>>These have 4 truss rods and are all wood construction. Typical for the day.
>>Downloading the large tiff file from the LOC and all details can be seen, right down
>>to the lettering on the trucks.
>>From Ray Breyer's post, it appears that the car in Monticello is from a later period.
Or, we're talking about different cars from the SAME time period. I've got clear photos of nine C&A trussrodded boxcars. Only one car clearly has four rods, and that car was built in the 1870s.
C&A 4468, 4 trussrods, built ca.1875
C&A 7213, 6 trussrods, built ca.1889
C&A 7786, 6 trussrods, built 1899
C&A 13130, unknown, built 1897-1899 (and 1904, according to the ICC val report), LoC image
C&A 15281, unknown, built 1899. LoC image
C&A 27469, 6 trussrods, built 1906
C&A 36839, 6 trussrods, built 1906
C&A 36959, 6 trussrods, built 1906
C&A car at Monticello (supposedly 3516, which is probably wrong), 6 trussrods.
Earlier, shorter cars (35' and less) in the 20 and 30 ton capacity range usually had only four trussrods, while longer cars (45-foot furniture cars), and anything above 35 tons had six trussrods. So it's "likely" that the two cars mentioned in LoC image 4a20233 only have four since they're 30 ton cars. But even playing with various values of the 157 meg Tiff file can't say one way or another (and the 1910 C&A diagram book isn't any help either). Both four and six trussrods were "typical for the day", depending on how much weight the underframe was supposed to bear.
The car in Monticello seems to be a 36000-series car; the 3516 number may have been its MOW number at one point. 1906 is slightly newer than 1899, but I wouldn't go so far as to call it from another era.
If anyone's thinking about converting an Accurail shorty into a trussrodded car, keep in mind that it's a BIG boxcar for the pre-WWI period, and would have been a 40 ton, six rod car.