na fence at a rate of abou a kilometer per hour. Such an obstacle is not very effective by itself, and concertinas are normally built up into more elaborate patterns as time permits.
Concertina wire is sometimes mistakenly called constantine wire. Constantine probably came from a corruption/misunderstanding of Concertina and led to confusion with the Roman Emperor Constantine. This in turn has led to some people trying to differentiate between concertina wire and constantine wire by incorrectly