Section 19 Classification of units not built under survey
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Offshore Units, July 2022 - Part 1 Regulations - Chapter 3 Periodical Survey Regulations - Section 19 Classification of units not built under survey

Section 19 Classification of units not built under survey

19.1 General

19.1.1 When classification is desired for a unit not built under the supervision of LR's Surveyors, application should be made to the Classification Committee in writing.

19.1.2 Periodical Surveys of such units, when classed, are subsequently to be held, as in the case of units built under survey.

19.1.3 Where classification is desired for a unit which is classed by another recognised Society, special consideration will be given to the scope of the survey.

19.2 Hull and equipment

19.2.1 Plans showing the main scantlings and arrangements of the actual unit, together with any proposed alterations, are to be submitted for approval. These should comprise plans of the main hull/structure, including midship section, longitudinal and transverse sections, columns, decks, pontoons, bracings, legs and footings and such other plans as may be requested. If the class notation DRILL or PPF is to be assigned in accordance with Pt 3, Ch 7 Drilling Plant Facility or Pt 3, Ch 8 Process Plant Facility respectively, plans and documentation covering the major structures of the plant are to be submitted as may be requested.

19.2.2 If plans cannot be obtained or prepared by the Owner, facilities are to be given for LR's Surveyor to obtain the necessary information from the unit. The unit's Operations Manual is also to be submitted, see Pt 3, Ch 1, 3 Operations manual.

19.2.3 Particulars of the process of manufacture, material grades and the testing of the material of construction are to be supplied.

19.2.4 In all cases, the full requirements of Pt 1, Ch 3, 5 Special Survey – Hull requirements are to be carried out as applicable. Units of recent construction will receive special consideration.

19.2.5 During the survey, the Surveyors are to satisfy themselves regarding the workmanship and verify the approved scantlings and arrangements. For this purpose, and in order to ascertain the amount of any deterioration, parts of the structure will require to be gauged as necessary. Full particulars of the anchors, chain cables and equipment are to be submitted. Loading instruments, where required, are to be in accordance with the Rules, see Pt 1, Ch 2, 1.4 General as applicable.

19.2.6 Safety and communication systems are to be verified in accordance with Pt 1, Ch 3, 16 Safety and communication systems and hazardous areas, see also Pt 1, Ch 3, 1.1 Frequency of surveys.

19.2.7 When the full survey requirements indicated in 19.2.4 and 19.2.5 cannot be completed at one time, the Classification Committee may consider granting an interim record for a limited period. The conditions regarding the completion of the survey will depend on the merits of each particular case, which should be submitted for consideration.

19.3 Machinery

19.3.1 To facilitate the survey, plans of the following items (plans of piping are to be diagrammatic), together with the particulars of the materials used in the construction of the boilers, air receivers and important forgings are to be supplied:

  • General pumping arrangements, including air and sounding pipes (Builder's plan).
  • Pumping arrangements at the forward and after ends of units with crude oil bulk storage tanks and drainage of cofferdams and pump-rooms.
  • General arrangement of crude oil storage piping in tanks and on deck.
  • Piping arrangements for bulk oil storage (F.P. 60°C or above, closed-cup test).
  • Bilge, ballast and fuel oil pumping arrangements in the machinery space, including the capacities of the pumps on bilge service.
  • Arrangement and dimensions of main steam pipes.
  • Arrangement of fuel oil pipes and fittings at settling and service tanks.
  • Arrangement of fuel oil and gas piping in connection with oil and gas burning installations.
  • Fuel oil and bulk oil storage overflow systems, where these are fitted.
  • Arrangement of boiler feed systems.
  • Fuel oil settling, service and other fuel oil tanks not forming part of the unit's structure.
  • Boilers, superheaters and economisers.
  • Air receivers.
  • Crank, thrust, intermediate and screw shafting.
  • Clutch and reversing gear with methods of control.
  • Reduction gearing.
  • Propeller (including spare propeller if supplied).
  • Azimuth thrusters.
  • Electrical circuits.
  • Hazardous areas.
  • Arrangement of compressed air systems for main and auxiliary services.
  • Arrangement of lubricating oil, other flammable liquids and cooling water systems for main and auxiliary services.
  • General arrangement of crude oil storage tank vents. The plan is to indicate the type and position of the vent outlets from any superstructure, erection, air intake, etc. Ventilation arrangements of storage tanks and/or ballast pump-rooms and other enclosed spaces which contain crude oil handling equipment.
  • Safety and communication systems, see Pt 3, Ch 1 General Requirements for Offshore Units.
  • Jacking arrangements on self-elevating units.

19.3.2 Plans additional to those detailed in 19.3.1 are not to be submitted unless the machinery is of a novel or special character affecting classification. If the class notation DRILL or PPF is to be assigned in accordance with Pt 3, Ch 7 Drilling Plant Facility or Pt 3, Ch 8 Process Plant Facility respectively, plans and documentation covering the plant are to be submitted as may be requested.

19.3.3 Where remote and/or automatic controls are fitted to propulsion machinery and essential auxiliaries, a description of the scheme is to be submitted.

19.3.4 For new units and units which have been in service less than two years, calculations of the torsional vibration characteristics of the propelling machinery are to be submitted for consideration, as required for ships constructed under Special Survey. For older units, the circumstances will be specially considered in relation to their service record and type of machinery installed. Where calculations are not submitted, the Classification Committee may require that the machinery certificate be endorsed to this effect. When desired by the Owner, the calculations and investigation of the torsional vibration characteristics of the machinery may be carried out by LR upon special request.

19.3.5 The main and auxiliary machinery, feed pipes, compressed air pipes and boilers are to be examined as required at Complete Surveys. Working pressures are to be determined from the actual scantlings in accordance with the Rules.

19.3.6 Pressure vessels for process and drilling plant are to be examined as required for Special Surveys in Pt 1, Ch 3, 17 Pressure vessels for process and drilling plant.

19.3.7 The screwshaft is to be drawn and examined.

19.3.8 The steam pipes are to be examined and tested as required by Section 11.

19.3.9 The bilge, ballast and fuel oil pumping arrangements are to be examined and amended, as necessary, to comply with the Rules.

19.3.10 Oil and gas burning installations are to be examined as required at Complete Surveys and found, or modified, to comply with the requirements of the Rules; they are also to be tested under working conditions.

19.3.11 The electrical equipment is to be examined as required at Complete Surveys in Pt 1, Ch 3, 9 Electrical equipment.

19.3.12 Where an inert gas system is fitted on units intended for the storage of oil in bulk having a flash point not exceeding 60°C, the requirements of Pt 5, Ch 15, 7 Inert gas systems on Tankers of 8,000 tonnes DWT and above of the Rules for Ships apply.

19.3.13 The whole of the machinery, including essential controls, is to be tested under working conditions to the Surveyor's satisfaction.

19.3.14 Safety and communication systems and hazardous areas are to be examined as required at Special Surveys in Section 16. The requirements of Pt 7 Safety Systems, Hazardous Areas and Fire are to be complied with.


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