How LNG fleet expansion could spur business for repair yards

Much has been written recently about the big growth in the LNG fleet expected over the next few years and the implications for the shipbuilding industry. For example, the UK's Ocean Shipping Consultants expects the current fleet aggregating 17.7 mm cm capacity to more than double to over 52 mm cm by 2020.
Although we are only talking about around 50 ships in service and similar number on order now, as the vessels get older maintenance and repair issues are going to become more important.

Very few LNG carriers have been scrapped; the pioneering Methane Progress and Methane Princess carried on for many years and many of the first generation of LNG carriers could be around for a long time yet.
These sophisticated vessels are expensive to build and, therefore, it's in the owners' interest to maintain them in good condition and get long service lives out of them. That is becoming increasingly important as the market grows and something of a spot market starts to develop.

With this in mind,French classification society Bureau Veritas (BV) has launched a Condition Assessment Programme (CAP) for LNG carriers. The CAP works in a similar way to existing Harmonised CAP programmes for oil tankers, but has special requirements unique to LNG carriers.
Bruno Dabouis, BV's commercial manager, said recently: “The LNG market is opening up and there are signs that a spot market for LNG carriers may further develop. That means charterers need to be able to demonstrate that they have taken special care when chartering in older vessels, a new phenomenon in the LNG market.”
Bureau Veritas, the only classification society present in all types of LNG containment systems and propulsion systems, and with a unique pedigree stemming right back to the very first LNG carriers, was well placed to support the current market changes with technical expertise.”

BV may be first with a CAP but other classification societies are well aware of the changing nature of the LNG trades. For example, Norwegian-based Det Norske Veritas (DNV) has been looking at the LNG scene and has warned that changes in the market, while demand for LNG expands rapidly, will put more demands on vessel strength, in particular as more LNG is carried around the Atlantic Basin.
DNV says: “Fatigue damage accumulation is twice as rapid in the North Atlantic than in the comparatively more benign environment where most of today's routes are.” It adds: “In addition, offshore LNG import terminals now under construction -- at which safe offloading can take place far from populated areas and busy ports -- may create more sloshing while offloading. This requires offloading carriers capable of operating without tank filling restrictions -- or with filling restrictions determined for the environmental conditions at the actual offloading location.”

According to the findings of a large-scale test recently carried out by DNV, impact peak pressure in LNG carrier tank systems can be expected to more than double if operating with no filling restriction, compared to currently-allowed filling rates.
“Fatigue considerations and tank sloshing loads will become much more important design parameters. Sloshing loads inside partly filled LNG cargo storage tanks and cargo transfer in open seas are examples of challenges that have to be addressed,” DNV cautions. It seems likely, then, that new LNG carriers will tend to be designed for a harder life. But the existing fleet will have to serve for many years and will need the increasing attention of the world ship repair yards.

Mr Dabouis says: “BV has brought together its deep research and development into sloshing loads and structural detail, its experience with lifetime structural maintenance, its successful and fully accepted tanker CAP programme and its experience with LNG carriers to develop a CAP for LNG vessels. It is fair to both owners and charterers, and has been accepted by Shell, BP and Total already.”
BV says that its experience with LNG carriers in service was also instrumental in it winning a tender to provide a life extension study, through its Tecnitas consulting arm, for seven existing LNG carriers working for Shell and operated by Nigeria LNG in the Nigerian Bonny Gas Transport project.

The LNG CAP has already been applied in practice to life extension studies on two LNG carriers. BV says the CAP is a voluntary programme by shipowners and can be applied at any time within the life of a vessel but is more relevant to LNG carriers approaching the age of 20 years. The programme covers hull, containment system, hull fittings, machinery, steam turbines and gear box systems, electrical installations, water tube boilers and cargo handling systems.
So, as more of the LNG fleet reaches the 20-year-old mark, ship repair yards who are trusted by owners to work on these large and sophisticated ships may find work on LNG carriers becoming an increasing part of their business.