NAVYPEDIA

Photo

CMB.112 and CMB.98ED  

Ships

Names	Builders	Completed	Losses	Transfers	Discarding
CMB.1, 2 CMB.3, 7.1918- DCB.3 CMB.4 - 8 CMB.9, 7.1918- DCB.2 CMB.10 - 12 CMB.13, 7.1918- DCB.2 CMB.40, 6.1918- Osea CMB.41 - 61 CMB112 CMB121 - 123 DCB.4 (ex-MB.1143) DCB.5 (ex-MB.1256)	Thornycroft, Hampton: CMB.1 - 10, 13, 40 - 42, 47 - 48, 50, 55 - 56, 112, 121 - 123 Tom Bunn, Rotherhithe: CMB.11, 12 Taylor & Bates, Chertsey: CMB.43, 49 J W Brooke, Lowestoft: CMB.44 - 45, 59 Frank Maynard, Chiswick: CMB.46, 53 - 54 Salter Bros, Oxford: CMB.51 - 52, 60 - 61 Wills & Packham, Sittingbourne: CMB.57 - 58	1916: CMB.1 - 13 1918: CMB.40 - 61, DCB.4, 5 1919: CMB.112 1921: CMB.121 - 123	CMB.1 (19.6.1917), CMB.2 (9.7.1918), CMB.5 (1922), CMB.8 (17.9.1917), CMB.10 (7.5.1918), CMB.11 (2.11.1917), Osea (11.8.1918), CMB.41 (1.8.1918, interned), CMB.42 (11.8.1918), CMB.44 (11.8.1918, interned), CMB.47 (11.8.1918), CMB.48 (11.8.1918, interned), CMB.50 (19.7.1918) 16 cancelled 11.1918. (presumably CMB.124 - 139)	Netherlands, 1928: CMB.123	1920: DCB.2, CMB.53, 60, DCB.4, 5 1921: DCB.3, CMB.4, 7, 45, 46, 51, 52, 54, 56 - 58, 61 1922: CMB.41, 43, 44, 48, 55 1925: CMB.6 1928: CMB.49, 59, 112 1929: CMB.121, 122 1935: DCB.1, CMB.12

Technical data

Displacement normal, t	5
Displacement full, t
Length, m	13.7
Breadth, m	2.59
Draught, m	0.82 - 0.92
No of shafts	1
Machinery	CMB.1 - 13: 1 Thornycroft V-8 or Thornycroft V-12 petrol engine CMB.40 - 61: 1 FIAT petrol engine CMB.112: 1 Thornycroft V-12 petrol engine CMB.121 - 123: 1 Green 12-cyl. petrol engine
Power, h. p.	CMB.1 - 13: 250 CMB.40 - 61, 112, 121 - 123: 275
Max speed, kts	CMB.1 - 13: 24.8 CMB.40 - 61: 35.1 CMB.112: 37.3 CMB.121 - 123: 37.8
Fuel, t	petrol
Endurance, nm(kts)
Armament	(1 - 2) x 2 - 7.7/94, 1 - 450 TT (stern)
Complement	2 - 3

Graphics

Project history

Twelve were ordered in January 1916 and all were delivered by mid-August 1916, after Thornycroft had submitted designs based on pre-war hydroplanes. The hull was a stepped planing type and the torpedo was launched tail-first over the stern. The original specification called for CMBs (a camouflage designation) to be light enough for hoisting in light cruisers' davits, but only the 'scout' Diamond was used for this purpose.

Modernizations

None

Naval service

CMB.40 became a nominal depot ship and was renamed Osea in June 1918. A further 16 boats of the CMB.121 group were cancelled in November 1918. Five were converted to Distant Controlled Boats (DCBs), including two 40-footers not previously taken into naval service (MB.1143 and MB.1256, which became DCB.4 and DCB.5). The survivors were mostly sunk as targets or sold post-war, only CMB.12 lasting until 1935. CMB.4 was lent to the Imperial War Museum from 1921 to 1928 and then preserved at Hampton, and is now once again in IWM hands at Duxford.

CMB.98ED

Stunningly detailed and beautiful boat model by John Simpson: http://www.thornycroft40.co.uk/