Ground frame for Ettinsmoor

[signalmaintainer]

I've posted a new entry on my blog (link below) regarding the design and construction of a ground frame for the quarry junction. I'd appreciate any feedback and insight anyone might care to offer!

 

Thanks!

[The Stationmaster]

Some pics might help with rodding run and crank layout (and does your drawing show the drive for the two point ends coming off different levers?)

 

 

 

 

And you should try to keep the drive from the rodding as near as possible at a right angle to the stretcher bar on the point.

 

[signalmaintainer]

Some pics might help with rodding run and crank layout (and does your drawing show the drive for the two point ends coming off different levers?)

 

Thanks much for the excellent reference photos, Stationsmaster. In answer to the question, I am showing two different levers, one for each point, and I will incorporate an EFPL for the main turnout.

 

And you should try to keep the drive from the rodding as near as possible at a right angle to the stretcher bar on the point.

 

I see I need to make an adjustment in the rodding alignment to the trap points stretcher bar. Perhaps a gentle arc in the 4-yard run would suffice?

[The Stationmaster]

Thanks much for the excellent reference photos, Stationsmaster. In answer to the question, I am showing two different levers, one for each point, and I will incorporate an EFPL for the main turnout.

You use a single lever to work both point ends and drive them off the same rod - if you look at the middle picture you can see (behind the detector box) how the drive is taken off the rod to work the crank for the nearer, mainline, point end. Note too (although not too clear) how the drive for the FPL lies parallel to the rails in the four foot.

 

I see I need to make an adjustment in the rodding alignment to the trap points stretcher bar. Perhaps a gentle arc in the 4-yard run would suffice?

No, the rodding should run parallel to the line it lies adjacent to. What you should do is take it under the nearer track at a right angle to that track then onto a special crank which is used to change the angle. The crank is straight and pivoted at one end with the rods attached opposite each other (to avoid any loss or gain of motion) at the other end so seen from above the set up looks like a capital 'T' with an angle change in the top bar. Alas I haven't got a pic of one of those cranks unless it's hiding among older stuff.

[signalmaintainer]

You use a single lever to work both point ends and drive them off the same rod - if you look at the middle picture you can see (behind the detector box) how the drive is taken off the rod to work the crank for the nearer, mainline, point end.

That would be the shorter rod, to the right of the detector, which is attached to the main rodding via the four bolts, I take it. OK, this is making things a bit simpler re: rodding coming from the ground frame hut.

 

No, the rodding should run parallel to the line it lies adjacent to. What you should do is take it under the nearer track at a right angle to that track then onto a special crank which is used to change the angle. The crank is straight and pivoted at one end with the rods attached opposite each other (to avoid any loss or gain of motion) at the other end so seen from above the set up looks like a capital 'T' with an angle change in the top bar. Alas I haven't got a pic of one of those cranks unless it's hiding among older stuff.

I think I can envision what you're saying. Perhaps there's a drawing of this type of crank in the Leonard P. Lewis book Railway Signal Engineering (Mechanical).

 

Appreciate the time and insights, Stationmaster!

[Eggesford box]

Hi,

at Calvert there is a lever for each end of the points though in this case what would be the trap point ends are extended to form shunt necks. The GFs use the LNWR stirrup catch handle type levers and I believe it was common practise on the LNWR to use a seperate lever for each end of a crossover in signalboxes. Was this also common practise on GFs? Incidentally, Calvert is on what was the Great Central, I suppose the GFs where put in when the line was part of the LM region. I do not know how common the use of EFPLs would be on a GF, certainly the ones at Calvert have seperate FPL levers. I will post a photo from when I next get out there. Perhaps someone more in the know could advise on the above?

 

Having said that,I would agree that a single lever for both point ends is more common practise

[beast66606]

Hi,

The GFs use the LNWR stirrup catch handle type levers

 

SK(etch)80 levers - very suitable for ground frame use.

 

and I believe it was common practise on the LNWR to use a seperate lever for each end of a crossover in signalboxes.

Was this also common practise on GFs?

 

No more, or less than other companies really. Depends on distances involved, locking requirements, and how smooth the rodding run is (i.e is it possible to actually move two point ends from the lever)

[LNERGE]

Some pics might help with rodding run and crank layout (and does your drawing show the drive for the two point ends coming off different levers?)

 

 

 

 

And you should try to keep the drive from the rodding as near as possible at a right angle to the stretcher bar on the point.

 

 

Good grief. The only thing stopping the key being extracted with the FPL lever reversed is a shallow notch in the quadrant?

[The Stationmaster]

Good grief. The only thing stopping the key being extracted with the FPL lever reversed is a shallow notch in the quadrant?

I think it's an idea the GW copied from lesser railways (actually the frame is a preservation era one of course and I don't know where it came from. Although I have seen a couple like it over the years it was a very unusual pattern for the Western.) And of course the locking also holds the FPL lever in reverse if the point lever is not standing normal.)

[Eggesford box]

 

Some photos of Calvert South GF. The point ends are not far apart and the line is straight so presumably one lever could have been used to move both point ends. In this case one end forms a shunt neck instead of just trap points. The GF uses lug locking, simple but effective. Also some shots of the rodding run. Seperate FPL though. I believe the Midland where fond of EFPLs and I think the only one remaining in this country now is at Appleby on the Settle and Carlisle. I know there was a bit in Railnews a while back of it being brought back into working order.

[signalmaintainer]

Many thanks, Eggesford box! This will help greatly.

[signalmaintainer]

I've posted a revised ground frame rodding template on the blog. I haven't been able to find a definitive drawing on the special crank to whichThe Stationmaster refers, so I've left it undefined in shape for now.

 

As always, feedback is welcome!

[TheSignalEngineer]

I had a look at the blog, but the pushes and pulls don't show up very well on my screen. The first attempt the trap appeared to be lying for the running position rather than throw off, and the second is indistinct.

 

The trap should normally lie for the throw off with the cross rod being a push to move it to the running side. If the track is laid could you post a definitive 'aerial photo' to get the exact relationship? That would make it easier to get the rodding run correct, if not have you got a clearer scan?

[signalmaintainer]

I had a look at the blog, but the pushes and pulls don't show up very well on my screen. The first attempt the trap appeared to be lying for the running position rather than throw off, and the second is indistinct.

 

The trap should normally lie for the throw off with the cross rod being a push to move it to the running side. If the track is laid could you post a definitive 'aerial photo' to get the exact relationship? That would make it easier to get the rodding run correct, if not have you got a clearer scan?

You're right, in the first attempt I did have the trap set for the running side; the second drawing corrects this. When I return home in two weeks I'll shoot an "aerial" -- which in hindsight is what I should have added to the blog.

[Eggesford box]

Hi,

being back at Calvert the other day to do some minor remedial work (hence the saw and lopers) my visit coincided with the arrival of a train for the sidings so I though the photos of the frame released may be of interest

Slightly off the subject but the engraving on the token is slightly unusual being;

 

AYLESBURY VALE

__________

 

CLAYDON LINE

 

Normally the engraving shows the section limits, Aylesbury Vale being at one end of the token section. What I suspect is that their was some confusion when the tokens where engraved as the signal box at the other end of the section is Claydon LNE Jc (as in London & North Eastern). Aylesbury Vale is under the control of Marylebone IECC.

 

Further off post still but a little to the south is the site of Grendon Underwood Jct. The connection to the UKF depot at Akeman Street (and before that the link to Ashendon Jct) has long been lifted but sitting in splendid isolation the FPL remains.

[signalmaintainer]

I've been contemplating discarding the ground-frame hut and going with an exposed platform instead, and the above photos from you just sealed the deal! Thanks for taking the time to shoot and post them.

[The Stationmaster]

Further off post still but a little to the south is the site of Grendon Underwood Jct. The connection to the UKF depot at Akeman Street (and before that the link to Ashendon Jct) has long been lifted but sitting in splendid isolation the FPL remains.

It's a few years since I went down to Akeman Street from there (on an Inspection Special in 1992 - the chap who specified the itinerary was an past expert at planning railtours and I suspect that was the only reason we went down there!).

[LNERGE]

Hi,

being back at Calvert the other day to do some minor remedial work (hence the saw and lopers) my visit coincided with the arrival of a train for the sidings so I though the photos of the frame released may be of interest

Slightly off the subject but the engraving on the token is slightly unusual being;

 

AYLESBURY VALE

__________

 

CLAYDON LINE

 

Normally the engraving shows the section limits, Aylesbury Vale being at one end of the token section. What I suspect is that their was some confusion when the tokens where engraved as the signal box at the other end of the section is Claydon LNE Jc (as in London & North Eastern). Aylesbury Vale is under the control of Marylebone IECC.

 

Further off post still but a little to the south is the site of Grendon Underwood Jct. The connection to the UKF depot at Akeman Street (and before that the link to Ashendon Jct) has long been lifted but sitting in splendid isolation the FPL remains.

 

Firstly i can't believe how overgrown Calvert has become. My visit many years ago to Grendon Underwood Junction coincided with a significant downpour and now if we refer to the location as Grendon Underwater Junction. The remaining crank on the FPL assembly is normally associated with a facing point lock bar. I have seen a few places where this type of crank has been incorrectly used on an FPL. A modern version of the correct crank can be seen in your picture of the Calvert ground frame. Super pictures.

[signalmaintainer]

I've been contemplating discarding the ground-frame hut and going with an exposed platform instead, and the above photos from you just sealed the deal! Thanks for taking the time to shoot and post them.

 

Well, so much for sealing the deal about an exposed ground frame.

 

It's back to Plan A: a recent RM author just broached the idea with me that due to Cumbria's rain fall, a groundframe hut should be reconsidered. And I think he's right. So, the repurposed Skaledale ready-to-plonk level-crossing hut is back in business: