The Gothenburg Port Authority’s design creates a system that is secure, cost-efficient, and environmentally responsible for tankers docked at the Energy Terminal, says an article published in Riviera.
Hazardous environment
Together, the port and the Swedish Transport Agency, as well as other national and international ports, classification societies, and ports on the island of Donsö, have formed this alliance.
The objective is to establish a new international benchmark for shoreside power for tankers berthed in dangerous areas.
Flammable products
Gothenburg Port Authority production engineer at the Energy Terminal, Jörgen Wrennfors said, “The greatest challenge is to ensure tankers that are scheduled to be built are fitted with shoreside power connectors that adhere to a common standard applied at all ports.”
He added, “A further challenge is the constant risk of an explosion when the vessel is berthed at an energy terminal, as the combustible and flammable products being pumped could easily be ignited by a spark from the electrical equipment. These challenges have become an intrinsic part of our planning strategy.”
Shoreside power supply
It is nothing new to provide power to ships at the quayside.
The Stena Line ships at Majnabbe were given shoreside power in the 1980s, and ever since then, a vast array of utility supply facilities have been built all across the Port of Gothenburg.
The most recent instance is quay 712 at the Roro Terminal, where ships can now shut off their diesel engines while loading and unloading thanks to the installation of green electricity through cable.
Despite this, it has proven difficult to come up with a solution that will allow the Energy Terminal to provide the same shoreside power supply to future tankers.
Explosive atmosphere
When tankers are at sea, their classification specifies a power supply point can only be located aft of the bridge.
Vessel designers have used this as a starting point when designing new vessels fitted with shoreside power connectors.
“This classification does not apply when the tanker arrives at an energy terminal. In the majority of cases it is superseded by the port’s classification, which means the entire vessel is deemed to be an explosive atmosphere, including the aft,” said Mr Wrennfors.
Long cables required
The disadvantage of an aft power supply point is that a vessel’s length might vary greatly.
The quays are typically much shorter than the vessels, which are frequently longer than 150 metres.
The ports would have to construct connection cranes at the quayside to reach the connector if the power connector was located at the aft.
In addition, enormously lengthy cables would be necessary, and complex, pricey cranes would be needed to hoist the wires.
The Port of Gothenburg has used reverse thinking to solve this problem rather than requiring each port to adapt.
Optimal solution
Mr Wrennfors said, “The standard we are proposing puts the power connection point in the centre of the vessel and we are in the process of formulating a technical requirement specification for shipbuilders to implement this novel approach. As all tankers have their loading crane in the centre of the vessel, this would be the optimal solution for lifting the power cable on board. As a result, the length of the vessel would no longer be an issue and the direction in which it docks is irrelevant. We regard this as the best technical solution and it offers substantial cost savings at each berth.”
Volatile and highly combustible
Even if the location of the power connector is agreed, the fact remains power still needs to be supplied in an explosive atmosphere.
“Volatile and highly combustible gases are present during bunkering and the risk of sparks during connection is a dangerous combination. We have now resolved the problem by working with overpressure in the spaces where the cable is housed and connected. This solution will shut out any explosive gases, making the facility safe,” said Mr Wrennfors.
Underlying benefits
Work from home may have gone without a hitch, but convincing the global shipping industry to accept the underlying advantages of the new standard being promoted and choose the Port of Gothenburg solution is not that simple.
International standardisation
Bringing about a change in underlying assumptions is essential.
“It is vital major ports, oil companies, public authorities, and classification societies are included to ensure we have a new standard in place that everyone adheres to. A solution is currently being produced here at the Port of Gothenburg and we are leading by example. It is our hope this will be noted and incorporated into international standardisation procedures in the future,” said Mr Wrennfors.
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Source: Riviera
