Jump to content
 

The distance between point rodding stools


Recommended Posts

  • RMweb Gold

I'm needing to make a start on the Callow Lane point rodding, but I can't find any of my references as to how far apart the individual rodding stools should be on a plain run of point rodding. I've looked at 10800's photos in the old forum of the SVR, and I'm thinking that 10 feet is about the maximum you can get away with, but should it be perhaps slightly less?

 

If anyone has an answer to this, I'd be very grateful!

 

Thanks.

Link to post
Share on other sites

  • RMweb Gold

You rang :)

 

There is no doubt a standard, and as this is GWR territory StationMaster will be best placed to answer, but remember their purpose - to support the rodding, so there will be variations due to local conditions such as "How good the ground is?"

 

I reckon more 8' for an average but I am happy to be shot down in flames.

Link to post
Share on other sites

This topic was discussed within the Brighton Circle egroup and although there is welter of conflicting evidence from contemporary sources, the conclusion was that a figure between 6 and 8 feet was permissible. Stephen Williams in his GWR trilogy cites GW practice with round rodding as 6 feet spacing, not to exceed 8 feet. There can't be a hard and fast rule as the spacing has to vary to accommodate the various accoutrements such as compensators and cranks, and to avoid sleepers and crossing timbers etc. In the first issue of Midland Record there is a view of rodding at St Pancras where it doesn't look as if any two spacings between stools are the same. Some lines, but not the Midland, I think, adopted the practice of extending sleepers for the stools, which would tend to suggest around 7' 6" although that would vary at the end of each rail length.

Link to post
Share on other sites

  • RMweb Gold

I'm needing to make a start on the Callow Lane point rodding, but I can't find any of my references as to how far apart the individual rodding stools should be on a plain run of point rodding. I've looked at 10800's photos in the old forum of the SVR, and I'm thinking that 10 feet is about the maximum you can get away with, but should it be perhaps slightly less?

 

If anyone has an answer to this, I'd be very grateful!

 

Thanks.

 

If you are using tubular rodding the answer is that stools should be 6 ft apart with the rods at 2.5" pitch (centre to centre, rod diameter would be c.1.25" and 1" for any solid rod and pinjoints).

 

If it is channel rodding then the stools are 9ft apart and the pitch is 2.75" although I suspect that in later years the former might have opened out to 10ft on straight runs (the 9ft figure is 1930s).

 

Length of tubular rodding sections was normally 16ft, channel rodding varied with dimensions quoted as 15 ft and 18ft6" in one source although I thought WR material was 18ft (might be wrong on that. it's a long time since I humped a load of it about :( ).

 

Don't overlook that fact that if you are modelling true Midland and have any FPLs there will only be a single rod to work them as the Midland was great user of economical FPLs. And don't forget compensators B)

Link to post
Share on other sites

  • RMweb Gold

Just remembered - I scanned the instructions so I could study them at work whilst still apprearing to work laugh.gif

 

Firmly fix the cut stools in a line along the side of the ballast in the direction of the points to be controlled. Place them at least 2ft3in (9mm) from the nearest rail, and typically 6ft (24mm) apart for a pre Grouping installation, and 8ft (32mm) post Grouping. Reduce this to 5ft (20mm) on curves.

It also states that

A compensating lever is required in each rodding run over 10 scale yards (l20mm) in length, positioned so it divides the run into two roughly equal lengths. More correctly, and allowing for any cranks in the run, the compens,ator should be positioned so the length of rodding being pushed is equal to that being pulled.

I have a question though, is the rodding always straight? if so, how does it work on curves?

Link to post
Share on other sites

  • RMweb Gold

Just remembered - I scanned the instructions so I could study them at work whilst still apprearing to work laugh.gif

 

It also states that

I have a question though, is the rodding always straight? if so, how does it work on curves?

 

On shallow curves the rodding simply follows the line of the curve but I don't know how tight the radius can be - when I laid out a run some years ago I just worked by eye to estimate if the radius was going to be ok :rolleyes: However motion is lost on curves so ideally a rodding run should be placed outside tighter curves in order to maximise the radius (although that then needs greater care with compensation) although I have seen runs cutting across the inside of a crurve in order to keep them that bit straighter!

 

Incidentally stools tend to be closer together on curves especially in poor ground.

Link to post
Share on other sites

  • RMweb Gold

I have a question though, is the rodding always straight? if so, how does it work on curves?

 

A curve is only a serious of small straight lines :icon_e_smile:

 

And as I recally bl**dy hard to get some of the beggars to swing and get detection afterwards

Link to post
Share on other sites

  • RMweb Gold

A curve is only a serious of small straight lines :icon_e_smile:

 

And as I recally bl**dy hard to get some of the beggars to swing and get detection afterwards

 

I didn't know you'd had a go in Reading West Jcn Dave :lol: Lever 89 I think it was which worked a trailer coming off Oxford Road Curve plus half a double slip with the end of the run on a curve and 'lifting a little' - it was hard but when young Master Karau (yes, the same one) had a go at it after me the lever was hardly out of the frame before he gave up.

Link to post
Share on other sites

  • RMweb Gold

Thank you folks for the swift replies, even if the answer wasn't quite what I was after... I had decided on 9', based on the MSE information (which, of course, I found about half an hour after posting - doh!), as the layout is set in the post-nationalisation era.

 

However, it is an ex-Midland Railway location, with round rodding (which I thought was solid, rather than tubular??). So, I'd worked out how many MSE cast whitemetal stools I needed of differing configurations and am about 25% through cutting them to size.

 

So, it seems that I ought to have the stools at 24mm centres, so that's rather more to cut out (they are cast as '9s', IIRC.

 

However, I have a query regarding the number of rodding runs there should be. This one is particularly pertinent in view of comments made by Stationmaster (on this thread) and by Beast (by PM a few months ago).

 

One of the sets of points - a facing point where the single running line becomes double track - used to have a FPL, but I am taking Beast's advice that it was removed at some unspecified time after the passenger service was discontinued in the 1920s (my period starts in 1959).

 

So, the question is - if one single rod was used to actuate both the point and the FPL, I don't need to do anything - just leave the rod in place to actuate the point end, even if there is no longer a FPL.

 

But, I was planning to leave a spare roller in each of the stools, to denote a rodding run (for the FPL) that has been removed.

 

So, as this is MR practice, should this particular rodding run consist of two rollers, with one disused, or just the one roller in each stool?

Link to post
Share on other sites

  • RMweb Gold

 

However, it is an ex-Midland Railway location, with round rodding (which I thought was solid, rather than tubular??).

 

Could be Tim - I'm not particularly expert on Midland kit. The GE and the GN used tubular so I understand, the GW definitely used solid rod but I don't know about the Midland. The only pics I can find aren't much help - Moorhampton looks very much like solid to me but Hay-On-Wye looks to be tubular :huh: If you happen to somewhere have a pic of Midland rodding you can post or direct me to I could probably tell you which it was as the method of jointing tube was quite different from that of jointing solid.

 

However 0.25 of an inch difference in diameter reduced to 4mm:1ft scale is hardly going to be noticeable I think :lol:

Link to post
Share on other sites

  • RMweb Gold

Not sure how original this is, but this is on the ex-Midland at Haworth on the KWVR, including an FPL.

 

post-6669-12566553829825_thumb.jpg

post-6669-12566554018682_thumb.jpg

 

 

At its earliest it is LMS and most likely BR (if it wasn't something the preservationists installed) as it is channel rodding which I don't think came into general usage (due to its expense) until the early 1930s and only really began to be seen in many more places postwar.

 

Round rodding was still a commonplace sight into the 1960s and in some places even lasted until the 1960s rash of power signalling came along (and in some others was replaced by channel rodding about a year or less before power signalling came along).

Link to post
Share on other sites

  • RMweb Gold

let me know if you run out Capt'n - I've got far more than I need for Summat Colliery's solitary catch point in the MSE starter pack .....

That's very kind of you Ian, but I'm surprised that Andrew had any left after I bought a load at Wells ;) ;) :lol:

Link to post
Share on other sites

  • RMweb Gold

Not sure how original this is, but this is on the ex-Midland at Haworth on the KWVR, including an FPL.

 

post-6669-12566553829825_thumb.jpg

post-6669-12566554018682_thumb.jpg

As Mike has said, I suspect that this was installed by the preservationists, and by that time it looks as if the rules required a seperate FPL rodding run, as in the photo. 'Callow Lane' would have had the old MR single rodding run to actuate both point and FPL (even though the latter was removed when it became freight only), but thanks for posting the info anyway.

Link to post
Share on other sites

At its earliest it is LMS and most likely BR (if it wasn't something the preservationists installed) as it is channel rodding which I don't think came into general usage (due to its expense) until the early 1930s and only really began to be seen in many more places postwar.....

 

The LNWR started using steel channel rodding in 1874 (through a Webb Patent), and as you can imagine had basically replaced any early tube rodding on the LNWR by circa 1900. The LNWR was churning out 6,000 yds of channel rodding a month in 1903 - re. expense, the LNWR was not known to be profligate.

 

The LMS adopted the LNWR's channel rodding as their standard fitting.

 

However back to CK's Midland rodding, looking through various books and photo's I have, those of the Midland pre-group era all seem to have Round rodding, examples are Chesterfield, Derby, Kings Norton, Halesowen etc., etc.,

 

If CK has the excellent booklet on the LNER's 'Railway Signalling and Communications' reprinted by Peter Kay and from the heart of DRAG country, all is there re. round rod fittings etc. (CK if you want to borrow mine, drop a PM).

 

Penlan

Link to post
Share on other sites

  • RMweb Gold

And don't forget compensators B)

Something like this then? ;) ;) (still needs the two central pivots finishing off)...

post-57-12566572243103_thumb.jpg

 

However 0.25 of an inch difference in diameter reduced to 4mm:1ft scale is hardly going to be noticeable I think :lol:

Indeed! I am using 0.45mm brass rod for the point rodding.

Link to post
Share on other sites

My view = one roller in the stool.

And the stationmaster agreed too,

 

But would it have been cost effective to have removed the outer (third) casting to remove the roller, there's the bolt at the top which held all three together, if you remove the outer casting too a shorter bolt is required to hold the remaining castings together, plus the two bolts that hold down the feet on the third one - Illustration below is GER type, but Midland 'look' similar.

 

If there had been some alterations/upgrading to the rodding and point operations in later LMS/BR times, would not the whole lot have been changed over to channel rodding, just a thought.

 

Penlan

post-6979-1256659205111_thumb.jpg

Link to post
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...