a.k.a. "Trust" (Lon More would recall).
Two teams 10-12 being typical.
Requirement : one large area ( e.g.dining room or bar) with a spare amount of wall space.
First team : One (or preferably two or three for buffer effect) stand with backs against the wall, in tandem. Wall guy locks arms around mate in front. Both have legs splayed.
First of the "bench" bends down with head between legs of wall team and also splays legs. Next man does same behind him ans so on until you have a line of guys so positioned coming out from the wall .
Second team: Each in turn runs up and jumps, i.e. does a flying leap, along the "bench" to land on it.Rapidly followed by the rest of the team, aim being to collapse the "bench".
(There are tactics to this, e.g. everyone pile on No .3- or worse, the end man) )
Once last man is aboard there is a count of ten whilst the second team attempt to break down the "bench".
Following the success or otherwise of this episode, the teams reverse and the next round is played.
Apparently banned in RAF messes for some many decades now ( can't think how I learned it
)