Minelayer

A minelayer is any warship, submarine, military aircraft or land vehicle deploying explosive mines. Since World War I the term "minelayer" refers specifically to a naval ship used for deploying naval mines. "Mine planting" was the term for installing controlled mines at predetermined positions in connection with coastal fortifications or harbor approaches that would be detonated by shore control when a ship was fixed as being within the mine's effective range.

An army's special-purpose combat engineering vehicles used to lay landmines are sometimes called "minelayers".

Before World War I, mine ships were termed mine planters generally. For example, in an address to the United States Navy ships of Mine Squadron One at Portland, England, Admiral Sims used the term "mine layer" while the introduction speaks of the men assembled from the "mine planters". During and after that war the term "mine planter" became particularly associated with defensive coastal fortifications. The term "minelayer" was applied to vessels deploying both defensive- and offensive mine barrages and large scale sea mining. "Minelayer" lasted well past the last common use of "mine planter" in the late 1940s.

The most common use of the term "minelayer" is a naval ship used for deploying sea mines. Russian minelayers were highly efficient sinking the Japanese battleships Hatsuse and Yashima in 1904 in the Russo-Japanese War. In the Gallipoli Campaign of World War I, mines laid by the Ottoman Empire's Navy's Nusret sank HMS Irresistible, HMS Ocean, and the French battleship Bouvet in the Dardanelles on 18 March 1915.

In World War II, the British employed the Abdiel minelayers both as minelayers and as transports to isolated garrisons, such as Malta and Tobruk. Their combination of high speed (up to 40 knots) and carrying capacity was highly valued. The French used the same concept for the cruiser Pluton.

A naval minelayer can vary considerably in size, from coastal boats of several hundred tonnes in displacement to destroyer-like ships of several thousand tonnes displacement. Apart from their loads of sea mines, most would also carry other weapons for self-defense, with some armed well enough to carry out other combat operations besides minelaying, such as the World War II Romanian minelayer Amiral Murgescu, which was successfully employed as a convoy escort due to her armament (2 × 105 mm, 2 × 37 mm, 4 × 20 mm, 2 machine guns, 2 depth charge throwers).

Submarines can also be minelayers. The first submarine to be designed as such was the Russian submarine Krab. USS Argonaut (SM-1) was another such minelaying submarine. Although there are no modern dedicated submarine minelayers, mines sized to be deployed from a submarine's torpedo tubes, such as the Stonefish, allow any submarine to be a minelayer.

In modern times, few navies worldwide still possess minelaying vessels. The United States Navy, for example, uses aircraft to lay sea mines instead. Mines themselves have evolved from purely passive to active; for example the US CAPTOR (enCAPsulated TORpedo) that sits as a mine until detecting a target, then launches a torpedo.