Irish Railway Records Dublin-seeking information on Thomas Cassin 1856-1891 & father James Cassin (1823?-1871?)

Hi Volunteers

I wrote to the Irish Railway Record Society in Dublin seeking information on my ancestor Thomas Cassin/Cassen about a month ago. I don't know if or when I might get a response, so wondering if there is a local researcher here who is familiar with their catalogue & what records are available.

I am seeking information on where & when Thomas was born & any information on his father James & hoping there might be employment records at the Railway archives. The spelling of the name could be Cassin, Cassen Cassan. 

I know that when Thomas married Kate Ryan from Wicklow in May 1882, his occupation was Railway Porter. His address at the time of marriage was Dundrum, South Dublin. His father James was noted as a Railway Gaffer so they may have worked together.

Thomas's death certificate notes that he was a Railway Guard, had been ill for 1 year, and died of TB on 31 Mar 1891 in Harold Cross Hospice. Aged 35. He is buried in Glasnevin in free ground, same as father James. No headstones unfortunately. (Confirmed by Kieran Jordan).

Thomas's address was 15 Richmond Place, South Dublin.

Thanks in advance for any information you can provide. 

Pam