Section 6 Loading guidance information

6.1.1 Sufficient information is to be supplied to every ship to enable the Commanding Officer or Master to arrange loading and ballasting in such a way as to avoid the creation of unacceptable stresses in the ship’s structure.

6.1.2 This information should include any limiting criteria that were applied to the structural design of the ship, e.g. the maximum and minimum still water bending moments, service area notation with details of service area restrictions.

6.1.3 This information is to be provided by means of a Stability Information Book or Loading Manual and in addition, where required, by means of an approved loading instrument.

6.1.4 An Operational manual which contains the ship’s assigned operational envelope is to be provided on board, see Vol 1, Pt 1, Ch 2, 2.2 Definitions 2.2.12 and Vol 1, Pt 5, Ch 1, 1.1 General.

6.2.1 A Loading Manual is to be supplied to all ships where longitudinal strength calculations have been required, see Vol 1, Pt 6, Ch 3, 4.2 Hull girder strength and Vol 1, Pt 6, Ch 4, 2.1 General. The Manual is to be submitted for approval in respect of strength aspects. Where both Loading Manual and loading instrument are supplied the Loading Manual must nevertheless be approved from the strength aspect. In this case the Manual is to be endorsed to the effect that any departures from these conditions in service are to be arranged on the basis of the loading instrument and the allowable local loadings shown in the Manual.

6.2.2 The Loading Manual is to be based on the final data of the ship and is to include well-defined lightweight distribution and buoyancy data.

6.2.3 Details of the loading conditions are to be included in the manual as applicable.

6.2.4 The Loading Manual is also to contain the following:

1. Values of actual and permissible still water bending moments and shear forces and where applicable limitations due to torsional loads.

2. The allowable local loadings for the structure.

3. Details of the carriage of any substances where there are constraints imposed by the use of an accepted coating in association with a system of corrosion control.

4. Where the ship has the capability to significantly alter the draught forward by filling water ballast tanks, then a note saying: ‘Scantlings approved for minimum draught forward of...m with ballast tanks No ... filled. In heavy weather conditions the forward draught is not to be less than this value. If, in the opinion of the Commanding Officer or Master, sea conditions are likely to cause regular slamming, then other appropriate measures such as change in speed, heading or an increase in draught forward may also need to be taken.’

6.2.5 Where applicable, the Manual is also to contain the procedure for ballast exchange and sediment removal at sea and the correct use of tanks.

6.2.6 Where alteration to structure, lightweight, cargo distribution or draught is proposed, revised information is to be submitted for approval.

6.3.1 In addition to a Loading Manual, an approved loading instrument is to be provided for all ships where LR is greater than 65 m except as noted below. The following ships are exempt from this requirement:

1. ships with very limited possibilities for variations in the distribution of cargo and ballast;

2. ships with a regular or fixed operational pattern.

6.3.2 The loading instrument is to be capable of calculating shear forces and bending moments, and where necessary cargo torque, in any load or ballast condition at specified readout points and is to indicate the permissible values. The instrument is to be certified in accordance with LR procedures for the approval of longitudinal strength and stability calculation programs.

6.3.3 The instrument readout points are usually selected at the position of the transverse bulkheads or other obvious boundaries. As many readout points as considered necessary by LR are to be included, e.g. between bulkheads.

6.3.4 Where the ship has the capability to significantly alter the draught forward by filling water ballast tanks, then a notice is to be displayed on the loading instrument stating: ‘Scantlings approved for minimum draught forward of... m with ballast tanks No ... filled. In heavy weather conditions the forward draught is not be to less than this value. If, in the opinion of the Commanding Officer or Master, sea conditions are likely to cause regular slamming, then other appropriate measures such as change in speed, heading or an increase in draught forward may also need to be taken.’

6.3.5 Where alterations to structure are carried out which result in a change in the lightweight or deadweight distribution, the loading instrument is to be modified accordingly and details submitted for approval.

6.3.6 The operation of the loading instrument is to be verified by the Surveyor upon installation and at Annual and Periodical Surveys as required in Vol 1, Pt 5, Ch 3 Local Design Loads. An Operation Manual for the instrument is to be verified as being available on board.

6.3.7 Where an onboard computer system having a longitudinal strength or a stability computation capability is provided as an Owner’s option, it is recommended that the system be certified in accordance with LR’s document entitled Approval of Longitudinal Strength and Stability Calculation Programs.