Mysore railway museum, situated beside the Mysore railway station, is a interesting place to visit. It has a collection of railway engines, caoches of the erstwhile royal family of Mysore. It was setup in the year 1979, but is exceptionally well maintained by the indian railways. If you want a technical review of whats kept there and its significance to the railways take a look at
The visiting hours for the same seem to be fixed between 9 am and 6 pm. I found the mini train ride rather pleasant after the walk through the museum. It can be noted here that Mysore has a huge railway campus near Ashokpuram, where train repair and design takes place. The rail museum has its entrance just opposite to the entrance of CFTRI.