Section 1 Introduction

1.1 A longitudinal strength and/or stability calculation program is a means by which it can be easily and quickly ascertained that still water bending moments, shear forces and/or stability characteristics of a particular ship in any given loading condition are within the values permitted by the Rules or applicable statutory regulations.

1.2 The calculation process of such a program is to be approved in accordance with the procedures detailed in this document. The hardware on which the program is run is to be Type Approved by LR in accordance with the Type Approval procedures detailed in “Type Approval System Procedure” and “Test Specification Number 1”. Alternatively, where Type Approved hardware is not installed, the program must be able to be run on two independent nominated computers, thus providing a back-up in the event of failure of the first computer.

1.3 The program would be supplied in addition to the approved Loading Manual, approved Trim and Stability Booklet and, if relevant, approved Grain Loading Manual, and not as a substitute. These documents shall be available onboard ship as required by the Rules and applicable statutory regulations.

1.4 In accordance with Pt 3, Ch 4, 8.3 Loading instrument of the Rules for Ships, provision of an approved program capable of carrying out longitudinal strength calculations is a Classification requirement for all ships having a length, L, exceeding 65 metres, the midship sections of which were approved on or after 26 July 1984, and which are approved for a non-uniform distribution of loading. Certain ship types are exempt from this requirement, as indicated in Pt 3, Ch 4, 8.3 Loading instrument 8.3.1 of the Rules for Ships.

1.5 In accordance with Pt 3, Ch 4, 8.3 Loading instrument 8.3.10 of the Rules for Ships, where a program having a longitudinal strength and/or stability calculation capability is provided as an owners requirement on a new ship, or newly installed on an existing ship, then it is recommended that the program is certified for such use.

1.6 The requirements in paragraph Ch 1, 1 Introduction 1.5 above are also applicable to ship units as defined in the Rules and Regulations for Fixed Offshore Installations, with an effective date of 20 July 1994, and Mobile Rules, with an effective date of 1 September 1996.

1.7 In accordance with the provisional Rules dated December 1997, all existing bulk carriers of 150 metres and above in length are required to be fitted with an approved longitudinal strength loading calculation program.

1.8 Bulk carriers, combination carriers etc. contracted for construction on or after 1st July 1998 are also required to be fitted with an approved loading calculation program, which includes those functions outlined in paragraph 2 of IACS Unified Requirements URS1A.

1.9 The program is to be of an approved type, that is:

• The program’s calculations have been examined in accordance with the procedure detailed in this document and found satisfactory.

• The format of the user manual is satisfactory, see Section Ch 1, Ch 3, 6 User's Manual.

• The functionality of the program is found to be acceptable.

• A “Certificate of Approval” has been issued, See Section Ch 1, Ch 3, 7 Approval Certificate.

1.10 When a program which has been granted general approval is installed on board a specific ship, it must be shown that:

• The test conditions for that specific ship have been verified by LR and accepted, see Section Ch 1, Ch 4 Certification for a Specific Ship;

• The user manual has been provided on board ship, see Section Ch 1, Ch 4, 4 User's Manual;

• An installation test of the program has been carried out satisfactorily on the ship using the endorsed test conditions, see Section Ch 1, Ch 4, 5 Installation Test.

1.11 It should be noted that the damage stability component of a calculation program will not receive general approval. Appraisal of the damage stability component for the specific ship may be carried out if the program is used only to assess the compliance of loading conditions with statutory regulations. In these cases, the damage stability software will be appraised as a means of providing guidance to the Master for assessing loading conditions, not included in the approved stability manual. Such loading conditions will still require to be examined and approved by or on behalf of the flag administration prior to loading to that condition.

1.12 Ships having undertaken major alterations or conversions affecting longitudinal strength and/or stability, such as lengthening or removal of decks, will generally be treated as new ships for the purposes of these requirements. Ships which have been assessed under the Condition Assessment Scheme may require a longitudinal strength program to be provided which is to comply with these requirements.

1.13 Where a longitudinal strength calculation program is installed as a Classification requirement (Pt 3, Ch 4, 8.3 Loading instrument of the Rules for Ships) the Class Notation “LI” will be assigned, and entered in column 4 of the LR Register Book.

1.14 A longitudinal strength and/or stability calculation program may also be installed, at an owner’s request. When such a program is approved for use in accordance with this procedure, at the request of the owner, a descriptive notation “LI” will be entered in column 6 of the Register Book.

1.15 Where National or International requirements exist for the approval of a stability calculation program, these requirements need to be satisfied in addition to the requirements described in this document.

1.16 Consideration will be given to the acceptance of the requirements of National Authorities as an alternative to the requirements of this document for stability calculation programs.