I'd guess it's been 30 or more years since I last saw pulpwood being loaded on woodracks here in NW Louisiana. But until about a year ago I'd often see whole unit trains of the old bulknead woodrack cars running north on the KCS at Shreveport carrying not pulpwood but large slabs of steel. All the cars in these trains had either KCS or SR reporting marks. I'd see these trains about twice a month running loaded northbound and returning empty southbound. Obviously I didn't see each and every movement so I'm sure they ran more frequently than that.
I'd estimate the steel slabs they carried to be about 4-5 ft wide, 20 ft long and a foot to 18 in thick. They were usually loaded six slabs/car, four on the deck of the car and two more on top of these four. I never learned the origin or destination of these loads but assumed it was foreign steel coming into the country from either Mexico or being off loaded from a ship at Port Arthur. The slabs were likely destined for a rolling mill in the upper mid-west.
I haven't seen any of these trains lately so they've either been discontinued or, if they're still running, now come through in the wee hours of the morning when I wouldn;t have a chance to see them.It was nostalgic to see these rusty, near 50 years old relics still in service even though they were no longer carrying pulpwood.