While the exterior of the traverses make them look like they were designed by a six-year-old on the beach with a sand pail, at least the concrete itself is interesting! It looks like the engineers just scooped up whatever dicarded garbage was handy and mixed it in. Perhaps it was the late 19th-century version of all those "conversation pieces" that some restaruants hang on their walls today, to give folks something to talk about while they wait for their food? When and if those traverses would be fully manned, the troops could have tried to spot the most interesting detritus in the walls of their station, while simultaneously endeavoring not to eviscerate themselves on the shards of glass sticking out of the concrete.