McAllister and Jensen refine an older design to produce an impressive new boat
Buckley McAllister, a 5,150-hp, 96-foot z-drive tug built by Senesco in Rhode Island for McAllister Towing & Transportation, is the 18th member of a class of boats designed by Jensen Maritime. But that doesn’t mean Buckley McAllister is just another copy of a tried-and-true model.
McAllister and Jensen have modified the 13-year-old design in a multitude of mostly small ways to produce a boat that is safe, quiet, comfortable, durable, efficient and well suited to its mission. Or in the words of Richard Dougherty, Senesco’s project manager for the construction of Buckley McAllister: “We’ve turned a nice boat into a real good boat.”
As Martin Costa, McAllister’s engineering manager, explained, “The vessel is purpose-built for escort and rescue work.” A multi-functional boat, it is equipped with a hawser winch for escorting and a towing winch with tow pins for rescue work. Also designed for firefighting, it is rated FiFi-1. “Crew comfort (was) not compromised for the mission design,” he said.
The Smith Berger towing pins.
Perhaps the most significant change in the design was requested by McAllister for safety reasons. In the earlier versions of the class, water had a tendency to pool against the deckhouse near the stacks. The solution was to create some camber in the main deck so that water would run off rather than collect.
Sean Testa, Jensen’s project manager for the Buckley McAllister design revisions, explained that five inches of height were added to the main deck along the centerline. As a result, the deck now slopes gently away from the centerline to the point where the deck meets the hull.
Figuring out how to execute this change was “a bit of a head scratcher,” Testa said. One problem was how to attach the deckhouse to the reconfigured main deck. In the end it was decided that the bottom of the deckhouse would rest on the high point, the centerline, while the sides would be lengthened so they met the sloping deck properly.
Rod Smith photo
The tug after launch at Senesco.
As a result of the change, the floor of the wheelhouse sits 5 inches higher than it did in the earlier boats, giving the navigation crew the benefit of a slightly greater height of eye. The change also produced a bit more headroom along the centerline in the drive space below the main deck. The creation of the deck camber represents “one of the more important changes for safety,” said Costa, because it means Buckley McAllister will have “a dry deck instead of a wet, slippery deck.”
Buckley McAllister also has a roomier engine room than its immediate predecessors in the Jensen Super 96 class. Rosemary McAllister and Andrew McAllister are 6,000-hp tugs with twin EMD diesels. The engines on Buckley McAllister are smaller — twin Cat 3516CHD Tier 3 diesels generating a total of 5,150 hp.
The tug has an extensive array of fendering: Shibata, upper bow; Viking soft-loop, lower bow; Viking laminate, chine and stem; two rows of extruded D-fenders, port and starboard, with airplane tires over them.
Its firefighting system, while more powerful than its predecessors, is more compact. Buckley has a single firefighting pump with a capacity of nearly 12,000 gallons per minute. Earlier tugs had two fire pumps with a total capacity of 11,000 gpm.
McAllister used the additional space to create a control room for the engineer. This space provides a clean, quiet, climate-controlled room where the engineer can sit with a laptop and plug into monitoring systems to check on the performance of every piece of equipment.
The control room also illustrates the extent to which McAllister and Jensen have gone to reduce noise and vibration through the boat. Its shared bulkhead with the engine room is sheathed with three inches of mineral wool, a layer of lead and an outer layer of one and a half inches of mineral wool with a faced outer surface that can be painted. In fact, all the bulkheads separating the engine room from the other work and living spaces are sheathed in these materials.
“This stuff is great,” Dougherty said of the faced mineral wool. “You cover it over with latex paint.” The insulation allows the control room to be a quiet space despite its proximity to the engine room. “It’s perfect because it is just quiet,” Dougherty said.
And the control room itself helps to keep down sound levels in the adjoining living space. “It’s another barrier between the engine room and the state room,” Costa said.
Rated FiFi-1, the tug has two FFS dual-flow fire monitors.
Even paint is used to keep down noise, as well as humidity from condensation. The paint, Mascoat Marine DTM — a composite ceramic coating — has both sound and heat insulating qualities. The thermal qualities of the paint help to prevent the sweating that occurs where cold steel meets moist air. The paint is used on the overhead in the engine room and on all steel in the living spaces.
In addition to conducting cold, steel also is a good conductor of sound. “Vibration from equipment permeates through steel,” Dougherty observed.
The Mascoat paint helps to reduce that transmission of noise and vibration. In addition, the main engines and diesel generators are all soft-mounted to isolate vibration.
The heating and cooling systems have also been designed to minimize noise. The heart of the system comprises two 4-ton Mitsubishi heat pumps located at the rear of the deckhouse. This system eliminates the noise of large volumes of air moving through ducts. It also means that all the spaces except the engine room (which has its own oil-fired hot-water heating system) have individual fans and temperature controls. The intent is to improve crew comfort, resulting in better rest and less fatigue. The system is effective for temperatures from 20° below to 120° Fahrenheit.
“It’s almost like a whisper,” Costa said of the sounds made by the system.
“This boat’s going to be extremely quiet,” Costa said. “A lot of thought went into it.”
A 1,300-hp CAT C32 Tier 3 engine provides power to the 11,967-gpm fire pump.
Buckley McAllister’s primary mission will be to escort tugs and barges transporting oil across Buzzards Bay and through the Cape Cod Canal in Massachusetts. In April 2003 an oil barge being towed across Buzzards Bay strayed from its route and struck a rock, resulting in a spill of No. 6 fuel oil. In response to the accident, tugs and oil barges on this route must have an escort.
“The whole thing,” Costa said of Buckley McAllister’s design, “was set up for Buzzards Bay escort.”
The new tug is outfitted with a JonRie hawser winch and a JonRie towing winch, along with Smith Berger hydraulic tow pins. The towing winch and towing pins both represent additions to the Jensen design.
The idea is that if an oil barge were to break loose from its tow, Buckley McAllister could quickly hook up to the barge and tow it away from trouble.
The boat’s mission also helps to explain the extent of the fendering and firefighting gear. The fendering includes Viking laminate on the chine and stem; two rows of D-fenders, plus airplane tires, both port and starboard; Shibata upper bow fenders; and Viking soft-loop fenders on the lower bow.
“We put a lot of thought into what could possibly occur,” Costa said, noting that the fendering extends half way down the hull and would allow the tug to approach an oil barge with very low freeboard.
The bow winch is a JonRie Series 250 single-drum hydraulic winch with a line pull of 90 tons. (The tug is expected to have a bollard pull of about 70 tons.) The winch features active heave compensation and constant tension capability.
The hydraulic towing winch is a JonRie Series 512 with a line pull of 67.5 tons and braking force of 142.5 tons. Both the towing winch and the hawser winch have a 30-hp electrical backup unit that would allow the boat to retrieve the line slowly in the event of the loss of hydraulic power.
The hawser winch is a hands-free design pioneered by JonRie. The hands-free feature can be of special value to the operator of a tractor tug, according to JonRie President Brandon Durar. The operator of a twin-drive tractor tug needs to keep a hand on each of the thruster controls, but with hands-free controls for the winch, he said, one person can easily run the winch and the tug using the winch’s foot-pedal control. When the operator pushes down with the toe, the line pays out. When the operator pushes with the heel, the line hauls in.
The tug is propelled by twin Schottel SRP1215 z-drives producing a bollard pull of 66.5 tons. Power comes from two Cat 3516CHD Tier 3 diesels generating a total of 5,150 hp through Lufkin gears.
“If (the captain) doesn’t want to get anybody out of bed, he can run the winch himself,” Durar said.
The winches also have conventional controls. “We still give them a joystick,” Durar said.
The relative simplicity of the JonRie designs makes them durable and reliable, Durar said. For example, his winches don’t have gearboxes. As a result, one revolution of the motor produces one revolution of the drum.
“I need to put it (the winch) on the boat and walk away from it,” he said. “It takes a licking and it keeps on ticking.”
The propulsion system also exhibits some relatively small yet significant changes. The high-speed Cat diesels have been paired with low-speed drive units and carbon fiber drive shafts, creating what Costa said will be a more dependable and efficient package.
This arrangement allows the elimination of articulated shafts in the drive lines, thereby reducing shaft vibration. The Cat engines will be fuel efficient in ship docking service and the low-speed drives will be more reliable, according to Costa.
Each z-drive will also have an electric-powered steering pump that can be used to steer the boat if the primary system fails. “Each unit has its own backup steering,” Costa said. This too is an innovation on the McAllister 96-footers.
The boat has a host of other small touches designed to enhance crew comfort and safe operations, right down to the color of the paint in the wheelhouse. “Everything in this wheelhouse is going to be black, non-glare,” Costa said. “With so many screens up here, you want to keep the glare down.”
The boat is named after Brian Buckley McAllister, who became president of the New York-based tugboat company in February 2013. Representing the fifth generation of McAllisters to lead the company since its founding in 1864, Buckley succeeds his father, Capt. Brian A. McAllister.
Senesco is also building the 19th boat in the Jensen 96-footer series, Eric McAllister, which is due for delivery in October.
While each of the changes made to the design for Buckley McAllister may seem small when viewed alone, together they create a boat that aspires to be a considerable improvement over its predecessors.
“This is going to be the pride of their fleet when we get done,” Dougherty said.