Boom chain (likewise blast safeguard, harbor chain, stream chain, chain blast, blast chain or variations) is an obstruction hung across a traversable stretch of water to control or hinder route.
In present day times they for the most part have common purposes, for example, to forestall admittance to a perilous stream channel. In any case, particularly by and large, they have been utilized militarily, determined to deny admittance to a hostile’s ships: a cutting edge model is the counter submarine net.
Boom chain have likewise been utilized to compel passing vessels to pay a cost.
A boom for the most part drifts on a superficial level, while a chain can be on a superficial level or underneath the water. A chain could be made to drift with pontoons, logs, ships or other wood, making the chain a blast too.
Particularly in bygone eras, the finish of a chain could be joined to a chain pinnacle or blast tower. This permitted safe raising or bringing down of the chain, as they were much of the time intensely fortified. By raising or bringing down a chain or blast, access could be specifically conceded instead of essentially delivering the stretch of water totally distant. The raising and bringing down could be achieved by a windlass system or a capstan.
Boom chains could be broken by an adequately huge or weighty boat, and this happened on many events, including the attack of Damietta, the strike on the Medway and the Battle of Vigo Bay. A Frequently, nonetheless, assailants rather held onto the protections and cut the chain or blast by additional traditional techniques. The blast at the attack of Derry, for instance, was cut by mariners in a longboat.
As a vital part of guards, blasts were generally intensely safeguarded. This elaborate shore-based chain towers, mounted guns batteries, or fortresses. In the Age of Sail, a blast safeguarding a harbor could have a few boats protecting it with their blasts, putting attacks on the blast down. On certain events, different blasts crossed a solitary stretch of water.