Flat cars and lumber loads

Hi,
I'd like to "prototypically" put some cut lumber loads on flat cars. I've seen photos of models so loaded, and they had extra long stakes extending slightly above the loaded lumber, which were then tied together cross-car over the loads with additional boards.
Many questions: did the DRGW do this on the NG? If so, were / how were the cross-car braces attached to the load? - because in the photos I've seen the lumber was banded in stacks less wide than the flat car. One would have to assume the cross-car boards were tied to the load somehow, otherwise they would really serve no purpose. If not, what type of hold-downs were used? Any reference photos available? Thanx in advance, Gary.