Hi Jarvey50,
PRONI's holdings of historical records kept by railway companies are listed under the "Ulster Transport Authority" (UTA) category.
You can browse this immediately from the initial page on their website
www.proni.gov.uk.
[Select "Search the eCatalogue", then "Browse the eCatalogue".]
Specifically of interest to you will be:
UTA/18 Banbridge Junction Railway
UTA/19 Banbridge, Lisburn & Belfast Railway
UTA/23 Great Northern Railway
However, none of these seem to include a category of "Personnel" under which "Salaries book, containing names of the employees, their occupations, dates of appointment and salaries per annum" might be found.
Such is extant e.g. within UTA/11/K/2-4 for the Belfast & Ballymena Railway, covering 1869-1911.
Records there were restricted to including only those employees who had served for at least 21 years.
[Presumably because they were then entitled to a pension (and a watch).
Employee records were only really kept (by the larger companies) once (private company) pensions came in.
My understanding is that the earliest was the Guinness Brewery in Dublin.]
Ref:
http://www.rootschat.com/forum/index.php?topic=438570.msg3023783Ref:
http://www.rootschat.com/forum/index.php?topic=438570.msg3134269Capt. Jock