Integrating the laser – Docking made easier with advanced systems engineering

With containerships getting ever bigger, ports should perhaps be looking to improve docking systems in much the same way as oil and gas terminals have.

“You damage a fender and it?s OK, but damage two fenders and that?s the cost of paying for the [docking] system. If you end up not being able to use the berth, the system looks very cheap,” says Simon Wilson, sales and marketing manager for Harbour & Marine Engineering Pty.

The company specialises in docking, mooring and monitoring systems: “We design and manufacture both the mechanical and the instrumentation software elements and then integrate other people?s equipment, such as the environmental sensors,” explains Wilson.

The future is laser

Most modern oil and oil product jetties, and chemical jetties have at least quick release hooks and capstans and the newer ones are equipped with monitoring and remote release. He says: “All of the recent LNG projects have fully integrated systems. I know that because we have done most of them.” The specifications requested include quick release hooks, capstans, a load monitoring docking system and environmental as a package, as well as integrating the ship to shore system with the package. This can also include load-monitoring data.

Radar systems are no longer used for measuring vessel approach, says Wilson: “The docking system originally worked on ultrasonics but, being water based, there were problems with fouling so the technology moved to radar. The biggest problem with radar is that it has to be sight configured as it?s not a focused sensing device and it picks up a lot of backscatter and erroneous feedback. You have to filter that out with software. So, while it?s possible to set a site up initially, if something on that site changes ? for example a crane is installed ? that could change the accuracy of the system requiring a software upgrade.”

In recent years there has been a steady increase towards laser sensors and all systems installed during the past three years, to the company?s knowledge, have been of this type. “We refuse to sell radar systems as they can be more trouble than they are worth,” says Wilson.

The company gets a lot of enquiries for laser based systems as part of an integrated package and last month budget quotations were put out for at least half a dozen LNG projects, all of which had the docking systems. Wilson told The Motor Ship: “This tends to be mostly aimed towards the oil and gas facilities but there are a couple of docking systems that are used for container terminals.”

There are quick release hooks thatare occasionally used for non-oil and gas purposes, but because those harbours tend to be relatively benign as they are inner harbour-type locations, the need for a more sophisticated level of mooring and monitoring equipment system is generally not called for.

He adds: “There might be a gradual change with containerisation because the larger vessels are going to become more difficult to handle. Containers work on turnaround time, so optimising this, a docking system allows you to accurately control the speed of approach and therefore the time of the vessel in landing it safely against the fenders, offloading the containers and sending it away again.”

Box of tools

Wilson was recently in India talking to the equivalent of the general manager of JNPT (Jawaharlal Nehru Port Trust) in Mumbai ? the large container port. He said: “With these large container vessels you can?t actually see the side of the dock once up close. So, anything that gives him better information is useful. Rather than taking anything away from the pilot, this adds to their ?box of tools? in bringing the vessel in safely and efficiently.”

The pilot has access to a large display board that is situated on the jetty and typically shows the bow and stern distance and speed. There are also traffic-type lights to show whether he is coming in at the right speed. “We also supply a pager-type device that shows the same information plus angle, which is intrinsically safe for use out on the bridge wing or a gas jetty,” says Wilson. The same information can be supplied on a laptop computer, though the handheld version can be less bulky and easier to use.

“There are three pages of information ? the docking information is on page one and page two would typically have feedback of the environmental information – so the pilot would be able to see the wind, wave conditions, wave period, wave height and current pattern information at the jetty,” he says. The company often also incorporates load monitoring, so once the vessel is alongside and tied up, the harbourmaster or mooring crew can have access to this information on a pager rather than having to constantly look at what is going on.

Integrating the system into the ship?s own systems revolves around two issues. That of compatibility, though Wilson says that it is possible to provide the information over the Internet to the vessel. He also believes there is an accessibility issue for the pilot but says that, perhaps, the main issue is that of ownership of the data: “The data is used by the terminal facility to safeguard its interests, rather than the interests of the vessel. It?s trying to make sure the vessel docks at the correct speed and doesn?t come in too fast, causing damage to fenders or the structure.”

Damage

He continues: “If a vessel comes in too hard and causes damage, there is a clear set of data ? the docking data logs at one second intervals ? that clearly show mooring operators what happened, and this can be corroborated by the pilot to avoid argument. It?s a very clear case on the vessel?s P&I, so the real issue is the ownership, which is also the feedback I have had from Shell.”

The company is looking to enhance the system, particularly in the approach of the vessel. At present, the docking system measures from 300m, which is limited by how far away the display board can be seen ? the laser will measure 700-800m. However, vessels will not realistically start lining up at that distance, says Wilson. “We are looking at DGPS systems to provide an additional level of information during the vessel?s general approach,” he explains.

He says that the company is looking to reference the vessel?s position against the available electronic chart, but still use the laser system because of its reliability and high accuracy, as well as the fact that it actually sits on the jetty, so fulfilling the ownership issue.

This requires an interface so that when a vessel comes within range of the laser, the docking information will swap from the DGPS-based system to a laser-based system, which could be interfaced back onto the electronic chart if the vessel required it.

Wilson told The Motor Ship: “We?re not looking to get into electronic charts business, what we?re trying to do is use our experience on the near shore vessel positioning and docking and integrate that into a workable common system.”

There are a couple of other areas that extend the instrumentation at the jetty but, at the time of writing, Wilson was unwilling to talk about them for commercial reasons. Though he did hint that new development would soon be revealed, saying: “Watch this space.”