What Percent Of Length Lost In 3ply Plait?

[charliehows]

I'm planning to plait a heavier mooring line - a simple 3 rope hand-over -hand plait - anyone know what percent of length is lost - ie if I start with 3 10metre lengths I know the final plaited rope will be less than 10 metres, but how much less? thx in advance.

[Hydra]

I would try to make a sample and measure it. I think that the "shrinking" depends on how tight the plaiting is.

Alain