Jack post

They are designed to be able to mechanically telescope to about twice their shortest length in order to span a wide variety of spaces.

Jack posts are mostly used for shoring: temporary supports during building repair or alteration work, rather than scaffolding: access platforms for workers.

As the plates on the end of the posts are typically small, they offer little sideways support.

[3] A similar lightweight European prop design exists, these have a maximum capacity of only 5 kilonewtons (1,100 lbf).

Size 1, 2 and 3 props can take about 34 kN unextended, dropping progressively to less than half of that when fully extended.