NAVYPEDIA

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M29 1915

Ships

Name	No	Yard No	Builder	Laid down	Launched	Comp	Fate
M29, 12.1925 - Medusa		485	Harland & Wolff, Belfast	3/1915	22.5.1915	6/1915	minelayer 1.1925, repair ship Talbot 9.1941
M30		486	Harland & Wolff, Belfast	3.1915	23.6.1915	7.1915	sunk 14.5.1916
M31, 12.1925 - Melpomene		487	Harland & Wolff, Belfast	3.1915	24.6.1915	7.1915	minelayer 1.1921, torpedo instruction vessel 9.1939
M32		488	Workman Clark, Belfast	3.1915	22.5.1915	6.1915	sold 1.1920
M33, 12.1925 - Minerva		489	Workman Clark, Belfast	3/1915	22.5.1915	6/1915	minelayer 2.1925, boom defence workshop 11.1943

Technical data

Displacement normal, t	355
Displacement full, t	580
Length, m	54.0
Breadth, m	9.40
Draught, m	1.80 deep
No of shafts	2
Machinery	2 VTE, 2 boilers
Power, h. p.	400
Max speed, kts	9
Fuel, t	45 oil
Endurance, nm(kts)	1440(8)
Armour, mm	gun shields: 152
Armament	2 x 1 - 152/45 BL Mk XII, 1 x 1 - 57/40 6pdr Hotchkiss Mk I
Complement	72

Graphics

Project history

Just after the 234mm monitors had been ordered, Queen Elizabeth class were instructed to land their main deck 152mm guns. As only two could be resiled in each ship there were 10 Mk.XII guns available, so a slightly modified version of the M15 design was drawn up, armed with 2 single 152mm guns. The 7t gun could range to 13.4km at 17.5° elevation, and the total weight of gun, mounting and ammunition came to only 62t as against 100t for the 234mm guns. Using these approximate figures it was unwisely assumed that both displacement and draught could be scaled down by 18%, as compared with the M15 hull. This was unfortunate as the designers had overlooked the need to provide sufficient deck area for two guns, and if the deck area could not be reduced the hull dimensions could not be reduced either. The result was a ship which bore no relation to her legend displacement of 355t and designed draught of 1.2m. However, this alarming discrepancy did not affect them too badly, apart from a tendency to trim by the head which made steering difficult. Although the ex-Queen Elizabeth class guns were the basis for the design the guns actually allocated to the monitors turned out to be new construction mountings from COW and most barrels came from Vickers.

Protection

Only guns had armoured shields.

Modernizations

1919, M31, M33: - 1 x 1 - 57/40; + 1 x 1 - 76/45 20cwt QF Mk I

1/1921, Portsmouth DYd, M31; (9/1923-1/1925, Devonport DYd), M29, (5/1924-2/1925, Pembroke DYd), M33: as minelayers without artillery, can carry 44 mines.

Naval service

M30 was sunk by Turkish coastal batteries off Smyrna 14.5.1916.

Many thanks to Wolfgang Stöhr for additional information on this page.