When freight cars reached the end of their useful life in "revenue service" a few were demoted to work trains where they provided storage for equipment and parts for track or wreck crews. Former CP 40ft boxcar, #51426, was acquired by the Society in 1990 for just that purpose.
There is also historic significance as the 40ft type boxcar has, for the most part, disappeared from Canadian railways for any kind of service. These have been replaced by longer/higher boxcars and special-use cars.
51426 is relatively young, compared to the other equipment owned by the Society, it was built by Canadian Pacific in 1956.