Section 8 Pillars and pillar bulkheads

8.1.1 Pillars and pillar bulkheads are to be constructed in accordance with the scantlings indicated in Vol 1, Pt 6, Ch 3, 12 Pillars and pillar bulkheads

8.1.2 Pillars are to be arranged to transmit loads from decks and superstructures into the bottom structure. Pillars are generally to be constructed from solid, tubular or I beam section. A pillar may be a fabricated trunk or partial bulkhead.

8.1.3 Where a residual strength assessment is required, this is to include an additional assessment for any pillars or pillar bulkheads identified as critical structure, see Vol 1, Pt 6, Ch 4, 4.1 Application 4.1.9.

8.2.1 Pillars are to be attached at their heads to plates supported by efficient brackets, in order to transmit the load effectively. Doubling or insert plates are to be fitted to decks under large pillars and to the inner bottom under the heels of tubular or hollow square pillars. The pillars are to have a bearing fit and are to be attached to the head and heel plates by continuous welding. At the heads and heels of pillars built of rolled sections, the load is to be well distributed by means of longitudinal and transverse brackets.

8.3.1 Pillars are to be located on main structural members. They are in general to be fitted below windlasses, winches, capstans, the corners of deckhouses, large items of equipment and elsewhere where considered necessary.

8.3.2 Wherever possible, deck pillars are to be fitted in the same vertical line as pillars above and below, and effective arrangements are to be made to distribute the load at the heads and heels of all pillars.

8.3.3 Where pillars support eccentric loads, or are subjected to lateral pressures, they are to be suitably strengthened for the additional bending moment imposed upon them.

8.3.4 Doublers are generally to be fitted on decks and inner bottoms, other than within tanks where doublers are not allowed. Brackets or insert plates may be used instead of doublers.

8.3.5 In double bottoms under widely spaced pillars, the connections of the floors to the girders, and of the floors and girders to the inner bottom, are to be suitably increased. Where pillars are not directly above the intersection of plate floors and girders, partial floors and intercostals are to be fitted as necessary to support the pillars. Holes are not to be cut in the floors and girders below the heels of pillars. Where longitudinal framing is adopted in the double bottom, equivalent stiffening under the heels of pillars is to be provided, and where the heels of pillars are carried on a tunnel, suitable arrangements are to be made to support the load.

8.4.1 In no circumstances are pillars to pass through tanks. Where loads are to be transmitted through tanks, pillars within the tanks are to be carefully aligned with the external pillars. The tensile stress in the pillar and its end connections is not to exceed 108 N/mm² at the tank test pressure. Such pillars are in general to be of built sections and end brackets may be required.

8.5.1 Pillars and pillar bulkheads are to be suitably protected against fire, and capable of resisting fire damage. They are not to be constructed of aluminium.