I got a bunch of sleeper off cuts from a woodworker. From these this bench was made.
The blocks was sorted and stacked so that the tops line up. Hole positions where marked and drilled for the threaded bars that runs through the stack. The wood was glued using waterproof wood glue and assembled.
It is a simple build that raised a number of unexpected problems. Each inside sections of the bench is made up of a pair of blocks. The wooden blocks are not the same thickness so there was a lot of time spend sorting them. Once the holes where drilled and you start stacking, you realize they don't line up. With wood this thickness, that means a lot of mallet-ing was needed.