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Releasable Chain Stopper

A photo of Niels Thomsen

Niels P. Thomsen (as a Lieutenant during World War II)

After World War II Niels P. Thomsen, for whom the U.S. Coast Guard’s Innovation Award is named, developed and patented the mechanical chain stopper. The chain stopper is used by buoy tenders to secure and safely release the chain and sinker for buoys. This innovative device has prevented countless accidents and serious injuries to personnel while dramatically reducing the amount of time required to conduct aids to navigation (ATON) operations successfully. Registered as Patent Number 2623255 in 1952, Thomsen assigned the rights to the government. Today his invention is used by numerous countries throughout the world.


Last Modified 11/17/2014