4.11 Bending test of the stiles

The test shall be carried out on the complete ladder, incase of extending ladders in the fully extended position.

It shall be carried out without supporting legs if these are not permanently fixed to the ladder.

Where the ascendable side cannot be determined by the construction of the product, or where it is a multiple part combination ladder the ladder shall be tested twice. For the second test the ladder shall be rotated 180° about the longitudinal axis.

The ladder shall be placed horizontally on supports situated 200 mm from each end of the ladder.

The supports shall be cylindrical with diameters between 25 mm and 100 mm and one shall be free to rotate the other shall be fixed.

The test load shall be slowly applied in the middle of the ladder equally to both stiles over a width of 100 mm while it has to be taken care that an applying by jerks is avoided.

A pre-load of 100 N shall be applied for the duration of one minute. The position of the ladder after removal of the preload is the origin for the measurement.

A test load F of 750 N (see Figure 21) shall be applied vertically on the centre of the ladder for a duration of at least 1 min.

Thereby the maximum permissible deflection fmax. as a function of the distance l between the supports shall be:
– fmax = 5 l 2 10−6 mm for ladders of length less than or equal to 5 m;
– fmax = 0,043 l − 90 mm for ladders of length more than 5 m and less than or equal to 12 m;
– fmax = 0,06 l − 294 mm for ladders of length more than 12 m.