Procedure di test per scale alla marinara
Di seguito viene riporata la procedura di test per scale alla marinara riportata nella EN ISO 14122-4.
5.2 Ladder with two stiles
5.2.1 Strength
Ladder elements shall meet the verification requirement of stability by calculation in 6.1 or by test in 6.2.
5.2.2 Rungs
5.2.2.1 Strength
Rungs shall meet the verification requirement of stability by calculation in 6.1 or by test in 6.2.
5.5 Fall protection device
5.5.1 Safety cage
5.5.1.1 Strength
The strength verification of a safety cage shall be iliade by tests.
6 Verification of safety requirements
6.1 General
6.1.1 General requirements
Safety requirements and/or measures shall be assessed by
— measurement,
— visual inspection,
— calculation and/or load test.
The methods and the results shall be documented (e.g. protocol).
For verification of safety requirements it is assumed that
— a safety cage is applied commonly in combination with ladders with two stiles, and
— a fall arrester is applied commonly in combination with ladders with one or two stiles.
6.1.2 Verification of stability by calculation
For calculation the loads shall be applied at the most unfavourable point.
For partial factors for actions specific material standards shall be applied.
6.1.3 Verification of stability by testing
A material factor of 1,75 for aluminium and steel has been already considered in the test loads.
The load duration shall be ≥1 min.
Measuring of the residuai deflection shall be carried out no less than one minute after removing the
test load.
6.2 Tests of fixed ladders with two stiles
6.2.1 Strength and bending of a ladder element
6.2.1.1 Test on stiles
For verification of required stability, the bending test of the stiles of the ladder element may be carried out by a simulated system in Figure 22.
The test is carried out without a preload in accordance with Figure 22 on at least eight rungs.
The test load (FTL) shall be 700 N.
A residual deflection of the stiles related to the length of the loaded part of the ladder (4x spacing of the rung) shall be not more than 0,3 %.
Figure 22 — Ladder with two stiles — Bending test
Key
FTL test load
A spacing of rungs
6.2.1.2 Test for rungs
A centred preload (FPL) of 200 N is applied for verification of adequate strength.
The position of the rung after removing the preload is taken into account as a reference position for test load FTL of 2600 N (see Figure 23) carried out in similar way.
The loads are perpendicular and may, in accordance with Figure 23. be considered as equally distributed on a length of 100 mm. The underlayment shall be rigid and shall have no sharp edges.
A residuai deflection of the rungs related to the length of the rung shall be not more than 0,3 %.
Figure 23 — Ladder with two stiles — Test of rungs
Key
1 underlayment
FPL preload
FTL test load
6.2.2 Test for safety cage
The test is carried out on a safety cage section with three hoops and five uprights which are fitted to the ladder element.
The test shall be carried out in accordance with Figure 24.
A preload (FPL) of 200 N is applied perpendicular at the most unfavourable point of the lower hoop. The position of the hoop after removing the preload is taken into account as a reference position for the test to be carried out with a test load (FTL) of 1000 N.
The permissible permanent deflection measured at the point of application of the load shall be no more than 50 mm.
Figure 24 — Test of safety cage
Key
FPL preload
FTL vertical test load
FH horizontal test load
For uprights, a load (FH ) of 500 N shall be horizontally applied at the most unfavourable point between two consecutive hoops. FH may be distributed overthree uprights.
The permissible permanent deflection measured at the point of application of the load is 10 mm
maximum.
The test is carried out under the sanie conditions as those likely to exist at the place where it could
be used.
6.4 Test of extensions of guard-rails
For verification of required stability, a load (FEX) shall be applied horizontally at the most unfavourable
position along the length of the upper part of the guard-rail extension, see Figure 27.
FEX = 300 N/m x L x y
where y is the material factor for steel and aluminium (y = 1,75).
After removing the load, the function of the extension shall not be impaired and no cracks or permanent deflection shall be identifiable by inspection.
Figure 27 — Test of extensions of guard-rails
Key
1 underlayment
2 extension
FEX preload
FTL test load
L length of extension