Section 6 Loading guidance information
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Special Service Craft, July 2022 - Part 5 Design and Load Criteria - Chapter 5 Global Load and Design Criteria - Section 6 Loading guidance information

Section 6 Loading guidance information

Parent topic: Chapter 5 Global Load and Design Criteria

6.1 General

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

6.1.2 This information is to be provided by means of a Loading manual and in addition, where required, by means of an approved loading instrument.

6.1.3 An Operational manual which contains the craft's assigned operational envelope is to be provided on board, see Pt 1, Ch 2, 2 Scope of the Rules and Ch 1, 1 Background.

6.2 Loading manuals

6.2.1 A Loading Manual is to be supplied to all craft where longitudinal strength calculations have been required, see Pt 5, Ch 5, 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 craft 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 cargo carriage constraints imposed by the use of an accepted coating in association with a system of corrosion control.

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

6.3 Loading instrument

6.3.1 In addition to a Loading Manual, an approved type loading instrument is to be provided for craft when it is deemed necessary by Lloyds Register (hereinafter referred to as LR).

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'sApproval 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 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 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 alteration to structure, lightweight or cargo distribution is proposed, 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 Pt 1, Ch 3 Periodical Survey Regulations for Service Craft. 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 strength 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. For systems having a stability computation capability and installed on a new ship, see also Pt 1, Ch 2, 1.1 General 1.1.10. For systems having a stability computation capability and installed on an existing craft, it is recommended that the system be certified in accordance with LR's document entitled, Approval of Longitudinal Strength and Stability Calculation Programs.

Copyright 2022 Clasifications Register Group Limited, International Maritime Organization, International Labour Organization or Maritime and Coastguard Agency. All rights reserved. Clasifications Register Group Limited, its affiliates and subsidiaries and their respective officers, employees or agents are, individually and collectively, referred to in this clause as 'Clasifications Register'. Clasifications Register assumes no responsibility and shall not be liable to any person for any loss, damage or expense caused by reliance on the information or advice in this document or howsoever provided, unless that person has signed a contract with the relevant Clasifications Register entity for the provision of this information or advice and in that case any responsibility or liability is exclusively on the terms and conditions set out in that contract.