scope:

GENERAL DESCRIPTION

Where the number of trains exceeds the numbers of vehicles passing over the crossing it reduces the workload of signallers if the normal position of the barriers is lowered across the road. Such crossings require a means for a user at the crossing to inform the signaller that they require to cross. This gives rise to the name for this version of an MCB which shall be known as an "On Call Barrier" or "MCB-OC".

This section sets out minimum requirements for an MCB-OC crossing.

An MCB-OC does not require Road traffic Lights (RTL's), or the camera column associated with a MCB-CCTV crossing. However RTL's and/or MCB-CCTV camera systems (complete with any appropriate floodlighting), may be provided if it is appropriate for other reasons.

NOTE One reason may be to make the operation of the crossing similar to existing MCB-CCTV types in the same signal box or workstation. If the extra facilities are provided, then they shall follow appropriate requirements of the MCB and MCB-CCTV sections but the RTL's shall extinguish and audible warnings shall silence when the barriers become fully lowered.

This type of crossing shall not be provided where there are more than two tracks, or the maximum permitted speed is greater than 90mph, or where there is a station adjacent.

intended Use:

Superseded by NR/L2/SIG/11201/ Mod X24 Issue 2, June 2012, which is in Word format and attached to thr front sheet of NR/L2/SIG/11201 ISSUE 8.