For enamelled, lined or coated apparatus and apparatus made from non-ferrous metal or plastics the application has to be checked. The vertical ladders are constructed for the following working loads: - rung load 1,5 kN; - total load 6 kN (3 kN per ladder beam). For stationary vertical ladders on physical structures applies DIN 18799-1. For stationary vertical ladders on machines applies DIN EN ISO 14122-4.