In addition to the above, while I have not come across a TSC, all the others are used in the UK. In UK practice, the ES is responsible for one worksite within a possession, a combination of which is the overall responsibility of the PICOP. ‘Lookouts’ are no longer used in Scotland as ‘Red zone working’ in which workers share the tracks with normal traffic, has been deemed too dangerous.
On reflection, it may be that TSC is the Irish version of the UK’s ‘COSS’ (Controller of Site Safety).