Section 21 Controlled atmosphere systems

21.1.1 It is a prerequisite of the CA notation that the refrigeration installation on board already conforms to a Clasifications RMC class notation. See Pt 1, Ch 2, 2.6 Class notations (refrigerated cargo installations (RMC), controlled atmosphere (CA) systems and carriage of refrigerated containers (CRC)) 2.6.1.

21.1.2 For the retention of Class, the CA systems are to be submitted for Periodical Surveys by LR's Surveyors as specified in Pt 1, Ch 3, 21.2 Annual Surveys and Pt 1, Ch 3, 21.3 Special Surveys.

21.2.1 Annual Surveys are to be carried out from the date of the Initial Classification Survey to verify that the CA system remains satisfactory.

21.2.2 The complete CA installation is to be visually examined and tested for the following main aspects:

1. CA zone sealing arrangements including cleats and hinges, pressure/vacuum (P/V) valves, door locks, ventilation of adjacent spaces, warning notices.

2. CA zones to be individually tested for airtightness to the design pressure. Testing by ship's staff, within one month prior to the survey may be accepted, based on a written report by the Master subject to visual inspection confirming the airtightness.

3. Operation and performance testing of the gas supply equipment, including controls, alarms, interlocks, safety devices.

4. Ventilation arrangements including fans.

5. Electrical supply arrangements.

6. Gas analyzers and analyzing equipment and calibration.

7. RH sensors and calibrations.

8. Permanent and portable gas monitoring, calibration and personnel safety equipment.

9. Witnessing of the air leakage.

10. Voyage logs, records of CA zone airtightness and calibration of instruments.

11. Verification that an Operating and Safety Manual is on board, is complete and that the responsible officers have countersigned to confirm that they are familiar with its contents.

21.2.3 On satisfactory completion of this survey, a new Annual Survey `AS', with date, will be assigned.

21.3.1 Special Surveys are to be carried out at intervals of five years from the date of the Initial Classification Survey to verify that all machinery, CA zones and safety arrangements remain satisfactory. On request from Owners, all surveyable items may be examined on a continuous basis. With this option, 20 per cent of all items are to be presented for survey annually.

21.3.2 Each CA zone is to be subjected to an airtightness test.

21.3.3 The extent of dismantling is to be at the LR Surveyor's discretion, but is to be sufficient for the Surveyor to be satisfied as to the condition of the installation.

21.3.4 On satisfactory completion of this survey, a new Special Survey `SS', or `RMC CS' with date, will be assigned.