6 Strength
NOTE It shall be noted that loads as given in the following apply to the working condition as described in clause 4.1.
6.1 The safety factor of the main member of the ladder, when a concentrated load of 3000 N is applied at the central point between the top eye pin and lifting point or the centre of the lower platform shall be 2 or more against the yield point for steel or against 0.2% proof stress for aluminium alloy respectively. The maximum deflection shall be 1/100 or less of the distance between the support points for steel, or 1/75 or less, for aluminum alloy.
6.2 The handrail and handrail stanchions shall withstand a uniformly distributed load of 500 N/m (51 kgf/m) in lateral direction imposed on the upper handrail.
6.3 The steps shall withstand a central point load of 1500 N.
6.4 The upper and lower platforms shall withstand a uniformly distributed load of 4000 N/m2. The upper platform frames and their supports shall be capable of withstanding a combined load of the weight of the ladder and the load given in clause 6.1 imposed thereon.
7 Tests and inspections
7.1 Visual inspection
The ladders shall be subjected to visual inspection, and shall satisfy the requirements of clause 4.
7.2 Strength inspection
7.2.1 The maximum deflection of the main member of the ladder, when subjected to the test load as given in clause 6.1, shall satisfy the requirements stipulated. When the test load is removed, there shall be no permanent set at each part of the ladder.
7.2.2 When a concentrated test load corresponding to the load given in clause 6.2 is applied to the top of the handrail stanchion in lateral direction and then removed, there shall be no abnormality such as permanent Set.
7.2.3 When the test loads given in clauses 6.3 and 6.4 are applied to the steps and platforms and then removed, there shall be no abnormality such as permanent set.
8 Designation
The ladders shall be designated by the title, class, and nominal length of ladder (L). The ISO number may be used in place of the title.
NOTE Example：
"Pilot Accommodation Ladder - S - 5 m" or "ISO 16848 - S - 5 m"
9 Marking
The following shall appear in clear marking on a readily visible part of the main member：
- "MAX. 3 persons";
- Manufacturer's name or mark;
- Year of assembly; and
- "lSO 16848".
