NAVYPEDIA

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B2 1900s

Ships

Name	No	Yard No	Builder	Laid down	Launched	Comp	Fate
B1	I21		Vickers, Barrow	1903	25.10.1904	4.1904	sold 8.1921
B2			Vickers, Barrow	1904	30.10.1905	12.1905	collision 4.10.1912
B3	I23		Vickers, Barrow	1904	31.10.1905	1.1906	sold 12.1919
B4	I24		Vickers, Barrow	1904	14.11.1905	1.1906	sold 4.1919
B5	I25		Vickers, Barrow	1904	14.11.1905	2.1906	sold 8.1921
B6, 8.1917- S6	I26		Vickers, Barrow	1904	30.11.1905	3.1906	patrol boat 8.1917, sold 1919
B7, 8.1917- S7	I27		Vickers, Barrow	1904	30.11.1905	3.1906	patrol boat 8.1917, sold 1919
B8, 8.1917- S8	I28		Vickers, Barrow	1905	23.1.1906	4.1906	patrol boat 8.1917, sold 1919
B9, 8.1917- S9	I29		Vickers, Barrow	1905	24.1.1906	4.1906	patrol boat 8.1917, sold 1919
B10	I20		Vickers, Barrow	1905	23.3.1906	5.1906	sunk 9.8.1916
B11, 8.1917- S11	I00		Vickers, Barrow	1905	21.2.1906	7.1906	patrol boat 8.1917, sold 1919

Technical data

Displacement standard, t
Displacement normal, t	287 / 316
Length, m	43.3
Breadth, m	4.12
Draught, m	3.43
No of shafts	1
Machinery	1 Vickers petrol engine / 1 electric motor
Power, h. p.	600 / 290
Max speed, kts	12 / 6
Fuel, t	petrol 16
Endurance, nm(kts)	1000(8.7) /
Armament	2 - 450 TT (bow, 4)
Complement	15
Diving depth operational, m	30

Graphics

Project history

The successors to the 'A' class were very similar, the main improvements being the provision of a more substantial deck casing to improve surface performance and a bigger reserve of buoyancy. They were also fitted with a pair of hydroplanes at the forward end of the conning tower to improve underwater handling. This innovation was not repeated in subsequent classes, but 50 years later it was reintroduced in US nuclear submarines for the same reason.

Modernizations

1917, S6-9, 11: were converted to surface patrols, electric motors were removed; + 1 x 1 - 76 12pdr 12cwt QF Mk.I/II

Naval service

The six boats went to the Mediterranean were not employed after the autumn of 1915 for lack of spares, and in order to make better use of them the Admiralty arranged with the Italian Navy to rebuild them as surface patrol boats at Venice in 1917. This involved removing the electric motors and batteries and building up the bow casing to form a forecastle. A small wheelhouse was provided, and 2 platform for a 12pdr gun. No note survives about their torpedo armament but presumably the tubes were not used. As S6-11 these patrol craft were employed in the Adriatic, and the survivors were sold at Malta in 1919.     B2 was sunk in collision with SS Amerika in the Dover Strait 4.10.1912. B10 was sunk in Venice DYd while undergoing conversion to surface patrol boat 9.10.1916, by Austrian bombing attack. B11 was sent to the Mediterranean late in 1914, and on 1 December negotiated Turkish minefields and nets to sink the coast defence ship Messudieh.