HMS Surly was a mortar vessel constructed for the Royal Navy at Blackwall Yard by Money Wigram & Son, with her keel laid down on 9 October 1854 and launched on 31 March 1855. She measured approximately 65 feet in length at her gundeck and about 52 feet 5 inches at the keel level, with a beam of 20 feet 10 inches and a hold depth of 7 feet 6 inches. Her burthen capacity was around 11.72 tons. The vessel was equipped with a single mortar cast by the Carron Company, designed for explosive shell bombardments. Commissioned during the Crimean War, HMS Surly was deployed to the Baltic Sea in 1855, serving with Anglo-French forces during the Bombardment of Sveaborg in Finland. Under the command of a petty officer, Surly participated in this significant attack aimed at Russian fortifications. During the bombardment, her mortar experienced technical issues, including a destroyed suspension gear that initially allowed independent targeting, and cracks at the base of the mortar chamber that necessitated multiple repairs. The mortar was reinforced with chains after its original band failed, and it fired a total of 78 shells over two days, demonstrating notable, though challenging, effectiveness. Despite technical setbacks, the bombardment inflicted substantial damage, destroying key Russian military and civilian infrastructure, including powder magazines, a hospital, granaries, and private residences. The operation resulted in approximately 2,000 Russian/Finnish casualties and 59 Allied fatalities and wounded. This engagement marked the last significant use of mortar vessels by the Royal Navy, as advancements in rifled artillery soon rendered them obsolete. Later in 1855, HMS Surly was renamed MV9, likely to free the name for a new gunboat. She remained in service until she was broken up in November 1863. Her service demonstrated the Royal Navy's experimental use of mortar vessels during the Crimean War and highlighted the transition in naval artillery technology.

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