Marine Barrier Technology:
Preventing Attacks and Resisting Natural Forces at Port and River Crossings

Marine perimeters present a unique security problem as they can be breached from both land and sea. As such, most maritime security deals with reactionary solutions to merely dampen the aftereffects of an attack. To preemptively secure these vulnerable areas from water-borne attacks, KKCS’ team of maritime experts has designed a Marine Barrier (MB) pendulum system for seawater. Made of barge-assembled steel reinforced concrete or HDPE (high-density polyethylene) planks, the MB provides a long-term deterrent, permitting detection and turning away of both terrorists and pirates with explosives or weaponry.

The MB pendulum system can provide an impenetrable wall at port facilities, between the outer pilings of a wharf, physically preventing attack access. At nuclear and DOD facilities the MB can physically prevent attack access up river channels by attaching to the underside of existing river crossing bridges between pilings.

Attack validation of the MB was performed and certified to resist the highest level of underwater cutting and torching attack tools available. Validation of prototype performance is at TRL Level 8+ for securing a seawater marine perimeter with MB technology, as it’s fully certified to meet BART criterion to prevent breach of any marine security perimeter with 10,000 degree Fahrenheit torches or high-power cutting tools. No explosives were used as deck collapse due to blast overpressure would have terminated the attackers, without any breach of the security perimeter.

Suspended from a wharf deck or river-crossing bridge with low-maintenance hinge bearings and a special polymer rotation surface, the MB pendulum requires annual inspection but should not require maintenance for 40 or more years.

MB pendulum systems thereby attain a uniquely resilient security level, functioning in water like a venetian blind at an open window. Our high tech analyses utilize ABAQUS/Aqua for structural performance simulations in seawater, accounting for an attacking vehicle’s forces as well as natural forces of extreme waves and earthquakes. Analytic calculations show the MB capable of arresting impact energy from both attack forces and the forces of nature. Piles and deck diaphragms can readily resist shock forces induced by impact.

Articulation of a large upper pendulum superstructure from a deeply embedded and fixed lower spike substructure system permits each to resist lateral forces (wave, seismic, attack) independently, without tearing apart or incurring significant flexural stress or shear stress. The free swinging pendulum panel design separating the superstructure and substructure’s seismic ground motions reduce stresses induced by strong-motion earthquakes as well as wave action and attack vehicles. The articulated pendulum was also chosen to reduce construction cost and compress construction schedules, permitting all-bolted connections to be made on board barges, with lower labor cost and more rapid assembly. Entire panels between pilings can then be launched complete with two pillow block rotational bearings.

The existing marine wharf deck or river-crossing bridge surface can induce high-frequency low amplitude seismic vibration at top of the upper pendulum as it sways in the seawater. The seabed can induce low frequency high amplitude seismic vibrations to the lower spikes, fixed to the piles and into the seabed. Tearing apart of the Marine Barrier due to out-of-phase motions is thereby prevented by separating the pendulum superstructure as it swings a tangential arc over the horizontal stainless steel plate set along the seabed.