Close timber shoring 

so glad we have screws/screw guns now. those nail pairs would be a PITA to get in and even worse to remove.

that guy hammering misses the nail every other swing lmao. great video explain though!

Incredible engineering idea how ever old it gets,never ceases to amaze me, seems like some thingIsambard Kingdom Brunel would have conceived and inventedhe was an incredible talented engineer

incredible , tried it and well worked though

Perfect!

2:30 you will be working in pairs one to dig the trench and the other to dig the dug out dirt

A lot of work, just to dig your own grave.