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HMS Douglas (1918)
HMS ''Douglas'' was an Admiralty type flotilla leader (also known as the ''Scott''-class) of the British Royal Navy. Built by Cammell Laird, ''Douglas'' commissioned in 1918, just before the end of the First World War. During the Second World War, ''Douglas'' served with Force H out of Gibraltar and as a convoy escort. She was sold for scrap in March 1945. Design and construction In December 1916, the British Admiralty placed orders for two Admiralty type flotilla leader, large flotilla leaders, and ''Douglas'' from Cammell Laird as a follow on to the prototype of the class, , which had been ordered in April that year.Gardiner and Gray 1985, p. 83. The ship was length between perpendiculars, long between perpendiculars and length overall, overall,Friedman 2009, p. 298. with a Beam (nautical), beam of and a Draft (ship), draught of . Design displacement (ship), displacement was normal and full load. The ship's machinery consisted of four Yarrow boilers that fed steam at t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cammell Laird
Cammell Laird is a British shipbuilding company. It was formed from the merger of Laird Brothers of Birkenhead and Johnson Cammell & Co of Sheffield at the turn of the twentieth century. The company also built railway rolling stock until 1929, when that side of the business was separated and became part of the Metro-Cammell, Metropolitan-Cammell Carriage & Wagon Company. History Formation from merger of Laird Company and Cammell & Co. The Laird Company was founded by William Laird (shipbuilder), William Laird, who had established the Birkenhead Iron Works in 1824. When he was joined by his son, John Laird (shipbuilder), John Laird in 1828, their first ship was an iron barge. John realised that the techniques of making boilers could be applied to making ships. The company soon became pre-eminent in the manufacture of iron ships and also made major advances in propulsion. In 1860, John Laird was joined in the business by his three sons, renaming the company John Laird, Sons & Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Draft (ship)
The draft or draught of a ship's hull is the vertical distance between the waterline and the bottom of the hull (keel). The draught of the vessel is the maximum depth of any part of the vessel, including appendages such as rudders, propellers and drop keels if deployed. Draft determines the minimum depth of water a ship or boat can safely navigate. The related term air draft is the maximum height of any part of the vessel above the water. The more heavily a vessel is loaded, the deeper it sinks into the water, and the greater its draft. After construction, the shipyard creates a table showing how much water the vessel displaces based on its draft and the density of the water (salt or fresh). The draft can also be used to determine the weight of cargo on board by calculating the total displacement of water, accounting for the content of the ship's bunkers, and using Archimedes' principle. The closely related term "trim" is defined as the difference between the forward and aft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oerlikon 20 Mm Cannon
The Oerlikon 20 mm cannon is a series of autocannons, based on an original German Becker Type M2 20 mm cannon design that appeared very early in World War I. It was widely produced by Oerlikon Contraves and others, with various models employed by both Allied and Axis forces during World War II. Many versions of the cannon are still used today. Blowback-operated models History Origins During World War I, the German industrialist Reinhold Becker developed a 20 mm caliber cannon, known now as the 20 mm Becker using the advanced primer ignition blowback (API blowback) method of operation. This used a 20×70mmRB cartridge and had a cyclic rate of fire of 300 rpm. It was used on a limited scale as an aircraft gun on ''Luftstreitkräfte'' warplanes, and an anti-aircraft gun towards the end of that war. Because the Treaty of Versailles banned further production of such weapons in Germany, the patents and design works were transferred in 1919 to the Swiss firm SEMAG (''Seeba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autocannon
An autocannon, automatic cannon or machine cannon is a fully automatic gun that is capable of rapid-firing large-caliber ( or more) armour-piercing, explosive or incendiary shells, as opposed to the smaller-caliber kinetic projectiles (bullets) fired by a machine gun. Autocannons have a longer effective range and greater terminal performance than machine guns, due to the use of larger/heavier munitions (most often in the range of , but bigger calibers also exist), but are usually smaller than tank guns, howitzers, field guns or other artillery. When used on its own, the word "autocannon" typically indicates a non-rotary weapon with a single barrel. When multiple rotating barrels are involved, such a weapon is referred to as a "rotary autocannon" or occasionally "rotary cannon", for short (particularly on aircraft). Autocannons are heavy weapons that are unsuitable for use by infantry. Due to the heavy weight and recoil Recoil (often called knockback, kickback o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
QF 2-pounder Naval Gun
The 2-pounder gun, officially the QF 2-pounder ( QF denoting "quick firing") and universally known as the pom-pom, was a British autocannon, used as an anti-aircraft gun by the Royal Navy.British military of the period traditionally denoted smaller guns in terms of the approximate weight of the standard projectile, rather than by its bore diameter, which in this case was 40 mm. References to 40-mm anti-aircraft guns invariably mean the Bofors gun, while references to 2-pounder anti-aircraft guns mean this gun. The name came from the sound that the original models make when firing. This QF 2-pounder was not the same gun as the Ordnance QF 2-pounder, used by the British Army as an anti-tank gun and a tank gun, although they both fired , projectiles. Predecessors - Boer War and the Great War QF 1 pounder The first gun to be called a pom-pom was the 37 mm Nordenfelt-Maxim or "QF 1-pounder" introduced during the Second Boer War, the smallest artillery piece of that war. It fir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ship Commissioning
Ship commissioning is the act or ceremony of placing a ship in active service and may be regarded as a particular application of the general concepts and practices of project commissioning. The term is most commonly applied to placing a warship in active duty with its country's military forces. The ceremonies involved are often rooted in centuries-old naval tradition. Ship naming and launching endow a ship hull with her identity, but many milestones remain before she is completed and considered ready to be designated a commissioned ship. The engineering plant, weapon and electronic systems, galley, and other equipment required to transform the new hull into an operating and habitable warship are installed and tested. The prospective commanding officer, ship's officers, the petty officers, and seamen who will form the crew report for training and familiarization with their new ship. Before commissioning, the new ship undergoes sea trials to identify any deficiencies needing corre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceremonial Ship Launching
Ceremonial ship launching involves the performance of ceremonies associated with the process of transferring a vessel to the water. It is a nautical tradition in many cultures, dating back thousands of years, to accompany the physical process with ceremonies which have been observed as public celebration and a solemn blessing, usually but not always, in association with the launch itself. Ship launching imposes stresses on the ship not met during normal operation and, in addition to the size and weight of the vessel, represents a considerable engineering challenge as well as a public spectacle. The process also involves many traditions intended to invite good luck, such as christening by breaking a sacrificial bottle of champagne over the bow as the ship is named aloud and launched. Methods There are three principal methods of conveying a new ship from building site to water, only two of which are called "launching". The oldest, most familiar, and most widely used is th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birkenhead
Birkenhead (; cy, Penbedw) is a town in the Metropolitan Borough of Wirral, Merseyside, England; historically, it was part of Cheshire until 1974. The town is on the Wirral Peninsula, along the south bank of the River Mersey, opposite Liverpool. At the 2011 census, it had a population of 88,818. Birkenhead Priory and the Mersey Ferry were established in the 12th century. In the 19th century, Birkenhead expanded greatly as a consequence of the Industrial Revolution. Birkenhead Park and Hamilton Square were laid out as well as the first street tramway in Britain. The Mersey Railway connected Birkenhead and Liverpool with the world's first tunnel beneath a tidal estuary; the shipbuilding firm Cammell Laird and a seaport were established. In the second half of the 20th century, the town suffered a significant period of decline, with containerisation causing a reduction in port activity. The Wirral Waters development is planned to regenerate much of the dockland. Toponymy The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keel Laying
Laying the keel or laying down is the formal recognition of the start of a ship's construction. It is often marked with a ceremony attended by dignitaries from the shipbuilding company and the ultimate owners of the ship. Keel laying is one of the four specially celebrated events in the life of a ship; the others are launching, commissioning and decommissioning. In earlier times, the event recognized as the keel laying was the initial placement of the central timber making up the backbone of a vessel, called the keel. As steel ships replaced wooden ones, the central timber gave way to a central steel beam. Modern ships are most commonly built in a series of pre-fabricated, complete hull sections rather than around a single keel. The event recognized as the keel laying is the first joining of modular components, or the lowering of the first module into place in the building dock. It is now often called "keel authentication", and is the ceremonial beginning of the ship's life ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
QF 3-inch 20 Cwt
The QF 3 inch 20 cwt anti-aircraft gun became the standard anti-aircraft gun used in the home defence of the United Kingdom against German airships and bombers and on the Western Front in World War I. It was also common on British warships in World War I and submarines in World War II. 20 cwt referred to the weight of the barrel and breech, to differentiate it from other 3 inch guns (1cwt = 1 hundredweight = , hence the barrel and breech together weighed ). While other AA guns also had a bore of , the term ''3 inch'' was only ever used to identify this gun in the World War I era, and hence this is what writers are usually referring to by ''3 inch AA gun''. Design and development The gun was based on a prewar Vickers naval QF gun with modifications specified by the War Office in 1914. These (Mk I) included the introduction of a vertical sliding breech-block to allow semi-automatic operation. When the gun recoiled and ran forward after firing, the motion also opened the bree ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of British Ordnance Terms
This article explains terms used for the British Armed Forces' ordnance (i.e.: weapons) and also ammunition. The terms may have slightly different meanings in the military of other countries. BD Between decks: applies to a naval gun mounting in which part of the rotating mass is below the deck, and part of it is above the deck. This allows for a lower profile of turret, meaning that turrets need not be superfiring (i.e. they can be mounted on the same deck and not obstruct each other at high angles of elevation.) BL The term BL, in its general sense, stood for breech loading, and contrasted with muzzle loading. The shell was loaded via the breech (i.e. the gunner's end of the barrel, which opened) followed by the propellant charge, and the breech mechanism was closed to seal the chamber. Breech loading, in its formal British ordnance sense, served to identify the gun as the type of rifled breechloading gun for which the powder charge was loaded in a silk or cloth bag and the br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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