Point rodding and signal wires

[Nick C]

53 minutes ago, 5BarVT said:

For those that don’t follow signalling terminology in as much detail as some of us . . .

Between N and R are 5 other positions A to E.  C is the easy one it’s right in the middle and is very rarely (if ever) used.  A is very close to N and E is very close to R.  Usually (on G(WR) at least) as lever band contacts that are not pure N or R (thus NA or RE).  That leaves B and D which are usually a lock position before the lever gets to the final N or R position about 1/4 and 3/4 through the quadrant.  (As described by RailWest and Harlequin above.)

Paul.

So when a lever is electrically locked (e.g. by a track circuit or line clear release), is that the A and E positions?

[5BarVT]

11 hours ago, Nick C said:

So when a lever is electrically locked (e.g. by a track circuit or line clear release), is that the A and E positions?

Depends (It’s that black art again) on how you do the economiser (i.e. preventing the lock being energised until you want to move the lever).  G(WR) used a plunger for the economiser and thus used straight N and R locks.  SR used the lever itself with an A or E contact so the locks were A or E.

Those are the two that I know of, there may have been other methods too.

Paul.

[RailWest]

13 minutes ago, 5BarVT said:

Depends (It’s that black art again) on how you do the economiser (i.e. preventing the lock being energised until you want to move the lever).  G(WR) used a plunger for the economiser and thus used straight N and R locks.  SR used the lever itself with an A or E contact so the locks were A or E.

Those are the two that I know of, there may have been other methods too.

Paul.

The L&SWR used a lot of foot-plungers, whereas the GWR plungers were shelf-mounted.

[The Stationmaster]

15 hours ago, RailWest said:

Yes, the 'B' and 'D' positions of the lever. 

 

The idea is that, by moving the lever from N to D, but NOT all the way to R, you move the locking sufficient to prevent conflicting moves, but not enough to release other moves until it has been proven that the point has moved fully over to the reverse position. Once that has been detected at the point, then the electric lock on the lever is freed to enable you to move the lever from D to R, at which stage the locking for the signal(s) for the new route becomes free. Conversely, when putting back, you go from R to B, wait for the points to be motored back and proven normal, then you can move from B to N.

 

Indicator in the signal-box could be a typical circular one like an arm repeater or similar, but with three indications NORMAL /  -  / REVERSE for the point position.

 

If you look at the picture here (Williton on the WSR) levers 12 and 16 are for motor points. The round white-faced point indicators are above them on the front of the shelf. Look closely at the lever quadrants and you will see the B and D position notches close to each other near the mid-stroke.

 

Why don't 12 and 16 have shortened handles?  Bit dodgy that and even the LMR idea of wrapping them with (usually green I think) tape would be safer than leaving them with nothing at all to show that they are different.   

 

15 hours ago, Harlequin said:

 

According to "GWR Signalling Practice" (my summary):

The relevant levers had extra slots at the 1/4 and 3/4 positions of the lever guides. You pull the lever to the 3/4 slot position and interlocking prevents it going any further. You then wind the hurdy-gurdy until the indicator shows the points have moved the full distance (not sure what indicator). Then the lever is released by the interlocking and it can be moved to the normal position. Same in reverse using the other slot.

 

I guess that the slots connect the generator to the point motor electrically and maybe each slot reverses the polarity of the other?

 

I think Kevin Robertson describes exactly this procedure in one of his books - possibly Burghclere Signalman or the Sutton Scotney book. I got the impression that these electric point motors were not 100% reliable, with signalmen worrying about setting routes that required using them and so getting it done as early as possible in case there was a problem. I think sometimes they had to go through the process a few times before the points were provably set correctly.

 

In terms of working the frame and hurdy-gurdy you first pull the lever to what many Signalmen called the 'Check position' (i.e 3/4 stroke  if pulling from normal)  where the circuit controller's electric lock will hold it even if you try to move it further.   When the point machine(s) motor(s) over in response to the hurdy-gurdy the repeater will change - as mentioned above - but you will normally hear the lock drop in the circuit controller so you know that the lever has been released to now be pulled to full stroke (no need to plunge for that part of the lock).

 

The points at Witham installed in 1972 only had one lever for each crossover but I don't know if the hurdy-gurdy directly energised the point machines or if it was done some other way.  Generally both crossovers there moved fairly quickly in response to the hurdy-gurdy and both ends of both crossovers had to detect in order to release the lock in the circuit controller one the lever which worked them.  I've an idea that one of the IRSE green booklets might have had some details about circuit controllers.  Incidentally I can't remember - in the nearly 5 years the 'box was on my patch that we ever had any problems with those points (except when somebody ran through one of them).

 

The photo below shows how electric locks (in the blue boxes) are connected to the locking on a Reading VT frame.   These are all electric locks, the circuit controllers were mounted in the same way but were in a much larger box

 

 

[The Stationmaster]

1 hour ago, 5BarVT said:

Depends (It’s that black art again) on how you do the economiser (i.e. preventing the lock being energised until you want to move the lever).  G(WR) used a plunger for the economiser and thus used straight N and R locks.  SR used the lever itself with an A or E contact so the locks were A or E.

Those are the two that I know of, there may have been other methods too.

Paul.

Were the SR lever economisers only on the Westinghouse A frames?   As far as i know they never altered any ex (G)WR frames to that method.

[5BarVT]

28 minutes ago, The Stationmaster said:

Were the SR lever economisers only on the Westinghouse A frames?   As far as i know they never altered any ex (G)WR frames to that method.

Exeter Central A is the specific example I remember from my training days.

Paul.

[Nick C]

1 hour ago, The Stationmaster said:

Were the SR lever economisers only on the Westinghouse A frames?   As far as i know they never altered any ex (G)WR frames to that method.

The ones at Alresford (Stevens frame) are done off the levers, but I don't know if they're original or a preservation-era addition.

[bécasse]

1 hour ago, The Stationmaster said:

Were the SR lever economisers only on the Westinghouse A frames?   

My recollection (of many decades ago!) is that lever economisers were standard fitment in SR boxes with electric locks* (unless foot pedal releases were provided) and an even ropier recollection suggests that the lock picked up when one grasped the lever catch handle. Generally the arrangement was easy to work, the one contrary example being Salisbury East which had ex-pneumatic slides which had to be pulled or pushed at precisely the right speed, too fast and the lock didn't pick up in time, too slow and the lock dropped out again, either of which blocked further movement of the slide. Moving the slide at the right speed wasn't helped by the fact that they were quite stiff and were mounted at an awkward height. Obviously the regular bobbies had the knack but for me it was by a long way the most frustrating frame I ever tried to work.

 

* Including those with miniature levers.

[RailWest]

4 hours ago, The Stationmaster said:

Were the SR lever economisers only on the Westinghouse A frames?   As far as i know they never altered any ex (G)WR frames to that method.

Although I never experienced them 'in the flesh', it became apparent recently when researching something about the S&DJR that they had examples of NA and RE locks on Stevens-pattern frames and I was lead to believe from further enquiries that this was quite common on the SR. AFAIK the contacts were closed by the movement of the actual lever, rather than the catch-handle.

[RailWest]

>>>>Why don't 12 and 16 have shortened handles?

 

Unless the situation has changed since I took that photo in 2017, AIUI it was a reluctance to 'damage' a heritage frame. Instead they adopted the GWR practice of marking '[Electric Switch]' on the lever-leads :-)

 

In the case of lever 1, I suspect that the original full-length lever there (for the once-working Up Distant) was moved into the previous Space 2 and a 'handy' cut-down lever from elsewhere put in its place.

Edited May 12, 2022 by RailWest

[Michael Hodgson]

58 minutes ago, RailWest said:

>>>>Why don't 12 and 16 have shortened handles?

 

Unless the situation has changed since I took that photo in 2017, AIUI it was a reluctance to 'damage' a heritage frame. Instead they adopted the GWR practice of marking '[Electric Switch]' on the lever-leads :-)

 

In the case of lever 1, I suspect that the original full-lenght lever there (for the once-working Up Distant) was moved into the space 2 and a 'handy' cut-down lever from elsewhere put in its place.

That sort of reluctance is not uncommon on preserved lines.  They often don't want to cut levers short because (1) having various levers cut down with an angle grinder does mar the otherwise tidy appearance of a frame and (2) should the lever ever be needed to work somethimg mechanical at a later date, they can't reinstate the handle.  BR tended to be able to find suitable spare lever (from the frame of some other box which has been closed) in S&T stores if that were ever necessary, but it is a lot harder to source spares these days.

 

Most signalmen on these lines aren't career railwaymen and are less at risk of back injury than professional signalmen who are much more likely to instinctively give a lever a good heave without thinking.  Short levers do restrict the amount of effort they can easily apply, whereas different wording on the pull plate wouldn't be as effective as you don't read it when you know the box.  However you can't predict that no retired signalmen will ever be working the box, so not shortening levers is still a practice that's a bit hard to justify on H&S grounds.

[RailWest]

Further down the line at Blue Anchor, when points 6 were converted to motor-working that handle was cut-down. At the same time lever 5, previously the FPL, was kept as a spare 'worked to maintain locking' - to avoid all the hastle of having to dismantle and alter so much of the 'stud' locking - and so painted white/blue and its handle was cut down also. Ironically IMHO that frame is far more 'heritage' in being the original 1904 frame in that box, whereas the one at Williton is the 3rd frame there and dates 'only' from 1937.

 

Incidentally, as an aside, IMHO Blue Anchor is unique (at least at the moment) in being the only - and oldest - GWR box with its original 'stud' frame in its original box structure in its original location and operational. The example at Buckfastleigh is about 2 years younger and of course not (currently) operational.

Edited May 12, 2022 by RailWest

[micknich2003]

Cutting down lever handles for power working is a BoT Requirement. Does anyone know when short handles in mechanical frames became accepted practice? If the sawn off piece is saved, it can if circumstances change be welded back.

[Nick C]

5 hours ago, RailWest said:

Although I never experienced them 'in the flesh', it became apparent recently when researching something about the S&DJR that they had examples of NA and RE locks on Stevens-pattern frames and I was lead to believe from further enquiries that this was quite common on the SR. AFAIK the contacts were closed by the movement of the actual lever, rather than the catch-handle.

I've just checked an article written by one of our S&T guys (can't reproduce here for copyright reasons), and that says that the economiser contacts are closed by lever movement. They are Westinghouse D4 locks.

[TheSignalEngineer]

1 hour ago, micknich2003 said:

If the sawn off piece is saved, it can if circumstances change be welded back.

Better to change the lever as it would be difficult to do the weld and get the handle smooth when in situ. There is also the question of getting the weld through the full thickness, you can't just tack it on.

[Michael Hodgson]

34 minutes ago, TheSignalEngineer said:

Better to change the lever as it would be difficult to do the weld and get the handle smooth when in situ. There is also the question of getting the weld through the full thickness, you can't just tack it on.

If a weld on a handle fails, that is almost guaranteed to give the bobby back injuries.  It would inevitably be whilst he was pulling it that it failed, and he would be catapulted to the back wall of the box.  It's what happens if the signal operating wire breaks. 

Whilst much less common it is not completely unheard of for lever castings themselves to snap under brute force applied to them by some chaps built like gorillas.

[TheSignalEngineer]

On 11/05/2022 at 16:02, The Stationmaster said:

A lot of it occurred when a major installations of colour light signalling took place as part of various schemes in the 1960s.  It happened on the WCML when the original resignalling budget for electrification was cut and mechanical boxes were retained between Crewe and the areas controlled by Nuneaton and Rugby psbs which saw a reversion o to the original policy of new power boxes.

Besides at Shunt Frames, the WCML retained mechanical boxes working colour light running signals on the Northampton Loop (prior to No.3 being replaced) then from Atherstone to Basford Hall excluding Norton Bridge, through the Independent Lines bypassing the station to Coal Yard then on to Liverpool excluding Weaver Junction and Edge Hill panel to Lime Street which retained its Westinghouse power frame. To that you can add Grange Junction to Macclesfield, Cheadle Hulme, Adswood Road, Edgeley Junction No.1 and No.2, Stockport No.1 and No.2 and Heaton Norris. A few still exist especially the latter five boxes where there is even some Absolute Block working shown in the current Sectional Appendix. I think that all of the points at the remaining boxes have probably now been converted to motor working.

[TheSignalEngineer]

55 minutes ago, Michael Hodgson said:

Whilst much less common it is not completely unheard of for lever castings themselves to snap under brute force applied to them by some chaps built like gorillas.

I saw a lever snapped in the frame at Duddeston Road. It was the one controlling the points at the entrance to Saltley loco shed, so a bit inconvenient. Fortunately with an LMR standard frame it was quite easy to change a lever and there was a spare in the frame that we could get out to change for the broken one. Job finished in about an hour, so not much delay, just disconnected the points then barred and clipped them as required whilst the change was done. Just fortunate that we were already working in the box when it happened.

[micknich2003]

Re welding lever handles, I recall reading in a Signal Record Society news letter that it had been done somewhere.

[TheSignalEngineer]

 

On 11/05/2022 at 20:46, 5BarVT said:

For those that don’t follow signalling terminology in as much detail as some of us . . .

Between N and R are 5 other positions A to E.  C is the easy one it’s right in the middle and is very rarely (if ever) used.  A is very close to N and E is very close to R.  Usually (on G(WR) at least) as lever band contacts that are not pure N or R (thus NA or RE).  That leaves B and D which are usually a lock position before the lever gets to the final N or R position about 1/4 and 3/4 through the quadrant.  (As described by RailWest and Harlequin above.)

Paul.

Evening Paul,

This is an explanation of lever positions and contacts we prepared earlier, about 32 years ago for some training notes actually.

Eric

Updated higher resolution attachment added 13May2022 12:36

Edited May 13, 2022 by TheSignalEngineer

[TheSignalEngineer]

12 hours ago, The Stationmaster said:

Why don't 12 and 16 have shortened handles?  Bit dodgy that and even the LMR idea of wrapping them with (usually green I think) tape would be safer than leaving them with nothing at all to show that they are different.   

We often did that during stagework and when a box was due to come out of use in the near future.

 

4 hours ago, micknich2003 said:

Cutting down lever handles for power working is a BoT Requirement. Does anyone know when short handles in mechanical frames became accepted practice?

I don't know when it was actually introduced. It was not in the 1928 requirements but certainly appeared in the 1950 edition.

[Michael Hodgson]

14 hours ago, TheSignalEngineer said:

I saw a lever snapped in the frame at Duddeston Road. It was the one controlling the points at the entrance to Saltley loco shed, so a bit inconvenient. Fortunately with an LMR standard frame it was quite easy to change a lever and there was a spare in the frame that we could get out to change for the broken one. Job finished in about an hour, so not much delay, just disconnected the points then barred and clipped them as required whilst the change was done. Just fortunate that we were already working in the box when it happened.

To most modellers a lever frame is just a lever frame, the various types being like differing choices of rolling stock livery.  Many on here will lack your knowledge of how much more disruptive that could have been with some other types of lever frame because of the way they are constructed.

[Michael Hodgson]

14 hours ago, TheSignalEngineer said:

We often did that during stagework and when a box was due to come out of use in the near future.

The point about green tape (and green items on drawings) is that the colour is an S&T convention for stuff that is to be removed.  Similarly, red is used for new things that are to be added.  It is an aid to avoid confusion as to what's actually operational.  During stagework, engineers can work on these without endangering the operational railway, but you don't want them to tamper with live equipment.  And it reduces risk of confusion if any fault finding is needed to the live system while a job is still in progress.

 

You often see green tape on stores of spares etc that the preservation movement has managed to salvage. 

[TheSignalEngineer]

2 hours ago, Michael Hodgson said:

Many on here will lack your knowledge of how much more disruptive that could have been with some other types of lever frame because of the way they are constructed.

Even then it can be awkward. On an LMR 1943 pattern frame I could probably get out about 80% of the levers with little problem. The rest could be a bit difficult especially next to a join in the locking trays.

Edited May 13, 2022 by TheSignalEngineer

[TrevorP1]

Reference the switch machines on the DN&S. Mention of Kevin Robertson's DN&S A New History found me on the website of that (in?)famous supplier of all things named after a South American river. My credit card was duly mugged and the book arrived today.

 

It is a mighty - and fascinating - volume and will see many hours disappear. On page 208 there is a very clear picture of the  hurdy gurdy at Winchester. It should be no problem fabricating one for Tremewan signal box when the time comes.