Trelleborg technical sales manager Steve Ward explains the importance of standardisation in the large-scale STS link sector
Large-scale ship-to-shore (STS) link system connectors are so important because they link the emergency shut-down (ESD) systems on one side of a ship-to-shore connection to the other.
When the two systems are properly linked, the connectors ensure that – if an ESD is initiated on either side – a mutual shut down happens. Pumps and valves on both sides of the connection shut down in a controlled way to avoid damage to loading arm seals and other important and expensive infrastructure.
However, the large-scale STS market has been around for more than 40 years and development of link system connections during that time has largely been unregulated. Consequently, the market has several legacy link system connectors that are not necessarily compatible with each other, a big concern according to Trelleborg technical sales manager Steve Ward.
“The ISO 28460, unfortunately, didn’t come out until 2010, so you’ve got quite a few years of terminals doing their own terminal configurations and expecting the ships to be compatible with what they’ve got at the shore,” Mr Ward says. He also notes that regulation around STS link systems is slowly expanding around the globe, with SIGTTO publishing recommendations in 2009, and the International Organisation for Standardisation (ISO) publishing theirs the following year.
Unfortunately, this means that owners who order a system today realistically need to ensure that it is compatible with connectors developed decades ago.
“If you look at the Pyle, it’s been around since 1976,” says Mr Ward. “There are only two specialist suppliers of this connector in the world. It is 37 pins; it provides ESD, telephony, mooring load monitoring (MLM) data and it does offer some additional functionality for use with things like FSRUs.
“[In] 1983, a six-pin Miyaki Electric plug was introduced into the marketplace and basically, the ESD signals are put on one connector, and the telephony were either on a second connector or even a third connector. So most of the LNG carriers these days are fitted with three Miyaki connectors.”
SIGTTO developed a five-pin electric connector in 1986 in an attempt to standardise connections, but it was not widely adopted because it only offered ESD.
“Unfortunately, owners that order a system today realistically need to ensure that it is compatible with connectors developed decades ago”
As well as ESD signals, most connectors also offer clear lines of communication between operatives on either side of the STS transfer and provide a slow-speed data transfer on quick-release hook moorings. Mooring line tension data is gathered within the docking and mooring system, and the STS link system can monitor the load on the line and pass that information across the link to the visiting LNG vessel.
As such, the market resisted SIGTTO’s mid-1980s attempt to standardise and carried on down various development pathways for connectors.
In 1989, Sumitomo-Furikawa Electric introduced fibre-optics to STS connections, which Mr Ward says was a major milestone, as it offered ESD, telephony and MLM.
For large-scale LNG bunkering, Mr Ward says there are one or two choices of connector that will cover most of the globe.
“If you order a new system tomorrow, we would recommend you need Pyle (power control plugs) and Fibre. That would cover you, basically, but there are other connectors available. Pneumatic is still sometimes used; obviously, that is for ESD only and if you have ESD only, then ITT Cannon were often used for telecoms in southeast Asia. And if you went to Das Island (Abu Dhabi), you were expected to have anti-surge connectors. But basically, Pyle and Fibre are the more common,” he says.
Massive growth potential
The small-scale LNG-fuelled market has massive potential for growth, according to Mr Ward and this equates to what he describes as “bunkering for the masses”, a concept that requires far more standardisation.
It is important however, that such standardisation does not target the minimum requirements.
“We believe that minimum should not be accepted as the best,” says Mr Ward. “Emergency shutdown is this final safety catch-all and the LNG transfer should be a managed process, not a managed emergency,” he says.
The solution, for Mr Ward and Trelleborg, is digital: “If you have the digital fibre-optic system, the cargo officer can, at the press of a button, see all of the tank data on the other side of the transfer process; similarly, the chief engineer will see all of the tank data on the other side of the transfer process.”
This means better visibility and improved monitoring from both sides of the LNG transfer, resulting in greater efficiency and reducing the need for operators to be in constant verbal communication via walkie-talkies.
Mr Ward cites a Trelleborg case study involving Harvey Gulf International Marine, which was an early adopter of digital fibre-optic systems, using Trelleborg’s Universal Safety Link (USL) product on its offshore support vessels and at its Port Fourchon, Louisiana LNG bunkering facility on the US Gulf of Mexico. The project has provided valuable experience and Mr Ward characterises it as a great success.
Harvey Gulf International Marine was an early adopter of digital fibre-optic systems, via Trelleborg’s Universal Safety Link
He uses the early adopter case study to make his final points on the topic.
“The requirements have changed over the last few years and who knows how they are going to change in the next five or so years,” he says.
He cautions that new applications being developed are often large-scale, multi-connection systems that increase costs and may create further compatibility problems.
He also reiterates his concern that early attempts at creating bunkering standards are referencing outdated STS links and threaten a reversion back to what he calls the “lowest common or cheapest common” system, lacking a proper focus on safety or improving management processes.
“Whoever is involved in [setting new guidelines] needs to talk and learn from the early adopters and the long-term users,” Mr Ward says. “Basically, we are talking about the process of transferring LNG from one tank to another. There has to be some common data requirements. Standardisation of data formats, we believe, is possible.”