Level crossing gate mechanism

[dsj672]

I'm some way along building a layout , based loosely on a closed prototype, which has a level crossing and crossing keepers hut.  The hut (Peco) has a couple of levers and a wheel to open the gates. I'm at the stage where it would be good to know how the hut was linked to the gates so that I can model this correctly.  Was the linkage covered by timber boards, for example?

 

Any advice would be most welcome.

[The Johnster]

IIRC the gates were chain driven, so the linkage is chains and pulleys.  This was covered by wooden planks on the pedestrian walkway and worked a drive wheel beneath the pivot posts.  

[wiggoforgold]

How far would the gates be from the signal box? Might the gates be controlled from a crossing keeper's hut? Was there any linkage between the box and the chain drive, or was it changed drive all the way? (Apologise for the thread hijack, but TJ's answer raised a few questions for me, which I hope are pertinent)

Alex

[Grovenor]

I have not seen any chain drive gates, usually the gate wheel in the box connects to the gates by rodding, similar to point rodding but a bit beefier.

In many cases with a crossing keepers hut the gates were just hand operated and there would not be a gate wheel.

Rgds

[Dunsignalling]

Don't forget, was also necessary for the signalman (or crossing keeper) to have a decent view of the road on either side of the line - no CCTV back when gated level crossings were put in.

  

I've never worked a mechanical L/C, but always got the impression that that it was difficult to keep the chains tight (where they existed) and avoid lost movement in the drive. If rod driven, weight, friction and expansion would be issues in the same way as they were/are with point rodding. ISTR recall seeing an old diagram of the arrangement in a (fairly tall) signal box where a chain took the drive from the gate wheel to ground level from where it in turn drove the rods. 

 

Convention was that the signal box was generally sited as close as possible to the crossing. That's not surprising, after all, in most locations both were installed at the same time or the box was newer than the crossing. In all cases I can recall, if there was any significant distance between them, a separate crossing cabin was provided. 

 

John

Edited December 11, 2018 by Dunsignalling

[Dunsignalling]

I have not seen any chain drive gates, usually the gate wheel in the box connects to the gates by rodding, similar to point rodding but a bit beefier.

In many cases with a crossing keepers hut the gates were just hand operated and there would not be a gate wheel.

Rgds

The crossing at Axminster (Castle Gates) was certainly rod driven from the adjacent keeper's cabin, though that also served as a block post at various times in it's history so might perhaps be best regarded as a very small signal box....

 

John

Edited December 11, 2018 by Dunsignalling

[johnd]

Depending on where in the world you are located (UK?) it may be worth visiting a preserved ( Heritage ) railway that still has operational gates . You will  usually find that enthusiasts will only be more than happy to explain/show how the gates work and the way they work.

[34theletterbetweenB&D]

Drive systems may well have varied. The signalling manufacturer McKenzie and Holland had a design where the Gate wheel drove a screw carriage which moved a lever (much like a screw reverser on a loco) and provision for mounting this mechanism at the end of their standard lever frames.

[The Johnster]

Any mechanical drive had to be very 'local'; loss of drive in the system is a big problem in both chain and linkage driven systems, and in any case the operator, signalman or crossing keeper. had to have a clear view of road traffic in both directions; he or she (crossing keepers were often women).  

 

The point at which the road crossed the railway was often a convenient place to put the signal box anyway, near the station throat where the points and signals were.  Such signal boxes often had windows in the rear wall of the box so that the signalman could have a clear view up the road.

[Coach bogie]

It is worth taking a look at surviving gates (there are many. Here is Sleaford, unusual as teh gates are only on one side. The various push rods open and shut the gates. There are separate locking levers with associated rodding to lock the gates in both open and closed positions and the wickets( Foot pedestrian gate).

 

The wickets are often always in the closed position, held in place by a balance weight with a chain or rod to the gate.

 

Mike Wiltshire

[DCB]

The hut is likely to have locking levers at most and the keeper will have to open and close the gates by venturing out in the darkness wind and rain to move them manually.  The crossing at Minety on the Gloucester Swindon line remained manned into he 2000s which was ridiculous when the signalling was from Swindon Panel Even in 1860 employing a bloke 24/7 was expensive so it made sense to have the crossing adjacent to a signal box. This need for the box to be adjacent to the level crossing often leads to the crossing being across the passing loop on stations on single track lines.  Very rare on models as most folk have the level crossing first on the single track and the loop points beyond.  Williton and Blue Anchor (both WSR) are surviving stations with feature.

Edited December 13, 2018 by DavidCBroad

[Coach bogie]

I agree with DavidCBroad. The smaller crossings would be, and still are in many locations, opened/closed by hand with gates released by a locking lever in the cabin.

 

 

Some just have a simple lock on the post.

 

Mike Wiltshire

 

Edit to try and turn images. No idea why they are appearing like this as original is correct orientation.

Edited December 13, 2018 by Coach bogie

[Coach bogie]

Post repeated for some reason

Edited December 13, 2018 by Coach bogie

[micknich2003]

Typical connections for a "Square" four gate crossing.

[88D]

Depending on where in the world you are located (UK?) it may be worth visiting a preserved ( Heritage ) railway that still has operational gates . You will  usually find that enthusiasts will only be more than happy to explain/show how the gates work and the way they work.

Just don’t watch ‘Oh, Mr Porter’ for guidance.

[dsj672]

Many thanks for the various replies, very useful indeed.