Standard Amphibious Undercarriages- Small and Medium Size Product Features 1) Pontoon Construction High Strength Weathering Cor-Ten plate steel is used in the fabrication of the pontoons. Cor-Ten steel is marine grade and corrosion resistance steel that has 5 to 8 times the atmospheric corrosion resistance and 20% more tensile strength than similar size 16Mn Q345B structural plate steel. In the pontoon, there are many supporting steel bars which reinforcing pontoon strongly. Each pontoon has 2 bulkheads, providing 3 independent watertight compartments with inspection plugs located on the outside of the pontoons. Each compartment of the pontoon has 1x25mm drain hole at bottom and 1x25mm inspection hole on side of pontoon near the top. Service man manholes on each pontoon are optional, made for easy maintenance and field servicing. Pontoons are shot blasted to ensure that the surface is thoroughly clean and free from contaminants and rust. In addition, this process presents the steel with a surface texture that provides excellent adhesion of prime coat of paint. Interior Metal Finish is coated with Zinc chromate rust inhibitor or Rust Inhibitor priming paint. Exterior Metal Finish is 2 part organic zinc epoxy base coat Primer, Epoxy topcoat. The bottom of the pontoon is reinforced for rough terrain operations. Especially the chains runway channels or paths are made of 3-layers steels, 2-part HD70 high tension steel plus the spring steel wear plate, which highly prolong the pontoon's service life. SUNTON Pontoon shape is quite uniquely designed that could reduce the resistance of the water or mud during its moving. The hydraulic hoses or pipes are shielded with steel from being damaged during operations. 2) Track Chains and Track Shoes Each SUNTON pontoon could be equipped with two, three or four strands of heavy-duty track chains. The chain link pads and track pads are all made of high tension steel HD70. The design and size of SUNTON track chain rollers and pins or bushes are all different from others with larger sizes. Tensile strength of link pads could reach 680Mpa. The chain roller paths/channels are lined with high strength abrasion-resistant steel and spring steel that matches the hardness of the chain rollers. Track shoes/cleats/pads are fabricated with heavy duty steel, which makes it less prone to cracking, due to the wider spread between yield strength and ultimate tensile strength. Track pad steel tensile strength reaches 620Mpa. Customer could select much harder steels, whose tensile strength could reach 860Mpa, but cost is higher. Track shoes are box-shaped, welded or bolted to the chains and fully covering the pontoons. UHMW wear plate or HDPE or HDMP plate, is the optional design to meet the challenge of wearing when machine often moves on stiff or tough ground. Usually there are two Ultra High Molecular Weight trackwear pads per cleat.