​U.S. Patent 1 & 2

U.S. Patent 3

U.S. Patent 4

Canadian Patent

Australian Patent 1

Australian Patent 2

ACDR (Air cavity Drag Reduction)

Tom Lang's New Ideas, Theories, and Inventions

Copyright © Thomas G. Lang. All rights reserved.

ACDR is defined  as the use of air cavities to reduce drag on underwater surfaces.  By forming air cavities over underwater portions of ships, submarines, and hydrofoils, drag can be reduced as much as a factor of 3, and possibly more. As a result, range can be increased, the size and cost of underwater vehicles and devices can be reduced, and/or fuel can be saved.

​U.S. Patent 1

U.S. Patent 2

U.S. Patent 3

U.S. Patent 4

Canadian Patent

Australian Patent 1

Australian Patent 2