IMO and the safety of bulk carriers

Bulk cargo carriers are often described as the "workhorses" of the world merchant fleet. There are about 4,600 of them operating in the world today, forming about 30% of the world fleet in tonnage terms. They include some of the world's biggest ships (only some crude oil carriers are bigger) and without them world trade and industry would be paralysed. Yet, for all their importance to modern life,  bulk carriers are among the most anonymous of ships. They usually operate between terminals situated well away from cities and traditional port areas and are rarely noticed by the general public. When they are seen they are often  mistaken for  oil tankers, with which they share some similarities in appearance. And when they sink - which they have done all too often in recent years  - they usually do so unnoticed by the world at large, far away from the television cameras and leaving little unsightly pollution to worry the environmentalists. This paper examines the development of bulk carriers, their contribution to the world economy, the safety problems they face - and what IMO has done to make them safer.

The development of bulk carriers

The bulk carrier was first developed to carry dry cargoes which are shipped in large quantities and do not need to be carried in packaged form. The principle bulk cargo consists of grains (like wheat), coal, iron ore, bauxite, phosphate and nitrate. The advantage of carrying such cargo in bulk is, that packaging costs can be greatly reduced, while loading and unloading operations can be speeded up. Before the Second World War, however, there was no real demand for special bulk carriers. Sea borne trade of all mineral ores amounted to only 25 million tons in 1937 and this could be carried in conventional tramp ships. By the 1950s, however, movements of bulk cargo was increasing. Very often ores and other commodities were found far away from where they were needed and the most convenient and cheapest way of shifting them was by sea. Companies in the United States, Europe and increasingly in Japan, began to build ships designed exclusively for the carriage of cargo in bulk. As demand increased and shipbuilding technology advanced so these ships tended to become bigger in size and carrying capacity. This afforded the same economies of scale that were to make the Very Large Crude Carrier (VLCC) so attractive to oil tanker operators in the 1970s.  Doubling the amount of steel used in constructing a ship enabled the amount of carrying capacity to be cubed, yet the size of the crew required did not increase greatly and other costs, such as fuel, also rose relatively slowly, especially since speed was not vital to bulk transport. The modern bulk carrier has evolved gradually but since the 1960s the standard design has been a single hull ship with a double bottom, large cargo holds with hopper tanks and topside tanks covered by hatches. As with crude oil tankers the engine room, navigating bridge and accommodation areas are nearly always located at the stern of the ship. By the 1970s bulk carriers of more than 200,00 dwt were operating and rivaled 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 by 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.

            By the 1970s ships were being built which could carry  oil, ore or other types of dry bulk cargoes. This was done to increase operational flexibility. One of the problems with the bulk trades (as with oil transportation) is that ships normally carry cargo one way but return in ballast because there is nothing to take back. However, oil/bulk/ore (OBO) ships have never become as popular as dedicated bulk or oil carriers, partly because their complexity increases building and operating costs. Today bulk carriers transport a high percentage of world trade - and in most cases they do so safely. According to the International Association of Dry Cargo Shipowners (Intercargo), in 1990-1994  99.90% of dry bulk cargoes were delivered safely. In the case of iron ore the figure was 99.71% and for both grain and coal reliability was 99.97%. The amount of cargo carried was enormous. In 1993, according to Intercargo, 993 million tonnes of iron ore, coal, grain, bauxite and phosphates were carried by sea. Their total value was US$77 billion, representing approximately 4% of the gross national product of the 24 developed countries within the Organisation for Economic and Cultural Development (OECD). A further 177 million tonnes of products such as steel, cement, non-ferrous ores and petroleum coke were also carried by bulk carriers.

The work of IMO

Because shipping is such an international industry, it is generally accepted that safety and other issues have to be dealt with at an international level. This is true of bulk carriers as well as other ship types and since it came into existence in 1959 the organization chiefly responsible for their safety has been the International Maritime Organization, the United Nations specialized agency concerned with shipping safety and the prevention of pollution from ships. IMO is the only United Nations agency to be exclusively concerned with shipping and the sea. It is a highly technical organization whose main tasks are often summed up in the phrase "safer shipping and cleaner oceans." It carries out this mandate primarily by developing conventions, codes and recommendations which are intended to be applied universally. The most important of these instruments have certainly achieved this target: several of the most important have been ratified by well over 120 countries and apply to more than 98% of the world fleet of merchant shipping. In practice, it is impossible to operate a ship on an international voyage which is not built and equipped to IMO requirements (although the way they are implemented can vary enormously). As far as safety is concerned, IMO has developed treaties dealing with the safety of life at sea, the prevention of collisions, the improvement of radio communications at sea, the training and certification of seafarers, the creation of an international system for search and rescue and other matters. The most important of all the Conventions adopted by IMO is the International Convention for the Safety of Life at Sea  (SOLAS). The first SOLAS Convention was adopted in 1914 (as a direct result of the Titanic disaster) and revised versions were adopted in 1929 and 1948. One of IMO's first tasks was to update the treaty again and the new version was adopted in 1960. Although bulk carriers as such were then still in the early stages of their development, the carriage of cargoes in bulk had been going on for many decades and one of IMO's many responsibilities was to improve the way it was done. It concentrated on two main areas - the safety of the cargo and of the structure of the ship itself.

Improving cargo safety

As we have seen, many different products are carried on ships in bulk and grains, such as wheat, maize, millet and  rye have been transported by sea for centuries - the wheat trade between north Africa and Italy was a major economic feature of the Roman Empire, for example. Since the last century, the grain trade has grown in importance and much of it is carried by sea. In 1993-1994 the biggest producers were the United States (32 million tons),  the European Union (18 million tons), Canada (17.7 million tons), and Australia (12.2 million tons). The biggest importers were Far East Asia (including Japan, China and the Republic of Korea) and Africa. Originally grain was transported in sacks, but by the middle of the present century the normal procedure was to carry it in bulk. It could be stored, loaded and unloaded easily and the time taken to deliver it from producer to customer was greatly reduced, as were the costs involved. However, there were problems.

            Grain has a tendency to settle during the course of a voyage, as air is forced out when the individual grains sink. This leads to a gap developing between the top of the cargo and the hatch cover. This in turn enables the cargo to move from side to side as the rolls and pitches. This movement can cause the ship to list and,  although initially the ship's movement will tend to right this, eventually the list can become more severe. In the worst cases, the ship can capsize. This problem was well known and the 1960 SOLAS Convention devoted an entire chapter (Chapter  6) to measures designed to prevent it from occurring. These regulations were more advantageous from an economic point of view than those adopted in SOLAS 1948 (which required a more extensive use of increasingly expensive temporary fittings and/or bagged grain) and many countries quickly put them into effect, even though the Convention itself did not enter into force until 1965. Experience soon showed, however, that the new regulations still had some deficiencies as far as safety was concerned, and during a period of four years six ships loaded under those rules were lost at sea.     IMO began studying this problem early in 1963 and in order to gain the necessary data initiated a study to which masters of ships of many nationalities contributed.  Further studies and tests showed that some of the principles on which the 1960 regulations were based were invalid.  In particular, it was shown that the 1960 Convention had underestimated the amount of "sinkage" which occurs in grain cargoes loaded in bulk.  The fact that the Convention had underestimated this sinkage made the basic requirements of the Convention unattainable. As a result, new grain regulations were prepared and adopted by the IMO Assembly in 1969 (resolution A.184).  These regulations became generally known as the 1969 Equivalent Grain Regulations. Governments were invited to use the new regulations instead of the requirements concerning grain contained in SOLAS 1960.  This was done because it was recognized that an amendment to the Convention would take a very long time to enter into force.  A recommended Code would, if implemented quickly by Governments, be much more immediate in its impact. Voyage experience over a three-year period showed that the 1969 Grain Equivalents were not only safer but were also more practical and economical than the 1960 regulations and, with slight amendments, based upon operational experience, they were used as the basis of new international requirements which were subsequently incorporated into chapter VI of the 1974 SOLAS Convention. Although grain was the only bulk cargo to be given a special chapter in the 1960 SOLAS Convention, the 1960 conference  recommended that IMO draw up an international Code of Safe Practice for Solid Bulk Cargoes (BC Code), which was adopted in 1965. The Code has been updated at regular intervals since then and is kept under continuous review by the Sub-Committee on Dangerous Goods, Solid Cargoes and Containers.  The practices contained in the Code are intended as recommendations to Governments, ship operators and shipmasters.  Its aim is to bring to the attention of those concerned an internationally-accepted method of dealing with the hazards to safety which may be encountered when carrying cargo in bulk. The BC Code was amended on several occasions, but in 1991 IMO decided to amend  Chapter VI of SOLAS and in the process completely re-write it. The main change made in the amendments, which entered into force on 1 January 1994, was to extend the chapter to cover other cargoes, including bulk cargoes. The new Chapter VI was re-titled Carriage of Cargoes.  It is a great deal shorter than the existing text, but its provisions are backed by a number of codes. The advantage of including requirements in a code rather than the convention itself is that codes can be amended much more easily. The codes that are most relevant to the safety of bulk carriers are the revised BC Code and a new International Code for the Safe Carriage of Grain in Bulk (International Grain Code). The latter is the only code referred to in the chapter which is mandatory. Like the original grain rules, the Code is designed to prevent the particular qualities of grain  threatening the stability of ships when it is carried in bulk. It applies to all ships - including existing ships and those of less than 500 tgt - which carry grain in bulk.  Part A contains special requirements and gives guidance on the stowage of grain and the use of grain fittings.  Part B deals with the calculation of heeling moments and general assumptions. The revised BC Code deals with three basic types of cargo: those which may liquefy; materials which possess chemical hazards; and materials which fall into neither of these categories but may nevertheless pose other dangers.            The Code highlights the dangers associated with the shipment of certain types of bulk cargoes; gives guidance on various procedures which should be adopted; lists typical products which are shipped in bulk; gives advice on their properties and how they should be handled; and describes various test procedures which should be employed to determine the characteristic cargo properties. The Code contains a number of general precautions and says it is of fundamental importance that bulk cargoes be properly distributed throughout the ship so that the structure is not overstressed and the ship has an adequate standard of stability. Loaded conditions vary according to the density of the cargo carried.  The ratio of cubic capacity to deadweight capacity of a normal ship is around 1.4 to 1.7 cubic metres per tonne and the ratio of volume of cargo to its mass is known as the stowage factor.  When high density bulk cargoes with a stowage factor of about 0.56 cubic metres per ton or lower are carried, it is particularly important to pay attention to the distribution of weight in order to avoid excessive stresses on the structure of the ship. All bulk cargoes when loaded tend to form a cone. The angle formed between the slope of the cone and the bottom of the hold will vary according to the cargo and is known as the angle of repose. Some dense cargoes, such as iron ore, form a steep cone while others - such as grain - have a much shallower angle. Cargoes with a low angle of repose are much more prone to shift during the voyage and special precautions have to be taken to ensure that cargo movement does not affect the ship's stability. On the other hand, the sheer weight of dense cargoes can affect the structure of the ship. After dealing with general precautions, the Code then goes on to deal with cargoes having an angle of repose of 35 degrees or less and then with those who angle of repose is greater than 35 degrees. Cargoes with a low angle of repose are particularly liable to dry-surface movement aboard ship.  To overcome this problem, the Code states that such cargoes should be trimmed reasonably level and spaces in which they are loaded should be filled as fully as is practicable, without resulting in excessive weight on the supporting structure. Special provisions should be made for stowing dry cargoes which flow very freely, by means of securing arrangements, such as shifting boards or bins. The Code says that the importance of trimming as a means of reducing the possibility of a shift of cargo can never be over-stressed.  This is particularly true for smaller ships of less than 100 metres in length.   Trimming also helps to cut oxidation by reducing the surface area exposed to the atmosphere.  It also helps to eliminate the "funnel" effect which in certain cargoes, such as direct reduced iron (DRI) and concentrates, can cause spontaneous combustion.  This occurs when voids in the cargo enable hot gases to move upwards, at the same time sucking in fresh air.  After listing various regulations adopted by the International Labour Organisation (ILO), which should be taken into account during cargo handling operations, the Code gives details of other dangers which may exist. Some cargoes, for example, are liable to oxidation which may result in the reduction of the oxygen supply, the emission of toxic fumes and self-heating.  Others may emit toxic fumes without oxidation or when wet.  The shipper should inform the master of chemical hazards which may exist and the Code gives details of precautions which should be taken. The Code gives details of the various sampling procedures and tests which should be used before transporting concentrates and similar materials and also contains a recommended test procedure to be used by laboratories. There are six appendices to the Code, giving information about particular cargoes.  A list of cargoes which may liquefy is contained in appendix A to the Code, for example while appendix B gives an extensive list of materials possessing chemical hazards.  Some of the classified materials listed also appear in the International Maritime Dangerous Goods (IMDG) Code when carried in packaged form, but others become hazardous only when they are carried in bulk - for example, because they might reduce the oxygen content of a cargo space or are prone to self-heating.  Examples are wood chips, coal and direct reduced iron (DRI). Appendix C deals with bulk cargoes which are neither liable to liquefy nor possess chemical hazards. More detailed information concerning test procedures, associated apparatus and standards which are referred to in the Code are contained in appendix D. Emergency Schedules for those materials listed in appendix B are contained in appendix E. Recommendations for entering cargo spaces, tanks, pump rooms, fuel tanks and similar enclosed compartments are shown in appendix F. In 1990 the MSC issued a circular (MSC/Circ.531) which warned against the risks of shifting cargo and requested Member Governments to implement revised recommendations for trimming cargoes which were included in the 1989 edition of the Code and are intended to minimize sliding failures.  It was agreed that a study into the use of voyage data recorders should be carried out.

Improving structural safety

The actions taken by IMO undoubtedly helped to solve many of the problems associated with the carriage of bulk cargoes, such as cargo shift and the consequent loss of stability. The number of accidents involving bulk carriers dropped during the 1980s and it seemed to many observers that the general problem of bulk carrier safety had been solved. Then, in 1990 the trend was dramatically reversed: 12 bulk carriers sank compared with only three the year before and in 1991 another 13 bulk carriers were lost. This development was so dramatic and so unexpected that alarm bells began to ring throughout the shipping world. It became increasingly apparent that many of the bulk carriers lost - some of them with heavy loss of life and often without trace - had suffered from severe structural damage. In some cases ships had simply broken apart like a snapped pencil. What had gone wrong? And what could be done to improve matters?

What went wrong

The analyses of bulk carrier that have been carried out during the last few years have shown that, although there were many different causes, certain conclusions could be drawn.

1. The importance of age

There is no doubt that there is a clear link between accidents and the age of bulk carriers. All but two of the ships lost in 1990 were over 18 years old. In July 1995 the classification society Lloyd's Register of Shipping published a table giving details of accidents to 88 bulk carriers between January 1990 and December 1994. Only three of the ships on the list were younger than ten years old and nearly half were over 20. What makes this so worrying is that the average age of bulk carriers has been rising steadily for the last decade and a half - from under nine years old in 1980 to more than 14 today. The reason for this upward trend is primarily economic. During the 1980s there was a glut of shipbuilding, mainly because the industry greatly over-estimated the way in which trade would develop. This was especially true of tankers, but it was true to some extent of bulk carriers as well and when trade increased much more slowly than had been forecast (and sometimes declined) the result was a fall in the demand for ships. Some older ships were scrapped and others laid up waiting the return of more favorable trading conditions.  But throughout the period there has generally been a surplus of unwanted ships and freight rates have usually remained low. This has discouraged the construction of new tonnage and has led shipowners and builders to explore new ways of cutting costs. This trend is potentially worrying because of the statistical evidence. A survey of bulk carrier safety issued in July 1995 by the classification society Lloyd's Register (entitled Bulk Carriers - an Update) says that  "an historically critical age group for bulk carrier casualties is from 14 to 18 years and that in three or more years' time a large proportion of bulk carriers in service will be in this age group unless the age distribution is changed by, for example, a substantial scrapping programme." For straightforward economic reasons there is little sign of such a mass scrapping taking place. Within a few years, then, we can expect the great majority of the world's bulk carrier fleet to have reached the danger point.

2. Corrosion and fatigue

The main reason why age is so relevant to shipping casualties is that corrosion and general fatigue both increase as ships grow older. This is partly because of the stresses to which the ship is inevitably subjected by routine operations, cargo handling, weather and waves and partly to the effect of sea water on steel. Although any water tends to causes metals such as steel to rust, sea water is much more harmful than fresh water because it contains so much salt. The bulk carriers used in the Great Lakes of North America, for example, frequently survive to fifty or sixty years of age - up to three times as long as the average ocean-going ship. Corrosion is a serious problem for anything built of metal which is exposed to the elements, but for a ship it can be fatal. Corrosion is likely to be more extensive and work more rapidly than on other structures simply because the ship is in continual contact with water, usually salt. It can also be accelerated by the effects of some cargoes, especially those carried in bulk.  The interior of cargo holds can be affected by humidity resulting from the moisture contained in some bulk cargoes. Sulphuric acid can be formed from sulphur residues (which can come from coal) combining with water resulting from condensation. There are various ways of preventing corrosion - or at least of preventing it from becoming a problem. Tanks can be painted with special coatings and can be carefully washed out. Above all, the condition of the hull and other structures can be continually checked for signs of corrosion or fatigue. This, however, is much easier said than done. There is, in the first place, a great deal of steelwork to be checked. A bulk carrier of 254,000 deadweight tons (representing roughly the amount of cargo it can carry) might be 320 metres long, 54 metres in breadth and 26 metres deep. The total hull area to be examined could thus be in excess of 54,000 square metres and that does not include the interior bulkheads, hopper tanks, brackets and other features. All of this has to be surveyed and inspected - a daunting task that requires the use of special staging, artificial light and a considerable amount of stamina on the part of the surveyor or surveyors involved. Yet for around 15 years the bulk trade has frequently been in the financial doldrums. The very factors that have discouraged some owners from investing in new ships and encouraged them to hang on to their existing vessels have made them seek economies in other areas - sometimes even at the expense of safety. Certainly corrosion seems to have played a significant part in many of the bulk carrier accidents of recent years - especially the most serious losses. An Intercargo analysis of 15 total losses in 1994 showed that 40% were caused by plate failure and subsequent ingress of water. A further 6.7% of losses were never explained because the ships involved disappeared. More than 70% of these losses occurred in heavy weather. Intercargo found that of 29 fatal accidents involving bulk carriers between 1990 and 1994 55% were due to plate failure. In terms of lives lost 81% were associated with sinkings and disappearances. In 12 cases adverse weather was a factor and in 67% of the cases iron ore was the cargo. Not surprisingly, the Intercargo report states: "The inescapable conclusion from this analysis is the fairly obvious one that it is plate failure, taking water and disappearance which cause the majority of fatal accidents. Thus, although during the whole period losses related to human factors account for 33% of all bulker and OBO losses, such accidents comprise only 10% of fatal accidents and involve only 7% of the total fatalities...it is structural failure, aggravated by bad weather and the carriage of iron ore which causes the majority of the really serious accidents involving loss of life." Other investigations carried out during the last few years come to similar conclusions. The American Bureau of Shipping said in 1991: "The recent spate of casualties on conventional bulk carriers appears to be directly traceable to failure of the cargo hold structure..." Lloyd's Register of Shipping concluded that the prime cause of most casualties is the inability of the side structure to withstand the combination of local corrosion, fatigue cracking and operational damage. The frequent references to iron ore are significant because once laden bulk cargo carriers get into trouble the consequences can be very sudden: they are designed to withstand bad conditions, but not to operate with several holds flooded and the combination of iron ore and a sudden inrush of sea water can result in more weight than the structure can stand. The evidence of the disastrous consequences of uncontrolled corrosion is overwhelming - but preventing it is not so easy as it sounds, if only because of the size of the ships themselves and the difficulties involved in assessing corrosion and plate thickness. A further report by Lloyd's Register in the autumn of 1991 says that the owner of one ten-year old Cape size bulk carrier estimated that the wastage rate of hold frames due to corrosion amounted to 0.5mm per year - and 1mm in some places. Some frames had suffered metal wastage of 20%. During one voyage from South America to Japan a bracket which was in good condition when the ship left became completely detached, leaving a 1.4mm crack. It was not detected because "the rust scale adhering to the surface of the hold structures presented a smooth and regular surface to the eye on visual inspection, making it difficult to detect any cracking." Since the side plates of a bulk carrier may only be 20mm to 29mm thick the loss of a few millimeters can be disastrous.

3. Operational factors

Like many of the other studies carried out, the Lloyd's Register report said that structural failures were due to a combination of factors. Corrosion was important - but so was physical damage suffered during operations. Bulk carriers are designed to withstand heavy seas. The massive structures of the largest ships will bend with the action of the sea. When the center of the hull is higher than the bow and stern the action is known as "hogging": the reverse is called "sagging". But the design assumes that the hull is sound. Corrosion or other damage can lead to weaknesses developing that invalidate the calculations of the naval architect and imperil the whole ship. Loading patterns can make the effect worse. Dense cargoes such as iron ore are often carried in alternate holds in order to raise the ship's center of gravity and moderate its roll motions. But this places greater stress on frames and girders and, because holds carrying iron ore are not completely filled, there can be greater side frame deflection. The overall result is increased stress on inner hull components, according to Lloyd's Register. This might be perfectly acceptable in a new ship - but not in a ship that has suffered from 20 years of hard service and neglect. Design features originally chosen for operational reasons may also have safety implications. Many bulk carriers are fitted with very large hatch openings to facilitate cargo loading and unloading. Yet these openings may represent points of weakness in the hull since they reduce the torsional resistance of the hull. Cargo handling methods have also been criticized. These have changed considerably in recent years, with the emphasis being to load and unload the ship as quickly as possible so that the berth can be cleared for the next ship. In some loading terminals iron ore can be loaded at up to 16,000 tons an hour by means of conveyor belts often several kilometers long. Stopping the loading process for some reason cannot be done simply by pressing a button - it has to be very carefully planned and can take several minutes to carry out. In these circumstances it is not surprising that sometimes bulk carriers can be overloaded. The International Association of Classification Societies (IACS) says that there is no evidence that high loading rates causes physical damage to the interior of cargo holds (assuming that they are in good condition to begin with) but "high cargo loading rates under an uncontrolled process could result in inadvertent overloading which could cause local or global damage." Dramatic proof of what can happen if something goes wrong during loading came in 1994 when a bulk carrier broke in half while being loaded at a port in South America. A study carried out by IACS members showed that a 5% overload placed in various holds could increase the still-water bending moment by up to 15% and the sheer force by up to 5% while a 10% overload could increase the still water bending moment by up to 40% and the sheer force by up to 20%. A 10% overload, according to IACS (in reply to questions submitted by the Nautical Institute) could be caused by a five to eight minute delay in stopping a conveyor belt with a capacity of 16,000 tons an hour. At the other end of the voyage other problems can be waiting. Bulk cargoes are removed from the hold by means of huge grabs which can weigh up to 36 tons. The last tons of cargo, which may be caught up in frame webs and other parts of the hold, are often removed by bulldozers and hydraulic hammers fitted to the extending arms of tractors. There is always a danger that the hull - especially if it is suffering from corrosion or fatigue - may inadvertently be damaged in the process.  Part of the problem is that modern loading and unloading  techniques were developed long after the ships they  are intended to load were built. The need for speed may have compounded the problem in some cases. An article in the August 1995 edition of the BIMCO Bulletin, the magazine of the Baltic and International Maritime Council, says: "There has been a growing body of evidence that terminals, which were often owned by the cargo owners or charterers of the ship, were putting pressure upon the ships to amend their loading plans or to load cargo to suit them, with little consideration about the overall safety of the ship."

4. A question of attitude

The idea that commercial considerations could threaten safety has been noted by other sections of the shipping industry. A study by Lloyd's Register discovered that "operational damage was accepted as the norm by the operators of bulkers and OBOs; second, there was little awareness as to the significance  of this damage and its likely consequences on the capability of the ship under adverse operating conditions." This might be put down to simple thoughtlessness, but that excuse cannot be made for shipowners who purposely move their vessels from one trade to another - to escape increasingly vigilant port State control inspections. That is what happened when Australia, alarmed by a number of accidents involving elderly bulk carriers visiting its ports, tightened its control procedures. The result was a rapid  switch of  tonnage from the Pacific to the Atlantic where inspections were apparently not as rigorous. According to Lloyd's List  "in the first nine months of 1989 there were nine voyages with cape size vessels aged 20 years or more in the transatlantic trades. In the corresponding 1993 period that figure had increased to 152." It is difficult to avoid the conclusion that the owners of at least some of the ships concerned moved them because they knew that the ships were in such bad condition that they would not be allowed to operate in Australia - or even leave port - without being repaired. The owners were presumably quite content to allow the crews to risk their lives on ships which they knew were un-seaworthy. It is not surprising in the circumstances that, when Lloyd's Register of Shipping began to investigate bulk carrier losses in 1991 it found that "one of the biggest problems facing LR ...is the general attitude of the industry. It is thought by some in the industry that cracking in these structures is inevitable due to the harsh nature of the cargoes and the rigorous operational procedures throughout their service life."

5. High tensile steel

Most of the current concern about the condition of bulk carriers has focused on old ships, especially those aged more than 20 years. But young ships are not immune to neglect and corrosion and there is also evidence that changes in the steel used on some relatively young bulk carriers could present even more serious problems than those experienced by earlier designs. The majority of ships operating today are built of mild steel. But since the early-1980s increasing use has been made of high-tensile (HT) steel, especially in the construction of bulk carriers. HT steel has been used in shipbuilding since 1907 but its recent popularity  is due to the fact that plates can be thinner without losing any strength. Whereas a normal side plate will be 24-29mm thick, this can be reduced to 20mm by using HT steel. The weight saving - which might amount to several thousand tons - cuts building costs and also enables the ship to carry more cargo. However, for these savings a price has to be paid. One is the simple fact that HT steel corrodes just as quickly as mild steel. Since HT plates are thinner than those of mild steel corrosion is likely to reach the danger point more quickly. A second problem is that HTS built ships are more prone to structural problems caused by the way in which load is transmitted through the ships' structural components and the inter-dependency of the structural response. A paper submitted to IMO by  IACS in 1992 said that the most common example where failure had occurred on HTS-built bulk carriers was at side longitudinal connections to web frames. According to Lloyd's Shipping Economist in September 1995 HTS-built ships are also prone to a phenomenon known as "springing": because the ships are more flexible they tend to vibrate with short sea waves. The article says: "Classification society rules have always been based on empirical evidence from previous generations of ships, but the increased use of HTS changed the characteristics of vessels and therefore represented a step into the unknown." It is clear from the above that HTS ships need at least as much care and maintenance as those build of mild steel, especially as they too are frequently subject to greater stresses in  cargo loading and unloading than was originally envisaged. Many shipping experts believe that whereas mild steel bulk carriers usually begin to experience major problems at the age of 20, those built of HTS will do so much earlier. Since most of them were built in the early 1980s are already into their teens, the danger is that there could be another rise in bulk carrier casualties, unless action is taken to prevent it.

What IMO has done 

The sudden increase in bulk carrier losses in 1990 and 1991 caused considerable alarm in the shipping industry. Several classification societies launched major research programmes and among those who were particularly concerned was the Secretary-General of IMO, Mr. William A. O'Neil, who felt that the situation was so serious that immediate action was called for. As IMO, like any other United Nations agency, is an inter-Governmental organization, the  normal procedure is for major policy initiatives to come from Member States or organizations which have been granted consultative status with IMO. But Mr. O'Neil felt that the situation was too serious and too urgent to rely on normal procedures. In October 1991 he therefore took the previously unprecedented step of presenting the IMO Assembly with a draft resolution on this subject.  He told the delegates: "In recent years bulk carriers have been sinking at the rate of more than one a month: another was lost in the Mediterranean shortly before the Assembly began.  In many cases these ships disappear without a trace and more than 300 seamen have lost their lives in the last two years.  A great deal has been done by IMO to improve the safety of ships carrying bulk cargoes, especially on the cargoes side, and the current feasibility study on voyage data recorders may prove valuable in the long run.  But something more needs to be done now." As a result, resolution A.713(17) was duly adopted.  It contains interim measures designed to improve the safety of ships carrying solid bulk cargoes. The preamble expresses concern at the continuing loss of bulk cargo carriers, sometimes without trace, and the heavy loss of life incurred.  The resolution notes that the nature of cargo and ballast operations can subject bulk carriers to severe patterns of bending and sheer forces and also to significant wear.  It refers to the dangers posed by some bulk cargoes through their high density and tendency to shift. It calls on the MSC to develop as soon as possible requirements for the design, construction and operational maintenance and survey of ships carrying solid bulk cargoes and to specify appropriate precautionary measures.  IACS is requested to develop survey and maintenance requirements for ships carrying solid bulk cargoes as soon as possible and to submit them to the MSC.  In the meantime, governments, classification societies, shipowners and shipmasters are urged to take immediate action to implement the interim measures, which are contained in an annex.  These measures are particularly concerned with the condition of the ship's structure and the detection of any corrosion. The importance of not overstressing the ship's structure during cargo operations is emphasized and governments are advised to pay particular attention to the structural integrity and seaworthiness of ships when port State control procedures are carried out under SOLAS. Owners are encouraged to fit vessels with equipment to monitor the stresses on the ship's structure during the voyage and during cargo operations.  They are also encouraged to install equipment required by the Global Maritime Distress and Safety System (GMDSS), which entered into force on 1 February 1992 but does not become mandatory for most existing ships until 1999. The impact of this resolution and action initiated by major classification societies was immediately beneficial. The number of bulk carrier losses dropped  to just two within the next year. What is most  significant about this improvement is that the resolution did not introduce any new measures but simply stressed the importance of implementing existing standards.  From this it is possible to conclude that at least some of  the  casualties that occurred in 1990 and 1991 were due not to defects in the regulations covering bulk carrier safety but to the ineffective way in which they were implemented.

Improving implementation

Poor implementation of regulations  is a problem that concerns all forms of shipping and is one that IMO has  in recent years been treating with even greater urgency. Successful implementation depends upon a  number of factors, but to be really effective it requires everybody involved to do job efficiently and with the necessary commitment and dedication.

They can be summarized as:

_          flag States - the Governments which have ratified conventions and thereby promised to put them into force

_          port States -  which have authority under conventions to check that foreign ships visiting their ports comply with IMO requirements

_          shipowners - who own the ships and have the greatest responsibility - and opportunity - for ensuring that they are maintained in good condition.

_          seafarers -  whose training and skill are vital to shipping safety and who stand to suffer most if something goes wrong.

            Some of the actions taken by IMO recently to improve implementation have been particularly important.

_          The Organization has established a new Sub-Committee on Flag State Implementation which  spotlights some of the problems Governments have in enforcing IMO conventions and provides guidance in overcoming them.

_          IMO has encouraged the establishment of regional port State control systems. Regional systems are especially useful in improving port State control because ships normally visit more than one country in a particular region.  Regional co-operation in inspecting and surveying ships ensures that few sub-standard ships avoid the net - and that ships in good condition are not inspected unnecessarily.

_          In 1989 IMO adopted guidelines on management for the safe operation of ships and for pollution prevention. These were replaced by an International Safety Management Code which was in turn adopted as a new chapter of SOLAS in 1974 and will become mandatory in 1998.

_          The STCW Convention was completely revised in 1995 and will become effective in February 1997. Not only do the revisions bring the Convention up to date, they also introduce strict new controls which will enable IMO to validate the training and certification procedures of Parties to the Convention.

            These actions are expected to lead to improvements in the safety of all ships, but in  April 1992  the MSC instructed various sub-committees to develop further requirements specifically for bulk carriers. The Sub-Committee on Ship Design and Equipment (DE) began work on measures to do with constructional safety, especially the hull integrity of large ships. One proposal considered was that they  should be fitted with voyage data recorders (VDRs) which would provide a record of the ship's loading condition, motion and global stress levels which would enable the causes of any loss to be determined. The Sub-Committee decided that although VDRs were technically feasible they were not vital because the reasons for bulk carrier losses were already well known thanks to information provided by Administrations and IACS. Instead, the sub-committee felt that it would be more useful to install a monitoring system that would provide information to the master of the ship during while the ship was under way and during loading and unloading operations. Instead of finding out what caused an accident such a system might prevent the accident from happening in the first place. This recommendation was accepted by the MSC in May 1994 and issued as MSC/Circ. 646. It contains guidance on the fitting of hull stress monitoring systems (HTMS) and recommends that they be fitted to bulk carriers of 20,000 dwt and above. Governments are asked to provide IMO with  information on experience gained. The Sub-Committee also considered ways of combating corrosion of seawater ballast tanks, a problem shared by both bulk carriers and oil tankers. Its proposals were adopted by the MSC in May 1994. They include a new draft regulation 14-1 in Chapter II-1 of SOLAS which requires all dedicated seawater ballast tanks to be provided with an efficient corrosion prevention system.  These guidelines were adopted by the MSC and then by the IMO Assembly in 1995 by resolution A.798(19). The regulation itself was included in amendments to SOLAS adopted by the 66th session of  the MSC in 1995 (see below) which will  enter into force in 1998.

Enhanced inspections during surveys

Resolution A.713(17)  emphasized the importance of regular inspections of bulk carriers, especially of older ships, and in 1993 guidelines on an enhanced programme of inspections during surveys of bulk carriers and oil tankers were adopted by the 18th Assembly by resolution A.744(18).  It was originally intended that the guidelines would apply to tankers but because of concern about the loss of bulk carriers they were extended to them as well.  The enhanced guidelines were regarded as so important to safety that amendments to SOLAS to make them mandatory were adopted in May 1994 and entered into force on 1 January 1996.   The guidelines apply to existing tankers and bulk carriers of five years of age and over - meaning that the vast majority of the world tankers and bulk carriers will be affected. The enhanced surveys  must be carried out during the periodic, intermediate and annual surveys prescribed by the SOLAS Convention.  The enhanced survey programme is mandatory for tankers under the International Convention for the Prevention of Pollution from Ships, 1973, as modified by the Protocol of 1978 relating thereto (MARPOL 73/78). The guidelines pay special attention to corrosion.  Coatings and tank corrosion prevention systems must be thoroughly checked and measurements must also be carried out to check the thickness of plates.  These measurements become more extensive as the ship ages.  The guidelines go into considerable detail to explain the extra checks that should be carried out during enhanced surveys.  One section deals with preparations for surveys and another with the documentation which should be kept on board each ship and be readily available to surveyors.  This should record full reports of all surveys carried out on the ship. Annexes to the guidelines go into still more detail and are intended to assist implementation.  They specify the structural members that should be examined, for example, in areas of extensive corrosion; outline procedures for certification of companies engaged in thickness measurement of hull structures; recommend procedures for thickness measurements and close-up surveys; and give guidance on preparing the documentation required. Guidance on planning the enhanced programme of inspections was adopted by the MSC in May 1994 and issued by means of MSC/Circ. 655.

Cargo handling

The Sub-Committee on Containers and Cargoes considered ways of improving the safety of loading and unloading operations. One aim was to amend Chapter VI of SOLAS so that masters would be provided with sufficient information on cargoes to be able to assess stress limitations. At the 32nd session in 1994 a questionnaire was developed and later sent out as MSC/Circ.611.  It deals with the loading and unloading of bulk cargoes and was based on a model plan prepared by the Nautical Institute and the International Federation of Shipmasters' Associations (IFSMA). Three other circulars were sent out by the MSC in December 1994 which were also based on work carried out by these two organizations.  MSC/Circ. 665 is concerned with the duties of Chief Mate and Officer of the Watch at bulk cargo  loading and discharge ports. It contains checklists which are designed to ensure that loading and unloading is carried out safely. The circular was superseded in June 1995 by MSC/Circ. 690 which contains an improved model ship/shore safety checklist. MSC/Circ. 666 contains a cargo operation form which is intended to ensure proper planning and calculation prior to the commencement of cargo operations.  MSC/Circ. 667 contains  general advice on bulk carrier safety. It stresses, for example, the importance of reducing corrosion within holds and ballast tanks by maintaining paint coatings and gives guidance on where corrosion is most likely to occur. Other organizations were also working to improve bulk carrier safety, including the leading classification societies, most of whom are members of the International Association of Classification Societies (IACS), which also has consultative status with IMO.  In 1994 IACS submitted to IMO copies of its manual on guidelines for surveys, assessment and repair of hull structures of bulk carriers.  It focuses on the IACS member societies' survey procedures.

Keeping up the pressure

In May 1994 the MSC reviewed the work carried out so far in improving bulk carrier safety. It concurred with the Secretary-General's appraisal  that the measures it and its subsidiary bodies had taken had resulted in a comprehensive set of standards.  However, during 1994 the number of casualties to bulk carriers again increased incurring considerable loss of life. A paper submitted to IMO by Intercargo in October 1994 also showed that the casualty rate could deteriorate very quickly. In the first seven months of 1994 there were seven major casualties involving bulk carriers, four of them due to plate failure or disappearance. Intercargo proposed a series of measures designed to improve safety in both the short and the long term.

            The Committee decided to establish a correspondence group co-ordinated by Australia which would consider the whole issue of bulk carrier safety, concentrating on six key areas. A different country or organization acted as the lead in each case. They were:

_          survivability standards (Italy)

_          design and construction standards (IACS)

_          operational standards (Canada)

_          survey requirements (United States)

_          ship/shore interface and (International Chamber of Shipping)

_          management and training (Norway).

            The correspondence group reported to the MSC's 65th session in May 1995 and made a number of proposals for improving the chances of a bulk carrier surviving in the open seas.  Their importance was emphasized by the group's statement that,  over the period 1990-1994, 97 bulk carriers were lost with a total of 532 lives.  Ships of 15 years of age and over represented most of the losses while 44%  were lost or had the potential to be lost through structural damage and/or heavy weather.  The group's proposals included calls for more attention to be paid to corrosion of steel in general and high tensile steel in particular. Concerns were expressed about the adequacy of existing designs in relation to structural continuity and the ability of an old ship to withstand a combination of severe weather and "as built" loading conditions when important structural members have corroded.  Particular mention was made of the practice of carrying cargoes in alternate holds. In the case of new ships there were suggestions for new mandatory requirements for damage stability using realistic loading conditions and a call for unified standards on scantlings and strength and design methodology, taking into account loading and unloading conditions encountered in modern bulk terminals and dynamic sea conditions.  Standards on the appropriate use of high tensile steel from the perspective of design and construction were proposed. It was generally agreed  that procedures for inspecting steel structures and repairing damage lack consistency and should be improved  as a matter of urgency.  The need for closer control of stresses during loading and unloading was called for and there were proposals for bringing port State control procedures to bear on this aspect. The need for shipboard documents  in a language  that can be readily understood by ships' officers was stressed. Knowing that a ship cannot be protected completely, the correspondence group recommended a reappraisal of the life-saving appliances on board so as to ensure that adequate and effective means of escape are available in an emergency. The correspondence group recommended that all the information from past surveys necessary to make informed judgements should be available on board. The group agreed that the Enhanced Survey Programme has the potential to be effective once the whole fleet has been subject to the programme in five years time but it would need to be implemented rigorously and, in particular, its success would depend on the ability of surveyors to conduct "close-up" inspections of all parts of a ship that are subject to high stress and/or corrosion. The group  agreed that  all organizations involved in the loading and unloading of bulk carriers should be aware of the intrinsic difficulties faced by the others.  The ISM Code should be used as a vehicle to ensure that responsibilities are clearly defined and the correct documentation is on board,  but additional guidelines may be necessary to account for the special factors in bulk carrier operations.  Training of shore personnel was considered  necessary to make them aware of the implications of loading and unloading operations for the safety of the ship.

           

            After considering this report and the recommendations of a working group on bulk carrier safety the MSC made a number of decisions.

_          The International Organization for Standardization (ISO) was requested to prepare quality standards for use by repair workers, surveyors and superintendents and to develop international shipbuilding quality standards on such matters as building techniques, quality control and qualifications and competency.

_          To improve safe operations at terminals the Committee agreed that SOLAS Chapter VI needed to be amended by adding a footnote referring to the Code of Safe Practice for the Safe Loading and Unloading of Dry Bulk Cargoes, then under development by the Sub-Committee on Dangerous Goods, Solid Cargoes and Containers (DSC). The MSC agreed that these amendments should come into effect on 1 January 1998.

_          It was recognized that there is a need for a bulk carrier endorsement to certificates of competency, similar to the one required for tankers, to reflect the special expertise required for bulk carrier operations.

_          A new Assembly resolution on bulk carrier safety was drafted and subsequently  adopted by the 19th Assembly in November 1995 as resolution A.797 (19) It refers to the work done since the adoption of resolution A.713 (17) by IMO and organizations such as IACS and, pending the outcome of the correspondence group, urges Governments, classification societies, shipowners, ship operators, shipmasters and terminal operators to implement measures contained in an annex. These measures are aimed at port States, flag States, shipowners and classification societies and contain practical guidance that is generally aimed at improving the way regulations are implemented.

_          Special consideration was given to the safety of single hull bulk carriers carrying density cargoes. A number of ships of this type have suffered progressive flooding in some cases involving the collapse of transverse bulk heads between holds. The Committee agreed that draft amendments to SOLAS should be developed, the aim being for them to be adopted by the 67th session in December 1996.

_          The correspondence group was asked to prepare draft amendments which would bar bulk carriers of 20,000 dwt and above from carrying high density solid bulk cargoes such as ore unless they complied with certain conditions.

These include being able to meet at least a one-compartment standard of subdivision for any cargo and in all relevant loading conditions; being able to establish that the transverse bulkheads have sufficient strength to withstand flooding of any single cargo hold; ships of ten years of age and above should have successfully undergone surveys of all holds to the minimum extent specified for the five yearly periodical survey according to the Enhanced Survey Programme; and the Safety Construction Certificate should be endorsed to show that this had been done.

_          SOLAS should be amended to require the installation of loading instruments on ships of  over 150 m in length.

            A number of proposals were made for existing ships, including a reduction in cargo carrying capacity, raising standards of subdivision and damage stability and preventing progressive flooding through collapsing bulkheads.  A new correspondence group was formed, again coordinated by Australia, to develop draft regulations to give effect to those decisions and to present for the consideration of the MSC a justification for any such proposals. In May 1996 the Committee met for its 66th session and once again bulk carrier safety was an important item on the agenda, particularly since some of the proposals made by the correspondence group had important technical and financial implications for the shipping industry. These proposals were based on  a  three part approach to defining the conditions under which bulk carriers of ten years of age and above would be permitted to carry high density cargoes. Its purpose was:

_          to ensure that the ship could survive flooding of one hold without sinking and thus provide a second line of defense against accidents

_          to ensure that the hold structure is adequate to withstand such flooding in a loaded condition, and

_          to provide for enhanced survey of the hold structure.

            The correspondence group was also directed to develop a regulation to make mandatory the fitting of loading instruments to enable ships' officers to control and monitor loading and unloading. The correspondence group prepared draft amendments which were further considered by a working group during the MSC's 66th session. They dealt with flooding, surveys and enhanced structural requirements for new bulk carriers which were readily agreed in principle. However, there was less agreement on the changes proposed in the regulations concerning existing ships. Some of these, either as a condition of assignment of load lines or in compliance with SOLAS damage stability regulations, have been designed to withstand the flooding of their holds from a stability point of view. All cargo ships (including bulk carriers) built since 1992 have been required by SOLAS to be able to withstand flooding. But while investigating the practicability of the correspondence group's three-part approach to bulk carrier safety, the International Association of Classification Societies (IACS) found that, even where a ship has been designed to withstand flooding it may not be able to withstand the head of water that results, especially if the ship is loaded and the seawater creates dynamic pressures in the flooded hold. The bulkhead between the flooded hold and the next one might collapse under this pressure.

Draft Code of Practice for the Safe Loading and Unloading of Dry Bulk Carriers

The MSC at its 66th session also considered the Code and associated draft Assembly resolution submitted by the DSC Sub-Committee. It is expected that this Code will be adopted at the next session of the IMO Assembly in November 1997.

            The Code is important because it addresses the important issue of safety in port - other measures taken by IMO have primarily been concerned with the safety of bulk carriers while at sea. It covers all solid bulk cargoes except grain and reflects current issues, best practices and legislative requirements. The Code contains a number of sections dealing with such matters as the suitability of ships; procedures between ship and shore; and loading and unloading cargo and ballast handling.

The future

During the last few years IMO has been involved in a major effort to improve the safety of  ships that have suffered hundreds of casualties - many of them fatal - over the years and yet have attracted little interest or aroused much concern outside the industry. The annual casualty returns have sometimes indicated that these measures have been effective - and sometimes that more needs to be done. There is general agreement that measures agreed, but yet to enter into force fully, or for all ships, will go quite a long way to improving the safety of bulk carriers. However, it is known that other measures are possible. The action currently being taken by IMO to improve bulk carrier safety is based on the premise that all possible aspects should be considered. It is recognized that the cost factor cannot be ignored, but the expense of changes to existing requirements should not be used as a rationale for delaying or not proceeding with the implementation of any necessary measures.

________

30 September 1996