Section 1 Rule application

1.1.1 Masts, derrick posts, crane pedestals and similar supporting structures to equipment are classification items, and the scantlings and arrangements are to comply with the additional requirements of this Chapter.

1.1.2 Certain lifting appliances on special purpose units which are considered an essential feature of the unit are to be included in the classification of the unit. Elsewhere, classification of lifting appliances is optional and may be assigned at the request of the Owner on compliance with the appropriate requirements.

1.1.3 Where the lifting appliance is considered to be an essential feature of a classed unit, the special feature class notation LA will, in general, be mandatory.

1.1.4 Proposals to class lifting appliances on unclassed units will be specially considered.

1.2.1 The scantlings of masts and derrick posts, intended to support derrick booms, and of crane pedestals are to comply with the requirements of LR’s Code for Lifting Appliances in a Marine Environment (hereinafter referred to as LAME Code).

1.2.3 Masts, derrick posts or crane pedestals are to be efficiently supported and, in general, are to be carried through the deck and satisfactorily scarfed into transverse or longitudinal bulkheads, or equivalent structure. Alternatively, the mast, derrick posts or crane pedestals may be carried into a deckhouse or equivalent structure, in which case the house is to be of substantial construction. Proposals for other support arrangements will be specially considered.

1.2.4 Deck plating and underdeck structure are to be reinforced under masts, derrick posts and crane pedestals. Where the deck is penetrated the deck plating is to be suitably increased locally.

1.2.5 The permissible stresses in the support structure are to be in accordance withPt 4, Ch 5, 2 Permissible stresses

1.3.1 Offshore units fitted with lifting appliances built in accordance with LR’s LAME Code in respect of structural and machinery requirements will be eligible to be assigned special features class notations as listed in Table 11.1.1. The notation will be retained so long as the appliances are found upon examination at the prescribed surveys to be maintained in accordance with LR’s requirements.

1.4.1 With the crane boom in the stowed position, the structure of the crane boom support structure is to be designed for the maximum reaction forces in any operating condition, taking into account the maximum design environmental loadings and inertia forces due to motions of the unit.

1.4.2 The crane boom support structure is also to be verified in the emergency condition defined in Pt 3, Ch 8, 1.4 Plant design characteristics.

1.4.3 The permissible stresses in the crane boom support structure and the deck structure below are to be in accordance with Pt 4, Ch 5, 2 Permissible stresses.

1.5.1 Runway beams are to be designed and tested in situ in accordance with a recognised Standard and marked with the safe working load, see also Appendix A.

1.6.1 Padeyes attached to the main structure which are to be used with a rated lifting appliance are to be proof tested after installation and marked with the safe working load (SWL). The proof load is not to be less than 1,5 x SWL.

1.6.2 Lifting lugs are to be permanently marked with the SWL, tested after installation and NDE to the Surveyor’s satisfaction. In agreement with LR, testing and NDE of lifting lugs with SWL < 1 tonne may be by sampling, provided design calculations can demonstrate a factor of safety greater than 2.

1.7.1 Pedestals and similar structures supporting installed gangways used for access to adjacent fixed installations are classification items and the scantlings and arrangements are to comply with the general requirements for crane pedestals and support structure in Pt 3, Ch 11, 1.2 Masts, derrick posts and crane pedestals.

1.7.2 The gangway is to comply with the relevant statutory Regulations of the National Administration of the country in which the unit is registered and/or in which it is to operate and design calculations for the supporting structure are to be submitted.