HMS Myrmidon was a Cormorant-class gunvessel of the Royal Navy, launched at Chatham Dockyard in 1867. As part of the Cormorant class, she was constructed as a wooden screw gunvessel designed for shallow water operations and shore bombardment. The ship featured a barque rig with three masts: the fore and main masts were square-rigged, while the mizzen was fore-and-aft rigged. Her hull was built to accommodate a single screw propeller driven by a 200 nominal horsepower (nhp) Humphreys and Tennant steam engine, making her the last of her class to receive this more powerful engine. Earlier ships in the class had different engines, with some completed as survey ships with 150 nhp engines. Myrmidon's armament was originally intended to include two 68-pounder muzzle-loading smoothbore guns and two 32-pounder guns, but she was completed with a single 7-inch/110-pounder Armstrong breech-loading gun, a 68-pounder muzzle-loading gun, and a pair of broadside 20-pounder Armstrong breech-loaders. Later modifications replaced the 68-pounders with 64-pounder muzzle-loading rifled guns. Her design included a draught exceeding the intended 8 feet; her actual draft was about 11-12 feet, which affected her shallow-water operational capability. Commissioned in October 1867, HMS Myrmidon served primarily on the North America and West Indies Station before transferring to the Australia Station in March 1885. During her time in Australian waters, she conducted hydrographic surveys along the coastline. Notably, she was involved in a collision with the troopship HMS Tyne near Sydney in April 1887. After completing her survey duties, she sailed to Hong Kong and was sold in April 1889 for £3,000. The ultimate fate of HMS Myrmidon remains unknown, but her service contributed to the Royal Navy’s maritime surveying efforts and demonstrated the versatility of the Cormorant class in various operational theaters.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.