Guides

Draft survey in Turkey

A draft survey works out how much cargo a bulk carrier loaded or discharged by reading the ship's draft before and after cargo work. In Turkey it is the standard way to settle quantity for scrap, steel, coal, grain, fertilizer and ore.

What a draft survey measures

A floating ship displaces its own weight in water. Read the draft marks, correct them, and the ship's hydrostatic tables give that weight. Take away everything on board that is not cargo — ballast, fresh water, bunkers, stores and the ship's constant — and what remains is the cargo. Do this once before cargo work (the initial survey) and once after (the final survey); the difference between the two is the cargo loaded or discharged.

Done carefully, a draft survey is usually within about 0.5% of the true figure. That is why buyers, sellers and charterers rely on it when there is no shore scale, which is the case at most bulk berths in Turkey.

Who can carry it out in Turkey

Quantity and quality surveys on cargo in international trade are done by inspection companies authorized by the Ministry of Trade (uluslararası gözetim kuruluşu, UGK). Each authorization lists the customs tariff chapters the company may inspect: chapter 72–73 for iron and steel, including scrap; 10–12 for grain and seeds; 25–26 for minerals and ores; 27 for coal and fuels; 31 for fertilizers; 89 for ships. On a typical call three surveyors attend together: one for the buyer, one for the seller, and an independent surveyor named in the sales contract, often called the official or contract surveyor. Each issues its own report, and the independent surveyor's figure is usually the one the contract relies on.

Portiva lists every authorized company by port and shows which chapters each one holds. Iskenderun, Izmir and Aliaga and Mersin have the most.

How the survey is done, step by step

1. Draft reading. The surveyor reads the six draft marks — forward, midships and aft, on both sides — usually from a boat or the quay, and notes the sea state. Swell makes reading harder; in an open anchorage it is often better to wait for calmer water than to average a moving mark.
2. Dock water density. A sample of the water around the ship is taken, usually at more than one depth, and its density is measured with a hydrometer. Density changes the displacement noticeably, especially near river mouths and in harbours with fresh water inflow.
3. Corrections. The readings are corrected for the position of the marks, for trim (first and second trim corrections) and for the hull bending (hog or sag, using the quarter-mean draft). The corrected mean draft goes into the hydrostatic tables.
4. Deductibles. All ballast tanks are sounded, together with fresh water. Bunkers are taken from the chief engineer's figures or sounded. Every tank must be checked at both surveys, and ballast must not be moved while the survey is under way.
5. Constant. At the initial survey of a loading ship (or the final survey of a discharging ship) the result is the ship's constant: the weight of everything on board that cannot be measured, such as spares, sediment and paint. A constant far from the ship's history is a warning sign worth investigating before cargo work starts.
6. Cargo figure. Net displacement at the final survey minus net displacement at the initial survey gives the cargo. The surveyor signs a report with every reading and calculation, which the master usually countersigns.

How long it takes

An experienced surveyor needs roughly one and a half to three hours for each survey on a handysize or supramax bulk carrier, longer on a larger ship or when the tanks are many and hard to sound. Two surveys per call — initial and final — is the norm. Intermediate surveys are sometimes added when cargo is loaded for more than one receiver.

What the ship and the parties should prepare

• The ship's hydrostatic tables, draft mark positions, tank sounding and ullage tables, and the deadweight scale, in a form the surveyor can read.
• All sounding pipes open and accessible, and a crew member who knows the tanks.
• No ballast or fresh water movement during the survey, and bunker figures ready from the engine room.
• A gangway or pilot ladder safe for boarding, and a boat if the drafts must be read from the water.
• For the cargo side: the bill of lading figure or the expected quantity, so the surveyor can flag a large difference straight away.

Quality and hold condition on the same call

The surveyors who carry out the draft survey usually also check the cargo itself and the holds. On scrap, steel and other bulk cargoes that means grading the cargo and estimating foreign material hold by hold during discharge, and inspecting hold condition before loading or at on/off-hire. Asking for all of these from the same company saves a second attendance.

Common sources of disputes

Most quantity claims after a draft survey come from the same few places: an unsounded or wrongly sounded ballast tank, a density sample taken at the wrong depth, a swell that was averaged rather than waited out, and a constant that changed between surveys without explanation. When the buyer's, seller's and independent surveyors read together and agree the figures on the spot, these disputes are far rarer.

Finding a draft surveyor in a Turkish port

Choose the port on Portiva to see every authorized company there, with the cargo chapters each holds. To get quotes, send one request and we pass it to companies working in that port. Survey companies abroad looking for a local surveyor to attend on their behalf can use the attending surveyor request.