Marine Engineering - Scrapping and Recycling Ships
A ship’s life comes to an end after being in service for twenty to thirty years. They are then scrapped with the machinery, bridge navigation equipment, lifesaving equipment, furniture and ships wireless being auctioned. The hull and the deck plates are cut and melted down to form new steel plates.
Ship Breaking
Introduction
In the past ships were scrapped in countries worldwide, Britain and USA being the chief processors in this industry.
However during the fifties this industry gradually shifted from the developed world to the developing countries in the Far East.
Today India, Bangladesh, Pakistan and China are the world leaders mainly because of the low labor cost and lax environmental laws.
Some of the components of the ship such as the machinery, furniture, lifesaving equipment and bridge navigating equipment, are sold and reused, Any fuel oil remaining on board is pumped ashore or into lighters and sold on, the steel being cut up and smelted to form new plates, with nonferrous metals reprocessed in a similar fashion.
In this article we will examine the scrapping of merchant vessels such as cargo, oil tankers and container ships, with a quick look at warship decommissioning and scrapping.
We shall start then with the different types of recyclable materials obtained from scrapping from merchant vessels.
Procedures used in Scrapping Ships
Ships that are deemed ready for scrapping by their owners are put up for sale and the highest bidder usually wins the contract. These ships can usually make it to the scrapping facility under their own steam avoiding a towing charge.
As we seen in the introduction, India, Bangladesh, China, and Pakistan are the forerunners, but Turkey is gradually entering the industry. Below are the percentages of vessels scrapped by country. These figures were compiled a few years ago, but reflect the Far Eastern yards dominance of the industry.
· India – 47%
· China – 22%
· Bangladesh – 19%
· Pakistan – 10%
· Others – 2%
As can be seen from above India and China are world leaders once again because of the abundance of cheap labor and little environmental constraints.
Categories of Materials Reused and Recycled
Typical Materials Recovered by Type of Ship
The worlds merchant fleet consists of different types of vessels which have their individual scrap values as shown below.
Oil Tankers
These have the highest scrap value mainly because of the weight of steel, especially the super-tankers which can be anything up to half a million tons. The other reason for the high scrap value is because of the lack of insulation used in the vessel, which is classed as hazardous waste. They produce the following materials expressed as a percentage of their dead weight,
· 86% ferrous metals
· 1% non-ferrous metals
· 2% furniture
· 3% machinery
· 8% waste
Bulk Carriers
Again a high scrap value for the above reasons, their materials by percentage weight are,
· 82% ferrous metals
· 1% non-ferrous metals
· 3% furniture
· 5% machinery
· 9% waste
General Cargo & Cruise Ships
These vessels attract the lowest scrap value, due to the amount of asbestos used in insulation and amount of furniture and fittings to tear out which is very labor intensive for little gain. Their materials by percentage weight are,
· 77% ferrous metals
· 1% non-ferrous metals
· 4% furniture
· 6% machinery
· 12% waste
An alternate method of disposal is to decommission the ships and sink them to form artificial reefs, at present an option to dismantling oil and gas rigs steel jackets. (See my article on decommissioning of offshore structures).
Scrap Reused, Recycled, and Sent to the Landfill
The ferrous metals which contains the highest proportion of scrap by weight is either cut out in plates and re-rolled for reuse or melted down and rolled into new plates.
Non-ferrous metals are mostly melted down by type e.g. brass, aluminium, copper and lead, and recycled into new components.
Furniture and fittings are sold off, as is the machinery which consists of the capstan, winches, a/c units, lifeboats, main and auxiliary engines and pumps, usually being auctioned.
Some of the waste of which a good proportion is classed as hazardous such as asbestos, which surprisingly is nearly all recycled, but other waste such as glass wool, oils and sludge from cargo space and machinery, pipework, and toxic chemicals should go to hazardous waste facilities which are geared up to deal with this waste. However, I researched this subject several years ago and found that a lot of the oil and sludge enters the water producing massive pollution, with the rest of the waste being dumped offshore or buried in a landfill. This is not to say that all breakers are land and water polluters, but a good percentage are.
Scrapping of Warships
These special and storied ships have served their respective countries since the Second World War. We shall look first at the British yards which are actively decommissioning and scrapping Royal Navy vessels.
The main one, Leavesley International, has successfully decommissioned and scrapped HMS Intrepid, a Falkland’s war veteran, for the admiralty. This company is complying with legislation brought out by the government departments of the Disposal Sales Agency and DEFRA, on the scrapping of ships strategy along with the Basel Convention report on cross-border shipping of waste. It hopes to get similar contracts from the government, and hopefully they will showing the rest of the ship scrapping industry that it can be done humanely and environmentally but still retain a profit margin. I noticed their advert on the EBay auction website for ships memorabilia, another environmentally friendly recycling innovation.
In the USA, a quantity of warships is lying tied up on the James River in Virginia as well as the other naval ships tied up elsewhere. A report was prepared (Rand Report) for Washington on the strategy of decommissioning these ex-US navy ships, which are known as the Ghost Ships.
One of the main points raised was, as usual, financial and stated that it would cost the US $1.8 billion to scrap this fleet, whereas to send them to India or China would cost just $170 million to scrap them.
Greenpeace commissioned a company to investigate current trends in this industry and to recommend financing a method of scrapping ships environmentally. They came up with a number of methods. One was to add an estimated scrapping fee at the construction phase, and another was to add a percentage into the ships insurance premium during its service life, to finance the best environmental methods of ship scrapping.