With a new 57-mm naval gun and instant intelligence exchange with other branches of the military, Bertholf, the first of the U.S. Coast Guard’s latest class of high-endurance cutters, is bigger and badder than its predecessors.
The ship is also a reminder that all Coast Guard vessels have multiple missions. Bertholf‘s flight deck can handle helicopters and drones. A stern notch, unusual on a ship of its size, leads to a ramp for launching and recovering two small boats. A waterline door on the starboard side, a feature borrowed from cruise ships, allows survivors, divers or detainees to disembark easily from boat to ship. All three improvements are designed to make boardings speedier and safer.
“That’s our business — to do the boardings, whether we’re in (the Eastern Pacific) doing narcotics control or up in the Bering Sea doing fisheries patrol,” said Capt. Patrick Stadt, the ship’s commanding officer. Bertholf and the next two vessels in its class of national security cutters — products of the Coast Guard’s Deepwater modernization program — will be home-ported in Alameda, Calif.
The bow and hawsehole viewed from above. |
At 418 feet and 4,300 tons, the ship is about a third again as large as the Coast Guard’s aging Hamilton class of 378-foot cutters. Endurance — 12,000 nautical miles at 8 knots — far exceeds current capabilities and permits worldwide deployment. Fuel capacity is 225,000 gallons. “This boat can operate for many more days than we can carry food for,” said Stadt.
For propulsion, the designers, Northrop Grumman Ship Systems, turned to a diesel/gas turbine combination with a RENK reduction gear set, an arrangement in use in three German Sachsen-class frigates. The ship runs mainly on its diesels, but the gas turbine allows it to put on a turn of speed — up to 28 knots (“Sounds like a hybrid!” one shipyard executive commented). Together the diesels can make 22 to 24 knots, about 6 knots faster than those in the outdated combined-diesel-or-gas (CODOG) used in the Hamilton class.
The gas turbine is a GE LM2500 rated at 29,500 shp, a common engine but new to the Coast Guard. Detroit Diesel, the propulsion system vendor, supplied two medium-speed MTU 20V diesels, each rated at 9,730 bhp; combined shp is 48,960. The twin shafts are 160 feet long in three sections separated by SKF hydraulic shaft couplings. The shafts turn 14-foot Rolls-Royce inboard-turning, controllable-pitch propellers with maximum rpm of 229.
The RENK reduction device brings the output of all three engines together and allows single or multiple engines to drive one or both shafts. “It’s a pretty herky piece of gear,” said Stadt, using Coast Guard Academy slang for herculean.
Cmdr. Jim Hurley, Bertholf‘s pre-commissioning engineering officer, said operating modes include harbor mode (for emergency maneuvering), cruise mode (one diesel driving both shafts), maneuvering mode (both diesels driving both shafts), gas-turbine only or CODAG mode with all three engines online.
The electric plant comprises three ship’s service diesel generators (Caterpillar 3512 diesels with a Baylor/National Oil Well generator rated at 1,360 kW) connected in a ring bus by six bus-tie breakers. The generator set supplies 450-volt, three-phase power to three switchboards. The plant is designed to operate with two generators online providing 2,720 kW and with one generator on standby; if the load on a single generator tops 85 percent of capacity for a set period of time, the standby generator kicks in automatically.
In harm’s way
The Coast Guard’s response to Hurricane Katrina, which struck the Gulf on Aug. 28, 2005, was one of its finest moments. Helicopters plucked survivors from rooftops; small boats navigated flooded streets. More than 24,000 lives were saved. But at Northrop Grumman’s shipyard in Pascagoula, Miss., Katrina struck back at the Coast Guard. Bertholf, on land and about 56 percent erected, was in the way of the storm.
Work crews sealed the ship, but damage was extensive, particularly to machinery in the yard and to equipment on the ground submerged by the storm surge. The bow thruster needed repairs. Valves had to be cleaned and washed; some were scrapped. Vent fans went back to the vendors, some for repair, others for replacement. But yard executives credit Royce Winbush, the ship’s superintendent, with quick thinking as Katrina approached.
The ship’s mast. The ship’s command and control gear allows it to relay tactical pictures directly or by satellite to other units of the armed forces. |
John Donnaway, Northrop Grumman’s ship director for the Deepwater program, said Winbush put his team’s welding equipment on tables and moved them to higher ground, keeping the equipment together so his craft workers could get straight back to their jobs. “He didn’t actually allow them to unload the trailers,” said Donnaway. “That puts you about 6 feet off the ground. So his equipment didn’t get saturated.”
Winbush said the hard part came later: “The biggest challenge was getting all the materials back.” But within two weeks, the first arc was struck; Bertholf was the first ship back in production. Winbush’s team won a Coast Guard award for its quick recovery.
Northrop Grumman said Katrina set Bertholf back 12 weeks. It also immobilized a gantry crane that blocked the ship from the wharf, so the move to a floating dry dock this fall will require complicated choreography. A year after the storm, however, with some units still to be loaded, the ship was in recognizable shape.
Bertholf‘s most eye-catching innovation is its stern launch ramp. Two hydraulic doors slide side to side on the transom to reveal a notch in the stern and a 40-foot-long ramp at a 15° incline. The ramp was built for two sizes of small high-speed boats, 11-meter and 7-meter; in late summer, designers were still working on the capture mechanism that will engage the boat’s bow and winch it up the ramp. The boat will swing into a cradle via an overhead gantry.
Stern ramps are common, but not on vessels of 400 feet. However, Stril Poseidon, a 300-foot Norwegian-built offshore support vessel, has a stern slipway that can pull lifeboats from the sea, and the designers studied its ramp closely (like Bertholf, Stril Poseidon also has side rescue capabilities). The Coast Guard requires that Bertholf be able to launch and recover small boats in sea state 5, and Stadt expects sea trials to determine the ramp’s handling characteristics. “I’m actually looking forward to riding that first one up,” he said. Recoveries are unlikely in following seas because of the danger of stern slamming. And to create a safe sill depth where the small boat enters the notch, the ramp will be wet. Seen from below, the hull sweeps gracefully up toward the stern, then flares down slightly at the transom, where a water management system below the small boat helps with wave surge.
Cameras monitor ramp movements from the bridge, and only one person will be needed on deck to operate machinery. The advantage over side launches is obvious: Using frapping lines and hydraulics to raise or lower a small boat typically ties up nine crewmembers.
A notch in the stem allows for launch and recovery of small boats used for boardings. |
Bertholf does have an Allied Systems single-point davit on the starboard side. The davit has an active-drive, constant-tension winch with a safe working load of 8,600 pounds and incorporates a 7-meter boat cradle.
Below the boat deck is the side rescue door, 8 and a half feet wide and 7 feet tall, which lowers to a horizontal platform. At slow speed, boats can disembark crew or passengers directly aboard ship; in port, the door can load cargo or provide waterline access to the vessel’s interior.
At 50 by 80 feet, Bertholf‘s flight deck will be very large for a cutter and almost completely automated — the landing-signals officer will be in a sealed compartment built into an aft, upper section of the hangar that overlooks the flight deck. Plans are to deploy with two HH-65 multimission cutter helicopters, but Bertholf can handle U.S. Customs, U.S. Navy and foreign helicopters as well; capture mechanisms are in place for unmanned aerial vehicles, but Congress has deferred funding. An integrated deck-handling system called ASIST from Curtiss-Wright Controls will secure choppers in conditions up to sea state 6 without requiring on-deck personnel and convey them via lightweight tracks into their hangars. Two automated fire monitors cover the flight deck, although firefighting protocols are still under discussion. As with the launch ramp, automated flight operations require fewer crewmembers.
The bridge has excellent visibility — “It’s 360° of glass,” said Stadt. Officers can monitor engineering components and artillery gear from the bridge. The integrated bridge system is by Sperry Marine; communications systems, navigation systems and electronic charting have all been integrated, reducing the typical workload.
Engine and shaft controls are in the center console with repeaters on the bridge wings (the machinery control and monitoring-system consoles themselves are in an air-conditioned compartment on the second deck with surveillance cameras in the machinery spaces). Since Sept. 11, the Coast Guard has emphasized protection against chemical, biological and radiological warfare, and the need for a tactical intelligence center. With command and control equipment from Lockheed Martin, Northrop Grumman’s Deepwater partner, the ship can relay tactical pictures back to the beach or up to satellites in a system shared by units of the Department of Defense.
Home comforts
The 418-foot, 4,300-ton ship is about a third larger than the Hamilton class cutters it is replacing. Able to cruise 12,000 miles at 8 knots, its endurance will greatly exceed that of any other Coast Guard cutters, enabling it to carry out missions anywhere in the world.
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Bertholf should be much more comfortable than the ships it’s replacing. Staterooms, all with toilet and shower, hold a maximum of six crewmembers. (Hamilton-class cutters have some staterooms with about 20 people in them, said Stadt.)
Mess deck, galley and food storage are all on the main deck near the elevator. And both Stadt and Hurley like the fitness center on the third deck. “It is bigger than any lounge area — subtle message?” said Hurley.
When three cutters enter service, the Coast Guard plans a four-crew rotation to increase each ship’s time away from home port from 185 days a year to 230. A similar Navy program, Sea Swap, has drawn mixed reviews.
Bertholf, named for Ellsworth P. Bertholf, the first commandant of the modern-day Coast Guard, is scheduled for delivery next August and hull No. 2, Waesche, is taking shape just to the north. Plans are for eight ships in all. Congress has backed the program, and the Coast Guard, recognizing the political appeal of a national security cutter, isn’t insisting on its own designation (“maritime security cutter — large”). But the cutters are part of a $24 billion, 25-year modernization program to integrate all of the Coast Guard’s deepwater operations (defined as beyond 50 miles offshore), and funding depends on continued congressional support.
With Bertholf, the service took a gamble and abandoned its traditional way of contracting for ships. Typically, the Coast Guard drew up vessel specs one design at a time and looked for a yard to build it. This time, with an alarming proportion of its ships and aircraft nearing the end of their working lives, it hired Integrated Coast Guard Systems (ICGS), the Northrop Grumman-Lockheed Martin joint venture, to look at its entire deepwater picture and recommend ships, aircraft and systems as needed.
Cmdr. Jim Hurley, Bertholf’s precommissioning engineering officer, examines the ship’s plans. Hurricane Katrina caused extensive damage to the ship and its gear in the Pascagoula shipyard, setting back construction by about three months.
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Because of the size of the overall prize, the Coast Guard was able to attract a top-tier shipyard. At the same time, the move placed much of the Coast Guard’s future in the hands of ICGS, the system integrator. Questions have been raised about whether the Coast Guard can keep Deepwater on time and on budget. And with today’s emphasis on national security, large cutters cost far more than they used to. The current estimate for Bertholf is $526 million, which reflects nonrecurring design and engineering costs and post-9/11 upgrades; follow on ships are forecast to average $355 million each. Midgett, the last of the Hamilton-class cutters, was launched in 1971 in Avondale, La., and cost $14,069,680 — about $70 million in today’s dollars.
Bertholf will carry a close-in weapons system upgraded for surface targets as well as air. The main armament is a 57-mm Bofors gun with a nine-mile range, a design in widespread use overseas but new to the United States. The Coast Guard pioneered its testing here and the manufacturer, BAE, is now supplying it to the U.S. Navy’s new littoral combat ships. The Bofors gun was responsible for a change in the lines of the ship. On learning that the rake of the bow prevented the gun from firing directly ahead and low in the water, the Coast Guard had the bow shaved down, cutting about 6 feet from the overall length. “The shape of the bow had beautiful lines — and it bugs me every time I drive down there,” Len Janowski, Northrop Grumman’s technical director for the program, said with a laugh. No doubt the story will soon be part of Bertholf lore.