11. Once in service they proved to roll badly so bilge keels were later fitted 12. "Black Jack " is steel-hulled with wooden bilge keels . 13. Four bilge keels were fitted to improve stability. 14. On commercial shipping the bilge keel is the form of a draft of the vessel. 15. Her engines were overhauled, she had bilge keels installed, and two masts removed. 16. Originally designed as a family Dinghy and very stable thanks to it's bilge keels . 17. To minimise rolling there were, at Froude's suggestion, enormous twin bilge keels . 18. It has twin fixed bilge keels , and a simple sail plan of headsail and mainsail. 19. This convinced the navy that bilge keels were necessary and they were subsequently installed on all three ships. 20. The ships had a metacentric height of, and were equipped with bilge keels to increase their stability.
