Sometimes you don't have enough room for a full size stair, but you don't want to use a 90 degree safety ladder because you want an easier climb. For those instances you can use a ships stair (sometimes called ship ladders). Ship stairs have a safe climbing angle between 50 and 70 degrees and have safety rails on both sides. Those handrails can terminate with the top tread for use as a roof hatch ship ladder, or can extend above the top tread like the handrail on a standard stair design.
After years of uncertainty of their usage allowance, OSHA is now officially recognizing these with standard 1910.25(d).
Ships stairs are required to have open risers with a height of 6.5" to 12". The minimum tread depth is 4" and the minimum tread width is 18". Treads can be channel, diamond plate or bar grating - bar grating tread is the standard option due to its superior slip resistance, self-cleaning design and economic price.
To order a ship ladder we will need to the dimensions of (A) and (B) below. If your run is flexible, just let us know. We can easily make the ships stair more steep (close to 70 degrees incline) or less steep (close to 50 degree incline). Standard finish is black grating treads and gray stringers and handrail. We can also provide ships ladders in a custom paint color or hot dipped galvanized.
If you are planning on taking the ship stair to a roof hatch, we would recommend our 30"x54" size. Smaller than 54" will create head clearance issues while climbing up the ship stair.