What dimensions of sleepers does IR use?

Wooden BG sleepers dimensions are usually 2.75m x 0.25m x 0.13m. MG wooden sleepers are 1.8m x 0.2m x 0.115m. NG sleepers are usually of the same thickness as MG sleepers, and are often made by cutting MG sleepers (sometimes discarded ones) to size and adding a new seat for the track. Most sleepers on the Darjeeling Himalayan Railway are wooden, of size 5' x 7" x 4-1/2", although 'remanufactured' MG steel sleepers are also used. On 2' NG, sleepers are usually 4-1/2' x 8" x 4" or 4-1/2' x 7" x 4".

Source - IFRCA.org