Point Rodding-How long?

[Lady_Ava_Hay]

I am building a layout that has no signal box on it but uses ground frames plus directly operated points.

 

I am familiar with ground frames and direct linkage manual point levers.

 

I have operated signal boxes and would guess that up to 100 yards ( ok 100 metres ) of rodding was being moved by a signal box lever. I recall that it seemed well within my capability to operate that length.

 

Is there a difference between a signal box lever and a ground frame lever in terms of pulling power?

 

Is there a maximum distance of rodding from the operating lever specified or was it left to operating experience?

 

Would this distance be affected by the size of the point being operated?

[Miss Prism]

Normal max reach from a pukka signal box was considered to be 440 yards, and would be a lot less for a ground-level lever because of the reduced leverage, but I'm not aware of any ruling or accepted norm for ground frames. The size of turnout would not be relevant.

[LNERGE]

Traditionally points could be operated by rod up to 350 yards. There were dodges out there to get round this but that is possibly out of scope for the question. I've just installed two ground frames for Network Rail with the furthest end 220 yards from the lever. I still had plenty of adjustment left so it would have worked if it was a longer run. The biggest problem for me was having to incorporate back drives on the main line ends. The current BRS-SM ground frame produces around four and a half inches of stroke. A signalbox lever can be made to give more.

Edited February 16, 2018 by LNERGE

[TheSignalEngineer]

It also depends on your era and rail type.

The first mention of point operating distances in the Board of Trade Requirements was 180 yards. Over time this was increased to 350 yards.

The problem is that at that time the standard rail was 95lb Bullhead, often with C or D switches. The pull needed for an E switch in 113lb Flat Bottom is considerably greater and when that was introduced the office I was in tended not to mechanically work over 200 yards, especially with double-ended points.

 

Ground Frames inherently by the nature of the operation tended to be at the points or in the middle of a double ended set or group.