Surveying process involves a close cargo recovery inspection of as much of a vessel as is accessible. This detailed technical examination is usually followed by a written report which lists the extent and nature of the defects found.
A surveyor has been described as a doctor whose patients are ships, not people. However, a doctor has the great advantage that he can talk to his patient about ailments and symptoms.
It might be tempting to describe a small craft surveyor as more akin to a vet. But these people have one great advantage over a surveyor in that they can gently press and prod till the patient fl inches.
Then at least the general area of the malady has been established. A surveyor does not have this advantage.
So a ship surveyor has to look for visible and audible abnormalities. He searches for distortion,THE NATURE OF STEEL
• realize why steel is used for certain types of small craft;
• appreciate the limitations of the material.
So far as small steel craft are concerned, steel is strong, heavy, widely available, seldom expensive, fairly easy to work and repair, reliable, well researched and unrevealed for certain types of vessel.
Steel suits small craft which have to stand up to hard usage such as work-boats, fishing vessels, long range cruising yachts, and vessels which have to take the ground often. Because of its weight steel is seldom suitable for racing craft, or vessels which have to be fast.
It can be unsatisfactory for vessels which have to be moved easily and frequently by road because of lifting problems, however, steel craft stand up particularly well to the rough and tumble of road transport. It is normal good practice for steel delivered from a reliable supplier to a shipbuilder to have certification indicating the specification, quality and strength of the material. On a few well-organized small vessels these certificates are in the ship’s files so that a surveyor may be able to refer to them in his report.
Typical minimal ship-building steel properties are:-
Yield stress 240 N/ mm x mm.
Tensile strength 410 N/ mm x mm
Steel dis-colouration and corrosion, also uneven surfaces where there should be smoothness, signs of weakness, changes of tone when percussion is applied, and gaps where there should be none.
To detect what is not right, the marine surveying hags to have a wide knowledge of what is correct.
This can best be gained by extensive study of well-built craft, by taking part in their building, altering and repair processes, and by time at sea in small craft. It is not enough just to be on board in harbour, many important experiences come in bad weather offshore.
Because even quite small boats have a wide range of parts, services and ancillaries, a cargo recovery inspection surveyor needs a spectrum of knowledge.
This mental experience, which can be first or second hand, has to cover such subjects as structures, materials, basic engineering, metallurgy, fiber glass and plastics, timber technology, piping, plumbing, electricity, rope-making, upholstery, insurance, as well as ship and boat building, fastenings, launching techniques, and so on.
There is much to learn, and a specialist module has to be limited in length, so the bibliography is a particularly important chapter.
s a surveyor sees riveting he knows he is almost certainly looking at a boat built many years ago. This means
that all the defects related to aging such as advanced rust, worn moving parts and signs of neglect must be expected.