New Gunboat For The Voyage Launched At Southampton - "Dragonfly" cheered by workman as she took the water. H.M.S. "Dragonfly", a navy gunboat for the Yangtse River, was launched by Lady Dent at the yards of John I. Thornycroft and Company, Limited, at Woolston, Southampton. A sister ship of the "Dragonfly", the "Grasshopper", is also being built at Thornycraft's. Each ship will have a displacement of 585 tons and embody considerable improvements in armament, protection and living accommodating over earlier types. December 08, 1938.