Managing Shipboard Power: Lessons in Load Shedding
by Lyman-Morse Boatbuilding 3 Jun 2019 01:01 PDT
Managing Shipboard Power © Lyman-Morse Boatbuilding
Toby Teele and Damien Kent design and build the brains and nervous systems for boats. They are Lyman-Morse's masters of the suddenly ubiquitous emerging technology in marine engineering called process logic controllers, or PLCs.
"A PLC is just a fancy word for being able to control anything, remotely," says Toby.
He and Damien work out of an office, cum supply room filled with control modules, circuit diagrams and parts catalogues on the second floor of Building 11, at Lyman-Morse's main campus in Thomaston. The two spend part of their day fielding questions from captains, mechanics, managers, and owners about how PLC systems can make a boat smarter. The rest of the time, they design and supervise the installation of systems in both sail and power boats.
"If you wanted to open that door with a press of a button, we can tell you all the rams, hydraulics, and optical sensors needed," says Toby. "If you have any kind of mechanical system, we can automate it."
Toby spent six years managing the production logic for a food automation company in central Florida. Damien has a degree in IT administration and learned his way around process logic control from hands-on work at Lyman-Morse. Both played a central role, back in 2010, in bringing the technology to the firm's first major PLC project: a 48-foot S&S daysailer called Aileen. And these days, both are deep in designing the process logic control tools in a massive refit of a Swan 100.
"We just kept bringing the idea of PLCs up because we knew they were the future," says Toby. "Now they play a major role in many of the jobs here."
What gets both Toby and Damien excited is explaining the bright prospects for PLCs, as costs drop and newer options from the technology flow into marine engineering. One of the more compelling new tools for lower-cost process logic marine control is CZone, a fast-growing New Zealand-based marine control company. While its line of monitoring and automation tools are nowhere near as powerful as the bespoke PLC systems Toby and Damien install, a CZone system can automate the basic systems for many boats, like hydraulics, power management, and ventilation.
"We just retrofitted one for a boat," says Damien. "It's not as flexible as a custom PLC system; but it brings most of the important features and it's much cheaper."
But they also have bigger ideas for low-cost PLCs. The most appealing is installing simple, so-called current transformers on the electrical lines that power the main systems in a boat, like air conditioning, hot water, electrical appliances, and deep-charging battery systems.
Such current transformers, or CT's as they are often called, can cost as little as a few hundred dollars and can be installed with simple screws and wiring. Smartly installed current transformers could offer powerful benefits similar to process logic controllers. CTs could sense and report the actual current flowing around a boat; and just like more complex PLC systems, pass that critical data to a low-cost display, alarm system or automatic cut-off switch.
"The average boat we see in the 55- to 60-foot range has become a city of technologies," says Toby. "They don't just have one fridge, they have three. All that complexity requires ever bigger generators and circuits."
In theory, a well-designed CT monitoring system that they propose would offer a low-cost means of easily rationing a boat's power. The secret is by simply tracking and then turning off unwanted capabilities. So, similar to how a well-managed smartphone turns off unwanted apps to extend battery life, if a boat is under sail with no need for climate control, the CT relay could signal the crew that it's time to turn off or shed the load of the air conditioning or heating.
Real-world applications could be more complex, since every individual boat has its own uses and power needs both say, but a simple, well-managed load-shedding system made with current transformers could be very affordably installed. "If you do it right, a CT system would allow you to install a much smaller generator that lasts twice as long and is far lighter and needs less fuel," says Toby.
"We could do that for pretty much every boat we touch here," says Toby. "And who wouldn't love that?"