In article ,
T i m wrote:
[snip]
ps Have you done this yourself (hydraulic post removal
not bikini wearing) ?

No. The thought was from an experience of lifting
two large gateposts out of Herefordshire clay,
using a car jack and levers. The hydraulic suction
was so large that it nearly defeated the job. The
saving grace in clay is that the post can be rocked
to break the seal.

--
Tony Williams.