Foss adds autonomy system to final ASD-90 tugboat
Foss Maritime has added autonomous command and control technology to the fourth and final tugboat in its ASD-90 series.
Foss, a Saltchuk Marine subsidiary, installed Sea Machines’ SM300 system on the 100-foot Rachael Allen. It is the first autonomous z-drive tugboat in the United States, although as of early May the company is still awaiting Coast Guard approval to operate the system.
Nichols Brothers Boat Builders delivered the tug in July 2021 based on the Valor-class design developed years ago by Jensen Maritime Consultants, now Crowley Engineering Services. Rachael Allen shares characteristics with the three other tugs in the series, from the twin 3,366-hp MTU Tier 4 engines to the Kongsberg/Rolls-Royce z-drives to the 92 tons of bollard pull. The SM300 autonomous system, however, sets it apart.
“It’s going to be a pretty neat system,” Dan Cole, a senior project manager for Foss, said of the autonomy package. “We are looking for efficiencies in operations where we have things that are repeatable or add a layer of safety to our transits. It offers enhanced situational awareness.”
“One thing people get scared about when they hear about autonomous systems is they think nobody is paying attention when the boat is driving itself,” Cole said, emphasizing that a crewman will be monitoring and overseeing the tugboat when it’s operating in autonomous modes.
Sea Machines’ SM300 gathers data from sensors, propulsion, steering and numerous other onboard systems, then feeds it into a powerful software and computing system. The technology can interpret the data to understand what is happening on and around the vessel. Based on that understanding, it can make decisions and take action that improves operational safety, according to Sea Machines, which is based in Boston.
Using parameters set by the human operator, the system can steer a vessel, just like an autopilot. It can proactively avoid collisions with rogue recreational craft or obstacles that might exist along a set path. Other features also reduce heave, pitch or roll based on limits set by the operator.
Remote operations are possible with an SM300 system, and Sea Machines has run multiple demonstrations around the world. Last fall, the company completed a 1,000-mile voyage around Denmark using a vessel steered almost entirely by licensed captains in Boston. Foss does not intend to remotely operate Rachael Allen initially, although it expects to do so in the future pending Coast Guard approval.
In addition to steering the tug between points and collision avoidance, the SM300 has a loitering mode that functions much like a virtual anchor. The operator can set parameters and the tug will stay within a certain area, just like it would with a traditional anchor.
“The integration with MTU engines and Rolls Royce-Kongsberg azimuth thrusters marks a first for Sea Machines,” said Philip Bourque, the company’s senior director of global sales. The SM300 will control steering and propulsion by interfacing with the existing azimuth drive control system, similar to an additional helm station.
Some operators, and a good share of mariners, see autonomous technology as a way to lower operating costs by reducing crewmembers. Foss does not intend to change manning on Rachael Allen. It will operate with the same three- to four-person crew as its three sister tugs.
“Foss is leveraging Sea Machines’ cutting-edge technology to take on the routine work and allow crew to focus on higher-level tasks and improve safety, while also increasing productivity and efficiency,” Will Roberts, Foss’ president and CEO, said last year.
As of late April, Foss had not yet used the SM300 system during commercial towing operations. The Coast Guard is still reviewing the company’s plans for use of the autonomous system. The service has no specific regulations in place for such systems on U.S. commercial vessels. It reviews proposed uses on a case-by-case basis.
Nichols Brothers delivered the four ASD-90 tugboats about 15 months apart. Jamie Ann, the lead boat, left the yard in late spring 2019 followed by Sarah Avrick, Leisa Florence and Rachael Allen, respectively. Sarah Avrick initially joined the AmNav fleet in San Francisco but is currently under charter with Signet Maritime. Foss and AmNav are sister companies under Saltchuk, which is based in Seattle.
“The ASD-90 newbuild program … will meet the current and future needs of the largest vessels of our customers calling on California ports,” Roberts said. “The tugs were built to satisfy the requirements we believe will soon be required of the rest of the country and the world.”
Construction on the ASD-90 series coincided with the arrival of Covid-19, which hit the Seattle region early and hard. Nichols Brothers and other shipyards shuffled production lines and took other steps to keep staff from catching the virus at work.
“While it certainly had a significant impact on production,” Nichols Brothers CEO Gavin Higgins said, “we were able to keep working and never had a cross infection at any of the facilities.
“Foss was an incredible team player with encouragement toward the safety of our people and operations” he continued. “I am very proud of the way our employees responded to the pandemic and their commitment as essential workers.”
Rachael Allen is named for a daughter of Saltchuk founding shareholder Len Shapiro. Since it left Nichols Brothers’ shipyard, the vessel has escorted and assisted tankers and containerships calling on ports around San Francisco Bay.
The two lead tugs in the series are equipped with a versatile winch package that allows for escort, ship assist and offshore rescue towing. This kind of versatility is possible through the 75-hp Markey Machinery hawser winch on the bow and the double-drum Markey towing winch installed on the aft deck.
The second two tugboats in the series, including Rachael Allen, swap the double-drum towing winch used primarily for emergency towing for a smaller Markey single-drum unit suited for handling barges. The hawser winches on all four tugs are spooled with 525 feet of Cortland Plasma line.
Propulsion across the four tugs consists of the two MTU engines supplied by Pacific Power Group of Vancouver, Wash. The mains drive Kongsberg US 255 z-drives through Vulkan carbon fiber shafts. Each main is paired with a selective catalytic reduction (SCR) system that reduces nitrogen oxides and particulate matter to meet EPA Tier 4 emissions standards.
Rachael Allen’s electrical power comes from three generators. Two 120-kW John Deere units supply power during normal operations. The third is a 65-kW harbor genset that is completely encapsulated in a sound-deadening enclosure. MER Equipment supplied all three gensets under its Bollard brand.
The spacious engine room with a very high ceiling is a common trait across Valor-class tugs, which are used by multiple West Coast operators, including Crowley and Baydelta Maritime. The engine space aboard Rachael Allen is protected by an FM-200 fixed fire suppression system supplied by Hiller.
Rachael Allen has a galley, mess, full head and staterooms for the captain and engineer on the main deck. Two other cabins are located below deck in the bow. Insulation helps reduce engine noise and vibration within the crew spaces. The engine mounts and SCR unit themselves dampen sound that travels to the crew spaces. The engines also have MTU Go, an engine and alarm monitoring system that lets personnel track parameters remotely through a dedicated mobile app.
The wheelhouse is equipped with top-end Furuno radar and AIS systems and a Rose Point navigation system. Communication between pilots and other vessels happens primarily through Icom VHF radios. Iridium satellite communications also are standard throughout the ASD-90 series.
The Sea Machines SM300 hardware is installed on the tugboat within its communications closet. The system itself is roughly the size of a dorm-room mini-fridge. Although it has remote access capability, allowing shoreside personnel to control the vessel from afar, Foss captains and mates will control the vessel from the tug using a dedicated laptop. The vessel also can be operated from a mobile “belt pack” steering system.
“The command is always by a human,” Michael G. Johnson, Sea Machines’ founder, told Professional Mariner last fall. “Whether that is a mate, a captain, or a helmsman, that person is in command.”