Rodding - design specifics

[Steve Taylor]

Afternoon all.

Here's a couple of queries from someone with a little awareness of mechanical installations, but no formal training.

 

1. Given a Victorian rodding run (1895, NER) serving two locking bars and effectively 3 crossovers (3 pairs of points worked in tandem), would anyone have any guidelines to work to that take into account the fact that the main run is in part in the 6' on a slight curve. How much extra space should be allowed in the 6' for the rodding run and (if i can get an approximate radius for the curve) for any end throw caused by the curve?

 

2. As originally installed this scheme had what the NER termed a junction - in practice a single line became a double line with down traffic moving across the formation when entering the double track. Traveling from single to double meant negotiating a crossover preceded by a locking bar. The trailing connection from this crossover was used as a trap for runaways and at some point before 1924 was moved west by about 270' (IIRC) to a point where the A end would be more or less in line with the signal box's lead off timbers. Would a direct connection be attempted or would the switch tips be offset from the rodding leaving the box to allow an adjustable final drive crank to be fitted?

 

3. The trailing connection at the start of the double track was latterly used as siding space for wagon storage (mid 1950's) but had no signal protecting the main from anything in that siding. Additionally on the up side there was a yard connection (1x L/h point worked with the catch points) this led to a road serving coal drops and a road that the sectional appendix indicates was to catch runaways and those failing to stop in time at the inner home. I believe the inner home was removed in the mid 1950's, however prior to that would the yard entrance points be locked with the inner home - ie to protect the single line ahead, the inner home would remain normal and the down starter could only be released in if the yard points were reversed to protect it? The coal drops road and the over run siding have no signal local to them but coming out of the yard (wrong road on the up) the first signal facing was a ground signal prior to a facing crossover (up to down). Would this signal also protect the main from the yard despite the distance or should i look for something else?

 

I have a copy of sketches of the signalling diagram from the 1920's as well as the 1950's a swell as the Board of trade plan of 1895, which i can make available later on if anyone is interested.

 

Thanks for reading and for any help offered.

 

Steve

[Steve Taylor]

Right I'm a bit more organised now.

 

This is the diagram submitted to the board of trade inspector in 1895 as the line west was doubled.

The rodding leaves the signalbox perpendicular to the box (and running lines) and splits east for points 7a/b and locking bar 6 and west for Points 9a/b, 12a/b and locking bar 10. these two runs go in the wide way between the up running line and the coal drop road and are formed from round rodding. The west run crosses the up main short of catch points 9a and runs westwards in the 6' to serve 12a/b. I have no clear evidence but suspect for ease of set up that the single rod splits off short of 12a to serve 12a and crosses the down running line and continues west to 12b.

 

IIRC the radius of the curve is about 1200chains (unfortunately VB wont's open so I can't check on templot for that figure right now) and the run is three rods wide. Would the curve and the presence of rodding stools lead for the 6' to be wider than the minimum required for the structure guage?

 

This is a composite diagram supplied a few years ago by Mick Nicholson. I've never seen any evidence for ground signal 5 or 13 though they make sense and add some scope to operating, and no pics have come to light of the bracket version of 16/11.

 

This is a drawing by Peter Singlehurst (possibly from John Mallon's notebooks). This is the scheme that appears in most pictures available. I have no dates for the alterations between the two but suspect some point between 1942 and summer 1954. Also at some point fairly early in the history of this place the crossover (or junction as the NER notes say) points 7a/b move west to almost square on to the box, though this does not appear on any signalling diagram it is apparent in photos.

 

Likely Locking: would the presence of the refuge siding on the up side (mentioned in sectional appendixes) mean that a train allowed/signalled onto the single line into the platform from the east would require 9 reversed to protect it from eastbound downgrade traffic running away? Also would ground signal 13 be acting as the yard exit and be just for a move from the yard across 12a/b onto the down?

 

In the later diagrams there is a trailing siding on the down from 7a/b. This is on a falling gradient and presumably the stop block was provided to stop any runaway ending up in the stream. Once the crossover was moved this becomes useful standage and photos show wagons stored on it. It never had a signal from it protecting the down running line? How would that work from an operational point of view.

 

Hopefully thats a bit clearer than my original version.

Thanks for any help offered.

 

Cheers

Steve