Inmates at a young offenders’ institution are learning how to vault 13ft high bars.

But the governor insists that their new skills will not be put to use for escape bids – because the jail walls are 20ft high and topped with razor wire.

About 30 prisoners aged from18 to 21 have attended pole vault classes at Portland Young Offenders’ Institute, in Dorset, which has a total of 560 prisoners.

Taxi driver Mike Lee, whose firm is used by the prison, said: “It struck me as funny that prisoners are being taught to pole vault. Next they will be teaching them rock climbing and ladder making.” Mr Lee, 60, of Weymouth, added: “Let’s hope they don’t get too good at it.”