Herman Family wrote:

If you want a very tough floor, then end grain up wood is among the
toughest. I've seen that in a railroad barn once. I don't know how the
wood has survived so long. It might be interesting to ask the road crew or
the transportation department what sort of wood was used.

Michael

This type of floor is quite common in manufacturing plants where dropping
a valuable piece of metal on concrete would be disastrous. Tire plants and
plants that make tire molds have acres of block floors.

The blocks are creosote or tar soaked oak 4" long set on end. No glue or
grout is used, the blocks are just wedged in. The man replacing a section
of floor uses a hatchet, wide chisel, and a mallet.

The plant where I worked had yellow spray paint outlines on the floor in
several areas, when I asked what the lines meant, I was told to wait for a
good rain then I would know. The lines indicated where not to walk after
a leak in the roof had wet down the blocks real well and caused the
floor to "blister up". As long as you didn't knock any of the blocks out
of the blister and make it fall in on its self, the blister would subside when
the wood dried out again.

The largest, and one of the first, blisters or domes I saw in one of these
floors
was in the main floor of a facility that was being shut down. The dome was
20 to 30 feet in diameter and 3 to 4 feet high in the middle.

ARM