Clearing the Strait of Hormuz

Using UUVs to Detect and Dispose of Maritime Mines in a Volatile Region


The U.S. State Department is on the record saying that they are committed to imposing “unprecedented financial pressure on Iran,” specifically through comprehensive sanctions levied against that nation’s ruling regime. Among the threats Iran has made in response to these sanctions, is the placement of maritime mines in the Strait of Hormuz, a vital passageway that provides the only sea passage out of the Persian Gulf to the Indian Ocean. With over one fifth of global oil exports passing through the strait, Iran’s threats are a startling proposition. U.S. officials estimate that Iran could position 1,000 mines in the Strait of Hormuz in less than a week. Is the world prepared to defend against such an assault?

The Mattis Plan

While in command of the U.S. Military’s Central Command (CENTCOM), Secretary of Defense James Mattis anticipated this scenario. As a result, Mattis oversaw the development of a plan to keep the Strait of Hormuz open, including safe passages for oil tankers. The plan supports a rapid multinational effort to prevent Iranian mine-laying and systematically clear any mines already deployed. Because of this plan, most observers believe that even if Iran acts on such threats, coalition forces could reopen the Strait within a week, though the operation to ensure it remains open could last for months. Of course, Iran also has armed submarines, cruise missiles, and at least 1,000 small attack boats, which could further threaten international shipping in the strait, but these are also considered in Mattis’ plan, and for this article, we are focusing on maritime mines.

The Strait of Hormuz provides the only sea passage out of the Persian Gulf to the Indian Ocean. Iran has threatened to place mines in its waters.

The Strait of Hormuz provides the only sea passage out of the Persian Gulf to the Indian Ocean. Iran has threatened to place mines in its waters.

To ensure preparation for multiple scenarios, the U.S. leads frequent mine identification and exploitation exercises in the U.S 5th Fleet’s area of operation, which includes the Arabian Gulf, Gulf of Oman, Red Sea and parts of the Indian Ocean. For the largest of these exercises, the International Mine Countermeasures Exercise (IMCMEX), navies and government agencies from more than 40 nations spanning four continents participate in a defensive mine countermeasures exercise in the Middle East’s international waterways. Beyond this, the U.S. 5th Fleet conducts quarterly mine countermeasure exercises with the U.K.’s Royal Navy. According to the participants, these exercises enhance cooperation, mutual mine countermeasure capabilities and interoperability, which demonstrates the shared commitment of ensuring unfettered operations of naval, support and commercial vessels throughout the maritime domain.

Two Task Forces (TF) under the U.S. Forces specialize in mine countermeasures. TF-56, Expeditionary Combat Forces: deploys highly trained, skilled technicians who are experts in explosives, diving, and parachuting. They also use rigid inflatable boats and riverine command boats, as well mobile construction equipment via the Seabees. TF- 52, Mine Warfare: provides command and control of all mine warfare assets in the region. The technology TF-52 deploys includes specialized helicopters, minesweeper ships, and unmanned underwater vehicles (UUV).

Open Systems Architecture

A critical requirement of the Navy’s Mine Countermeasure (MCM) technology package, including for UUVs, is its common open systems architecture design. Modularity of the mission package allows for platform flexibility and quick reconfiguration of the whole mission package in response to evolving and dynamic mission requirements the fleet will encounter day-to-day. In plain terms, that means that these UUVs can be seamlessly integrated into multiple ship systems and mission modules.

This has become more important as the Navy trends towards a mix-and-match set of people, platforms and sensors to detect and destroy mines, a departure from the simpler legacy mine countermeasures setup with a single helicopter type and a single wooden-hull ship class, set for replacement by the new Littoral Combat Ship and its neatly defined mission package. In fact, the Navy says that when it comes to deploying UUVs, they’re not limiting deployment to U.S. ships, they’re working with the ships of coalition partners as well. For example, in 2017, the Navy conducted tests with USS Independence (LCS-2) to test their ability to deploy personnel and UUVs off the Australian built LCS, after doing similar tests on the Lockheed Martin-variant USS Freedom (LCS-1) last summer.

Speaking last year at the National Defense Industrial Association’s annual Expeditionary Warfare Conference, Capt. Michael Egan, Commander of Task Force 52, said “We’ve taken our ExMCM company with their Mk 18 family of UUV systems, we’ve put them aboard cruisers and destroyers and had them do extensive rehearsals of the actual operations – and in some cases, in exercises and operations we’ve actually used those platforms.”

Why do this? According to Capt. Hans Lynch, head of the mine warfare branch within OPNAV N95, speaking at the same conference, if an adversary were to deploy mines in a busy shipping area, “I can’t imagine a scenario in which we would actually have enough LCSs to mass that capability as quickly as we need it.”

In such a scenario, Capt. Lynch says, every deployment option would be used, “Shore-basing makes a lot of sense. ESB (Expeditionary Sea Base) makes a lot of sense. EPF (expeditionary fast transport) makes a lot of sense. Coalition platforms. And really I think there are opportunities for even DDG-1000s, they have enough room that we can put a USV or UUVs onboard. Aircraft carriers even or some of our big-deck amphibs could support some of our mission platforms that we have.”

Clearly, the Navy is considering every possible scenario. So, let’s take a closer look at some of the key mine counter measure technologies used by the Navy’s 5th Fleet. This is by no means an exhaustive list, but it should give you an understanding of how coalition forces would defend against the types of threats Iran is making in the Strait of Hormuz.

The Avenger class mine countermeasure (MCM) ships USS Dextrous (MCM 13), USS Gladiator (MCM 11), USS Devastator (MCM 6), and USS Sentry (MCM 3), part of Commander, Task Force 52, sail in formation as part of a photo exercise in the Arabian Gulf, Dec. 6, 2016. The combined MCM force enhances mine-hunting capabilities in searching, identifying and neutralizing mines threatening the freedom of navigation and the free flow of commerce. Photo credit: Petty Officer 2nd Class Christina Brewer, U.S. Navy.

The Avenger class mine countermeasure (MCM) ships USS Dextrous (MCM 13), USS Gladiator (MCM 11), USS Devastator (MCM 6), and USS Sentry (MCM 3), part of Commander, Task Force 52, sail in formation as part of a photo exercise in the Arabian Gulf, Dec. 6, 2016. The combined MCM force enhances mine-hunting capabilities in searching, identifying and neutralizing mines threatening the freedom of navigation and the free flow of commerce. Photo credit: Petty Officer 2nd Class Christina Brewer, U.S. Navy.

Avenger Class Mine Countermeasures (MCM) Ships

Avenger Class MCM ships are designed to clear mines from vital waterways. Using variable depth sonar scans, UUVs, and other methods, Avenger-class MCM ships employ high-resolution sonar and video systems, cable cutters and a mine detonating device that can be released and detonated by remote control. They are capable of detecting, classifying, and neutralizing both moored and bottom mines as well as conventional sweeping measures. The ships are of fiberglass sheathed, wooden hull construction. There remain 11 MCMs in current service to the fleet, including four that are based out of Manama, Bahrain.

MH-53E Sea Dragon Helicopter

The MH-53E is used primarily for Airborne Mine Countermeasures (AMCM), with secondary missions of vertical shipboard delivery and assault support. It can operate from carriers and other warships and is capable of towing a variety of mine hunting/sweeping countermeasures systems, including the Mk 105 magnetic minesweeping sled, the AQS-14A side-scan sonar, and the Mk 103 mechanical minesweeping system. When performing the assault support mission, the MH-53E can be fitted with the GAU-21 .50-cal. machine gun ramp-mounted weapon system. It can also be used to deploy lightweight UUVs.

An MH-53E Sea Dragon, from Helicopter Mine Countermeasures Squadron (HM) 15, prepares to land on expeditionary mobile base platform ship USS Lewis B. Puller (ESB 3). Puller is deployed to the U.S. 5th Fleet area of operations. Photo credit: Mass Communication Specialist 2nd Class Kevin J. Steinberg, U.S. Navy.

An MH-53E Sea Dragon, from Helicopter Mine Countermeasures Squadron (HM) 15, prepares to land on expeditionary mobile base platform ship USS Lewis B. Puller (ESB 3). Puller is deployed to the U.S. 5th Fleet area of operations. Photo credit: Mass Communication Specialist 2nd Class Kevin J. Steinberg, U.S. Navy.

Teledyne Seabotix vLBV

SeaBotix vectored Little Benthic Vehicles (vLBV) are portable ROVs ideal for mine detection. The vLBV300 is only 18 kg (40 lbs) in air with various payload packages available, meaning that it can be easily deployed via helicopter. It’s also versatile, with uses in a wide range of applications including underwater inspection. The system features dual vertical thrusters and is capable of carrying a wide variety of sensors and tooling including imaging sonars and multi-function manipulators. Standard features include LED lighting that tracks the high-resolution camera, auto-depth, heading and trim (speed), depth and temperature sensors, low-drag, neutrally buoyant tether on a reel with slip ring, and a choice of control consoles

A Sailor pilots a Seabotix ROV while searching for a simulated mine during a training exercise. Photo credit: Mass Communication Specialist 2nd Class Charles Oki, U.S. Navy.

A Sailor pilots a Seabotix ROV while searching for a simulated mine during a training exercise. Photo credit: Mass Communication Specialist 2nd Class Charles Oki, U.S. Navy.

SeaFox Mine Disposal UUV

The Seafox UUV manufactured by Atlas Elektronik was developed based on the expendable mine disposal vehicle (EMDV) principle. The semi-automatic UUV is primarily used for the disposal of mines and other identified ordnance in sea. It can detect and classify the mines and sea objects. It is guided by a fiber-optic cable. The SeaFox can also be used in damage estimation, intelligence, route survey, maritime boundary control and harbor surveillance missions. The complete SeaFox system includes a console, a launcher, and the SeaFox vehicles. It can be launched from a range of naval platforms such as dedicated mine counter measures vessels (MCM), surface combatants, rubber boats and helicopters.

A Seafox UUV sits on the deck of HMS Middleton (M34), Oct. 14, 2016 in the Arabian Gulf. Photo credit: Petty Officer 2nd Class Tyler Thompson, U.S. Navy.

A Seafox UUV sits on the deck of HMS Middleton (M34), Oct. 14, 2016 in the Arabian Gulf. Photo credit: Petty Officer 2nd Class Tyler Thompson, U.S. Navy.

Hydroid MK 18 Swordfish and Kingfish UUVs

The Mk 18 Mod 1 Swordfish UUV is capable of performing mine countermeasures operations such as search, classification, mapping, reacquire, and identification. The UUV can navigate via acoustic transponders in long-baseline or ultra-short-baseline mode or via P-coded GPS. Its upward- and downward-looking acoustic digital velocity log improves dead-reckoning accuracy. Follow-on block upgrades combine two separate UUV programs into the MK 18 family of systems to deliver improved detection capability against buried mines in high clutter environments.

This year, at the direction of the Navy, the Mk 18 was upgraded to a Mod 2 version. Resembling a conventional torpedo, they are launched from ships or mid-sized rigid-hull boats for mine countermeasure work. The Kingfish mounts a Small Synthetic Aperture Sonar Module that provides high resolution underwater scan imagery and is capable of detecting buried targets.

The Kingfish Mod 2 is nearly 4 meters long and weighs over 600 pounds. It is deployed and recovered using a small crane. It features better sonar, endurance and coverage abilities then the smaller Mk18 Swordfish model it serves alongside. The Kingfish is capable of being deployed off of the Littoral Combat Ship (LCS) as part of the LCS's countermine mission for coastal waters alongside the larger General Dynamics Knifefish UUV.

Brian Dinkel, assigned to Commander, Task Group (CTG) 56.1, recovers a MK-18 Mod 2 Kingfish UUV after testing it's autonomous topographic large area survey, forward looking sonar. Photo credit: Mass Communication Specialist 1st Class Blake Midnight, U.S. Navy.

Brian Dinkel, assigned to Commander, Task Group (CTG) 56.1, recovers a MK-18 Mod 2 Kingfish UUV after testing it's autonomous topographic large area survey, forward looking sonar. Photo credit: Mass Communication Specialist 1st Class Blake Midnight, U.S. Navy.

General Dynamics Knifefish UUV

Knifefish is a heavyweight class MCM UUV designed for deployment off LCS. The Knifefish provides the mine warfare commander with enhanced mine-hunting capability by detecting, classifying and identifying both buried mines and mines in high clutter environments. Knifefish’s job is to detect, avoid and identify mine threats by operating in the minefield as an off-board sensor while the host ship stays outside the minefield boundaries. Knifefish also gathers environmental data to provide intelligence support for other mine warfare systems.

In late 2018, General Dynamics released a two-man-portable MCM-capable UUV, the Bluefin-9, which provides high-resolution data and rapid navigation, data processing and mission turnaround time in a two-man portable UUV. Featuring a full carbon fiber body, an integrated suite of sensors, latest generation communications and navigational components, and new onboard processing capabilities, it will be interesting to watch whether a UUV based of this design will be deployed to the Navy’s 5th Fleet.

Staying Prepared

As this article was being written, the U.S. and U.K. were joining together in their fourth mine countermeasures exercise of 2018. Given the advanced skills and technology with which these forces are armed, there can be no doubt that they are prepared for the dangers posed by maritime mines.