Mined Beaches: If You Can't Avoid 'em, Breach 'em

By Captain Roni Meyerhoff, U.S. Marine Corps

Doctrinal Changes

There is a reluctance to integrate MCM fully with amphibious forces during training exercises. The last war brought to the forefront a grave concern about the level of interest and effort given to our mine-warfare capability. Such concern aroused doctrinal development in the form of the handbook Amphibious Operations in a Mine Environment , and changes within existing doctrine described in EXTAC 620 and Joint Doctrine for Amphibious Operations . The handbook is the only document that describes tactics, techniques, and procedures for amphibious operations in a mine environment. EXTAC 620, which is the NATO version of Amphibious Operations in a Mine Environment , has undergone the same revision as Joint Doctrine for Amphibious Operations in the area of command responsibility for the breach.

It has been confirmed through exercises that the commander amphibious task force (CATF) maintains the pre-ponderence of assets and decision-making capability to effect the amphibious breach. The MCM commander, who maintains neither assets nor the expertise within the surf zone (from ten-foot depth to the high-water mark), is doctrinally responsible for directing mine clearance from the seaward edge of the mine threat area to the high-water mark. Hence, doctrinal revision has placed the responsibility for directing mine clearance from the surf zone inland with CATF. Ultimately, this change places new requirements on the amphibious task force to tackle this naval problem, which involves both blue and green assets during the transition from ship to shore.

Training and Exercises

Training operations like Kernal Blitz, Purple Star, and other joint task force exercises have attempted to validate this doctrine and its proposed tactics, techniques, and procedures, but have met with limited success—mainly because mine countermeasures forces were not fully integrated into the amphibious scheme of maneuver. During these exercises, traditional Navy MCM forces operating in the shallow-water region (from 200-foot to 40-foot depth) were separated physically from the amphibious objective area, and conducted deception operations for the amphibious task force. In this way, the task force was able to avoid the mine problem, which diminished the significance of the mine-warfare effort. In addition, the amphibious breach (e.g., MCAC firing line charges from the surf zone inland; combat engineers landing ashore with proofing; and using clearing assets like the D7G Dozer with a mine plow and Mk 154 amphibious assault vehicle with triple-shot line charge) was conducted within the confines of an exercise timeline.

The landing force was thus prepared to "clock" its efforts rather than react to event-driven scenarios. These large exercises bringing together carrier battle groups and amphibious ready groups do very well in satisfying the checklists of goals and objectives for Marine expeditionary unit (special operations capable) (MEU [SOC]) qualification, but they do not fully integrate MCM with the more attractive warfare areas. Either our list of priorities has to change, or the frequency of conducting such exercises must increase. As the cycle of interest wanes, so too does our training in integrated amphibious operations.

MCAC versus LCAC

What does the Marine air-ground task force (MAGTF) commander sacrifice for a deliberate breaching capability? This is the focal point of the debate over competing tactical exigencies between the MCAC and LCAC (an MCAC is simply an LCAC with modifications for the breaching mission). Certainly, if we consider the limited number of LCACs available in a Marine expeditionary force (MEF)-size forcible entry scenario, approximately 25% of total lift, if not more, may require MCAC conversion. Approximately four MCACs must be available to clear all boat lanes required for a regimental landing team. We also have a requirement for brute-force explosive munitions (e.g., M 58 line charges and shallow-water assault breaching system with distributed explosive technology) to create a gap within a mine and obstacle belt from the surf zone inland. Each MCAC with the Mk 5 mine-clearance system must carry approximately 11,000 pounds of C4 explosive, so we must find ways to accommodate the significant lift (and space) requirement associated with such a capability.

Given this high logistical impact, why then do we choose the MCAC to support near-term surf zone breaching? The first rationale is that the MCAC is fast and has a large payload capability. Second, its air-cushion design permits greater survivability in mineable waters. We have not resolved the problem of simultaneously conducting surf zone breaching and moving combat power ashore rapidly. The figure of 25% required MCAC conversion is speculative, based on recent exercise experience—the reality may be higher. Furthermore, because of restrictions put on exercise timelines, no baseline time-space planning figure can be given to the formula of one MCAC firing 12 line charges (full load), reloading, firing a second set of 12 charges, and finally being reconverted to an LCAC. We need to make this information available through test and validation. This information will give the MAGTF commander a better sense of cost and the impact on his tactical lift priorities. Finally, we may debate the vulnerability an MCAC has against the potential coastal threat and the accuracy and reliability of brute force explosives—but as an expeditionary force, we must understand that this deliberate amphibious breaching tool is all we have to counter the mine and obstacle threat.

Navigation Limitations

Despite continued navigational technological advances, today's landing craft and amphibious assault vehicles have a limited ability to navigate safely from ship to shore within narrow cleared lanes. After our MCAC brute-force tactics create an initial gap, we must get the surface assault force through it safely. Traditionally, surface craft have been used as waterborne guides; this tactic does not work, however, in a mine environment where minimal navigational errors prove fatal.

Presently, experimental equipment like the breach lane navigation system (a two-color "high-speed flashlight") directs ship-to-shore traffic down a straight azimuth from 4,000 yards seaward during the day to 5,000 yards at night. Where the breach land navigation system will come from and how it will be inserted still have not been determined, however. More important, secondary measures are limited and have been left to the fleet's initiative. Finally, we have begun to debate whether we should rely completely on the Global Positioning System (GPS) or instead mark the seaward side of transit and boat lanes (beyond the potential effectiveness of the breach lane navigation system) with some type of buoy mechanism for redundancy and to reduce our reliance on GPS technology. The rationale for physical lane markers is that there will be inadequate time to relay GPS coordinates to assault and follow-on forces (assault forces will follow directly behind the MCACs) to mark the actual breach, which may differ from the planned breach. Valuable accuracy also is lost with the plethora of navigational systems, cartographic products, inaccuracy of plotting, and inaccuracy of reporting. Redundancy and simplicity are needed during the transition from ship to shore.

Land Countermine Systems Shortcomings

Once ashore, our assault forces must contend with the deliberate approach of our land countermine systems. More often than not exercises assume unimpeded movement ashore when land countermine operations are required. Exercise timelines—rather than event-driven circumstances—drive our training evolutions and ultimately dilute the effect mines and obstacles would normally have on the landing force. Through exercises, however, we have determined that the breach is the beginning of the assault—not the end of the MCM effort. The latter position implies that the assault forces must be accompanied by combat engineer land proofing and clearing assets, in order to continue the breach inland (suppress, obscure, secure, reduce, and resupply). Thus, the assault load mix and wave assignments will greatly affect land proofing and clearing operations.

Land proofing and clearing equipment requirements have sparked great debate over the means by which such delivery is made ashore. Specifically, using large dozers with "farm implements" and tanks with track-width mine plows on landing craft is better than using the LCAC in the initial wave. An LCAC must come off-cushion in a craft landing zone (coming off-cushion in the surf endangers propellers) to offload heavy equipment designed for clearing and proofing. Therefore, this action places the LCAC—along with the assets it carries—on ground that has not been proofed. The LCU, on the other hand, delivers proofing assets at the high water mark and allows for buried and hardened mines to be plowed aside before assets are brought ashore. If the enemy can lay mines—deliberately or in haste—then our forces must be adequately prepared to come ashore blade first.

The Bottom Line

Our preparedness for an amphibious operation in the near future requires further examination and training. It is imperative that as an expeditionary force we make integration of all naval forces a top priority in future amphibious exercises. It is not enough to employ the MEU (SOC) in joint task force exercises—we also must promote Marine expeditionary force-size force participation in such an exercise. Today's forcible entry capability does not have the speed and surprise associated with a seamless over-the-horizon approach from ship to shore. Our capability is lift-intensive, slow, deliberate, and overt. It requires physical navigational aids and force protection. Hence, we have a long way to go in developing an in stride breaching capability to support operational maneuver from the sea. More importantly, we must be ready today to execute an amphibious breach with the assets and means we have available. Our maneuver warfare concepts should not deter our readiness when mine-avoidance is not possible.

Captain Meyerhoff is presently assigned to Combat Service Support Detachment 27 in support of MAGTF-8. He is finishing his subject tour and will return to his parent command, the 8th Motor Transport Battalion.

 

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