The ability to have a fully flexible ISO standard refrigerated container, suitable for use in any location throughout the world and capable of being transported in any containership, is the shipper’s goal. In response to strong interest by owners for this increased flexibility to store integral containers, not just above, but below deck, Lloyd’s Register has carried out a detailed study to find out how this can be done and it has published a new set of Rules for the Carriage of Refrigerated Containers in Holds.
These new LR’s rules, will form Part 7, Chapter 10 of Ships 2001. A dedicated notation, to cover the design, installation and testing of the ventilation system to allow the carriage of a specified number of integral refrigerated containers below deck, is also available.
The Rules are based upon appraisal of the ventilation system design and its specified air volume against predetermined acceptable airflow values. The type of ventilation system proposed, its design, installation, ductwork sizing, fan sizing, maximum air velocity, hold space temperature limitations and air sealing arrangements are at the discretion of the system designer. The Rules specify the aim of the ventilation system and the equipment that is to be provided, and requests sufficient information to be submitted to allow a heat balance to be calculated, while safety and redundancy aspects are covered by a small number of prescriptive Rules.
In developing these Rules, various ventilation arrangements, such as supply, exhaust and louvred exhaust air systems, have been considered and minimum airflow requirementscalculated.
The design requirements of container refrigerating equipment manufacturers havebeen considered to determine minimum acceptable hold space air flow data, and models in appraising design proposals, and to confirm the suitability of the proposed air flow arrangements.