[1] They are a product owned and patented worldwide by Poseidon Alliance Ltd. Open channel applications include bank stabilization, flow and grade control, scour protection for bridge piers, and biostabilization.
The advantage of A-Jacks over other hard armoring solutions is the comparatively large area available in the interstitial spaces for native vegetation to take root, ultimately helping to restore the stream bank to a more natural state while continuing to protect against erosion.
In breakwater applications, A-Jacks can be an economical alternative to quarried rock, which can be both heavier and unwieldy; over the course of a breakwater construction project, the number of transportation cycles to deliver product to the site can be reduced substantially, since A-Jacks are delivered flat on trucks whereas rock rip-rap would be brought in dump trucks.
For example, rock can weigh between 150-175 lb;[2] a suitable rip-rap boulder comparable to a 96 inch A-Jacks unit (about 36 c.f.)
For artificial reefs and habitat development, typical reef-building biota find areas of low turbulence within the open spaces to establish colonies.