Can you share the issue date so I can dig around the online archives?
The few images of pre-USRA B&O reefers that I’ve seen have been truss rod cars with a straight steel center sill. The M-15 boxcars had a fish belly center sill and no truss rods.
The M-18 boxcar class was similar to the M-15 car design but had truss rods and a steel center sill. About 3000 M-18 cars were put into service in 1916. These are low numbers in comparison to the M-15 cars.
In 1917 the B&O ordered a batch of steel underframe freight reefers. Plans were published in the "Railway Age"
trade magazine. The article stated that the underframe was supplied by Ralston. My question is this-is this the SAME underframe as the M-15 DS box cars i.e. did B&O have a standard underframe design?I can see that the two cars have similar underframes: what I want to know is whether they were exactly the same-say like the Pennsy
X23 and X25 and R7 all have the same underframe.(Things like this come up when you're a rivet counter...)
Thanks for any help you can give