HMCS Burlington

The Halcyon class was a class of 21 oil-fired minesweepers built for the British Royal Navy between 1933 and 1939. They were given traditional small ship names used historically by the Royal Navy and served during World War II.

The Fundy-class minesweepers were a class of four minesweepers operated by the Royal Canadian Navy during the Second World War. All four ships entered service in 1938 and the class were discarded in 1945, sold for mercantile service. Three ended up sold to Chinese interests, while one remained active in Canada until 1987.

The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is called a compression-ignition engine. This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine or a gas engine.

Length overall is the maximum length of a vessel's hull measured parallel to the waterline. This length is important while docking the ship. It is the most commonly used way of expressing the size of a ship, and is also used for calculating the cost of a marina berth.

The beam of a ship is its width at its widest point. The maximum beam (BMAX) is the distance between planes passing through the outer extremities of the ship, beam of the hull (BH) only includes permanently fixed parts of the hull, and beam at waterline (BWL) is the maximum width where the hull intersects the surface of the water.

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 displacement or displacement tonnage of a ship is its weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into weight. Traditionally, various measurement rules have been in use, giving various measures in long tons. Today, tonnes are more commonly used.

The knot is a unit of speed equal to one nautical mile per hour, exactly 1.852 km/h. The ISO standard symbol for the knot is kn. The same symbol is preferred by the Institute of Electrical and Electronics Engineers (IEEE), while kt is also common, especially in aviation, where it is the form recommended by the International Civil Aviation Organization (ICAO). The knot is a non-SI unit. The knot is used in meteorology, and in maritime and air navigation. A vessel travelling at 1 knot along a meridian travels approximately one minute of geographic latitude in one hour.

Fuel oil is any of various fractions obtained from the distillation of petroleum. Such oils include distillates and residues. Fuel oils include heavy fuel oil, marine fuel oil (MFO), bunker fuel, furnace oil (FO), gas oil (gasoil), heating oils, diesel fuel and others.

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.

The bridge, also known as the pilothouse or wheelhouse, is a room or platform of a ship from which the ship can be commanded. When a ship is under way, the bridge is manned by an officer of the watch aided usually by an able seaman acting as a lookout. During critical maneuvers the captain will be on the bridge, often supported by an officer of the watch, an able seaman on the wheel and sometimes a pilot, if required.

A depth charge is an anti-submarine warfare (ASW) weapon. It is intended to destroy a submarine by being dropped into the water nearby and detonating, subjecting the target to a powerful and destructive hydraulic shock. Most depth charges use high explosive charges and a fuze set to detonate the charge, typically at a specific depth. Depth charges can be dropped by ships, patrol aircraft, and helicopters.

The keel is the bottom-most longitudinal structural element on a vessel. On some sailboats, it may have a hydrodynamic and counterbalancing purpose, as well. The laying of the keel is often the initial step in the construction of a ship. In the British and American shipbuilding traditions, this event marks the beginning date of a ships construction.

Ontario is one of the thirteen provinces and territories of Canada. Located in Central Canada, it is Canada's most populous province, with 38.3 percent of the country's population, and is the second-largest province by total area. Ontario is Canada's fourth-largest jurisdiction in total area when the territories of the Northwest Territories and Nunavut are included. It is home to the nation's capital city, Ottawa, and the nation's most populous city, Toronto, which is Ontario's provincial capital.

Halifax is the capital and largest municipality of the Canadian province of Nova Scotia, and the largest municipality in Atlantic Canada. Halifax is one of Canada's fastest growing municipalities, and as of 2022, it is estimated that the CMA population of Halifax was 480,582, with 348,634 people in its urban area. The regional municipality consists of four former municipalities that were amalgamated in 1996: Halifax, Dartmouth, Bedford, and Halifax County.

A convoy is a group of vehicles, typically motor vehicles or ships, traveling together for mutual support and protection. Often, a convoy is organized with armed defensive support and can help maintain cohesion within a unit. It may also be used in a non-military sense, for example when driving through remote areas.

The Battle of the Atlantic, the longest continuous military campaign in World War II, ran from 1939 to the defeat of Nazi Germany in 1945, covering a major part of the naval history of World War II. At its core was the Allied naval blockade of Germany, announced the day after the declaration of war, and Germany's subsequent counter-blockade. The campaign peaked from mid-1940 through to the end of 1943.

German submarine U-123 was a Type IXB U-boat of Nazi Germany's Kriegsmarine that operated during World War II. After that conflict, she became the French submarine Blaison (Q165) until she was decommissioned on 18 August 1959.

The Gulf of St. Lawrence is the outlet of the North American Great Lakes via the St. Lawrence River into the Atlantic Ocean. The gulf is a semi-enclosed sea, covering an area of about 226,000 square kilometres (87,000 sq mi) and containing about 34,500 cubic kilometres (8,300 cu mi) of water, at an average depth of 152 metres (500 ft).

A corvette is a small warship. It is traditionally the smallest class of vessel considered to be a proper warship. The warship class above the corvette is that of the frigate, while the class below was historically that of the sloop-of-war.

HMCS Arrowhead was a Flower-class corvette that was originally commissioned by the Royal Navy but served primarily with the Royal Canadian Navy (RCN) during the Second World War. She fought primarily in the Battle of the Atlantic as a convoy escort. She was named for sagittaria, which is an aquatic water plant that is sometimes known as arrowhead.