Perhaps not surprisingly, one of the first EPA Tier 4 emissions-compliant tugboats is destined for California, a state where residents and regulators are passionate about clean air.
JT Marine in Vancouver, Wash., is building the 110-foot Caden Foss, named after Caden Hansen, a great-great-grandson of company founders Andrew and Thea Foss. Foss Maritime has chartered the 6,772-hp azimuth stern drive (ASD) vessel, owned by Vessel Chartering LLC, a subsidiary of Baydelta Navigation Ltd. Delivery is scheduled for late June 2017.
Caden Foss is a multipurpose tugboat designed and equipped for standby, ship-assist and escort assignments. It is also available for rescue towing. The vessel will work from Chevron Long Wharf in Richmond, Calif., for Foss client and energy giant Chevron.
“Chevron committed to put a Tier 4 tugboat into service as part of the Richmond Refinery Modernization Project approved by the city of Richmond in 2014, so that was the driver for us to look for a Tier 4 boat,” said Foss Chief Operating Officer Scott Merritt.
Caden Foss in March.
Foss worked to develop a tugboat design that could be built quickly and also meet Chevron’s specifications and deadlines. Within days of choosing a shipyard, Foss learned about the Tier 4 tug Vessel Chartering was building on spec at JT Marine.
Merritt said the vessel was similar to the one Foss designed but with several improvements. Given the good business history between Foss and Vessel Chartering, as well as the capabilities and delivery date of the spec vessel, Foss decided to charter it for three years with an option to buy.
“It gave us a little more comfort in the timeline, but also, in our minds, provided a little bit better platform for what we wanted to do. So it was kind of a win-win,” Merritt said.
Jensen Maritime Consultants and Vessel Chartering jointly designed Caden Foss, which is essentially a stretched version of Jensen’s proven 100-foot ASD tug. Initially, the tug will assist and escort tankers to and from San Francisco Bay refineries. Merritt is confident in the design.
Baydelta’s Vice President Peter Zwart (left) with company CEO Capt. Ron Charlesworth during a vessel tour this spring.
Increasing fuel capacity for ocean and rescue towing is a primary reason for stretching the hull. But the safer aft deck area for crew making up the tows is an added bonus. “By stretching it out 10 feet, you put the tow point in a better place as it relates to the propellers and steering, and it gives more afterdeck area for the crew to work on,” Merritt said.
As a standby and harbor tug, the additional length adds to the vessel’s overall comfort. Two captains, the engineer and AB have the luxury of their own stateroom. For ocean towing and rescue missions, Caden Foss can carry enough crew for three-man watches.
Finally, the extra 10 feet allows for a more direct shafting arrangement between the main engine and the ASD unit at the stern. It also creates additional space for the urea tank and selective catalytic reduction (SCR) system needed to meet Tier 4 emissions standards.
The SCR system injects a liquid reductant agent, usually automotive-grade urea known as diesel exhaust fluid (DEF), through a catalyst into the exhaust stream of a diesel engine. The DEF sets off a chemical reaction that converts nitrogen oxides into nitrogen, water and tiny amounts of carbon dioxide, and sends them up the vessel’s stacks.
The SCR modules, dosing pump, dosing cabinet and DEF tank can be configured in a number of ways, dependent on the available space. Richard Floyd, marine sales for Peterson Power Systems of San Leandro, Calif., said the units can be positioned in front of, in back of or above the main engines.
Baydelta CEO Ron Charlesworth examines the large skeg on Caden Foss, which will improve its escort abilities.
The SCR units are directly above the main engines on Caden Foss. JT Marine built the 4,600-gallon urea tank and located it aft of the main engines.
Designing the tug on spec presented Baydelta Navigation and Vessel Chartering with several questions. In particular, the company wondered where the tug would work and what mission it would perform.
The answer was to build a multipurpose tug capable of handling multiple assignments, said Peter Zwart, Baydelta’s vice president of operations and new construction. They started with the basics — ship-assist and escort duties — then looked for ways to make the tug more appealing to potential customers.
“Originally, not knowing yet where the tug would end up, we decided to also set her up for ocean towing,” Zwart said during a March inspection alongside Capt. Ron Charlesworth, CEO of Baydelta Navigation and Vessel Chartering.
Vessel Chartering has worked with Jensen Maritime Consultants since 2006, designing six Delta-class tugs built by Nichols Brothers Boat Builders of Whidbey Island, Wash. To better withstand heavy seas, Jensen raised the bow and pilothouse 4 feet. A watermaker also was installed to boost its long-range capabilities.
Rolls-Royce US 255 FP z-drive units awaiting installation.
“The main reason for stretching the boat from 100 to 110 feet was to get more fuel capacity for ocean towing,” Charlesworth said. “The 100-foot Delta-class tugs have 73,000 gallons of fuel capacity. This one has 123,000 gallons. We are getting 90 to 95 tons of bollard pull from the 100-foot Delta-class boats and we expect we’ll get the same from this one.”
Two Caterpillar 3516E Tier 4 diesel engines rated at 3,386 hp at 1,800 rpm provide propulsion. Carbon-fiber Centa shafts connect the mains to Rolls-Royce US 255 z-drives with fixed-pitch nibral propellers. Two Caterpillar 150-kW gensets and a Caterpillar 65-kW unit provide auxiliary power.
A massive shipyard-built staple on Caden Foss’ bow fronts a single-drum Markey Machinery DEPCF-52 electric hawser winch wound with 450 feet of Cortland 3-inch-diameter Plasma 12×12 rope and a 12×12 LoCo pendant.
This is the seventh Baydelta tug Markey has outfitted with a bow winch. This model is powered by a 75-hp electric motor and generates 30,800 pounds of line pull at 378 fpm. It features wheelhouse controls with on-deck emergency stop and freewheel pushbuttons, and has a digital/analog line tension display system.
The SCR aftertreatment system on Caden Foss is installed over the Caterpillar 3516E Tier 4 mains.
“This particular winch, with the latest Markey NexGen Controls and Markey Render/Recover, represents the best available technology for ship-assist and escort duty,” said Blaine Dempke, president of Seattle-based Markey Machinery. “We trust this winch will serve our customer well for decades to come.”
On the aft deck, Rapp Marine developed a double-drum electric towing winch wound with 2,500 feet of 2.5-inch wire. Both drums can spool 90 feet of 3-inch chain on top of the steel wire. Merritt said the ability to spool up to a shot of chain on the winch drum is a significant safety feature, especially during rescue towing.
“You don’t have to mess around with a bunch of chain on deck, probably the most dangerous interface when you’re making a connection to a tow and getting a wire up,” he said. “This will allow for a much safer operation on the afterdeck and more flexibility.”
Another feature of the Rapp winch is an electric “come home” drive, which will serve as a backup to the main drive train.
Johann Sigurjonsson, president of Rapp Marine US, said the winch is driven by a single 100-hp motor that can pull over 75 tons on the first layer. It utilizes pneumatic cylinders in place of hydraulics, keeping fluid off of the deck. The sturdy brakes offer a force of 250 tons on the barrel layer.
Caterpillar supplied the aftertreatment system and JT Marine built the 5,116-gallon urea tank.
The main winch controls, located in the wheelhouse, employ Rapp Marine’s PTS Pentagon Control System. The Pentagon system features a touch screen with tension and wire-length readouts, auto-tension capability and automated haul-in and pay-out settings, as well as capacity for logging data, with a secondary set at the winch. There is a second set of controls located at the winch. At the extreme stern of Caden Foss, Rapp supplied twin 14-inch tow pins.
“Working closely with Baydelta has resulted in developing an ideal tow winch for the market,” said Sigurjonsson. “We view this project as a big step forward.”
With new EPA and Coast Guard ballast water treatment requirements on the horizon, the tug was designed without ballast tanks, said Jensen Maritime Vice President Johan Sperling. This eliminates the need for ballast water discharge and the potential transfer of invasive species. In lieu of ballast tanks, the tug will transfer fuel as necessary to maintain proper trim.
“We are excited to get the boat,” Merritt said. “Caden Foss will be positioned in our San Francisco fleet and work within our pool of tugs in the Bay area, performing standby general ship-assist and tanker escort duties.”