I'd agree about the contraction of "plimsolls"

Plimsoll:
British, American and Australian sneaker, Australian also runner, Australian also sandshoe
noun [C]
a flat light shoe which has a top made of heavy cloth and a bottom made of rubber, and which is worn esp. for sports
Plimsolls may either be fastened with laces, or have a strip of elastic at the front so that they can be slipped on.}
http://dictionary.cambridge.org