In 1972, U.S.C Combat Systems replaced the LVTP-5 with the LVTP-7, otherwise known as an Amphibious Assault Vehicle (AAV) (1).
The vehicle is used by the Marines to land personnel and equipment on land from the sea. A unique feature of AAVs is that they can traverse both land and water, giving assaulting units an advantage on beachfronts.
The problem with the vehicles is that they tend to corrode with prolonged contact with salt water (2).
Of course, there is always a way to fix a problem, and if there’s a way, there’s a will. The military will fix it.
It’s Time to Replace the Rubber
Amphibious Assault Vehicles are built with an outer layer of steel and inner layer of steel sandwiched with a layer of rubber in the middle.
Through a series of tests and applied research, the Navy has discovered types of rubber that are less corrosive than what is currently being used on its AAVs. Those rubbers are called polyureas.
One type of polyurea used commercially can be found in the bed of pickups. The bed liners you see are polyureas. It maintains a better bond than polyurethanes because it has more hydrogen.
What makes the poyureas so powerful is the fact that they stretch up to 10 times their original length. That gives them an extra toughness not found in polyurethanes.
What Are Polyureas Used For?
Polyureas are already commonly used today, primarily as coatings and sealants. They are often poured over concrete and steel for corrosion protection and abrasion resistance (3). Because polyureas are flexible, they can be molded and shaped easily.
Spray polyureas have or can be used for:
–> Pipe and pipeline coatings and linings
–> Bridge coating
–> Joint fill or caulk
–> Tank coatings
–> Tank linings
–> A variety of marine applications
–> Roof coating
–> Waste water treatment linings
–> Manhole and sewer linings
–> Truck bed liners
–> Theme park and decorative design uses
–> Flooring and parking decks
–> Aquarium lining
–> Landscape and water containment
–> Architectural design
–> Water parks and playgrounds
–> Rail car lining and track containment
–> Line striping
–> Spray molding
–> Fuel storage and containment
The qualities and characteristics of polyureas are what give the material distinct advantages for military use. These include no volatile organic compounds, tolerant to extreme weather, resistant to thermal shock, high flexibility, waterproof, excellent bond strength, low permeability, and it is resistant to many solvents and mild acids.
Evidently, it is resistant to salt water corrosion as well.
If you appreciate how the military can just float around all over the world and move back and forth between land and sea at will, then send your thanks to a Marine.
If improving the military’s equipment leads to protections of American lifestyles, it’s likely because a team of scientists continue to advance their knowledge of the materials used in basic military equipment. Thanks to polyureas, there may be other ways to improve military equipment.
References & Image Credits:
(1) Military Factory
(2) Naval Research Laboratory
(4) Assault Amphibious Vehicles