An older class of submarine, the Clam Class is a backbone vessel of the World Navy fleet.
Built forty years ago, the Clam Class was upgraded in the 2050s with redesigned bridge and conning tower sections. Extra missile launchers and onboard VTOL aircraft capabilities were added as well. The VTOL aircraft capability allows for one light, VTOL plane to be launched when the craft is surfaced.
Most of the Clam Class are being phased out due to the new Barracuda class. A few of the vessels have been seconded to SPECTRUM, who will continue to use them for a number of years.
- These craft appear in the book Inside the Worlds of Gerry Anderson.