Survey Procedures, Inspection Techniques and Reporting: Scope, Evidence and Records
This domain tests how a surveyor plans, executes and records work. Questions ask which survey applies at a given point in the cycle, what evidence supports a finding, how a defect is graded, and what must appear in the report and the class or statutory record.
The survey cycle
Class and statutory surveys include initial, annual, intermediate, special (renewal), occasional (damage or repair) and bottom surveys. Bottom surveys may be replaced by an in-water survey where the class rules permit it and the conditions on visibility, marking and thickness measurement are met. Tailshaft and boiler surveys run on their own cycles. Continuous survey of machinery spreads items across the five-year period. The Enhanced Survey Programme, applied to bulk carriers and oil tankers, prescribes close-up survey of selected structures in cargo holds and ballast tanks, thickness measurement and tank testing, with the scope growing at the intermediate and special surveys.
Inspection technique
Start from the records: previous reports, conditions of class, memoranda, thickness measurement trends and repair history. Then inspect visually at close range, supplement with hammer testing for wastage and loose coatings, ultrasonic thickness gauging, and non-destructive testing where a defect is suspected. Confirm watertight integrity by hose, pressure or tank testing, and verify that openings, closures and air pipes match the conditions of assignment.
Grading and reporting
Wastage is graded against the allowable diminution, usually 20 per cent of the as-built thickness for structural members. Substantial corrosion lies between 75 and 100 per cent of that allowance and triggers annual examination and gauging. Findings are recorded as conditions of class, memoranda, recommendations or statutory deficiencies, each with a defined follow-up. A certificate is not issued until outstanding conditions are closed or formally deferred by the Administration.
Worked example
A deck plate is gauged at 12.4 mm against an as-built 15.0 mm, with an allowable diminution of 20 per cent, that is 3.0 mm. Actual wastage is 2.6 mm, or 87 per cent of the allowance. The plate is acceptable in absolute terms but falls in the substantial corrosion band, so close-up survey and annual gauging are required and the finding goes into the report and the class record.
Traps
Confusing intermediate and special survey scope; accepting an in-water survey where docking is mandatory; issuing a certificate with open conditions of class; omitting memoranda items from the record so they vanish at the next survey.