Floating threats

There are no designated mine laying surface ships in the Indian Navy’s inventory but it has submarines that can lay naval mines with greater stealth and hence greater surprise element for the intended enemy. What it does have is a diminishing fleet of “mine counter-measure” (MCM) vessels which is a different way of describing minesweeping-as distinct from minelaying - capabilities.

Innovation in this particular field of warfare is more the norm rather than the exception. With shore based radars more densely arrayed along a coastline the use of surface vessels or even aircraft are more vulnerable to attack by shore based missile batteries and aircraft. That leaves the submarine as the best platform for laying mines intended to blockade an enemy port or naval facility.

The Indian Navy for example has nine diesel-electric submarines of the Sindhughosh class (the ex-Russian Kilo class) that have been fitted with 24 DM-1 mines launchable through torpedo tubes.

Most nations have done away with dedicated minelaying ships and are increasingly resorting to laying mines by air as are the US and some of its allies.

Aerial mine laying is not restricted strictly to coastal barrages but can also be used to mine riverine waterways that are used as logistics supply routes in times of emergencies. One of the several capabilities intrinsic to the newly acquired Boeing Poseidon P-8I maritime reconnaissance and strike aircraft by India is minelaying.

Since the Poseidon is an American aircraft the possibility that the naval mines it carries are not the type required to be delivered by parachute which is a dead giveaway of the whole mining operation. The Americans have developed more modern mines that do not require parachutes for deployment. They are freefall weapons capable of surviving high impact on landing on water.

The DM-1 naval mine is a Russian product which belongs to the super heavy class of underwater weapons. It was specifically designed for deployment by submarines and appears to be an intrinsic part of the Kilo class submarine-original equipment for all export version submarines.  It is described as being “super heavy” and capable of being deployed through one of the six 533 mm torpedo tubes that are part of the Kilo class configuration.  

Deploying mines

Normally mines can be planted by aircraft, submarines, surface ships, underwater robots, and frogmen (naval divers), as well as merchant ships, fishing ships, ferries and motor boats. The airborne and surface vessels used for mine laying would be used by those who want it to be known that mines have been laid so that it acts as a deterrent and imposes the need to clear the mines to be able to utilize the marine asset again. However, when stealth and surprise are intended the delivery by submarine is more appropriate.

Under certain circumstances commercial liners with crane-loading capabilities can be pressed into service to deploy mines. The Libyans under Colonel Muammar Gaddafi were suspected to have mined the approaches to the Suez Canal by using roll-on, roll off cargo vessels to offload mines in an unsuspecting environment. Ships with rear ramp doors like amphibious assault vessels can also be deployed for mine laying in emergency situations. Ships with cranes on board too can deliver mines over either side if the need arises.        

Aerial delivery of mines has been in fashion since World War 2. It tends to create a psychological situation where the intended victim can see the mines floating down on parachutes. This makes it doubly careful in handling its own shipping and thereby enhances the effect of an intended blockade of a port or harbor. Nonetheless the erratic nature of such aerial deployment can undermine the whole mine warfare capabilities of a nation.

The Germans, for instance, mined the British coastline but one of the mines floated into a mudflat and was defused and its mechanism studied. Britain was thus able to defuse many of this particular type of mine deployed by the Germans along its coasts and thereby nullified the effect of an intended German blockade.   

Aerial minelaying is a very in-your-face type of activity. India has the Poseidon maritime reconnaissance and strike aircraft with mine-laying facility but a more appropriate approach to the sub continental situation would be deployment of mines by submarines. It would be a completely clandestine operation and achieve both surprise and optimum destruction of the enemy’s shipping within the port and harbor.

India has four submarines of the Shishumar class built under license from the German HDW shipyard. They carry 24 strap-on mines that can be attached by onboard divers to a passing ship (or submarine) and timed to explode either well away from the attacking submarine or well after it has entered the safety of a harbor or port.

Mine warfare

This method of deployment of mines can prove to be extremely useful in places where the prospective target has laid nets or chains to entangle any submarine attempting to raid the harbor and destroy ships at the anchorage. It converts the enemy’s own vessels into Trojan horses carrying a self-destruct device into the sanctuary.

One of the tactics of mine warfare is the ability to deny the use of certain portions of the ocean to the naval forces or the commercial carriers of an inimical nation. This can be done in the immediate vicinity of a port so that any attempt to leave the port must be accompanied by minesweeping operations intended to ignite the mines well before a ship leaves the port.

It is a time consuming effort especially if the mines are set to explode only when the pre-taped engine or propeller acoustic signature matches that of the vessel leaving the harbor. Such selectivity makes mine warfare more ominous than the indiscriminate mining of portions of the ocean to prevent the use of it by a particular enemy.  A minefield laid close to an enemy’s shoreline will keep visitors out and prevent the enemy vessels from leaving the port-a blockade that bottle up all commercial/military activity within that particular stretch of water.

In 1971 Pakistan sent its diesel-electric submarines, the PNS Ghazi to mine the approaches to the Vishakhapatnam harbor on India’s eastern seaboard in the hope of hitting the Indian aircraft carrier INS Vikrant which was known to be using the port for replenishment of weapons and victuals for its crewmen.

It was used to blockade the harbors of Chittagong, Cox’s Bazaar and the approaches to Dhaka via the sea. It sailed slowly well outside the territorial waters of the former East Pakistan and its aircraft pounded shore establishments with impunity. As a final coup de grace an Indian pilot sent a rocket through the ventilator of the Pakistani Governor’s House where an emergency meeting was underway to assess the course of military operations. That rocket confirmed that it was futile to continue fighting and the Pakistani Army surrendered the next day as per instructions dictated by Indian Army Chief of Staff General Sam Manekshaw.

And as for the fate of the PNS Ghazi, it was blown up outside Vishakhapatnam harbor. The Indians say it was lured to its death by the INS Rajput which had dropped depth charges which must have been near enough to shake up the Pakistani submarine so badly that its torpedoes exploded. That is why some of the wreckage retrieved by the Indian Navy showed signs of an internal explosion with the pieces of the hull having exploded outwards.