Interesting.  The second

Interesting.  The second graphic shows and SDPX hopper car from my home state!  They aren't new anymore either.

Rib side cars make up the backbone of my HO scale grain fleet.  I have fond memories of BNSF moving grain in SE South Dakota.  Long trains of ribside BN cars with a few jumbo oxide red BNSF cars mixed in.  For fun, there were always a couple green AOK cars of CNW heritage thrown in.  Power was a new-ish Dash 9 and a pair of SD40-2 units from ATSF or BN still in legacy colors.   I intend to backdate even farther and use mostly BN cars with a few Hill Lines and Frisco representatives in for good measure.

Eric Carlson
Crooks SD

Certificates Of Transportation

Around 1990 the railroads began offering what are sometimes called Certificates Of Transportation*.  In effect, a grain elevator placed orders for blocks of cars well in advance of when they needed them, and the railroad promised to deliver those cars on or very close to that date, and the elevator had a certain amount of time to load them.  How much time depended on the elevator and how many cars.  Most of the cases I saw were two business days.

So now rather than the elevator needing to hold onto a small fleet of cars so they weren't at the mercy of the railroads' car supply, the burden was on the railroad to have enough cars.  The first impact of this was many of the lease fleet cars (PTLX, etc) with elevator and grain marketer lettering got leased or sold to the railroads.  Then when that supply dried up orders went out for new cars.  At first they were mostly new PS-2/4750s built by Trinity, which bought Pullman in 1984.  When the increase in the "100-ton" Gross Rail Limit from 263000 to 286000 pounds effective January 1995 was announced a few intermediate designs were produced, like Trinity's rib-sided 5127cf, which looks like a 4750 with deeper sides.  But in 1995 the "curved side" 286k cars took over the market, and they sold like hotcakes.  This created the "brown worms" (BNSF) and "grey worms" (NS and UP) that are such common sights today.  Many of these "worms" carry 500,000 bushels of grain.  It takes a big elevator to load that much grain in a couple days.

*COTs were at least what BN called them.  I don't recall if other roads used the same term.

Scott Chatfield