Page 107: of Maritime Reporter Magazine (November 2016)

by moving from hydraulic to electric one direction to 1,000 rpm in the other tight spaces without the need for a tug when you are operating electric motors thrusters. In general, the interface of direction in less than 10 seconds - a full or push boat. in some of the worst conditions pos- an electric motor and VFD is more ef- reversal in less than 10 seconds. You sible,” said Moorehead.

? cient, the system reacts far quicker and can’t do that consistently with a stan- Custom Cabinets requires less maintenance. dard induction motor and a standard Master Boat’s new class of 220 ft. ves- Additional Applications

The electric system also eliminated scaler type VFD, they just can’t take the sels contain the fourth iteration of drive As the Master Boat building team and the complex interface between the me- abuse,” said Mitchell. enabled design at 800 hp. This move has their boat owner customers have become chanical thrusters and the DP software The direct torque control (DTC) tech- increased the width of the drives beyond more comfortable with the electronic required with the hydraulic system; in- nology in the ABB drive, and the low the tight space available within the boat, systems, motor and drive packages have cluding an electronic board that convert- inertia aspects of the AC motor, provide where every inch of space is a premium. spread to other areas of the offshore sup- ed signals to a processor that drove the excellent control throughout the entire Working together Master Boat, Gulf ply vessels. Since 2012 the electronic hydraulic motor coupled to the shaft of speed range, from 2 rpm to 1,800 rpm. Coast and ABB created a custom design packages have been used in the follow- the thruster. The intricate set of moving They allow ef? cient acceleration, de- that reduced 30 inches of width on each ing areas: parts limited the performance of the DP celeration and full reversals, reducing drive cabinet, saving ? ve feet of space • Mud Pumps: an ef? cient mud deliv- system and was prone to frequent break- generator load and increasing the overall with the two cabinets mounted side by ery system that increased ef? ciency and down. performance of the system. side. eliminated some existing mechanical is-

Master Boat’s Dubroc added, “These “By everybody collaborating together sues. It allows softer starts so the mud

The Motor and Drive Package boats will basically hold in 10 knots of ABB basically created a whole new pump doesn’t go right to 1,800 rpm, po-

Before bringing Gulf Coast into the wind at the beam. In other words, you drive for us,” said Moorehead. tentially damaging the hoses and pipes. electric thruster initiative, Master Boat could have the wind coming from the ABB provides a complete system in- Mud, or liquid cement, is used in the oil had contacted a Baldor Electric distribu- beam into the side of the vessel and it cluding the drive and the motor, and then drilling process.

tor for initial information about potential will hold. works with Gulf Coast to integrate them • Ventilation Systems: allows better electric motor and drive products. If the wind or current was coming from into the master DP control system, from control of the fans that ventilate the en- “Gulf Coast was already providing the bow, you could probably hold in hur- initial engineering through to commis- gine room, ef? ciently varying the loads 24/7 service to Master Boat and their ricane force winds.” sioning and start-up. to better balance air in? ow and out? ow.

customers on existing ships, so bringing Bow and stern thrusters are also used Gulf Coast supports the effort with • Fire Pumps: allows operators to vary them into the electronic thruster equa- for docking the boats and maneuver- an experienced team that has all the the speed of the water ? ow to feather the tion made sense. Master Boat also saw ing in tight spaces like rivers and ca- Homeland Security clearances and in- water load to whatever spot is desired, the bene? t in purchasing product and nals where boats may be passing within surance necessary to ? y out to an oil rig providing better accuracy in ? ghting service from one organization, so Gulf three feet of each other. The demand on or directly to one of the larger offshore ? res. It also eliminates the huge back

Coast became involved in the electric the drives is not as severe as in the DP supply vessels, covering the area from pressures that result when controlling thruster business, setting the stage for system, but precise performance is still Brownsville, Texas to Tampa, Fla. the water ? ow with the nozzle.

further growth,” said Mike Mitchell, required. The thrusters essentially allow “In 10 years I think we have had three • Deluge Pumps: to better control the the ABB application manager who has the boat to move sideways to negotiate warranty calls. That’s not a bad record ? re protection system on the ship.

worked with Master Boat on the electri- cal systems from the beginning.

In 2011, just after ABB acquired Bal- dor, the switch was made to the ABB

ACS800 VFD and the Baldor RPM AC motor, providing additional system per- formance and longevity.

The ABB motor and drive package is especially suited for the rigors of the marine environment and the intense de- mands of the DP system.

“Because of their modular construc- tion the ABB drive is perfect for the ma- rine industry. When you are under con- tract to an oil company, the people way out on that rig are depending on the boat to bring groceries, fresh water, cement or whatever their needs might be. You just cannot have any extended downtime,” said Moorehead.

When the vessel is on station or in a positioning mode, depending on wave th

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The ability for the ABB ACS800 and the Baldor RPM AC motor to execute very quick and rapid accelerations and decelerations simpli? es the positioning process.

“In the DP application, the VFD will typically be ramping from 1,000 rpm in www.marinelink.com 107

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