Section 3 Launching
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Construction & Classification of Submersibles & Diving Systems, July 2022 - Part 7 Hyperbaric Rescue Facilities - Chapter 1 Hyperbaric Evacuation Systems - Section 3 Launching

Section 3 Launching

Parent topic: Chapter 1 Hyperbaric Evacuation Systems

3.1 Launch method

3.1.1 As persons under pressure are substantially at risk once they have left their on board habitat, arrangements for the safety of the launching crew should be such that they can defer launching until it is quite certain that launching will ultimately be necessary, and even then not before the last possible moment.

3.1.2 In the case of fire or irreparable damage to life-support systems, the ability to transfer a hyperbaric evacuation unit by crane direct to another vessel is desirable, If reliance is placed on this means of evacuation in the case of fire, then there must be available a second crane or other means of transfer, such that it is very unlikely that both will be rendered ineffective by the fire which is necessitating evacuation.

3.1.3 For ships, ‘Float Off’ is acceptable as an alternative to davit launching provided reliance can be placed on an alternative means of evacuation in the case of fire or irreparable damage to life-support systems.

3.2 Launch mechanisms

3.2.1 Means should be provided for the safe and timely evacuation and recovery of the unit and due consideration should be given to the environmental and operating conditions, the dynamic snatch and impact loadings that may be encountered. Where appropriate the increased loading due to water entrapment should be considered. Where the primary means of launching depends on the ship’s main power supply then a secondary and independent launching arrangement should be provided.

3.2.2 The launch mechanism should be such that the capsule/chamber can be disconnected from the diving system. Gas systems and normal power supply are to be readily detachable and holding down arrangements suitable for easy disconnection. The launch mechanism should also be capable of recovering the capsule chamber to enable it to be reconnected to the diving system.

3.2.3 All the arrangements should be capable of being disconnected by either one of the following methods, as laid down in the specification:
  1. From within the capsule/chamber without the aid of external personnel;
  2. By external personnel.

3.2.4 Release mechanisms and lowering equipment should also be able to be triggered from within the capsule/chamber and should not rely on external power sources from the installation being available. Gravity systems should be fitted with an override mechanism so designed that the capsule/chamber and its occupants are protected from shock on entry into the water.

3.2.5 Lifeboat type HEU’s should carry an attendant for release and otherwise comply with all rules relevant to lifeboats.

3.2.6 ‘Float Off’ type HEU’s must have a quick release arrangement such as explosive bolts to be operated only when it seems likely that once afloat the HEU will not again contact the ship.

3.2.7 HEU’s shall be capable of being launched in situations where normal power supply is unavailable.

3.2.8 If the power to the handling system fails, brakes should be engaged automatically. The brakes should be provided with manual means of release and control.

3.2.9 The launching arrangements provided should be designed to ensure easy connection or disconnection of the hyperbaric evacuation unit from the surface compression chamber and for the transportation and removal of the unit from the ship under the, same conditions of trim and list as those for the ship’s other survival craft.

3.2.10 Where a power actuated system is used for the connection or reconnection of the hyperbaric evacuation unit from the surface compression chamber then a manual or stored power means of connection or disconnection should also be provided.

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