COLUMN | Ending the burden of lashing [Grey Power]

COLUMN | Ending the burden of lashing [Grey Power]

Photo: Hyundai Heavy Industries

With winter storms whirling around the northern hemisphere, masters of containerships will be worrying about whether the lashing gangs in their last ports were as particular as they ought to have been as they hurried around the towering stacks of containers. In the event something gives way, and some of these containers end up in the sea, you can no longer attribute their loss to “heavy weather” as the regulators in the nearest coastal state will be conducting their enquiries with an eye on a prosecution. They will be poring over the ship’s lashing plans while minutely examining the lashing rods and their connections, checking for signs of corrosion or wear and tear, which can be blamed on somebody in court.

With the ever-increasing size of containerships and the need to stack the boxes on deck ever higher, the securing of these has become an ever-greater burden. It certainly isn’t helped by the demand for greater haste in port to make up for the planet-saving slower passage speeds, with the onus on the lashing gangs to get the ship-loader cranes working as quickly as possible and with the cargo finished, the ship away out to sea again. It is heavy work at the best of times, working at height on the lashing bridges, with the risk of a rogue twist-lock falling about your ears. Think of the time and money that could be saved if you didn’t need to lash those wretched boxes, employing a system that has not really changed much over half a century.

So, there will be some considerable interest in a clever new design from South Korea’s giant shipbuilder Hyundai Heavy Industries (HHI). The design incorporates a “lashing free” system and moreover does away with the need for heavy pontoon hatch covers to weather tight the holds and support the high deck load. These are early days yet, but the design has been approved by the classification society ABS, and it is obviously a big step to its eventual adoption by some innovative ship operator.

“The concept of the ‘hatch-coverless’ containership goes back to the 1990s.”

The design features container guides that are extended above the weather deck level up into the full height of the proposed deck load so that lashing rods would no longer be required with the boxes held securely by the guides themselves. Hatch covers would be also eliminated, saving more handling time, with their supporting role for the deck stack substituted by what HHI terms a “portable bench” that will transmit the weight of the boxes above deck to the structure of the hull itself.

It sounds an ingenious solution to a very long-standing problem, although the concept of the “hatch-coverless” containership with no lashing requirements goes back to the 1990s and a small fleet of short-sea vessels operated in European waters by Bell Line of Ireland. While never designed for a deck load (as all the boxes were carried in the holds), the vessel carried 300 TEUs in six tiers, and it was found that the drainage arrangements and pumps were well able to cope with rain and spray accumulations at sea. It was said that savings in cargo handling time could be more than 25 per cent without the need to be handling hatches, an important factor with the ship in and out of port, sometimes several times in a day.

At the same time, a series of 3,500TEU and 4,000TEU ships described as the “ultimate container carrier” was being built in Japan for the Dutch Nedlloyd company. The seriesh combined the elimination of most of the hatch covers with the requirement for lashing the deck cargo. The brainchild of the Nedlloyd chief naval architect Ernst Vossnack, these ships had the hold container guides extended well above the weather deck so that up to four containers high could be kept secure without the need for lashing.

Seven of these (then) big ships were built by IHI and Mitsubishi Heavy Industries in Japan and were to go on to have a successful operational life, their designer pointing out that not a single container was ever lost from them. Of course, four boxes high would be a very modest height in today’s terms, which makes the weight transference system of the Hyundai design of great interest.

“Some realists might suggest that the real problem with the giant ships of today is getting the cargo in and out of the terminal.”

While there are a number of hatch coverless container ships at sea in short sea trades, there was no great rush to copy the Nedlloyd designs, not least because of the exponential growth in ship sizes and stack weights in deep-sea ships. With the elimination of hatch covers, these ships were also penalised by the system of measuring gross tonnage, then used for harbour dues and other charges. Nedlloyd Asia and her sisters carried a higher proportion of the cargo under deck, with the ship’s high freeboard increasing safety but financially counting against them. Ernst Vossnack understandably was a severe critic of the Tonnage Convention, which he said led to ships carrying far too much of their cargo exposed on deck.

But perhaps more important was the problem that despite the time savings from not having to handle hatch pontoons, the crane drivers found that they were slowing up as they were impeded by the extended container guides as they dug into the holds, so that stevedores found them difficult. If the Hyundai designs are translated into steel, it will be interesting to see how that earlier difficulty is handled. If it works, it will herald important savings, although some realists might suggest that the real problem with the giant ships of today is getting the cargo in and out of the terminal rather than the ship itself.

Michael Grey

Maritime industry legend, and former long-term editor of Lloyds List, Michael Grey kicks off each month with topical issues affecting the maritime world at large.