HMS M3 (1918)
| Industry | Shipbuilding |
|---|---|
| Headquarters | Newcastle Upon Tyne , United Kingdom |
HMS M3, an M-class submarine of the Royal Navy, was constructed by Armstrong Whitworth in Newcastle Upon Tyne.
Construction and commissioning
The submarine M3 was ordered from Armstrong Whitworth on 28 July 1916 and its keel was laid down at Elswick in December under the designation K20, classified as an M-class submarine. She was launched on 19 October 1918 and officially commissioned as M3 on 16 March 1920. Following the completion of her trials on 17 August, she was subsequently placed into reserve status.
Service
M3 was recommissioned on 4 July 1921 with Lieutenant-Commander Hugh Marrack assuming command, and subsequently joined the 1st Submarine Flotilla on 17 February 1922.
Between 9 and 14 May 1926, M3, alongside submarines K26 and L23, participated in supplying electrical power to the Royal Victoria Dock, Royal Albert Dock, and King George V Dock in London during the General Strike of 1926. This operation, known as Operation Blackcurrant, saw M3 alone maintain power for four meat cold stores, two cranes, and several critical pumps.
Minelayer
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On 15 October 1926, M3 was placed into reserve status until 13 June 1927, when she arrived at Chatham for conversion into an experimental minelayer under the terms of the Washington Naval Treaty. Politically, this modification was described as a refit. To accommodate a large free-flooding superstructure covering approximately three-quarters of her length, her 12-inch (305 mm) and 3-inch (76.2 mm) guns were removed. Within this structure, two sets of rails ran along the pressure hull capable of holding up to 100 standard Type B contact mines. Deployment of the mines was facilitated by a conveyor chain that passed through a single large stern door.
The conversion was completed on 8 October 1928 at a cost of £10,235 (contemporary value), with trials concluding by mid-November. Initially, only 80 mines were carried aboard, with the remaining 20 added subsequently.
The addition of minelaying equipment and mines increased M3’s displacement by roughly 54 tons and negatively impacted her diving performance. Flooding the expansive casing—which contained about 600 tons of water—required approximately five minutes to submerge in calm conditions and extended to at least thirteen minutes during rough seas. Additionally, achieving proper trim was perilously slow. In May 1930, Rear Admiral Martin Dunbar-Nasmith, head of the Submarine Service, expressed that "...at present M3 is not efficient or reliable as a submarine and could not with safety be used in war."
Although initially scheduled for scrapping in 1933, M3’s decommissioning was expedited due to these unfavorable assessments of her minelaying capabilities. She was withdrawn from service on 6 February 1932 and dismantled at Newport by April of the same year.
Insights gained from M3’s conversion influenced the design of the Porpoise-class minelaying submarines, which featured mines arranged in a single row.
Other ships
The monitor HMS Raglan briefly bore the name HMS M3 for a short period.