The idea of strappado is to lift the hands tied behind the back. In order to pull the hands up the self-tightening devices can be used. I used the weight method. This is an illustrational photo session or proof of concept with no real unescapable self-bondage.

I was wearing the following:

• Speedo water-polo swimsuit
• Danskin Ultrashimmery professional tights
• Gerbe fish-net pantyhose
• High-heels
• DIY butt-plug
• Rubber gag
• Latex hood

After setting everything up (see "Self-tightening method") I made a cinch noose on the end of the pull rope, inserted my wrists into the wrist coil and tightened up the noose.

Then I pulled out the trigger rope and undid the shoe-lace knot what released the weight.

The weight was not heavy enough to lift your hands up, no. But it was heavy enought to immediately pull out the slack, if you allow the slack to appear.
This is how you can achieve the double hammerlock position (also see here).

A little bit higher and "hammerlock" converts into "strappado".

A little bit higher and ... I reached my limits

A little bit higher and ... I think this position is called squassation (the hands are tied in the front).