A climbing device made of wood, metal, or fiberglass and consisting of a series of equally spaced
rungs or steps between two side rails
(1) STEPLADDER — A ladder of fixed height with two front and two back legs connected by
hinges and a spreading device that open to make the ladder self-supporting or close for storage.
(2) STRAIGHT LADDER — A non-self-supporting ladder of fixed length with two parallel rails
joined by rungs. (3) EXTENSION LADDER — A non-self-supporting ladder with two or three
sections that fit together in such a way that the ladder length can be adjusted. (4) TRESTLE
LADDER — A self-supporting ladder constructed like a stepladder, except that it is designed to
hold one end of a plank. Two trestle ladders and a plank form a work platform. (5)
ARTICULATED LADDER — A ladder with joints that can be locked into a variety of positions
so it can be used as a straight ladder, stepladder, etc. (6) PLATFORM LADDER — A stepladder
with a platform at the highest standing level.