Now that all the commotion has died down over tankers the focus is again on bulk carriers. The IMO and IACS are bringing in new regulations for implementation such as water ingress alarms in cargo holds and forward spaces. Later on there are likely to be regulations requiring double side shells on newbuilding larger than 150m. .
However, William O?Neil, secretary-general of IMO pointed out at an after dinner speech earlier this year; "It would astonish most people to discover that, in terms of average annual loss rates per million flight, or voyage, hours at risk, the loss rate for commercial aircraft is three times that for merchant ships, and that, since 1988, the merchant ship loss rate per 1,000 units at risk has been consistently lower than the commercial aircraft rate."
On the question of double hulls, he went on to say that, all single-hull oil tankers are to be phased out. "We know that, it is one of the provisions of MARPOL and the only question currently being addressed is whether or not the timetable for doing so should be accelerated again. No new single hull tankers have been built since the mid 1990s and so there will come a time, sooner or later, when all oil tankers will have double hulls. What will that mean? Will it mean no more oil spills? Will it signify the final solution to the problem of tanker safety? Of course not. It will simply mean that the next generation of tanker to spill its cargo on a beach somewhere because it has been either poorly built, poorly maintained, poorly repaired or poorly operated, or any combination of these, will be a double-hull ship. Because, while a double-hull may offer some additional protection in certain circumstances, it is just as vulnerable to malpractice as any other. My point is that all the regulation in the world will not prevent accidents from occurring and so we must address the need to pursue sound maintenance and operational practices if casualty rates are to be improved still further."
DNV is in agreement as Tor Svensen, maritime chief operating officer says; "If the new IACS and IMO requirements are complied with and the bulk carriers are properly maintained, both single and double skin bulk carriers meet today?s safety requirements." He pointed out that the purpose of classification is to manage risk, that is, to bring the risk of losing ships and crew down to a level which is acceptable to society.
The actions taken to strengthen existing bulk carriers in Chapter XII of the International Convention for the Safety of Life at Sea (SOLAS) and the IACS/IMO requirements proposed in 2002/2003 accomplish this purpose. "If these requirements are complied with and the bulk carriers are properly maintained, both single and double skin bulk carriers meet today?s safety requirements," says Svensen.
He explains "there might be operational or commercial reasons for some owners switching to a double skin design, but we should not confuse the issue. An early phase out of single skin bulk carriers would immediately create a two-tier market and push safe bulk carriers into oblivion. Such a removal of what are today?s workhorses of the world fleet should at least not be argued for as a safety concern," he concludes.
Bernard Anne, managing director of Bureau Veritas? marine division is also in agreement saying; "We are concerned that, in the rush towards demanding double hulls for everything, our political leaders may have lost sight of practicality." He continues: "Double hulls for new tankers are now a fact and have become the standard design. This concept is now beginning to be applied to bulk carriers. But we all know that double-hulls are not a panacea and they have pros and cons." Anne explains that single-hull bulk carriers can be just as robust as double hulled vessels. "I would much rather see a single-hull ship built to high standards and then well maintained by a quality owner, than have a double-hull ship built down to shipyard minimums, then maintained at minimum levels." says Anne
In an effort to improve safety in the Asia-Pacific region, the Tokyo MOU is targeting bulk carriers as defined in SOLAS74 IX/1.6, which are above 15,000 GT and more than 12 years old, particularly those carrying high density or corrosive cargoes and trading on the spot market. Inspection of as many bulk carriers as possible started on September 1, and will continue until November 30.
Double hulls on offer
A number of shipyards and designers are now offering double-hull bulk carriers, more recently Chinese Shipbuilders, which are developing four types of bulk carrier designs. They are in the 53,800dwt, 75,000dwt, 90,000dwt and 174,000dwt classes ? in a project that began earlier this year and is due for completion by February next year.
Another double-hull bulk carrier design to be built at a Chinese yard is that of the 53,000dwt ships developed jointly by Cardiff-based Graig Group and Denmark?s Carl Bro, which will be built in Shanghai, China - four at the New Century yard and three at Chengxi, for delivery in 2005-06. All are for prominent Greek, British and Scandinavian owners, as are nine further options so far placed.
Graig?s CEO, Hugh Williams, describes the new vessels, termed the Diamond 53 design, as combining a robust and practical double-hull concept with an attractive financial package and delivery schedule. "Given China?s proven newbuilding experience, together with the ships? promised operational cost savings and safety features, we expect many more owners to follow these three leaders."
Savings for owners and charterers stem from lower capital and operating costs, shorter discharge and cleaning times, and the safety and environmental protection afforded by the double-hull design.
The Graig/Carl Bro joint-venture company, based in Shanghai, now plans to expand the Diamond class range of bulk carriers to include both Panamax and Capesize vessels.
While orders for the design have already been placed, the design had not, as this issue of The Motor Ship went to press, been finalised. However, Ole Noerskov-Lauritsen, divisional director of the marine department at Carl Bro assures The Motor Ship that the basic design (classification drawings) will be finished within a month.
The new generation of vessels, typically used for carrying grain, iron ore, coal etc have been designed to better withstand collision like the recent one off the Danish island of Bornholm. The entire structure is stronger, and the double hull provides better protection if collision with other vessels should occur. High tensile steel has been used in the upper deck and wing tank structures (NV-36) to the tune of 10% and 33% of the double bottom structure uses NV-32.
This strength is carried further as N?rskov-Lauritsen explains; "The cargo section of the vessels is double-hulled. This increases security and makes the vessels easier to inspect. They are also double-hulled round the oil tanks ? this minimises the oil-spill risk in connection with collisions etc., which means that the design helps to reduce the risk of marine pollution."
N?rskov-Lauritsen says, "the design is strong and robust, and we make a point of using steel plate that is thicker than what is normally used ? but only in relevant places." This approach enables the vessels to carry a heavier cargo and improves rust resistance. "The design makes it easier to maintain the vessels, which makes for longer life," he explains. The structure will also make it easier for authorities, port chiefs etc. to examine the condition of the vessels.
When explaining the vessel?s strength advantage to The Motor Ship, N?rskov-Lauritsen says it has stronger hatch covers and the bulkhead can withstand flooding to comply with URS18, and the hull girder can withstand flooding to URS17 (70% wave loads). The vessels are also equipped with safe under deck passage to fore decks, water ingress alarms and a freefall lifeboat. The BC-A notation ensures a strong hull girder, which says N?rskov-Lauritsen, offers "a. larger margin for over stressing the cargo hold structure during loading and discharging."
DNV has been involved in the project from the beginning and have given a lot of input regarding present and coming rules, structural review and review of possible yards. Safety has not been compromised in what Carl Bro considers to be advantages in the way of cargo handling. The vessels will be fitted with large capacity cranes of 36 tonnes capacity at 28m and wide hatch openings for easy cargo spotting. The flush inner hull will also stop cargo getting trapped between exposed structures.
The secret with any new design is safeguarding it against future regulations to avoid costly upgrading. Without a crystal ball it is difficult to tell what the future will bring. However, the Carl Bro has addressed all of the regulations coming into force and working closely with DNV will have given them a good idea of what the future holds for bulk carrier design. It is this that probably gives N?rskov-Lauritsen the confidence to say, "we fulfil all known future regulations."
