pm

Re: Mystery apparatus at Radstock

Postby Will L » Sat Mar 09, 2019 11:05 pm

RedDragon wrote:There does not seem to be any connection between the point rodding run that seems to be unbroken between the rodding stools either side of the outlined device.

Why mention the point rodding there was no suggestion these were convected?
Enlarging the image shows no evidence of a cable (I assume you mean wire) run operating the device and connected at different points to the device providing the additional leverage force ?

On the contrary, there is a very obvious set of the pullies used to support signal wires right next to the point rodding and in line with the mystery device. I'm not surprised the wires themselves don't show in the image, the stay wires in the picture are much thicker and they are not that clear.

Edited to remove the predictive text take on the world (spelling)
Last edited by Will L on Sun Mar 10, 2019 8:48 am, edited 1 time in total.

John Palmer
Posts: 575
Joined: Fri Jul 15, 2011 11:09 pm

Re: Mystery apparatus at Radstock

Postby John Palmer » Sun Mar 10, 2019 2:09 am

BryanJohnson wrote:I passed this query on to to a friend with an interest in the S&D, who in turn circulated it around an S&D group. I offer the following response from a retired S&T engineer in that group.

"It is a Gainstroke Lever, used where there is an excessive pull of wire to a remote signal. It is usually employed on a Distant signal which can be up to a mile away from the box.
They are usually installed mid-way between the box and signal. I have known this to vary where there is sometimes curvature of the line. A case in point is one on the Crewe Shrewsbury line at Wem on the Distant signal reading towards the Crewe direction from Salop.

It works on the basis of a very long vertical crank, the wire from the box direction is terminated at this point higher up the crank. A new wire is made off lower down the crank and continues to the signal. The difference between the two terminations gives extra stroke or travel hence its name of Gainstroke. Because of the weight and length of the wire a weight is usually added to the other end of the crank arm to take up the slack in the wire."

Thank you, Bryan, I think we have a winner!

A gainstroke lever was one of the two applications I had in mind when composing my original post, the other being the possibility of this being a wire slot for Writhlington Up Distant, which is mounted beneath Radstock East Up Starting signal. However, I've never come across such a slotting arrangement in LSWR/SR practice, which seems to have followed the conventional arrangement of grouping levers on the post/mast to form the slot.

A gainstroke lever at this location makes good sense on the basis that it multiplied the the pull on Radstock West's (S&D) Down Distant, which was mounted beneath Writhlington's Down Advanced Starting signal, a distance of 1609 yards from the West box. I must admit that I'd been thinking in terms a device to multiply the pull on an East box lever, but it was your correspondent's reference to its installation at the mid-point of the run that prompted me to look at its possible application to a lever in the West box. I haven't checked the distances involved, but know that the apparatus isn't far removed from the mid point between West box and its Down Distant signal.

Incidentally, I offer for consideration the possibility that, rather than being a simple lever, this is a gainstroke wheel and that the wheel itself can be seen in the photograph about one-third of the way up its mounting post. In this configuation, the pull from the signal box lever is taken to the centre of the wheel, with the wire onward to the signal having one end anchored locally to the wheel and being then passed around the circumference of the wheel in order to provide the required mechanical advantage.

As to Ivo's tripod, I'm a little curious as why there are so few shots of Radstock in his published work. For whatever reason he seems not to have favoured the location, so it's probably one of the places on the Bath Extension where his tripod is least likely to have been planted.

essdee
Posts: 380
Joined: Sat Nov 29, 2008 4:47 pm

Re: Mystery apparatus at Radstock

Postby essdee » Sun Mar 10, 2019 11:39 am

John,

I am delighted to find that I now have to model yet another detail in my proposed 'north from Tyning' opus......!

Seriously, some very useful detective work from fellow SDRT Northern Group member Mel Roberts, via Bryan Johnson - so thanks to all. I have checked through my Radstock collection, and cannot find another depiction of this item, so thanks to Ronald Toop too.

No, I will not be making a working version.

On Ivo's absence hereabouts, yes an enormous shame - I bet he would have taken a view showing the north end of the goods shed, so sparsely covered in the record. Chris Handley and I did discuss this omission when we were working on the 'Radstock Coal and Steam' volumes thirty+ years (!) ago. Chris had actually spoken to Ivo, who admitted he was not a fan of grubby industrial environments (as opposed to the granduer/rurality of Welsh slate quarries or Jurassic ironstone lines along field edges). This is (sub?)consciously emphasised in the sub-title of his first OPC S&D album 'an English Cross Country Railway' ? Ivo undoubtedly begrudged time amid the pit batches when he could be motoring out to so many other splendid S&D locations. Still, a great shame, especially for those of us of the Radstock persuasion. Which I see now includes our esteemed Editor, effectively?!

See you at Wakefield? The last non-SDJR product is just now rolling out of Highbridge Works Export Division.

Steve

John Palmer
Posts: 575
Joined: Fri Jul 15, 2011 11:09 pm

Re: Mystery apparatus at Radstock

Postby John Palmer » Sun Mar 10, 2019 3:32 pm

Steve, thanks for identifying Mel Roberts as the ultimate source of the information about the gainstroke device and, of course, my thanks too to Mel himself for this.

Having taken a look at other S&D signalling layouts I have formed the view that Radstock West Down Distant must have been the longest manual pull on the Joint Line. The distance from the box of this signal was probably only exceeded on the S&D by Templecombe No.2 Junction Down Distant after closure of No.3 Junction box (in about 1933 I think?). This Distant stood about 2600 yards from No.2 Junction box but, in its later years at any rate, was power worked. No surprise, then, that a gainstroke device was found necessary for the Radstock Distant.

I well remember how eagerly we S&D Circle members working at Radstock looked forward to publication of 'English Cross Country Railway' and its arrival at Wightman's Bookshop in Bath. In general we weren't disappointed but I think Ivo missed a few tricks by not pointing his lens at the Radstock attractions more frequently.

Yes, my plans for Wakefield have been laid - another outing for the amazing technicolour blazer may be in prospect.

dal-t
Posts: 625
Joined: Mon Jan 11, 2010 8:06 pm

Re: Mystery apparatus at Radstock

Postby dal-t » Mon Mar 11, 2019 8:45 pm

Feeling ever so slightly 'smug' that my intuitive 'guess' was what it turned out to be, despite failing to find any documentary evidence to support my feeling, which held me back from posting before the experts had spoken. But I am now fretting (a habit I seem completely unable to shake) over where I could have come across such a device previously in order to recognise it, even if hazily. One thing is sure, it could not have been Radstock, so it looks like I'll be poring over 1950s maps to try and spot a long-range distant somewhere (not so) near one of my old spotting sites ...
David L-T


Return to “Semaphore Signals”

Who is online

Users browsing this forum: No registered users and 2 guests