Chief Sharkey was bald on top
Actor Terry Becker wore a hairpiece as Chief Sharkey. Here is Becker with his normal hair in an episode of The Twilight Zone:
http://oi66.tinypic.com/ibg9yr.jpg
And with extra hair on Voyage:
http://www.seaviewstories.com/sitebuildercontent/sitebuilderpictures/becker.jpg