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Ground Frame Set up

You are here: Home > Forum > Miscellaneous > The real thing (signalling) > Ground Frame Set up

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Ground Frame Set up 18/04/2011 at 19:00 #2876
headshot119
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Ok take a look at the diagram below which is for a ground frame.




There are 5 levers.
Lever 1 - Controls two shunt signals labeled 1 (This protects the train standing at 5/1 from being hit from the right.)
Lever 2 - Controls the Facing point lock on point 3
Lever 3 - Controls the facing point 3 (mainline)
Lever 4 - Controls point 4
Lever 5 - Controls the shed road to mainline shunt signal.

So for a train to leave the shed :

On one train working you take the OTW staff place it in the frame. Replace lever 1, pull 2, 3 ,4. Replace 2, then pull 5. Train draws down passes the bracket signal. Remove the token jobs a good en.
Box open phone the bobby, get the occupation key out the box. Same as OTW except don't pull number 5 unless one of the bracket signals is off.

For a train to return to the shed. :

Note this is an un-signalled move!
Stop short of the bracket signal (right side) Go to frame put the token or occupation key in the frame. Replace 1, pull 2,3,4 replace 2. Now here is the funny bit. Do you pull lever 5.

One group say yes, it confirms that the points are swung and the FPL is locked in correctly. Fair comment your confirming the interlocking.
The other group say no. Pulling lever 5 allows a train from the shed to head on collide with a train on the main line.

So thoughts on that one.

"Passengers for New Lane, should be seated in the rear coach of the train " - Opinions are my own and not those of my employer
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Ground Frame Set up 18/04/2011 at 19:00 #15202
headshot119
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4869 posts
Ok take a look at the diagram below which is for a ground frame.




There are 5 levers.
Lever 1 - Controls two shunt signals labeled 1 (This protects the train standing at 5/1 from being hit from the right.)
Lever 2 - Controls the Facing point lock on point 3
Lever 3 - Controls the facing point 3 (mainline)
Lever 4 - Controls point 4
Lever 5 - Controls the shed road to mainline shunt signal.

So for a train to leave the shed :

On one train working you take the OTW staff place it in the frame. Replace lever 1, pull 2, 3 ,4. Replace 2, then pull 5. Train draws down passes the bracket signal. Remove the token jobs a good en.
Box open phone the bobby, get the occupation key out the box. Same as OTW except don't pull number 5 unless one of the bracket signals is off.

For a train to return to the shed. :

Note this is an un-signalled move!
Stop short of the bracket signal (right side) Go to frame put the token or occupation key in the frame. Replace 1, pull 2,3,4 replace 2. Now here is the funny bit. Do you pull lever 5.

One group say yes, it confirms that the points are swung and the FPL is locked in correctly. Fair comment your confirming the interlocking.
The other group say no. Pulling lever 5 allows a train from the shed to head on collide with a train on the main line.

So thoughts on that one.

"Passengers for New Lane, should be seated in the rear coach of the train " - Opinions are my own and not those of my employer
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Ground Frame Set up 18/04/2011 at 19:42 #15204
jc92
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3687 posts
id say no. if the point lever and fpl have both located in the frame and the operator is happy he just needs to handsignal the loco over the crossover. theres no need for the interlocking to be confirmed on such a localised movement. i can confirm we use this system at peak. a disc to allow a move from loop to main but handsignals only used the other way

also technically, considering the way theyre used, 1 and 5 coud be replaced with a yellow disc

"We don't stop camborne wednesdays"
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Ground Frame Set up 18/04/2011 at 19:46 #15206
AnyFile
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I actually do not understand about lever 1 (the par that start with this protect ...)

My opinion is that shunt signal 5 should not be cleared.
You should not clear a shunt signal in opposite direction.

As the movement is unsignalled the person who is working the ground frame should be satisfied that the route is set correctly and then should instruct the driver to precede (by talking to him directly, by radio or hand or flag signal).

I am a little bit surprised that the junction is in the single line section. If the line became double just a little bit ahead, I would think to another way of connecting the junction, so that a train coming out from the shed could go directly into the loop without interfering with the main (single) line.

By the way what is in the upper right part? Is it a siding or does it connect to a running line?

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Ground Frame Set up 18/04/2011 at 19:55 #15207
Late Turn
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Clearing signal 5 would be unlikely to prove that 3 points were fully normal with the FPL in at that end. 2 points and associated FPL would (should?) be mechanically detected by signal 5, but there'd be no reason to provide mechanical detection for the end that's trailing to that movement. So no, as I say, clearing signal 5 for a move in the opposite direction would achieve very little.
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Ground Frame Set up 18/04/2011 at 19:55 #15208
headshot119
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The bit about level 1 and the protection is it stops a train waiting at signal 5/1 from being hit from the right.

The upper right line goes to a shed. The other two are the mainline.

"Passengers for New Lane, should be seated in the rear coach of the train " - Opinions are my own and not those of my employer
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Ground Frame Set up 18/04/2011 at 19:57 #15209
jc92
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i would have lever 5 as a yellow and lever 1 as red which sits normally clear for the shed line.
trains are unlikely to collide at slow speed operating local movements. this is a ground frame not a signal box lol

"We don't stop camborne wednesdays"
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Ground Frame Set up 18/04/2011 at 20:00 #15210
Firefly
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521 posts
I'm somewhat confused.

This doesn't look like "The real thing (signalling)" as per the title of this forum.

Both ends of the points would normally be operated by a single lever. (probably Lever 3). There's no purpose in having the ends swung individually.

You most definitely do not pull lever 5 for moves into the shed. As has been said, it allows trains to collide head on with inbound trains.

FF

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Ground Frame Set up 18/04/2011 at 20:11 #15211
headshot119
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It is real as per the title of the forum.

And yes the points are controlled off separate levers.

"Passengers for New Lane, should be seated in the rear coach of the train " - Opinions are my own and not those of my employer
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Ground Frame Set up 18/04/2011 at 21:49 #15213
TomOF
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452 posts
Having points controlled from two levers is very unusual indeed - I've only seen this where there was an overlap between the two, the protecting signal being approach controlled with TPWS to mitigate an overrun. Stranger still is the use of two facing point locks but I assume there is a good reason for this. As for opposing locking this is permissible under certain circumstances.
I'm also a bit stumped as to why you have two signals called the same thing. Does this mean that when you pull off lever one two signals clear at the same time?

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Ground Frame Set up 18/04/2011 at 21:55 #15215
TomOF
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headshot119 said:
Pulling lever 5 allows a train from the shed to head on collide with a train on the main line.

Also how are main line trains signalled past the ground frame in the first place? Surely if the ground frame was released then the protecting signals woule be locked at danger preventing the GF from being released - therefore if no trains are running then there should be no collision risk

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Ground Frame Set up 18/04/2011 at 22:55 #15218
jc92
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if this is real, where is it in real life (i think i know)
"We don't stop camborne wednesdays"
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Ground Frame Set up 18/04/2011 at 23:37 #15220
BarryM
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2158 posts
Further information.
http://en.wikipedia.org/wiki/Lever_frame
Barry

Barry, Sydney, New South Wales, Australia
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Ground Frame Set up 19/04/2011 at 05:49 #15221
Late Turn
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Just a couple of observations:

Tom - it's not unknown for both ends of a crossover to be worked off individual levers. I think the LNW were generally keen on it, but there's a few other examples. I'm sure (without checking) we've got one going in at Swithland.

Opposing signals worked off the same lever aren't entirely unknown either. They provide much the same function as a yellow disc (that is, unrestricted movement along the headshunt until the points out onto the main need to be swung reverse), but might be more desirable where you've got things stabled on the road(s) to the right rather than just a headshunt that should be normally empty (thus eliminating the risk of anything approaching from the right, unchecked, whilst the crossover is reversed).

Finally (not sure who said otherwise), a minor point: the lever working a yellow disc would be red, not yellow.

Tom

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Ground Frame Set up 19/04/2011 at 11:20 #15234
headshot119
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TomOF said:
headshot119 said:
Pulling lever 5 allows a train from the shed to head on collide with a train on the main line.

Also how are main line trains signalled past the ground frame in the first place? Surely if the ground frame was released then the protecting signals woule be locked at danger preventing the GF from being released - therefore if no trains are running then there should be no collision risk
My point with that is as another train could be leaving the shed road; which is un-signalled you shouldn't pull lever 5 to prevent a head on collision.

And JC92 if you want to PM me your location idea.

"Passengers for New Lane, should be seated in the rear coach of the train " - Opinions are my own and not those of my employer
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Ground Frame Set up 19/04/2011 at 11:24 #15235
Danny252
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The shortest and simplest answer is that if the points are not set correctly, the FPL won't go in (it's implied that FPL 2 applies to Points 3 both normal and reverse). In addition, as a handsignalled move, it's the footplate crew's responsibility to check the points are lying correctly.
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Ground Frame Set up 19/04/2011 at 11:34 #15236
Firefly
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Yep, I don't have a problem with there being 2 x No. 1 signals. (I would suggest they should be called 1A and 1B to avoid confusion). They just prove the GF points normal and allow trains to move backwards and forwards without the need for a GF operator.

Perhaps a little more information on the location, types of working etc. I gather OTW with staff when the signal box is closed. What is the method of block working on the single line when the box is open?

In any case, to answer your question, No. 5 should definitely not be pulled off for a train entering the shed. As Danny has said, the GF operator must check the points are in the correct position and FPL is locked.

As far a two separate levers are concerned it is particularly unusual. Assuming this is a preserved railway I wonder why the decision was taken to provide separate levers?

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Ground Frame Set up 24/04/2011 at 18:20 #15328
BoxBoyKit
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I would argue that the FPL going in when the points are reversed is proof enough, but if the GF operator could reverse 5 half way, enough to test the interlocking but not enough to clear the signal. Plus if these is nothing standing at 5, then clearing it completely should pose no risk. I know at Levisham on NYMR when running locos round trains in the platforms, they pull the platform starter (in advance of the coaching stock) to prove the route off the single line into the platform, as no calling-on signal is provided. As for double ended points being controlled by two levers, I'd say it is rare but again on NYMR the main cross-over at Grosmont is done in this way, something to do with the Rodding bending I believe, not quite sure though.
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Ground Frame Set up 24/04/2011 at 20:48 #15331
Danny252
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BoxBoyKit said:
they pull the platform starter (in advance of the coaching stock) to prove the route off the single line into the platform, as no calling-on signal is provided.
I'd say that's less about proving and more about telling the driver when the route has been changed and he can move! But yes, the signal proving the route is a useful addition.

(Pulling off a normal signal for shunting moves isn't unique - Station Yard Working (Rules 96-98) explicitly allow it, where authorised)

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Ground Frame Set up 25/04/2011 at 16:27 #15346
BoxBoyKit
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It is for proving the route. Atleast it was the only times I've ever seen it happen, the signal box being at the far end of the loop to where the locomotive and thus this set of points were. The Driver was instructed to pass the Inner Home @ Danger via telephone.
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Ground Frame Set up 25/04/2011 at 17:10 #15347
Late Turn
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Although clearing an opposing signal would prove the interlocking (and, as above, could not convey any authority to a Driver to pass a signal at Danger in the opposite direction), it still wouldn't prove detection on points that become facing. If this is provided electrically, then you still have to check that - so I must admit I don't see the point in that strange and potentially misleading method of working. Everywhere else seems to manage it with thorough checking of the route and routesetting cards in some cases!
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