Section 3 Loose container securing fittings, materials and testing

3.1.1 Randomly selected samples of loose container securing fittings are to be subjected to prototype testing and, upon satisfactory completion, will be granted General Approval.

3.1.2 Randomly selected samples drawn from production runs are to be subjected to production testing prior to delivery to the ship in accordance with Pt 3, Ch 14, 3.4 Production testing.

3.1.3 Loose container securing fittings, certified by an organisation other than LR, will be accepted where the certification scheme is to the satisfaction of LR.

3.1.4 In the following, the term ‘fully automatic fitting’ is used to describe fittings which do not require manual operation during unloading of the containers. It should be noted that usually these fittings do not mechanically secure the container in the vertical direction (perpendicular to the hatch cover) in the upright condition when subjected to pure vertical motions. Other modes of operation and novel design will be specially considered.

3.2.1 Steel used for loose container securing fittings is to comply with the requirements of the Rules for Materials or with an equivalent specification acceptable to LR.

3.2.2 Where loose container securing fittings are intended to operate at low ambient temperatures, special consideration is to be given to the specification of the steel.

3.2.3 Proposals for the use of materials other than steel will be specially considered.

3.2.4 Locking devices and other fittings which are inserted into the container castings on the quayside before lifting on board are to be such as to minimise the risk of them working loose under the effects of vibration and the risk of them falling out.

3.2.5 For twistlocks, bottom twistlocks, midlocks, stackers with intermediate plates and fully automatic fittings, the contact areas, for both tension and compression between the fitting and the corner castings of the containers, are to be such as not to exceed a bearing stress of 300 N/mm2 under the safe working load of the fitting. No increase in the permissible stress level will be given due to higher strength material of the fittings. In the case where the design is such that the contact area is sloped or inclined and not parallel to the container corner casting, the effective contact area will be specially considered.

3.3.1 Prototype tests are to be in accordance with Pt 3, Ch 14, 2.3 Prototype testing 2.3.1, except that Table 14.3.1 Design breaking loads and proof loads for loose container securing fittings and Table 14.3.2 Test loads and test modes for loose container securing fittings are to be applied in lieu of Table 14.2.1 Design breaking loads and proof loads for fixed cargo securing fittings and Table 14.2.2 Test loads and test modes for fixed container securing fittings respectively.

3.4.1 The nature and extent of proposed production testing will be considered by LR, but the arrangements are to be at least equivalent to one of the following testing procedures:

1. For:

   1. Loose container securing fittings except chain or wire rope lashings. One randomly selected sample from every 50 pieces, or from each batch if fewer than 50 pieces, is to be proof loaded in accordance with Table 14.3.1 Design breaking loads and proof loads for loose container securing fittings.

   2. Chain or wire rope lashings. One randomly selected sample from every 50 pieces, or from each batch if fewer than 50 pieces, is to be tested to breaking.

2. All fittings, securing devices and lashings are to be proof loaded to the SWL of the item and in addition, one randomly selected sample from every batch of chain or wire rope lashings is to be tested to breaking.

3.4.2 Permanent deformation (other than that due to initial embedding of component parts) will not be accepted unless tests are conducted in accordance with Pt 3, Ch 14, 3.4 Production testing 3.4.1.(a).(ii) and the SWL of the sample is 250 kN or greater. In this case, consideration may be given to acceptance of permanent deformation in the load range between SWL + 125 kN and the proof load, provided that satisfactory manual operation can be achieved after completion of tests.

3.4.3 In the event of premature failure or serious plastic deformation occurring in a test sample, a further randomly selected sample is to be selected for testing. In the event that this sample is found to be unsatisfactory, the associated batch will be rejected.

3.5.1 For fittings of novel design or with special features, in addition to the prototype and production testing, a function test may be required to demonstrate that the fitting is fit for purpose. Details of the function test will be considered on an individual basis, taking into consideration the mode of operation of the fitting. In addition, LR reserves the right to require environmental tests. The actual test depends on the individual design of the fitting. The tests are to verify that environmental and ageing effects, such as corrosion, icing, debris contamination, etc. do not impinge on the safe operation of the fitting. In this case, LR reserves the right to require the submission of maintenance instructions as part of the approval procedure.