The class RR tie blocks I use are no where near as heavy as a cement block.
We sometime camp in primitive areas that require all different size wood blocks and ramps (length and thickness) for a tandem axle trailer to get it level and to get the truck on a close enough plane to get unhooked/hooked.
When the trailer is level and the pin box is head high or maybe in another camp spot the trailers bumper is 4' of the ground..... then lots of blocks are needed.
Or maybe one side of the trailer is dug down and the other side is on 10"-12" of blocks
I have a big selection of wood 2" x 8" by various lengths..... 4"x8" various lengths, two with one I chain sawed at a angle for drive on ramps......5"x5" various lengths.....RR ties 12" long all in the front storage box.
I also use them under my rear stabilizers and front landing jacks.
"good judgment comes from experience, and a lot of that comes from bad judgment" ............ Will Rogers
'03 2500 QC Dodge/Cummins HO 3.73 6 speed manual Jacobs Westach
'97 Park Avanue 28' 5er 11200 two slides