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AOCL+B or ABCL

Unread postPosted: Mon Jul 3, 2017 9:48 pm
by Peter Gibbons
Can anyone explain the differences between these two types of crossings, please?

In the Network Rail electronic Kent, Sussex and Wessex Sectional Appendix it shows that the level crossing at Winchelsea (East Sussex) is now an AOCL+B. It was formerly an AOCL crossing.

Yet the same publication shows Yalding Crossing (Kent) as an ABCL. It too was formerly an AOCL crossing.

To me it seems that the way both types of crossing work is identical.

Thank in advance, to anyone who can answer my query.

Re: AOCL+B or ABCL

Unread postPosted: Tue Jul 4, 2017 6:49 am
by AN106
Peter Gibbons wrote:Can anyone explain the differences between these two types of crossings, please?

In the Network Rail electronic Kent, Sussex and Wessex Sectional Appendix it shows that the level crossing at Winchelsea (East Sussex) is now an AOCL+B. It was formerly an AOCL crossing.

Yet the same publication shows Yalding Crossing (Kent) as an ABCL. It too was formerly an AOCL crossing.

To me it seems that the way both types of crossing work is identical.

Thank in advance, to anyone who can answer my query.


As I understand it, an AOCL+B uses the existing AOCL circuitry, and adds additional circuitry to control the barriers. If an AOCL crossing such as Yalding is replaced with an ABCL, all the existing circuitry would have been recovered (with the possible exception of track relays, etc.) and new circuitry put in instead. I must admit I've never worked on AOCL+B crossings, but I suspect they don't meet all the standards of an ABCL, which is why they are only a temporary arrangement.

Re: AOCL+B or ABCL

Unread postPosted: Tue Jul 25, 2017 7:34 am
by AndyB
If I remember rightly, the DWL does not confirm barriers down at an AOCL+B.

I think the decision is taken on the basis of whether the AOCL in question is due for renewal anyway.