Albacore class gunboat (1855)

HMS Raven, one of the Albacore class
Class overview
Name:	Albacore class (1855)
Operators:	Royal Navy
Preceded by:	Dapper class
Succeeded by:	Cheerful class
Built:	1855–6
In commission:	1855 – 1881
Completed:	98
General characteristics
Type:	'Crimean' gunboat
Tons burthen:	232  68⁄94 tons bm
Length:	106 ft (32 m) (gundeck) 93 ft 2.5 in (28.410 m) (keel)
Beam:	22 ft 0 in (6.71 m)
Draught:	6 ft 9 in (2.06 m)
Installed power:	60 nominal horsepower 270 ihp (200 kW))
Propulsion:	2-cylinder horizontal single expansion steam engine Single screw
Speed:	7.5 kn (13.9 km/h)
Crew:	36–40
Armament:	1 × 68-pounder (95cwt) MLSB gun 1 × 32-pounder MLSB gun 2 × 24-pounder howitzers

The Albacore-class gunboat was a class of 98 gunboats built for the Royal Navy in 1855–56 for use in the Crimean War.

The Albacore class, designed by W.H. Walker, was almost identical to the preceding Dapper class, also designed by Walker. The ships were wooden-hulled, with steam power as well as sails, but of shallow draught for coastal bombardment in the shallow waters of the Baltic and Black Sea during the Crimean War.

Half of the ships had two-cylinder horizontal single-expansion trunk steam engines, built by John Penn and Sons, with two boilers. The other half had two-cylinder horizontal single-expansion direct-acting steam engines, built by Maudslay, Sons and Field, with three boilers. Both versions provided 60 nominal horsepower through a single screw, sufficient for 7.5 knots (13.9 km/h; 8.6 mph).

Ships of the class were armed with one 68-pounder (95cwt) muzzle-loading smoothbore gun, one 32-pounder muzzle-loading smoothbore gun (originally two 68-pounders were planned but the forward gun was substituted by a 32-pounder) and two 24-pounder howitzers.