Between threat and bluff

In the context of the Iran conflict, we are currently hearing a lot about mine warfare and mines in the Strait of Hormuz. We see the symbolic bullets with nasty thorns in the background on TV, reminding us of figurative viruses. These weapons cause fear and terror, you can't see them, they don't announce themselves, they are sneaky and cause enormous damage. They sink ships, hinder free navigation, are extremely difficult to localise and even more problematic to remove. Reports on the possible clearance of mines in the Hormus and European involvement in this are also currently full of drama. But what do mines really look like, how do they work and what danger do they pose? How do you lay mines, how do you find them, and when does it make sense to mine at all? Before the myths are ranked any further, here is an explanatory piece for all those who would like to have a quick overview of mine, i.e. just the essential facts for categorisation or discussion.

What types of sea mines are there and what is the operating principle behind them? 

What we all have in mind are Anchor buoys. They are basically 200 years old and are held by an anchor rope just below the surface of the water and triggered by touch. The spikes are bent and break out an acid capsule inside, which makes electrical contact and detonates the explosive charge. The correct depth setting is crucial, as too deep or too shallow a position impairs the effectiveness or camouflage. According to the Hague Convention, they should be disarmed by a technical safety device when they float to the surface, i.e. when they are torn loose from their anchoring or mechanically separated by a mine-clearing harness; however, this may well fail in the case of old mines. They then float on the surface and in this state are referred to as drifting mines. The intended production and transport of Propellant mines is classed as unlikely, they practically do not exist - they are almost always just detached anchor mines.

Base mines lie on the seabed and act as remote detonation mines on passing ships. They do not detonate through direct contact, but react to changes in the environment, such as the magnetic field, noise or water pressure. The explosion creates a gas bubble that first lifts the ship's hull and then causes it to fall, which can lead to the ship breaking apart. It is questionable whether a single mine can sink a tanker. Nor is a large warship more or less endangered depending on the depth of the water and the proximity of the detonation. In any case, a shock wave runs through the ship, which can tear equipment from its moorings, bring machinery to a standstill and put people at considerable risk.

Modern bottom mines combine several sensor systems, can have delays and counters and thus target specific types of ships. The target of a mine is not the minesweeper, but the valuable, large transport or warship.

In addition to these two types, there are special modifications and special mines that have been developed for use in deep water or against landings. These Anti-invasion mines (for rivers and shore zones) are used in shallow water and are not dissimilar to landmines. They also have magnetic or acoustic sensors and are aimed at landing craft and hovercrafts. Their charge is small but effective. Types include the German "Seemine Antiinvasion" (SAI) DM 51 or the U.S. NAVY's "Quickstrike", which is dropped from aircraft. Mines can also be switched on and off or remotely detonated from land.

Torpedo mines, such as the American MK-60 "Captor", consist of a platform and a torpedo that automatically launches itself at the target when approached. There are also torpedoes that remain in place as bottom mines after use, such as the MK-67, which is a modified MK-37 torpedo with additional firing devices and is fired from submarines - useful for waters that are controlled by the enemy or are too shallow. Iran has mines with their own propulsion, including the EM-52, which fires to the surface as a „climbing mine“. Other newer mines such as the EM-56 can change position independently, which makes mine defence much more difficult.

How do you lay them - and with what?

In principle, any seagoing vessel can lay mines, depending on the size. Anchor mines and sea bottom mines of German design, for example, are guided to the discharge platform on rolling racks via special rails on the upper deck and „laid“ in the water, as they say. Depending on the type and explosive charge, the weight varies from 500kg to around 1000kg. Mines on the often-mentioned Iranian small combat boats (not speedboats) can therefore only be laid in small numbers and as light mines with a small explosive charge. Military minelayers - these can be minesweepers and speedboats in their alternative role - usually have around 30-40 mines on board. Mines are laid after a tactical assessment of the sea area and the definition of the military condition to be achieved. Each minefield is subject to precise prior planning with documentation that enables subsequent clearing with pinpoint accuracy. Throwing mines without a plan is more likely to be seen as an act of desperation, especially off one's own coast. Attention: Mines change the geography, for both the attacker and the defender. Once mines are live in the water, there is no turning back under wartime conditions. So you have to be clear beforehand whether or not you can accept an environmental catastrophe off your own coast by damaging oil tankers. This is something to bear in mind if you want to believe the rumours about mines being laid. Psychologically, the simple claim that mines have been laid is enough to frighten everyone and paralyse shipping. Mines also hinder friendly shipping.

How do you actually clear mines?

The methods of mine clearance are as varied as the mine threat itself. Mine warfare) is perfidious - and anyone who knows how to clear mines is also aware of the weak points, which in turn feed into the development of new types of mines. Mines can be laid from almost any platform, including aircraft and submarines, but clearing them is considerably more complex. Mine clearance therefore requires specialist knowledge about mines, it requires specially trained personnel, it requires specially equipped units - and it requires Time! The mine in the water can wait, even years. However, the mine defence vessels can only start their tedious job when the surrounding area is sufficiently safe. And since shipping can't wait either, it is more important to initially concentrate on so-called „clearance channels“ and clear safe passages than to search entire sea areas.

The Methods of clearing are based on the findings as to which mines or which mix has been transported and is to be expected in the clearance area. Anchor mines are cleared with a towed crockery They are separated from their anchor chain mechanically or with small explosive devices, then float up and can be destroyed by explosive charges. These floating mines (floating mines, see above) are always dangerous. Detonating them by shelling is difficult and requires a lot of ammunition (the author knows what he is writing about). This makes little sense, especially as the hollow body can be broken without detonating the charge. If the mine then sinks, it is invisible but still highly dangerous.

Mechanical minesweeping was even carried out by small destroyers during the last world war. This old method has long since been replaced by the use of remote-controlled drones. This is why we still talk about mine hunting today. Speaking of destroyers: A news report claimed that American destroyers had travelled through the Strait of Hormuz to clear mines. Let the reader judge for himself at the end of the text how likely this is.

In simple terms, there are two methods for clearing bottom mines and special mines: using the Simulation rooms and the Mine hunting. At the Simulation rooms the magnetic field and the acoustic signature of a ship are generated by a towed harness. This harness essentially consists of a gigantic power cable and towed sound generators. Using high currents and various adjustable frequencies, the mines can be tricked into believing they are any kind of ship in order to trigger their switch - to make them "move". Since this method requires the mines to be overrun by the minesweeping unit, minesweepers are designed to be non-magnetic and quiet (formerly wooden, now GRP hulls, or non-magnetic steel). Since the 1980s - long before such things were called "drones" - the German Navy has been using unmanned small vehicles as an alternative, known as "remote sweepers" or "sea dogs", which can simulate a large target ship with the appropriate equipment. This is technically complex and time-consuming, but today it is safer and faster: with the Mine hunting. While the aforementioned methods could still be used provisionally on other warships, technically complex mine hunting is a case for absolute specialists. Minehunters have a sonar in the bow (hull mounted), which is designed to search the seabed. In a sophisticated detection and identification process - coupled with seamanship - cable-bound or self-guiding drones are steered towards the mine and lay explosive charges to destroy the object. These drones can be equipped with cameras as well as their own sonar. If it is not advisable to blow up the mine, be it in harbours or near critical infrastructure, mine divers are deployed. These highly specialised explosive ordnance disposal experts defuse the mine under water. Diver intervention boats - basically specialised minesweepers - have been specially designed for their use and are equipped with pressure chambers and extensive diving equipment, among other things.

What can the German Navy do?

The German Navy has a well-equipped minesweeper squadron (3rd MSG) in Kiel, which has something to counter almost all common mine threats. It is the only remaining minesweeper squadron that still has ten Frankenthal-class boats in various stages of equipment and development. It is proficient in all of the above-mentioned clearance methods, including the use of mine divers, although mechanical clearance has now been dispensed with. The navy calls it „linked sea mine defence“. As the mine divers were bundled into the sea battalion years ago, they have to be embarked on the mine diving boats for operations. The Frankenthal-class boats made of non-magnetic steel are the latest evolutionary stage of several generations of minesweepers, whose task during the Cold War was to keep the Baltic Sea approaches clear as part of the defence of NATO territory. Although they have been in service for around three decades, they are a continuously modernised and very robust ship design. After reunification, the German Navy's mine defence forces were left with the never-ending task of clearing the post-war Baltic Sea of thousands of mines and enormous amounts of old munitions. The resulting experience led to an expertise in the navy and in the German shipbuilding industry that was unique in NATO. At the same time, the former mine countermeasures flotilla was the most extensive flotilla in the navy - equipped with state-of-the-art sonar and long-range guidance systems and sophisticated procedures. In numerous NATO manoeuvres, they consistently demonstrate their capabilities on an equal footing with other „minehunting nations“ such as Denmark, the Netherlands, Belgium and France - often in a leadership role. Many navies have adopted German concepts and adapted them for themselves. Other countries such as Indonesia have recently acquired the latest units from German shipyards or, like Turkey, are having them built under licence.

It has proven itself today that these skills have been tenaciously held on to over the last few decades of disarmament and an enormous effort has been made to prevent an even greater loss of knowledge. Tasks such as patrols in the Mediterranean (UNIFIL) were not conducive to the level of specialised training. It was only with the recent development in the Baltic Sea, the focus on national and alliance defence, that the guardians of the hidden treasures - or rather, female guardians - were remembered, as the first female commanders were to be found in this squadron. Incidentally, this combat unit is currently led by the first female commander.

Unfortunately, the German priorities in recent years have not been minehunting boats. Mine defence is more of a nautically demanding craft than an operational-tactical art, and anti-aircraft armament does little to change this. The focus was more on prestigious combat units such as frigates for worldwide deployment. After several conceptually complicated and rejected successor approaches and several postponements of new procurement, the result is shocking, but not hopeless: the old units are being painstakingly modernised and maintained on life support until a successor system has been fully developed. Based on the navy's plans, a German shipyard already has a system „in the drawer“ that takes the further development of unmanned systems very much into account. However, this is not yet of any use for deployment in the Persian Gulf.

What can the navy do in the Iran conflict?

The slogan of the Kiel „miners“ is: „We make the sea routes safe!“ Especially in the current situation, the association is demonstrating its fundamental value in the Baltic Sea. And what you can do in the Baltic Sea also applies to the Persian Gulf: you could - if you fulfil a few conditions. But it will not be a „walk in the park“ It will cost an enormous amount of time and effort. First of all, intelligence and information from the secret services must be used to determine what mine threats exist in order to assess the feasibility of the already risky procedure. And there should be a ceasefire in the sea area, because mines cannot be cleared responsibly for life and limb under threat from missiles and armed speedboats. The biggest challenge, however, is getting there: an enormous feat in every respect - logistically, operationally and in terms of time. In 1990/91, in the aftermath of the Gulf War, the navy had already proven with „Operation South Flank“ that it was recognised as being up to the task. But at that time there were still half a dozen fully operational minesweeping squadrons. In addition, compulsory military service had not yet been suspended, which made the personnel situation more relaxed than it is today. The experiences from this deployment are hopefully well documented! One thing is clear: it will take several years to deal with the lasting logistical „damage“ of such a mission. Recognition of what was achieved also remained low - due to the circumstances of those years. This can and must be organised more professionally today.

Political will?

Ultimately, it must primarily be a fundamental political decision to withdraw important units from the Baltic Sea and use them to represent German interests in the Gulf. This is not about helping the mighty US Navy, whose limited mine defence capability has rarely been able to match the performance of its European allies - despite the new mine countermeasures mission package of the American Independence-class LCS trimarans. It is more about helping the friendly states in the Gulf, which are bearing the brunt of the war. Germany would benefit from this in the long term. That is for Berlin to decide - not Rostock.

hsc, ajs