The first flat-iron gunboat was launched in 1867, and the last in 1894, with the vast majority being built in the years 1870 - 1880. They were designed as a cheap coastal defence weapon, a role they failed to achieve successfully; they found their greatest utility in offensive coastal bombardment. Strongly built, they lasted in some cases into the late 20th century, and saw action in both World Wars. The hull of the British flat-iron Medway lies in shallow water off Bermuda, and the Norwegian flat-iron Tyr was afloat as recently as October 2009 under the name Bjorn West.