The Case Of The Bendy Boxer Part 2

 

She was a fast lady, but like many fast ladies
she had a hidden, fatal flaw

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Part 2

It was almost surreal: A devout Christian Zulu cattle herder walking the beach of Branscombe Bay, Dorset, on 20th January 2007 would have felt quite at home among the bibles falling from the containers washed ashore from the wreck of the MSC Napoli, all in his own language.

The words of the Almighty were protecting finely-coopered oak barrels from the Napoleonic forests of Alliers, France bound for South African vineyards. Many of those found a home with a Somerset Cider maker to age a special cider brandy called, appropriately, Shipwreck.

Other found their dreams fulfilled from this cornucopia by brand new BMW motorcycles, most of which remain on the missing list.

Yet, there were small, personal tragedies. Although no-one died in the incident, lives were, in a sense, lost, like that of the family moving overseas with the memories of decades of their lives, the family treasures, the childhood mementoes, the bric-a-brac so meaningless to others, in one of those containers, now scattered forever at the hands of the scavengers of Branscombe Beach.

Over the next five months fuel oil and the remaining containers were removed from the MSC Napoli. In early July an attempt was made to refloat her, but it soon became clear she was finished, she was beached for a second time three days later and preparation were made to take her apart.

On 20th January, the Dorset hills echoed to the thunderous claps of explosions as the ship was blasted in two, just forward of the engine room and accommodations. The forward section was floated to Harland and Wolff shipyard in Belfast, once home to the Titanic.

Her after section was still off Branscombe when the UK’s Maritime Accident Investigation Branch published its report fifteen months later.

That report reprised the MAIB’s earlier condemnation of the container industry in the wake of the collapse of containers aboard the Annabella in 2007: “the commercial advantages of containerisation and intermodalism such as speed and quick turnarounds appear to have become the focus of the industry at the expense of the safe operation of its vessels…While key industry players will attest that safety is of paramount concern, evidence obtained during this and other MAIB investigations into container shipping accidents suggests that in reality, the safety of ships, crews and the environment is being compromised by the overriding desire to maintain established schedules or optimise port turn round times.”

Strong words, and ones against which the industry could find no substantive defense. Zodiac Maritime Agencies, which operated the vessel, did issue a statement that the shipowners, Metvale Limited, believed that there were inaccuracies in the report that would benefit from further technical review. Maritime Accident Casebook asked Zodiac Maritime Agencies to clarify those inaccuracies. It hasn’t yet done so and if it does you’ll find the details on our website. Until then, we have to depend on the findings of the MAIB report.

MSC Napoli’s voyage to the Harland and Wolff Shipyard by way of Branscombe Beach began 16 years before at another shipyard, Samsung Heavy Industries, in Koje, South Korea, where she was built as the CGM Normandie in 1991 under the eyes of French classification society Bureau Veritas.

From the bow to the area of the engine room bulkhead, she was constructed with longitudinal frames, the shell plates, the metal plates making up the hull itself, were reinforced by stiffeners running fore and aft, and supported by transverse floors about 3.2 metres apart.

At the engine room bulkhead, about 207 metres from the bow, that changed to transverse frames with plate floors some 800mm apart.

In that same area the thickness of the upper deckplate reduced from 44mm to 36mm. Thinner deck plate is, of course, cheaper.

These changes were not a good idea. Generally speaking, a ship is an elliptical shape and most of the stresses get greater the further one gets from the bow until amidships, then get less towards the stern. Traditionally the scantlings, the frame units that make up the skeleton of the ship, get larger as they approach the centre of the ship and smaller as they go from the centre to the stern. That’s okay because they pretty much follow the stresses on the hull.

Traditionally, engine room are well towards the stern, where stresses are less, but as containerships got larger and longer, engine rooms sort of migrated up the deck, to where the stresses are often much the same as amidship.

In fact, the Bureau Veritas requirements during construction were: ‘Scantlings13 are given for the midship region and the end regions… In the intermediate regions, scantlings are to vary gradually from the midship region to the end regions.”

In the design of the MSC Napoli, however, the forces in the area of the engine room and the accommodation were much the same as those amidships, but the change in structure introduced a line of weakness across the hull. It’s like sharply bending a sheet of paper to make it easier to tear.

Being a responsible organisation, Bureau Veritas wanted to be sure that the ship would not buckle in service and conducted a 3D stress analysis. The rules at the time only required such a analsysis for an area one fifth of a ship’s length forward and one fifth of a ships length aft of the amidships position. Their analysis was regarded as satisfactory.

If you have a good memory, you’ll recall that the engine room bulkhead was around 207 metres from the bow. The area covered by the Bureau Veritas analysis covered an area extending from about 83 metres to around 193 metres from the bow, just 14 metres in front of the engine room bulkhead. It satisfied the Bureau Veritas rules at the time but didn’t cover the engine room and accommodation area.

In 2002, the ship went into class with Det Norsk Veritas, DNV. Both Det Norsk Veritas and Bureau Veritas are members of the International Association of Classification Societies, ICAS. Each member of the society may have its own rules, but it also accepts the rules of other members, so DNV did not reassess whether the vessel met it’s own rules, it accepted those of Bureau Veritas. So DNV inherited a ship with a fatal weakness without question.

Of course, it helps the world of business go around if classification societies accept each other’s rules when a ship changes class rather than be picky and ensure that ships meet their own individual rules. Classification societies are paid by shipowners to ensure that the shipowner’s vessels meet classification society technical standards. It’s called running with the hares and hunting with the hounds and it is an entirely self-regulated business.

In general, the building of what was to become the MSC Napoli followed the design parameters but there were anomalies. The girders along the port side of the ship were continuous, They’d failed midframe when the ship snapped. The centreline and starboard side was different story, the girders were not continuous, they’d been welded together and they fractured where they’d been welded.

And the centreline girder turned out to be made of mild steel, not thew high tensile steel specified in the ship’s drawings. Mild steel is, of course, cheaper than high tensile steel.

Liker any ship, The MSC Napoli had it’s fair share of misfortunes. In January 2001 some of her plates were bent during drydocking; in April that year she ran aground at full speed in the Malacca Strait, in December that same year she thumped a berth in Jeddah, and ran aground in Jeddah the following year. None of those incidents contributed to her final demise but what is relevant is that a number of repairs and welds were not reported to the relevant classification society.

So let’s move on to what was going on when the MSC Napoli hit the storm. First, there’s slamming, which comes in two flavours. First when the ship’s hull, or part of it, comes out of the water and smacks back onto the surface of the sea. Above the ship’s hull there’s a flare at the bow and stern to accommodate the deck, when that flare buries itself in the sea, they’re called bow and stern slamming.

But there’s another effect, it’s called whipping. If a ship is sagged, its midship lower than its bow and stern, slamming can lead to hogging, a flex in the other direction, which can add 10 to 50 percent of wave loading on the ship and it’s probably increased with the length of the ship.

In the case of the MSC Napoli it could have added as much as 30 percent to the bending moment of the vessel. When the Napoli left the River Schelde, she was already at around 99 per cent of her maximum permissible bending moment so when she hit the storm she had no safety margin left.

Could whipping have caused the hull of the MSC Napoli to snap? The fact is that nobody knows because the research hasn’t been done. Technical knowledge hasn’t kept pace with industry development. Ships have got bigger, they’ve got faster, but our knowledge of how those ships react is little further now than when the MSC Napoli was built.

The fact is the industry looks to the past for safety and to the future for its profits.

Classification societies have been around for a while, and, whatever criticisms one might have of classification societies, there is a code of conduct. There is no organisation for the container industry and no of conduct, although moves are afoot to fuill that gap through the International Chamber of Shipping, and we’ll being telling you more about that when it happens. While classification societies like to think in terms of self-regulation, there is no self-regulation of the container industry. One can only echo Mahatma Gandhi’s response when asked what he thought of Western civilisation, he thought it would be a good idea.

The weight of a container and where it is placed on the ship may be critical to that ship’s survival.

Of the 700 containers on the deck of the MSC Napoli, 660 survived the predations of the sea and the Branscombe Bay scavengers. When 137 of those containers were weighed they were, on average, 3 tonnes different to their declared weight, one was a whole 20 tonnes heavier, and, in total, they were 312 tonnes heavier than on the cargo manifest.

Seven percent of the containers on deck weren’t even in the place recorded by the terminal operator, placements entered into the ship’s loading computer to ensure the stability of the vessel. In fact, at least ten percent of all container placements are normally wrong.

So, a ship with an inherent fault introduced during her building, undiscovered because of gentlemanly agreements among classification societies, built to rules that lagged far behind developments, with unreported structural damage, subject to a force that nobody knows much about, loaded in a way which is unsafe but common practice in the industry, goes out overloaded into a storm generating waves of up to 9 metres.

But nobody worried too much so long as schedules were met.

Yes, as the MAIB report suggests, the master might have been more prudent, he might have lowered his speed, but his main concern seems to have been the safety of the containers on the foredeck.

True, the sort of thing that happened to the Napoli is very rare, only one other catastrophic hull failure of a container ship is recorded. Of more than 1,500 ships screened after the MSC Napoli incident only 12 were identified as needing to be fixed, and a further 10 were on the borderline and results were awaited on another eight, 30 suspect ships in all.

Det Norske Veritas concluded that the MSC Napoli incident did not indicate that there was a problem with containership ship design generally, and they’re probably right. But one has to look at the industry’s record holistically, at the lives lost and people injured in container loading and unloading operations, the thousands of containers lost overboard due to poor lashing arrangements, the collapse of containers due to bad stacking and understrength containers, incidents with the potential for death, injury and pollution by hazardous materials.

One common element is speed.

The container industry is driven by speed. That inevitably means narrower safety margins, just as F1 race cars operate to narrower safety margins than, say, family saloons. Those narrower margins mean that stricter safety measures must be in place and the emphasis on safety must be heightened.

The container industry would do well to learn from the oil and gas industry and organisations like the Marine Safety Forum and the International Marine Contractors Association and their safety alert systems.

But you, too, must be pro-active. If you’re not part of the solution, you’re part of the problem.

We can get so caught up in doing things faster that we forget to do them safer.

This is Bob Couttie wishing you safe sailing.

MAIB Report On The Napoli

MAIB Report On The Annabella

DNV Powerpoint Presentation “:Why The Napoli broke its back”

DNV Animated Videos

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