The Railway Stand was a very dull white elephant (shite elephant?) to get Stark's Park up to the SPL's 10,000 seat rule. It basically went unused for about twenty years and fell into disrepair. When Hearts/Hibs/Rangers were in the Championship the club renovated the "away" end and got it up to code, and those bucket seats add somewhere in the region of an extra 1,000 tickets to the away capacity.
The "home" end is still mothballed, without any seats. We'd need 5,000 home fans to rock up before we needed it, and that's just not going to happen any time soon. Every now and again there's talk of that section being converted into terracing or hospitality facilities, but as of yet it hasn't come to anything.