Wednesday, May 16, 2012

Huge LNG and Container Vessels Require Sturdier Port Furniture

Growth in Supertankers Means Investment Necessary
Shipping News Feature

UK – WORLDWIDE – Every sector of ocean freight has seen an explosion in larger vessels over the past few years with container vessels like Maersk’s Triple E series and the biggest LNG carriers in the world, the Q-Max series, so called as this is the maximum size which can be accommodated at Qatar’s gas export terminals. Such developments bring their own specific problems, not least the inability of other global ports to cope adequately with the extra drafts and sheer masses involved. For the Liquefied Natural Gas (LNG) sector, in particular, port downtime is an absolute premium, meaning that replacing outdated systems can be problematic.

A best practice example of industry working to pro-actively tackle potential issues is when Trelleborg Marine Systems was contracted by Volker Construction International to supply several docking, mooring and fendering products for the upgrade of jetty ten and the construction of a new jetty at the National Grid LNG terminal on the Isle of Grain, Great Britain. Trelleborg also worked with the main contractor, Chicago Bridge and Iron (CB&I) to supply monitoring instrumentation for the project.

The UK’s indigenous gas supplies are declining, and yet the UK is the second largest gas consumer in Europe and one of the fastest growing markets for gas imports. As such, the need for adequate infrastructure to support the import and storage of LNG in the UK is an important topic. National Grid Grain LNG is the first truly commercial LNG terminal in the UK. As one of four strategically located LNG sites, it plays a significant role in securing the UK’s gas supply. Isle of Grain is a prime example of a port that is cognisant of the demands of increasing vessel sizes, and is leading the way in pre-empting these needs.

The objective for the upgrade of jetties eight and ten at Isle of Grain was to enable the new breed of large LNG vessels to berth and discharge or load contents to and from the facility, thus improving the production rate at the plant. The terminal can now facilitate LNG carriers with a capacity of up to 266,000m³ and jetty eight is capable of accommodating the world’s largest LNG ships, even the Q-Max class vessel. The work carried out on these two jetties was part of a multi-million pound scheme to upgrade and expand the existing terminal and storage facility. The National Grid Isle of Grain terminal is a state-of-the-art port and as such required the highest quality of bespoke solutions.

The work on jetty ten involved the construction of a new deep water jetty into the River Medway, allowing LNG tankers to dock and unload. This jetty consists of a long approach trestle for the maintenance roadway and the LNG pipelines, from the shallow areas, to deep water. Also required was a jetty platform for the unloading of the liquid gas and eight dolphin piles of 3.5 metres in diameter for berthing and mooring – these dolphin piles were required with a length of up to 45 metres, and weigh up to 140 tonnes each.

The work on jetty eight included the demolition of the existing jetty and the design and construction of a replacement, including the approach trestles, jetty head and the mooring and breasting dolphins. The design and build of this jetty is similar to that of jetty ten, but with some improvements. It consists of an approach trestle for the maintenance roadway and LNG pipelines, a platform for the unloading of the LNG, both jetties were also connected by a steel walkway. Commenting on his firms involvement Richard Hepworth, Managing director of Trelleborg Marine Systems, said:

“Vessel sizes have been on the increase since the 1970s but some ports have been slow to upgrade their infrastructure. Despite this, we’ve seen a definite increase in enquiries and orders for the new breed of ‘super-sized’ fenders designed to tackle greater load-bearing requirements, the principle of ‘bigger fenders for bigger ships’ certainly rings true.”

Besides supplying a range of Quick Release Hooks, SmartHook load monitoring systems, SmartDock Docking Aid Systems and a Central Integrated Monitoring System, Trelleborg also supplied five SCN 2000 super cone fenders. Bigger vessels require these premium and more integrated solutions to ensure that ports can operate safely and efficiently. This project demonstrates how fenders, hooks and monitoring systems can be used together to produce these benefits.

The SCN 2000 super cone fender is the largest model that Trelleborg offer with a height of 2.0 metres. Super cone fenders are renowned for their excellent energy capacity and low reaction force. The combination of these two factors gives the most efficient performance of any fender type. The conical shape means it maintains stability under all combinations of axial, shear and angular loading. Super cone fenders are ideal for berths where heavy impacts need to be accommodated – and to support the vessel sizes expected at Isle of Grain, the largest examples were required.

Photo: The giant LNG carrier Al Hamla used to carry gas from Qatar to the UK under construction at the Samsung Heavy Industries yard. Courtesy of Qatargas.