Section 2 Mechanical equipment
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 5 Main and Auxiliary Machinery, Systems and Equipment - Chapter 2 Machinery - Section 2 Mechanical equipment

Section 2 Mechanical equipment

Parent topic: Chapter 2 Machinery

2.1 Propulsion and dynamic positioning machinery

2.1.1 Details of the type of machinery proposed for the propulsion and dynamic positioning of a submersible are to be submitted for approval. In selecting the machinery the following factors should be taken into consideration:
  1. Noise and vibration levels, see Pt 5, Ch 2, 2.3 Noise and vibration levels.
  2. Standard of containment of high speed rotating parts in the event of mechanical failure.
  3. Reliability of known similar machinery (which may be prototype).
  4. Probability of contamination of life-support gases in the event of mechanical or other failure.
  5. Probability of injury to crew, passengers, divers or recovery staff by moving parts.
  6. Degree of protection of moving parts against damage, obstruction or jamming by fish, seaweed, mud, plastic sheeting, or other substances that may be encountered in service.
  7. Design life of the various component parts.
  8. Ease of access for maintenance, fault tracing and repair.

2.2 Equipment — General

2.2.1 Equipment external to the pressure hull is, where practicable, to be faired to reduce the possibility of mechanical damage.

2.2.2 It is recommended that repair by replacement be adopted where practicable, unless it is easier to make repairs in situ.

2.2.3 Propellers and means of traction where applicable, are to be fitted with guards for the protection of divers.

2.2.4 Process production equipment and systems within submersible habitats should be designed and manufactured to relevant Codes of Practice.

2.2.5 Provision should be made to compensate for differential thermal expansion between the habitat and process/production equipment.

2.3 Noise and vibration levels

2.3.1 Apart from the sonar or echo sounding devices, vibration and noise generation from all equipment should be kept as low as possible, especially when helium breathing mixtures are employed.

2.3.2 Noise levels should in general be kept below 65 dB(A) inside chambers excluding self-induced noise.

2.3.3 Vibration levels in vertical and horizontal planes should conform to the following limits:
  1. Vertical direction:
    1. 1 ≤ f ≤ 8 Hz v ≤ 0.3 m/sec2 r.m.s.
    2. 8 ≤ f ≤ 80 Hz v ≤ 10(log f – 2.50) m/sec2 r.m.s.
  2. Horizontal direction:
    1. 1 ≤ f ≤ 2 Hz v ≤ 0.02 m/sec2 r.m.s.
    2. 2 ≤ f ≤ 80 Hz v ≤ 10(log f – 2.00) m/sec2 r.m.s.

Where “f” is vibration frequency in Hz and “v” is the acceleration in m/sec2 r.m.s.

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