Definition of "banksman"

It was signalled forward by a banksman and as it passed him at low speed, the amber lights on the level crossing illuminated, [...] The banksman was facing away from the crossing when signalling the lorry driver and did not notice the crossing's activation for about five seconds, [...] After being alerted by another member of staff, the banksman ordered the lorry to reverse as the barriers started to lower.

2020 January 2, “Safety procedures addressed after Essex level crossing near-miss”, in Rail, page 15