Average ocean going ship don't hold much tonnage. They cannot weigh more than a fraction of what they carry. Newly built bulk carriers are another kettle of fish.
Of the world's commercial shipping fleet of almost 50,000 ocean-going ships (container ships, freighters, ferries, refrigerated ships, tankers and so on) every year, some 700 are scrapped. The average age of these ships to be scrapped is 29 years. The number of ships scrapped grows each year. The market leaders in shipbreaking are India (with 70%) followed by Bangladesh, Pakistan, China and the Philippines. Well over 100,000 workers are estimated to be employed at shipbreaking yards world-wide.
Depending on their size and function, the scrapped ships have an unladen weight (l.d.t.) of between 5,000 and 40,000 tonnes (average 13,000 t). 95% of this is steel, coated with between 10 and 100 tonnes of paint containing lead, cadmium, organotins, arsenic, zinc and chromium. Shipbuilding materials also contain other hazardous wastes: sealants containing PCBs and, on each ship, up to 7.5 tonnes of various types of asbestos in pure and processed form. In addition, there are several thousand litres of oil (engine fuel, bilge oil, hydraulic and lubrication oils and greases); tankers additionally hold up to 1,000 cubic metres of residual oil. A scrapped ship thus contains a wide range of toxic substances. In Europe, such materials are subject to special monitoring and their disposal is highly regulated and expensive. Most of them are already defined as hazardous under the Basel Convention.
I don't really give a ship about these matters, but I thought I would comment.
en.wikipedia.org
An average salty could carry about 10,000 tons of product. Lakers carry much more up to 30,000 tons or ore. A large carrier of the modern Pacific crossing type can carry up to 250,000 tons. Ships have increased in size by an order of magnitude in modern times.
By the 1970s, bulk carriers of more than 200,000 dead weight (dwt) were operating and rivaled the VLCCs as the largest ships afloat. There are several other similarities between bulk carriers and tankers, which help to explain the frequency with which they are mistaken for each other. The simplest way of telling a bulk carrier from an oil tanker is that the holds of the bulk carrier are covered by hatches raised above the deck level, while the deck of the tanker is covered with fuel pipes. A bulk carrier of 36,000 dwt may have five cargo holds while one of 250,000 dwt may have as many as nine. |
