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Passenger trains over Goods Loops - allowable or not?

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Passenger trains over Goods Loops - allowable or not? 09/07/2015 at 19:16 #74065
Pinza
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6M55 (0700 Portbury Coal Terminal to Rugeley B Power Station) is timetabled to sit in Sutton Bridge Jn UGL from 1042 to 1150, before avoiding the station and going round the triangle from English Bridge Jn to Abbey Foregate Jn and joining the Wellington line.

Wrongly routed it at Sutton Bridge and sent it on Up Main rather than onto the Up Goods Loop.

Had also set up route onto Wellington line and then locked up whole station as 6M55 refused to move off early (waiting for booked time and/or train crew relief?).

Managed to cancel onward route (with adverse aspect warnings, of course!).

This freed up Shrewsbury station but left me with class 1 passenger trains on block half way back to Hereford stuck behind it!

Have been routing these stuck class 1 passenger trains via the UGL to get past 6M55 - bit like overtaking on the inside lane of a motorway - ie possible but naughty!

Shrewsbury Sim let me do this - albeit with a warning of Passenger train routed via a Goods Line each time!

Got me out of a fix rather than last resort of removing 6M55 or sweating it out and leaving massive delays for rest of the day...

Simple question: Would I be allowed to use Sutton Bridge Jn Up Goods Loop for passenger trains in real life?

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Passenger trains over Goods Loops - allowable or not? 09/07/2015 at 19:30 #74066
headshot119
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In real life control would have to authorise it.

I'm not near any diagrams but I have a feeling the exit points from Sutton bridge loop don't have an FPL so passenger use would be an absolute no unless the points where clipped and scotched.

"As the last track dropped, and the route became free, came the cry BROMLEY " - Opinions are my own and not those of my employer
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The following user said thank you: Pinza
Passenger trains over Goods Loops - allowable or not? 09/07/2015 at 19:37 #74067
Pinza
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" said:
In real life control would have to authorise it.

I'm not near any diagrams but I have a feeling the exit points from Sutton bridge loop don't have an FPL so passenger use would be an absolute no unless the points where clipped and scotched.
Thanks for that - pretty much assumed that would be the case ie Emergency scenario only after points clipped and scotched.

Could you please explain what the term FPL means?

Cheers
Pinza

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Passenger trains over Goods Loops - allowable or not? 09/07/2015 at 19:38 #74068
JamesN
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" said:
6M55 (0700 Portbury Coal Terminal to Rugeley B Power Station) is timetabled to sit in Sutton Bridge Jn UGL from 1042 to 1150, before avoiding the station and going round the triangle from English Bridge Jn to Abbey Foregate Jn and joining the Wellington line.

Wrongly routed it at Sutton Bridge and sent it on Up Main rather than onto the Up Goods Loop.

Had also set up route onto Wellington line and then locked up whole station as 6M55 refused to move off early (waiting for booked time and/or train crew relief?).

Managed to cancel onward route (with adverse aspect warnings, of course!).

This freed up Shrewsbury station but left me with class 1 passenger trains on block half way back to Hereford stuck behind it!

Have been routing these stuck class 1 passenger trains via the UGL to get past 6M55 - bit like overtaking on the inside lane of a motorway - ie possible but naughty!

Shrewsbury Sim let me do this - albeit with a warning of Passenger train routed via a Goods Line each time!

Got me out of a fix rather than last resort of removing 6M55 or sweating it out and leaving massive delays for rest of the day...

Simple question: Would I be allowed to use Sutton Bridge Jn Up Goods Loop for passenger trains in real life?
Generally locations where this is permissible are listed as such in the sectional appendix. Sutton Bridge UGL has no such dispensation that I can see.

This isn't the be all and end all, Special Instructions can be issued in advance to permit such moves, but this would only be for planned engineering works or a major long-term issue.

In an emergency, control can authorise such moves on an ad-hoc basis, but it would only be to get trapped trains around a failure as a last resort. Signaller error (which the root cause of this is) would not qualify.

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The following user said thank you: Pinza
Passenger trains over Goods Loops - allowable or not? 09/07/2015 at 19:59 #74070
Pinza
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In an emergency, control can authorise such moves on an ad-hoc basis, but it would only be to get trapped trains around a failure as a last resort. Signaller error (which the root cause of this is) would not qualify.

Thanks for that James.

Was indeed Signaller Error by me (albeit first run on Shrewsbury Sim).

Will sleep easy as it is only a game after all and won't get a disciplinary hearing for my error as I did at work last month in real life....!

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Passenger trains over Goods Loops - allowable or not? 09/07/2015 at 20:41 #74071
Steamer
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" said:


Could you please explain what the term FPL means?
Facing Point Lock.

Sutton Bridge Jn is a mechanical box, with most of the points (the one at the entrance to the UGL definitely being an exception) controlled directly by rodding from the lever in the box. Pulling the lever over does not guarantee that the point is all the way over and safe for trains to pass- small items of debris can hold the blade open slightly, while flexibility in the rodding (and a good pull from the signalman!) allows the point lever to move all the way over in the box. This is obviously a derailment risk, so on passenger lines a Facing Point Lock is provided. This consists of a 'tongue' of metal that slides into one of two gaps in a stretcher bar* (one for Normal, one for Reverse). If the points are not in the correct position (I think the error margin is one thousandth of an inch, but don't quote me), the FPL lever in the box won't go all the way over in the box, alerting the signaller to the problem. The interlocking won't allow the signal to clear without the FPL engaged.

As Karl says, if an FPL is not provided, one blade must be clamped to the appropriate rail, and a scotch (posh word for a lump of wood!) stuck between the blade and rail on the other side.

Motor worked points detect themselves by a set of rods between the point blades and the box containing the motor.

In the box, point levers are painted black, FPLs blue and motor-worked points have a blue top half and black bottom half.

*A stretcher bar is a piece of metal between the two moving rails in the point.


Image from RMweb:


"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)
Last edited: 09/07/2015 at 21:16 by Steamer
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Passenger trains over Goods Loops - allowable or not? 09/07/2015 at 20:52 #74072
BarryM
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Steamer, your explanation is worth putting in Wiki (FAQ)

Barry

Barry, Sydney, New South Wales, Australia
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Passenger trains over Goods Loops - allowable or not? 10/07/2015 at 16:14 #74086
DanC
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" said:
" said:


Could you please explain what the term FPL means?
Facing Point Lock.

Sutton Bridge Jn is a mechanical box, with most of the points (the one at the entrance to the UGL definitely being an exception) controlled directly by rodding from the lever in the box. Pulling the lever over does not guarantee that the point is all the way over and safe for trains to pass- small items of debris can hold the blade open slightly, while flexibility in the rodding (and a good pull from the signalman!) allows the point lever to move all the way over in the box. This is obviously a derailment risk, so on passenger lines a Facing Point Lock is provided. This consists of a 'tongue' of metal that slides into one of two gaps in a stretcher bar* (one for Normal, one for Reverse). If the points are not in the correct position (I think the error margin is one thousandth of an inch, but don't quote me), the FPL lever in the box won't go all the way over in the box, alerting the signaller to the problem. The interlocking won't allow the signal to clear without the FPL engaged.

As Karl says, if an FPL is not provided, one blade must be clamped to the appropriate rail, and a scotch (posh word for a lump of wood!) stuck between the blade and rail on the other side.

Motor worked points detect themselves by a set of rods between the point blades and the box containing the motor.

In the box, point levers are painted black, FPLs blue and motor-worked points have a blue top half and black bottom half.

*A stretcher bar is a piece of metal between the two moving rails in the point.


Image from RMweb:

Out of interest, why have these as a requirement for passenger traffic but not freight? Surely it's just as dangerous and catastrophic to have a freight train derail? Or am I missing something :blink:

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Passenger trains over Goods Loops - allowable or not? 10/07/2015 at 16:49 #74088
Danny252
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" said:
Out of interest, why have these as a requirement for passenger traffic but not freight? Surely it's just as dangerous and catastrophic to have a freight train derail? Or am I missing something :blink:
In short, lumps of coal complain less about being thrown off a train than people do!

(I suspect it's related to lobbying/complaints by companies in the 19th century, who complained about just about every safety measure imposed on them)

" said:
If the points are not in the correct position (I think the error margin is one thousandth of an inch, but don't quote me)
I'd love to see any exposed, outdoor mechanical system that could manage an accuracy of 25 microns! I believe the requirement for detection is/was something like 1/16th of an inch, whilst FPLs seem to be slightly less stringent than that (given how often I've had FPLs go in whilst the detection was still foul).

Quote:
Motor worked points detect themselves by a set of rods between the point blades and the box containing the motor.
I'm not sure what you're getting at here. Motor worked points have FPLs, and manual points (can) have detection.

Last edited: 10/07/2015 at 16:56 by Danny252
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Passenger trains over Goods Loops - allowable or not? 10/07/2015 at 16:52 #74090
Danny252
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" said:
If the points are not in the correct position (I think the error margin is one thousandth of an inch, but don't quote me)
I'd love to see any exposed, outdoor mechanical system that could manage an accuracy of 25 microns! I believe it's closer to something like 1/16th of an inch.

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Passenger trains over Goods Loops - allowable or not? 10/07/2015 at 18:23 #74091
DanC
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" said:
" said:
Out of interest, why have these as a requirement for passenger traffic but not freight? Surely it's just as dangerous and catastrophic to have a freight train derail? Or am I missing something :blink:
In short, lumps of coal complain less about being thrown off a train than people do!

(I suspect it's related to lobbying/complaints by companies in the 19th century, who complained about just about every safety measure imposed on them)

" said:
If the points are not in the correct position (I think the error margin is one thousandth of an inch, but don't quote me)
I'd love to see any exposed, outdoor mechanical system that could manage an accuracy of 25 microns! I believe the requirement for detection is/was something like 1/16th of an inch, whilst FPLs seem to be slightly less stringent than that (given how often I've had FPLs go in whilst the detection was still foul).

Quote:
Motor worked points detect themselves by a set of rods between the point blades and the box containing the motor.
I'm not sure what you're getting at here. Motor worked points have FPLs, and manual points (can) have detection.
I appreciate that...still reckon a village would complain about being half destroyed by a freight train derailing same as if it was a passenger train though (Heaven forbid)

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Passenger trains over Goods Loops - allowable or not? 10/07/2015 at 19:27 #74093
Forest Pines
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" said:

I'd love to see any exposed, outdoor mechanical system that could manage an accuracy of 25 microns! I believe the requirement for detection is/was something like 1/16th of an inch, whilst FPLs seem to be slightly less stringent than that (given how often I've had FPLs go in whilst the detection was still foul).
From memory of what the gauge looks like I'd assume, detection is tested by a 1/16th gauge and the FPL by a 1/32nd gauge (or 63 thou and 31 thou if you prefer). I am guessing the exact amounts, but the test gauge's "FPL end" is about half the width of the "detection end".

However that test is a "must not go in if" test - all that's tested is that the relevant kit doesn't work in the given circumstance. So it's entirely legit if, say, the blades are 20thou out, detection fails, but the FPL will still go in. It would also be legit if the blades were 40thou out, detection worked, but the FPL didn't.

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Passenger trains over Goods Loops - allowable or not? 10/07/2015 at 20:32 #74097
Steamer
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" said:

" said:
If the points are not in the correct position (I think the error margin is one thousandth of an inch, but don't quote me)
I'd love to see any exposed, outdoor mechanical system that could manage an accuracy of 25 microns! I believe the requirement for detection is/was something like 1/16th of an inch, whilst FPLs seem to be slightly less stringent than that (given how often I've had FPLs go in whilst the detection was still foul).
Fair enough, I've obviously misheard or got confused at some point.

Quote:
Quote:
Motor worked points detect themselves by a set of rods between the point blades and the box containing the motor.
I'm not sure what you're getting at here. Motor worked points have FPLs, and manual points (can) have detection.
Sorry. What I was trying to say is that motor worked points don't have the FPL arrangement seen with mechanical points, instead it's all done inside the motor box. Please could you expand on how FPLs work on motor worked points?

" said:
I appreciate that...still reckon a village would complain about being half destroyed by a freight train derailing same as if it was a passenger train though (Heaven forbid)
FPLs would only be omitted on low-speed lines, so a derailment wouldn't be that severe.

"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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Passenger trains over Goods Loops - allowable or not? 10/07/2015 at 21:29 #74100
jc92
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Steamer.

Clamplock Points lock the blade which a motorised Clamp on both blades. the motor removes the clamp, then moves the blades, then replaces the clamp. there is no FPL so these might be the ones you're thinking of as they're probably one of the most common.

we do have an old form of Point motor (can't remember the name) at Peak rail which has an FPL. the motor pulls the FPL out, slides the points then replaces the FPL

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Passenger trains over Goods Loops - allowable or not? 10/07/2015 at 21:47 #74104
Steamer
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" said:
Steamer.

Clamplock Points lock the blade which a motorised Clamp on both blades. the motor removes the clamp, then moves the blades, then replaces the clamp. there is no FPL so these might be the ones you're thinking of as they're probably one of the most common.
Thanks.

Can I check- is this the type of point you mean? It's confused me slightly as the clamp appears to be fully built in to the point, as opposed to being a separate item.

"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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Passenger trains over Goods Loops - allowable or not? 11/07/2015 at 10:21 #74119
Stephen Fulcher
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" said:
" said:
Out of interest, why have these as a requirement for passenger traffic but not freight? Surely it's just as dangerous and catastrophic to have a freight train derail? Or am I missing something :blink:
In short, lumps of coal complain less about being thrown off a train than people do!

(I suspect it's related to lobbying/complaints by companies in the 19th century, who complained about just about every safety measure imposed on them)

" said:
If the points are not in the correct position (I think the error margin is one thousandth of an inch, but don't quote me)
I'd love to see any exposed, outdoor mechanical system that could manage an accuracy of 25 microns! I believe the requirement for detection is/was something like 1/16th of an inch, whilst FPLs seem to be slightly less stringent than that (given how often I've had FPLs go in whilst the detection was still foul).

Quote:
Motor worked points detect themselves by a set of rods between the point blades and the box containing the motor.
I'm not sure what you're getting at here. Motor worked points have FPLs, and manual points (can) have detection.
Significantly more importantly than their ability to complain about being thrown from a train (which happens in regular traffic anyway), lumps of coal cannot be killed or seriously injured in a derailment.

Contrary to popular belief, not all types of point machine have internal detection capability, and not all have integral facing point locks either. The requirement as to whether or not a set of points needs an FPL are the same for machines as for mechanical points, namely passenger moves being made over them.

The rods themselves do not do the detection or locking functions, they merely drive a blade which passes through the machine which in turn actuates the mechanisms that provide the detection, and the FPL lock dog inside the machine engages with the lock blade preventing movement of the points.

The FPL function on a clamplock is a more positive hold as the lock arm, which is attached to the switch rail, is forced up by the hydraulics behind the stock rail, physically "clamping" the rails together.

In all cases, the FPL is set so that it will engage with a 1.5mm gauge between the switch and stock rail above the first P-Way chair (or in the case of clamplocks directly above the lock arm), and so that it will not engage with a 3.5mm gauge above the first P-Way chair (including clamplocks).

Detection is set so that it will be made with a 3.5mm gauge in the points, and broken with a 5mm gauge.

Back to the original query, Sutton Bridge Junctions 19 points exiting the Up Goods Loop are fitted with a facing point lock, so would not need to be clipped up to allow a passenger train to exit the loop. With the scenario described here however, the Signalman would just send the goods train on to the next convenient regulating point rather than route passenger trains around it. I suggest you step up the timetable to next location Shrewsbury and just let the train run early.

Whilst not ideal, I have on one occasion seen a train sent via a goods loop to get round a Signalmans error - but this would not be the first choice. If sending a passenger train via a goods loop, the Signalman is required to set the route both in AND out of it before allowing the train to enter. This is to guard against the fact that loops were not generally provided with overlaps in historical installations, although in modern times they often are. The Driver would also have to be stopped and told he is to go through the loop BEFORE the protecting signal is cleared, although with SimSig this isn't possible and you have to take the wrong route call and tell the Driver to accept the goods line.

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Passenger trains over Goods Loops - allowable or not? 11/07/2015 at 10:23 #74120
Stephen Fulcher
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" said:
" said:
Steamer.

Clamplock Points lock the blade which a motorised Clamp on both blades. the motor removes the clamp, then moves the blades, then replaces the clamp. there is no FPL so these might be the ones you're thinking of as they're probably one of the most common.
Thanks.

Can I check- is this the type of point you mean? It's confused me slightly as the clamp appears to be fully built in to the point, as opposed to being a separate item.
This is a conventional clamplock yes.

http://www.templot.com/forum_img/clamp_lock_dwg.png is a fairly good diagram of them.

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Passenger trains over Goods Loops - allowable or not? 11/07/2015 at 10:36 #74121
AndyG
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Lots of information on Adrian (the Rock) Roscalen's signalling web site, including FPL explanation.
I can only help one person a day. Today's not your day. Tomorrow doesn't look too good either.
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Passenger trains over Goods Loops - allowable or not? 11/07/2015 at 23:44 #74147
Pinza
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Sincere thanks to everybody who has contributed to the thread I started last week.

Diverted some class 1 passenger trains over a Goods Loop to get round a mis-routed/regulated freight train.

Asked if this would be permissible in real life.

Expected a simple yes/no answer.

Told no - as Sutton Bridge Jn UGL has no FPL.

Had to ask what an FPL was!

Humbled at the professionalism and technicality of the detailed follow-up to that...

Apologies if I offended anyone earlier by saying this was just a 'game'!

Clearly, rather, a highly accurate simulation with great back-up via the forum.

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Passenger trains over Goods Loops - allowable or not? 07/02/2016 at 00:07 #80443
Adrian the Rock
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Actually, Steamer's explanation isn't quite the whole story.

The purpose of an FPL is not to prove that the point blades are fully home - there is a separate piece of equipment called a Detector that does that, it's the grey box on the far side of the point in the example photo. The actual purpose of the FPL is to prevent the points moving or being moved under a train. In the original installations - and a rare couple of these in fact still survive at Crewe Junction - the FPL rods were also linked to pivoted bars placed just below the flangeway immediately behind the toes of the points. When the FPL lever was worked to lock or free the points, these bars were pushed upwards in mid-stroke such that they would be fouled by the train wheels if anything was on the line there. This prevented signalmen erroneously freeing the points under trains. Nowadays, track circuits are normally used instead, with the FPL lever locked electrically if the TC is occupied.

Detectors can be either manual or electrical: the one in this photo looks like one of the latter.

Here are a couple of links to photos on my site of FPLs and detector equipment:

FPL with mechanical detector (at Crewe Jn)
FPLs with old-style mechanical bars (ditto)

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