Re: When were double doors put on 1937 AAR 40' boxcars?
Does anyone know when railroads (e.g. northern pacific) started putting double doors on 1937 AAR 40 foot boxcars (since these originally had single doors, right?)?Go to the equipment pages of the NPRHA website
Select freight cars and go to the second page of box car diagrams (scroll down to the bottom of the first box car page and use the > symbol to go to diagrams 31-60.
The NP started purchase and building of new plug+sliding door cars in the late 1950's in response to shipper use of forklifts to handle lumber. In its final decade, NP leased rebuilt STMFCs with double doors, also for that service. These were rebuilt with a second door by the lessors.
For their time on the NP roster, the cars about which you asked all fall into the period beyond 1960; you can see lease dates on the diagrams.