Clemson-class destroyers (along with the preceding Wickes-class) were the most numerous class of destroyers the US Navy had during/before WWII. More than 30 of these destroyers were converted as Fast-Attack Transports: the number of stacks were reduced to 2, all torpedo tubes removed, and on some the 4"/50 guns were replaced with 3"/50. Four landing crafts (either LCVP, LCP(L) or LCP(R)) on davits were fitted amidships.
http://en.wikipedia.org/wiki/Wickes-class_destroyerhttp://en.wikipedia.org/wiki/Clemson-class_destroyer