On 26/07/2018 11:38, Bert Coules wrote:
Tim,

Many thanks for your thoughts.Â* The collapse has to be pretty much
instant, so any release of pressure on an inflatable dummy would need to
take immediate effect or nearly so.

snip

Instead of the dummy being inflated using a pump via the usual small
orifice, use a big hole with a blower. Maybe cut a foot off and have a
tube going up through a shoe.

https://en.wikipedia.org/wiki/Tube_man

Cheers
--
Clive