The recent rapid expansion in the world’s fleet – and the even faster-growing proportion of large vessels – has prompted some to warn that global ship repair capacity may come under serious strain in the years ahead. Facilities in appropriate locations capable of accommodating latest generation ultra large container ships, for example, which ideally require dockings at either end of their mainhaul trade, are likely to find their services in increasing demand whilst other yards capable of working on large vessels will also be able to rely on a steady stream of VLCCs, Capesize bulkers and the latest generation of vast ore carriers.

Established drydocking practices – at least for container ship owners – look likely to change, however, as class societies and flag states investigate the scope for extending drydocking intervals out to as many as 90 months. The possibility of pushing out docking intervals to more than five years has been discussed in class circles for some time, with various pilot projects initiated at Lloyd’s Register (with Maersk), ABS (also with Maersk), Germanischer Lloyd, DNV and ClassNK. However, flag states have been less than enthusiastic and, until recently, class has found its hands firmly tied.

This looks set to change, however, as a number of prominent flag states appear more receptive to lengthier drydocking intervals. With their weighty container ship focus, it is no surprise that Denmark and Germany have been in the vanguard of the latest developments but other flags embracing these moves include Liberia, Singapore, the UK and the Marshall Islands. And it is no coincidence that these flag states are also home to a significant number of container ship owners who stand to benefit from any changes to the present regime. Bulk carriers and tankers will not be eligible for extended dockings because the requirements of the Enhanced Survey programme require a drydocking at every Special Survey.

Lloyd’s Register’s work with Maersk and the Danish Maritime Authority has been under way for more than five years and the class society is keen to stress that extended docking intervals are certainly not a means by which Special Survey controls and requirements can be side-stepped. Under the scheme, it is explained, certain drydockings are replaced by in-water surveys carried out by approved diving companies. This provides more flexibility for operators to choose a suitable drydocking window and, of course, there are potential cost savings too in the form of reduced off-hire and lower drydocking expenses.

Earlier this year, ABS announced a deal with Maersk covering 14 container ships which may also stay in the water for up to 90 months between dockings. The vessels will be allowed to have two in-water surveys before having to re-dock, meaning that their second drydocking could be as many as 15 years into the ships’ operating lives. This means that only new or relatively young vessels are eligible and the programme will not apply to ships of more than 15 years in any case.

Germanischer Lloyd is introducing a similar scheme, with an extended drydocking option for general cargo and multipurpose vessels, as well as container ships. However, to qualify for the German scheme, owners must meet a range of conditions, including GL class notation – in-water (IW), flag state approval, age restrictions, GL-approved hull and machinery planned maintenance systems and a shaft bearing and sealing system approved by the class society and subject to regular condition monitoring.

Although these developments may be welcomed by the major container lines, there are still those who are sceptical. They point out that despite the claims of coatings companies, the efficiency of hull antifoulings reduces over time and although some of the most sophisticated coatings may offer scope to last 90 months, there are issues of mechanical damage to consider, as well as the reduced impact on fuel savings as coatings get older. Latest generation silicone-based hull coatings may be very effective at limiting plant growth, but the development of slime over time is still a challenge. The loss of a fuel saving of just a few per cent could very easily cancel out all of the potential benefits and more, they suggest.

Republished by kind permission of: A&A Thorpe, 131a Furtherwick Canvey Island, Essex SS8 7AT Tel: +44 (0) 1268 511300 Fax: +44 (0) 1268 510467 shipaat@aol.com

The views of the Publishers do not necessarily correspond to the views of Lambos Maritime Services Ltd.