The Monitor was historically a class of relatively small warship which was neither fast nor strongly armoured but carried disproportionately large guns. They were used by some navies from the 1860s until the end of World War II, and saw their final use by the United States Navy during the Vietnam War.
In WW2, the British Royal Navy fielded two 2 ship classes of monitor, The Erebus Class featuring WW1 veterans HMS Erebus and HMS Terror,
HMS Erebus
HMS Terror
and the new heavier Roberts Class featuring HMS Roberts and HMS Abercrombie.
HMS Roberts
HMS Abercrombie
The smaller Royal Navy monitors were mostly scrapped following World
War I, but HMS Erebus and HMS Terror survived to fight in World War II. When requirement for shore support returned, two large new Roberts class monitors, Roberts and Abercrombie, were constructed and fitted with 15-inch (380 mm) guns from older battleships.
HMS Roberts DDay
Allied monitors saw service in the Far East, and in the Mediterranean in support of the British Eighth Army's desert and Italian campaigns. They were part of the offshore bombardment for the Invasion of Normandy in 1944 and the followup assaults to recapture the Channel Ports and the Scheldt.
Plans HMS Roberts
Profile HMS Roberts
Plans HMS Abercrombie
HMS Abercrombie Profiles
Cross Section Comparison
Erebus underway
Specifications:
Erebus Class
Name: Erebus
Builders: Harland and Wolff
Operators: Royal Navy
In service: 1916 - 1946
In commission: August 1916
Lost: One
General characteristics
Type: Monitor
Displacement: 8,000 tons (standard)
8,450 tons (full load)
Length: 405 ft (123 m)
Beam: 88 ft (27 m)
Draught: 11 ft 8 in (3.56 m)
Propulsion: 4 oil fired boilers, 2 shaft reciprocating engines, 6,000 hp (4,500 kW)
Speed: 12 knots
Complement: 204, rising to 315 later
Armament:
(Original):
* 2 × 15-inch /42 Mk 1 guns in a single turret
* 2 × single 6-inch (150 mm) guns
* 4 × single 3-inch (76 mm) anti-aircraft (AA) guns
(After refit):
* 2 × 15-inch /42 Mk 1 guns in a single turret
* 8 × single mount 4 inch guns
* 2 × single mount 3-inch AA
* 2 × quadruple .50-inch (13 mm) Vickers machine gun AA mounts
Armour: Belt and bulkheads: 4 inch
Barbette: 8 inch
Turret: 13 inch
Deck: 4 inch
Anti-torpedo bulges: 9 ft (2.7 m) wide
Roberts Class
General characteristics (Roberts & Abercrombie[1])
Type: monitor
Displacement: Roberts:
7,973 tons (Standard)
9,150 tons (Full load)
Abercrombie:
8,536 tons (Standard)
9,717 tons (Full load)
Length: 373 ft (114 m)
Beam: 89 ft (27 m)
Draught: Roberts: 13 ft 6 in (4.11 m)
Abercrombie: 14 ft 5 in (4.39 m)
Propulsion: 2 shaft, Parsons steam turbines, 2 boilers, 4,800 hp
Speed: 12.5 knots (14.4 mph)
Complement: 442 - 460
Armament: 2 × 15-inch/42 Mk 1 guns in a single turret
8 × 4-inch AA guns (4 × 2)
16 × 2-pdr "pom-pom"s (1 × 8, 2 × 4)
20 × 20 mm guns
Armour: Turret: 13 inch
Barbette: 8 inch
Belt: 4-5 inches
Bang-Bang!
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