Stair towers Stairways

When scaffold platforms are more than 2 feet above or below a point of access, portable ladders, hook-on ladders, attachable ladders, stair towers (scaffold stairways/towers), stairway-type ladders (such as ladder stands), ramps, walkways, integral prefabricated scaffold access, or direct access from another scaffold, structure, personnel hoist, or similar surface shall be used. Crossbraces shall not be used as a means of access. 

Stair tower (Scaffold stairway/tower) means a tower comprised of scaffold components and which contains internal stairway units and rest platforms. These towers are used to provide access to scaffold platforms and other elevated points such as floors and roofs. 

Stair towers (scaffold stairway/towers) shall be positioned such that their bottom step is not more than 24 in. (61 cm.) above the scaffold supporting level. A stair rail consisting of a top rail and a mid-rail shall be provided on each side of each scaffold stairway. The top rail of each stair rail system shall also be capable of serving as a handrail, unless a separate handrail is provided. 

---