ISO/TC 67/SC 7/WG 6 - Weight engineering

This document specifies requirements for managing and controlling the weight and centre of gravity (CoG) of offshore facilities by means of mass management during all lifecycle phases including; conceptual design, front end engineering design (FEED), detail engineering, construction and operations. These can be new facilities (greenfield) or modifications to existing facilities (brownfield). Weight management is necessary throughout operations, decommissioning and removal to facilitate structural integrity management (SIM). The provisions of this document are applicable to fixed and floating facilities of all types. Weight management only includes items with static mass. Snow and ice loads are excluded as they are not considered to be part of the facility. Dynamic loads are addressed in ISO 19904-1, ISO 19901-6 and ISO 19901-7. This document specifies: a) requirements for managing and controlling weights and CoGs of assemblies and entire facilities; b) requirements for managing weight and CoG interfaces; c) standardized terminology for weight and CoG estimating and reporting; d) requirements for determining not-to-exceed (NTE) weights and budget weights; e) requirements for weighing and determination of weight and centre of gravity (CoG) of tagged equipment, assemblies, modules and facilities; This document can be used: f) as a basis for costing, scheduling or determining suitable construction method(s) or location(s) and installation strategy; g) as a basis for planning, evaluating and preparing a weight management plan and reporting system; h) as a contract reference; i) as a means of refining the structural analysis or model.

ISO 19901:2016 specifies requirements for controlling the weight and centre of gravity (CoG) by means of mass management during the engineering and construction of structures for the offshore environment. The provisions are applicable to offshore projects that include structures of all types (fixed and floating) and materials. These structures can be complete new installations or the modifications to existing installations. Maintaining the weight control of existing installations is not part of the main body of this part of ISO 19901, but some guidance on this is included in the Annex G. ISO 19901:2016: - specifies quality requirements for reporting of weights and centres of gravity; - specifies requirements for weight reporting; - provides a basis for overall project weight reports or management reports for all weight control classes; - specifies requirements for weight and load budgets; - specifies the methods and requirements for the weighing and the determination of weight and CoG of major assemblies; - specifies requirements for weight information from suppliers, including weighing of equipment and bulk materials for offshore installations. It can be used: - as a basis for planning, evaluating and presenting the client's, contractor's or fabricator's weight management and reporting system; - as a means of refining the structural analysis or model; - as a contract reference between client, contractor and suppliers; - as a basis for costing, scheduling or determining suitable fabrication method(s) or location(s).

ISO 19901-5:2003 specifies requirements for controlling the weight and centre of gravity (CoG) by means of mass management during the engineering and construction of structures for the offshore environment. The provisions are applicable to offshore projects that include structures of all types and materials. ISO 19901-5:2003 differentiates between projects where considerations with regard to weight and CoG have a high priority as a result of weight and/or CoG sensitivity, and projects where weight and CoG are of little consequence. This differentiation has been made by the introduction of three different classes of structure (Class A, Class B and Class C). Depending on the degree of control necessary, different clauses of ISO 19901 will apply; clause 4 provides guidelines for assigning one of these classes. ISO 19901-5:2003 specifies quality requirements for reporting of weights and centres of gravity, specifies requirements for weight reporting, provides a basis for overall project status reports or management reports for all classes, specifies requirements for weight and load budgets for offshore installations, specifies the methods and requirements for the weighing of major assemblies and the determination of weight and centre of gravity, specifies requirements for weight information from suppliers, including weighing of equipment and bulk materials for offshore installations. It may be used as a basis for planning and presentation of the contractor's weight-reporting system; as a basis for evaluation of the contractor's weight-reporting system; as a means of refining the structural analysis/model; as a contract reference between the ordering client and the contractor; and as a basis for costing.