The Transformational REMUS 620 Unmanned Underwater Vehicle

 

 

Picture: Unknown photographer,© IWM Q 75584

 

If it is not possible to prevent the enemy laying naval mines by destroying their mines and mine layers before they can be used then it becomes necessary to determine where mines have been laid by means of a survey and effective use of time and resources dictates doing this ahead of friendly vessels,consequently the speed of advance of those vessels shall be constrained by the speed of the mine survey.

 

 

Picture: Grand Logistics

 

A mining sloop locates mined areas by deploying it’s Mine Hunting Launches which survey a lane at a speed of up to fifteen nautical miles per hour,advancing up to three hundred and sixty nautical miles per day whilst relaying contacts in real time and when a mined area is detected clearing a lane at a rate of advance of up to fifteen knots (depending on the width of the lane,the density of contacts and the number of launches available for the task).

 

 

Picture: Unknown artist,Huntington Ingalls Industries image

 

The REMUS 620 Unmanned Underwater Vehicle with a Kraken AquaPix MINSAS 120 mine hunting sonar and two batteries has a maximum speed of eight knots and,at speeds of less than three knots,it has a maximum range of one hundred and thirty-two nautical miles and a maximum endurance of fifty hours (electrically powered submersibles have very low performance because their batteries have low energy density).

 

 

Picture: Chell Hill

 

If deployed from the Royal Fleet Auxiliary Motor Vessel Island Crown a REMUS 620 would take fifty hours to survey sixty-six nautical miles ahead and then return,due to the limits of submarine communication only after resurfacing may sonar images be analysed,assuming a clearance speed of fifteen knots it would take over fifty-four hours to survey and clear a sixty-six nautical mile lane,fifty hours longer than it would take a mining sloop which could survey and clear up to eight hundred and sixteen nautical miles in the same time (because it's Mine Hunting Launches have air breathing diesel engines and can analyse sonar imagery and relay contacts by radio in real time) and yet some think using toy submarines to hunt mines would be transformational.

 

Defining The Modern Brig

In the days of sail the term "brig" referred to a two masted square rigged vessel.

Brigs were used as minor warships,smaller than sloops,although there were also brig rigged brig-sloops.

Such low cost vessels were not well suited to operating with the larger vessels of the battle line.

Often they were used for patrol,constabulary and other low threat tasks.

Although the historic meaning of the term "brig" has no relevance to today's vessels,there are many modern naval vessels which mirror the low cost,limited fighting capacity and many roles of the historic brig:

Mine hunters.

Mine sweepers.

Offshore patrol vessels.

 Survey vessels.

 Coast guard cutters.

Like their ancestors,modern brigs are lightly armed,carrying the most basic naval weapon,the cannon.

In situations short of war the brig may find it's self very close to potentially hostile vessels.

Unlike missiles,cannons have no minimum engagement range and high ammunition storage density,making them ideal for generating low cost,high volume fire against short range and low value targets.

Such armament is well suited to dealing with civilian vessels involved in fishing,smuggling and piracy.

It is also adequate for dealing with other brigs.

Many of the brig's roles will require the facilities for launching boats.

Helicopter hangars and flight decks are also useful for many roles.

Requiring little in the way of weapons,sensors and trained manpower,brigs cost little to buy or operate.

It is this low lifecycle cost which makes the brig preferable to a sloop or a frigate.

However,with only limited ability to defend themselves from anti-ship threats the modern brigs cannot operate in a hostile environment without an escort.

Consequently they are of limited utility in war fighting operations.

These limitations were illustrated during the Argentine invasion of South Georgia.

Her Majesty's Ship (H.M.S.) Endurance,a brig armed icebreaking patrol vessel was faced with threats including missile armed corvettes.

Brigs are incapable of engaging true fighting ships,that is properly the task of the more capable frigates or sloops.

Brigs should only be used independently in low threat environments.

The modern brig may perform roles such as mine hunting and surveying in support of a task group but will require the protection of other warships to do this.

A defenceless brig is more of a burden to a task group than a war fighting vessel like the sloop.

Brigs may relieve more capable task group vessels of minor roles such as search and rescue and providing assistance to damaged ships.

Particularly large brigs may be required to meet the demands of speed,range,endurance and seakeeping needed for fleet operations or long range patrol duties.

If armed with a large enough gun,brigs may provide naval fire support for ground forces.

If fitted with mine rails,they can perform minelaying tasks.

Low cost weapons such as these are in keeping with the low cost nature of the brig.

However,the brig's lack of fighting ability limits it's utility to such an extent that it is an inapropriate choice if there is any prospect of the vessel being used for warfighting.

Brig armament can be recommended only for those roles which are unlikely to involve combat operations or for those navies which cannot afford a more capable vessel.

For more fluid environments,the frigate or sloop is a more suitable vessel than the brig.