I have used the PA Historical and Museum Commission, website for railroad records is:
http://www.portal.state.pa.us/portal/server.pt/community/rai...

The site will give you a list of records available. The one I requested information from was the PA Railroad Voluntary Relief Fund. This was a "retirement" fund but was completely voluntary--my ancestor did not contribute but may be you will get lucky. I cannot remember the cost (it was years ago I requested it) but I do also have a phone number 717-772-5070.