Section 3 Surveys

301. General

The survey for Offshore Support Vessel are to be in accordance with this Section in addition to the requirements specified in Pt 1, Classification of Steel Ships.

the requirements specified in

Ch 2 of Rules for the

6 Guidance for Offshore Support Vessels 2015

Ch 2 Classification and Survey Ch 2

302. Annual Survey

1. Hull, equipment and fire-extinguishing appliances

(1) All Offshore Support Vessels (all-type)

Installations related to the specialized functional service of the Offshore Support Vessel and their supporting structures

(2) For self-elevating Offshore Support Vessels

(A) Legs above the waterline

(B) Jack-frame and attachment to upper hull or platform

(C) Jacking or other elevating systems and leg guides, externally

(D) Plating and supporting structure in way of leg wells

(3) At the 1st Annual Survey after construction, Column Stabilized and Self-elevating Offshore

Support Vessels may be subject to examination of major structural components including non-de- structive testing, as deemed necessary by the Society. If the Society deems such survey to be necessary, the extent should be agreed to by the Society and the Owner prior to the commence- ment of the Survey.

2. Machinery, electrical equipment and additional systems

(1) All forms of Offshore Support Vessels

General survey for machinery and electrical equipments related the specialized functional service of the Offshore Support Vessel. Where considered necessary by the Surveyor, the performance test may be required.

(2) For Vessels with a dynamic positioning system

General survey for elements with test procedure.

(3) General survey for electrical

of age, insulation resistance whether the surveyor accepts

that it is suitable.

and performance test for dynamic positioning system accordance

equipments installed in hazardous areas. For ships over ten years is to be carried out. However, measurements may be omitted that the measurement record material is maintained on board and

(4) For vessels with self-elevating system, survey on the conditions of leg guide and jacking or el- evating system.

303. Intermediate Surveys

At the Intermediate Survey, in addition to all the requirements for Annual Survey, the following items are to be surveyed.

1. Hull, equipment and fire-extinguishing appliances

(1) For self-elevating Offshore Support Vessels

For ships over 5 years of age, an internal examination and thickness measurements for at least two pre-load tanks are to be conducted. If the protective coating of those tanks is in GOOD condition, thickness measurements may be dispensed with.

2. Machinery, electrical equipment and additional systems

(1) Survey in accordance with 302. 2 is to be carried out.

(2) For self-elevating Offshore Support Vessels

General survey for jacking system is to be carried out. Where considered necessary by the Surveyor, overhauling of jacking system may be required.

304. Special Surveys

At the Special Survey, in addition to all the requirements for Annual Survey, the following items are to be surveyed.

1. Hull, equipment and fire-extinguishing appliances

(1) For self-elevating Offshore Support Vessels

(A) All legs including chords, bracings, gussets, racks, joints, together with leg guides. Tubular or similar type legs are to be examined externally and internally, together with internal stiff- eners and pinholes.

(B) Structure in, around and under jack-frame and leg areas may be required

(C) Leg jacking or other elevating systems externally.

may be required

walls. Non-destructive testing of suspect

Non-destructive testing of suspect areas

Guidance for Offshore Support Vessels 2015 7

Ch 2 Classification and Survey Ch 2

(D) Leg connections to bottom mats or spud cans, including non-destructive testing of leg con- nections to mats or spud cans.

(E) Jetting piping systems or other external piping, particularly where penetrating mats or spud

cans.

(F) Spud cans or mats. Where the spud cans or mat are partly or entirely obscured below the mud line when the Special Survey is otherwise being completed, consideration will be given to postponement of these examinations until the next move of Offshore Support Vessel.

2. Machinery, electrical equipment and additional systems

(1) Survey in accordance with 302. 2 is to be carried out.

(2) For self-elevating Offshore Support Vessels

General survey for jacking system is to be carried out. Surveyor, overhauling of jacking system may be required.

Where considered necessary by the

305. Docking survey

1. Requirements of survey

(1) For self-elevating Offshore Support Vessels

(A) External surfaces of the upper hull or platform, spud together with their connections as applicable, are to be of the attending Surveyor and examined.

cans, mat, underwater areas of legs, selectively cleaned to the satisfaction

(B) At each Dry-docking Survey or equivalent, after Special Survey No. 2, the Surveyor is to

be satisfied with the condition of the internal structure of the mat or spud cans. Leg con- nections to mat and spud cans are to be examined at each Dry-dock Survey or equivalent. Non- destructive testing may be required of areas considered to be critical by the Society or found to be suspect by the Surveyor.

2. Ballast spaces

In conjunction with Dry-docking Surveys (or equivalent) after Special Survey No. 1 and between subsequent Special Surveys, the following ballast spaces are to be internally examined, thickness gauged, placed in satisfactory condition as found necessary, and reported upon. If such examination reveals no visible structural defects, the examination may be limited to a verification that the corro- sion control arrangements remain effective.

(1) For self-elevating Offshore Support Vessels

Representative ballast tanks or free-flooding compartments in mat or spud cans, if accessible, and at least two representative hull pre-load tanks.

306. Surveys of propeller shaft and stern tube shaft, Etc.

Survey of Propeller Shaft and Stern Tube Shaft, Etc. is to be in accordance with Pt 1, Ch 2, Sec

7 of Rules for the Classification of Steel Ships.

307. Boiler survey

Boiler Survey is to be in accordance with Pt 1, Ch 2, Sec 8 of Rules for the Classification of Steel Ships.

8 Guidance for Offshore Support Vessels 2015

Ch 3 Hull Structures and Equipment Ch 3