The maritime industry as a whole is conservative to the point of anachronism — we still give a bottle of whiskey to the pilot who brings us safely into port.
But the offshore workboat industry, which is less than 100 years old and still establishing tradition, has proven itself eager to embrace innovation. So when a radical hull design and unconventional tankage offered a new company the chance to break through the “liquid-mud-to-deadweight-ratio” barriers, Jackson Offshore Operators LLC took it. The result is the striking offshore service vessel Breeze. Delivered in September to the New Orleans-based operator, the 252'×60' vessel is the first of four OSVs to be built for Jackson Offshore at BAE Systems Southeast Shipyard in Jacksonville, Fla.
“The Breeze is a mud boat,” said Jackson Offshore chief operating officer Matthew Rigdon. “We designed her around that mission. Of course, she’s a full-service supply vessel with capacity for bulk material, chemicals and deck cargo. But when we talked to Guido Perla and Associates [GPA, the designers], we stressed that we were looking for capacity of at least 10,000 barrels of 16-pound mud in no more than 4,000 deadweight tons. And that’s what we got.”
ENCLOSED BOW
Rigdon downplayed the vessel’s most striking feature — its enclosed bow. “We’re planning to use this bow on all of our future newbuilds, but it’s not a big deal. It’s just a matter of building the supporting structure strong enough to meet weather and sea conditions without adding too much weight.”
But the bow design is indeed striking. It rises up from the bulbous bow, flares out before reversing direction towards the wheelhouse and then wraps around behind it. “Generally the new real estate [for accommodations] and the enclosed foredeck was the primary motivation” for the GPA 675J design, said Stefan Wolczko of GPA. The Breeze is currently the largest GPA-designed offshore service vessel operating in the U.S. Gulf of Mexico.
The enclosed bow creates a dry working compartment forward for the deckhands with no change to the hull needed. “We had sufficient stability and buoyancy in a traditional underbody,” Rigdon added, “and with the protection against water breaking over the bow, it was an easy choice.”
Another easy choice was the mating of diesel-electric propulsion to two Rolls-Royce AZP 100 Azipull propulsion thrusters aft. “Those Azipulls are the wave of the future,” Rigdon said. “They’re a natural outgrowth of the azimuthing thruster design. With an Azipull, the propeller is upstream of the strut rather than downstream, as in a conventional design. This gives the propeller clean water to bite into with a real increase in efficiency. And there’s no difference in the stresses on the strut whether the propeller is ahead or behind it.”
According to Rigdon, tank testing showed an increase in efficiency of up to 20% over traditional azimuthing thrusters.
The Breeze’s first mate, William Martinez, confirmed the handling advantages. “Cleaning up the waterflow to the propellers makes a real difference in handling. The autopilot and DP system don’t work nearly as hard because you don’t have those small side loads. The whole system just reacts quicker.”
Rigdon pointed out that using conventional drives in DP mode is soon going to be a thing of the past. “Constantly clutching in and out, trying to get enough flow over the rudders for stern control … with advances in generating efficiency and thruster design, that makes no sense.”
To meet its DP-2 designation, the Breeze is fitted with two Rolls-Royce 2000 DPN tunnel thrusters forward, each developing 1,250 hp. All four thrusters are controlled by a Rolls-Royce Icon DP system from the forward and aft bridge control stations. The massive generating power needed for propulsion, stationkeeping, and house load comes from four main generators and an emergency generator, all housed on the main deck and producing 6,220 kW (8,341 hp) of total power.
“That’s the beauty of diesel-electric,” Rigdon said. “We’ll never build a conventional-drive vessel again. To get 10,752 barrels of mud in a 252-foot boat, we had to think outside the box, and putting the machinery down in the bottom of the box doesn’t make sense anymore.”
The same reserve stability that allowed an enclosed foredeck also allowed the insertion of a machinery deck at the main level, and having the entire bottom of the boat filled with 10,000 barrels of 16-pound mud also adds to the vessel’s stability.
“Putting it [the engine room] up forward and above the tank farm you are really maximizing the amount of space you have below for a full tank farm,” said Wolczko.
ONE-STOP PROPULSION
The Rolls-Royce engine-and-control package allows the bridge and the machinery control room to operate the engines remotely, but it also allows Rolls-Royce technicians ashore to monitor and even control the system from its head office.
“We were having a problem with the engines,” said Ken Dawson, Jackson Offshore’s vice-president of operations, “and the engineers onboard were having trouble figuring it out. Well, the engines’ computer modules are connected to the bridge computers by wireless router, and the boat’s computers can talk to the Rolls-Royce computers, so we hooked their office engineers directly up to the engines. They fixed the problem.”
Working in unison or individually, the two Caterpillar 3516C main generators, producing 2,100 kW each, and the two Caterpillar C32 main generators, producing 910 kW each, power the Azipulls and tunnel thrusters through the Rolls-Royce control system. If needed, the Caterpillar C9 emergency generator, producing 203 kW and standing by for an automatic switch-over, can pick up the house load and even maintain DP in moderate seas. With all four main generators online, the boat can hit 14 knots.
Rigdon was emphatic about the advantages of contracting with Rolls-Royce to install the entire propulsion package. “A single vendor simplifies everything,” he said. “No more cross-finger-pointing. Caterpillar only had to install the engines and supply power to the thrusters. Then Rolls-Royce took over and finished the job. Any questions we had, a single phone call got results. That’s the way we’re going to build all of these boats.”
Another innovative approach involved the machinery-spaces fire-suppression system, traditionally supplied by a CO2 smothering system with inherent asphyxiation dangers. “We designed a water-mist system,” Dawson said. “The peace of mind is great. No more worries about activating the [CO2] system and killing somebody.”
The innovations and refinements found throughout the boat show the close cooperation between Jackson Offshore, the designers and BAE. Typical is a custom-designed air-dryer system for the vessel-wide pneumatic control system to reduce corrosion of system components. “Oh, yeah, it works,” laughed the vessel’s first engineer, Yohanan Abdul-Shakir. “Five days out of the shipyard, the reservoir was full of water that it sucked out of the system.”
Another small but typical feature is the design of the watertight-door closing mechanism. Single-wheel mechanisms often become difficult to operate when the door goes slightly out of adjustment, and even when new require some effort to force the dogs into their clips. However, the stainless-steel assemblies on the Breeze’s watertight doors have roller bearings on the dogs, so the doors close with just some finger-pressure.
Forethought also shows in the mud delivery system. With the capacity to pump 1,660 gals. of 16-lb. mud per hour with its two pumps to a maximum height of 250', the system has tank segregations to handle two different mud products. Flyte agitators in the tanks keep the mud mixed and the solids in suspension during the voyage.
Matt’s father Larry advises the company and explained the advantages of the design’s round tanks at an OSV conference in Houston in September: “Circular mud tanks can deliver the product with less loss of weight from settlement and reduce the time and cost of reconstituting the muds on the rig,” he said in his presentation, “and the cost and time to clean are significantly less.” Rigdon added that the tanks slightly reduce the cubic volume that can be designed into a hull but the small loss of cubic capacity “is well worth the cost reductions they offer to our customers.”
In keeping with its full-service role, the design can pump 2,130 bbls. of methanol at 440 gph to a maximum height of 250'. It has 10,200 cu. ft. of dry bulk material capacity with separation into two systems to allow the vessel to carry two different types of bulk material, each with an 80 psi discharge system.
“Oil companies are getting smart,” concluded Matt Rigdon. “They don’t just look at total liquid mud volume any more. Especially in the far-offshore oilfield, they want to know that the boat can carry everything the rig needs with its tanks full of 16-pound mud, and do it with cost and fuel efficiency. And that’s what the Breeze was built to do.”
BREEZE SPECIFICATIONS
Builder: BAE Systems
Designer: Guido Perla & Associates
Owner: Jackson Offshore Operators
Mission: Oilfield service vessel
Length: 252'Beam: 60'
Depth (Molded): 25.7'Draft: 12' (light)
Deadweight Tonnage: 4,040 LT (at operating draft)
Main Propulsion: (2) Caterpillar 3516C diesel engine, 2,100 kW (2,815 hp) @ 1,800 rpm; (2) Caterpillar C32 diesel engine, 910 kW (1,220 hp) @ 1,800 rpm
Z-Drive: (2) Rolls-Royce AZP 100 Azipull azimuthing stern thruster
Thrusters/Thruster Engines: (2) Rolls-Royce 2000 DPN bow tunnel thruster, 1,250 hp
Controls: Rolls-Royce Icon integrated navigation/machinery control system
Speed (knots): 14 (max.), 12 (service)
Hull Construction: Steel
Cargo Deck: 157.5'x49.5'; 1,476 LT capacity
Crew/Passenger Capacity: 34 in 14 two-person cabins and 6 four-person cabins
Capacities: 253,577 gals. fuel; 468,826 gals. rig water; 10,752 bbls. liquid mud; 2,130 bbls. methanol; 119,184 gals. potable water (cargo); 47,207 gals. potable water (ship’s water); 10,200 cu. ft. dry bulk material
Electronics: Furuno X- and S-band radar with ARPA, gyrocompass, autopilot, depth sounder, speed log, GMDSS station, VHF transceivers, weatherfax, Navtex, and PA/loudhailer
Ancillary Equipment/Systems: Vessel-wide pneumatic system with air dryer; (2) deck fire monitor at 5,280 gpm; water mist fire smothering system; two separate systems for bulk material and liquid mud
Classification/Certification: ABS +A1 Offshore Support Vessel, +AMS, +FIFI-1, +DPS-2, ACCU, “Circle E”, SOLAS, USCG Subchapter I and L, Full Ocean
Delivery Date: September 2014
