Annex - Amendments to the Guidelines for Evaluation and Replacement of Lifeboat Release and Retrieval Systems (MSC.1/Circ.1392)

"21 The Administration, or a recognized organization acting on its behalf, may allow that hook fixed structural connections of the release mechanism and supporting structure which are not made of material resistant to corrosion in the marine environment, as required by paragraph 4.4.7.6.9 of the LSA Code, need not be replaced if they are in a good condition and installed in a sheltered position inside the lifeboat. The assessment for verifying that fixed structural connections and supporting structures are in 'good condition' should be carried out by the manufacturer or by one of its representatives in accordance with paragraph 23 below.

The assessment for verification is not required if the materials of the foundation, bolts and supporting structure, both internally and externally, are made of materials resistant to corrosion in the marine environment.

• .1 Method of assessment:

  The assessment of fixed structural connections of the release mechanism and supporting structures should be carried out according to the manual developed by the manufacturer. However, if either such a manual or the original equipment manufacturer, or any entity which has taken legal and legitimate responsibilities for equipment when the original equipment manufacturer no longer exists or supports the equipment, do not exist, this assessment should be carried out according to the following method:

  • .1 100% visual examination of all components within clear sight in order to assess the general condition and look for signs of corrosion. No dismantling or removal of components is required at this stage.

  • .2 At least 25% of bolts for each hook fixation should be removed for visual examination^footnote. Additionally, a non-destructive testing (NDT) technique, such as magnetic particle inspection (MPI), where suitable, may be applied. If any of the removed bolts of the hook fixation shows signs of corrosion or are deemed to be in "bad condition", then the rest of the bolts for the same hook fixation should be removed and examined. As a general rule, any bolt that has lost material to corrosion of 2% from the original dimensions should be deemed to be "in bad condition" and replaced. Replacement bolts are to be made of material corrosion resistant in the marine environment based on a like for like principle.

  • .3 If fixed structural connections of the release mechanism or supporting structures show signs of corrosion, then ultrasonic thickness measurement and corrosion mapping should be performed. For this non-destructive examination (NDE) to be possible, the probes need to have adequate access and the surface needs to be smooth and appropriate for ultrasonic scanning. As a general rule, a backing plate that has suffered corrosion wastage of 10% or more from the original plate thickness should be deemed to be "in bad condition" and replaced. Replacement of structural connections, backing plates, etc. are to be made of materials resistant to corrosion in the marine environment and based on a like for like principle.

  • .4 If after the assessment, the bolts, backing plates, keel shoes, etc. are in good condition, then all parts are to be cleaned and recoated, if necessary.

.2 Backing plates and bolts installed outside the lifeboat and deemed to be in 'good condition' after the assessment need not be replaced even when not made of material resistant to corrosion in the marine environment."