Access Covers and Grates are designated by classes A, B, C, D, E, F & G according to load capacity set out in the table below. This table is an extract from AS3996-2006.
The appropriate class for a cover or grate depends on the location of installation. Some examples are outlined in this table; however it is the responsibility of the designer to ensure an appropriate class is selected and/or specified. Specifics of the location should be taken into consideration when selecting the right cover or grate.
The speed of traffic, wheel type and the physical position (turning area) should all be assessed.
1. Nominal wheel loads are given as a guide only. Consideration should be given to the type, size and pneumatic pressure of the load applied. 2. Class B design loads exceed AS5100.2 requirements for footway loading. 3. Class D design loads exceed AS5100.2 requirements for a W80 wheel load. 4. Class C loads are based on an intermediate load. 5. The serviceability load is set at 2/3 of the ultimate limit state design load. 6. A force of 1kN approximately equal to 100kg.