Glossary

Allies: A term dating back at least to the early nineteenth century but used commonly during the First World War to describe the members of the Triple Entente, more properly known as the ‘Entente Powers’, which were the United Kingdom, France and Imperial Russia. During the Second World War it was used for just the UK and France initially, later including the Soviet Union and then the United States.

ASDIC: Derived from the initials for the Anti-Submarine Detection Investigation Committee originating in the First World War and today known as sonar. Such equipment emits audible pings and then traces submerged objects through their echoes.

Auxiliary carrier: Term applied by the Royal Navy to what are commonly called escort carriers; see below.

Auxiliary cruiser: Merchant vessel taken up from trade and armed with a naval crew. The British used these as convoy escorts, but the Germans used them as surface raiders. In neither case could they survive contact with major warships.

Axis Powers: The alliance formed by Germany, Italy and Japan. Unlike the Allies, there was very little co-ordination at times, especially between Japan and Germany or Italy, or cross-fertilization of ideas or technical developments.

BARBAROSSA: Code-name for Germany’s invasion of the Soviet Union.

Battle-cruiser: A warship usually with battleship-calibre armament, but in which armour was sacrificed to give greater speed. The German battle-cruisers Scharnhorst and Gneisenau had guns of just 11in calibre; these were supposed to be replaced by guns of 15in calibre, although this never happened.

Battleship: Designation given to large heavily-armed and heavily-armoured ships. Second World War battleships generally had guns of 15in calibre, but some British battleships had 14in or 16in and some Japanese ships had 18in guns.

CAM ship: Catapult-armed merchantman, a merchant vessel with a fighter aircraft that could be catapulted off to shoot down enemy aircraft. The fighter pilot was usually from the RAF, but a number of Fleet Air Arm personnel also flew such aircraft. The weakness of the concept was that the aircraft had to be sacrificed at the end of a single sortie unless within sight of land, and this meant that there was always a reluctance to use it in case a greater need came later in the voyage.

Capital ship: A major warship such as a battleship or battle-cruiser, but by the end of the war the aircraft carrier had joined these as a capital ship and many would say had even usurped their position.

Case White (Fall Weiss): German code-name for the invasion of Poland.

Coastal Command: Royal Air Force command that provided maritime-reconnaissance and anti-submarine patrols as well as search and rescue (SAR) in the open seas, and was generally meant to be tasked by the Admiralty. SAR in coastal waters was provided by RAF Fighter Command.

Corvette: During the Second World War this term was adopted for a warship specifically designed for convoy escort duties, smaller than a frigate or destroyer and also slower and of broader bream than the latter, as well as less heavily-armed.

Cruiser: Warship smaller than a battleship or battle-cruiser but much larger than a destroyer. The Washington Naval Treaty of 1922 laid down that light cruisers had a main armament of 6in guns and heavy cruisers a main armament of 8in guns (displacement tonnage was not taken into account). The Royal Navy’s Town-class cruisers had up to twelve 6in guns in four turrets but were classified by the service as ‘heavy’. In addition there were auxiliary (see above) or armed merchant cruisers, and anti-aircraft cruisers that were usually older ships modified to allow continued use.

Cruiser war: A term sometimes used for commerce raiding.

Destroyer: Small fast warship, and by the Second World War much larger than its First World War counterpart. Armament varied between 4in and 4.5in on British ships, but some German ships were larger and the French had their contre-torpilleur destroyers with 5.5in armament.

DYNAMO: code-name for the evacuation of British and French forces from Dunkirk.

E-boat: Enemy fast motor gunboat or motor torpedo-boat, known to the Kriegsmarine as S-Boot for Schnellboot or ‘fast boat’.

Electro U-boat: German U-boat development that appeared from 1943 onwards, with an enlarged hull to enable additional batteries to be fitted for higher underwater speeds.

Empire: A prefix given to the name of a merchant vessel owned by the British government but managed and crewed by a commercial ship-owner. Such ships included enemy vessels seized either on the high seas or caught in an Allied port on the outbreak of war; ships that were built at government expense to compensate for losses or ships taken up for use by the armed services; or US-built ‘Liberty’ vessels supplied to the United Kingdom under the Lend-Lease Programme.

Enigma: Code used by all the German armed forces, but broken once a machine and codebooks fell into British hands. The breaking of the Enigma codes was a major factor in the Allied victory and especially in countering the U-boat threat to Atlantic and Arctic convoys.

Escort carrier: small aircraft carriers sometimes converted from merchant vessels, but later increasingly using merchant vessel hulls to allow conversion to a merchant vessel post-war. Limited in the number of aircraft that could be carried and in operational speed. Sometimes known as ‘auxiliary carriers’ and indeed, many were used as aircraft transports, maintenance carriers and as carriers for aircraft providing cover for invading troops.

FELIX: Code-name for a planned invasion of Gibraltar should Spain have seized the territory; however, it soon became clear that Spain intended to be neutral, although much used as a base by German agents.

Fleet Air Arm: Originally that part of the Royal Air Force deployed aboard British warships, but it reverted to Admiralty control in May 1939 and naval airmen gradually replaced their RAF counterparts, although a large number of RAF personnel transferred to the Royal Navy.

Flotilla: A command of smaller warships such as destroyers, corvettes or submarines. No definition of the number of ships, but usually it would be between six and nine.

Frigate: Originally a general-purpose sailing warship much smaller than a ship of the line (predecessor of the battleship). Frigates disappeared from the world’s navies during the late nineteenth century. They were reinvented during the Second World War as a convoy escort larger than a corvette and slower than a destroyer, and were usually dedicated to anti-submarine or anti-aircraft duties. In more recent times, they have reverted to their general-purpose role.

JUDGEMENT: code-name for the Fleet Air Arm attack on the Italian Fleet in its major base at Taranto.

Kaiserliche Marine: ‘Imperial Navy’, the old name for the German navy.

Kriegsmarine: ‘War Navy’, the official name given by Adolf Hitler to the German navy in 1935 to replace the post-First World War name of Reichsmarine or ‘State Navy’.

Lend-Lease: A programme under which the United States provided ships, aircraft and other war matériel without payment from the British government and on condition that the equipment be returned to the United States at the end of the war (naturally, anything that had been lost on war service could not be returned). In return, the United States armed forces were allowed to use bases in British colonies, mainly in the Caribbean.

Luftwaffe: German Air Force or Air Arm that controlled all German service aviation from the early 1930s to the end of the Second World War. Although autonomous, it developed as primarily a tactical air force without long-range heavy bombers until too late in the war for them to make an impact.

MAC-ship: Merchant aircraft carrier, a ship that continued as a grain carrier or oil tanker with a Merchant Navy crew, but with a wooden flight deck built over the cargo areas and the superstructure moved to starboard so that naval personnel could fly Fairey Swordfish on anti-submarine patrols around a convoy. Most were British-manned, but two were manned by Dutch personnel including air-crew and maintainers from the Royal Netherlands Navy.

NAS: A suffix following a squadron number to denote ‘naval air squadron’.

Reich: The German state (‘realm’).

Reichsmarine: Official name of the German navy after the abdication of the Kaiser and the creation of a republic or ‘Reich’.

Reverse Lend-Lease: Equipment provided by the United Kingdom to the United States. While much smaller in quantity than that received by the UK, this included some warships equipped with ASDIC and radar.

RMS: Royal Mail Ship, a designation allowed the fast ocean liners that, as well as conveying passengers in comfort, also carried the mails. Not to be confused with the Royal Mail Line, a shipping company; ships prefixed ‘RMS’ always belonged to ship-owners, i.e. private enterprises.

Squadron: In naval use, a command of major warships such as battleships, battle-cruisers, cruisers or aircraft carriers, sometimes comprising as few as two ships.

U-boat: In German, Unterseeboot, a submarine.

Wardroom: Royal Navy name for the officers’ mess, also used by some merchant shipping lines such as P&O.

Wolf pack: A group of submarines deployed against a convoy.