Mr. Mel: Taking Care of Business Powered By "Cats"

Diamond Services Corp. knows the importance of staying competitive in the oilfield service industry, which is why the Morgan City, La., company broke the conventional rules of "propping" and built Mr. Mel, the first water jet-powered crew/supply boat to work in the Gulf of Mexico. Considered an innovative propulsion system for a crewboat, the diesel engine/water jet combination offers advantages of increased speed, maneuverability and flexibility over propellers. The 145 ft. (44 m) aluminum monohull, built at Swiftships, Inc., was delivered in February 1995. At that time, Mr.

Mel was powered by four 815 bhp (611 bkW) diesels driving four Hamilton HM-571 water jets through a Twin Disc MG-5202 gear with a 2:1 reduction ratio. Mr. Mel is capable of carrying 79 passengers with a full load of fuel and 30 tons of deck cargo at 24 knots, and can achieve 28 knots light.

Since 1995, Mr. Mel has worked continuously in the Gulf of Mexico, running supplies and crewmen to deep water oil rigs. The water jets, as expected, have performed flawlessly, making them a worthwhile investment in the eyes of Diamond Services. But there was a second factor to the equation.

"We began experiencing engine problems," says Mike Swiber, the company's purchasing manager. "What began as piston ring wear turned into larger, more frequent problems." Swiber adds that for the first three years, the engines went through several repairs and overhauls in an attempt to alleviate the problems. While much was covered under warranty, it was downtime that the company could not afford.

"It got to the point where enough was enough," he says. "We continued to successfully serve our customers during these times, but the original engines weren't durable enough to meet our standards. It's no secret that in this industry, engines take a beating, and these simply weren't cut out to be crewboat engines." With business potentially at stake, Diamond Services decided to pull Mr. Mel's original diesel power plants. The company looked to its fleet, powered by various engine manufacturers, for clues as to which type of engine would meet the company's requirements.

The answer was found with Diamond Services' Lisa Ann and Mr. D. Lisa Ann was built in 1997 to the same specifications as Mr. Mel, but powered by Cat 3412 engines. The same year, the 17- year-old Mr. D, equipped with conventional props, was repowered with the June, 1999 same model engines. The propulsion history was good and performance results were strong for both vessels, so Diamond Services ordered four Cat 3412 engines, each rated 825 bhp (619bkW) @ 2,100 rpm, from the local Cat dealer Louisiana Machinery Power Systems.

The repower was completed in May 1998. After passing all the necessary performance tests, Mr. Mel was back to work in the Gulf the following month. "The Cat engines have been performing very well, and they work well in tandem with the jets," Swiber states. "Most importantly, there's a sense of security that they will help us serve our customers' needs. The engines are still pretty new, but if they have a track record like the ones in Lisa Ann and Mr. D, I expect they'll perform reliably." Durability, comparable horsepower ratings and competitive pricing were the top reasons Diamond Services selected Cat engines for the repower, Swiber says. He adds that the availability of parts and service from Caterpillar was also an important factor for a boat that operates continuously.

"There's even a Cat dealer located in Del Cormen, Mexico, which is in the region where Mr. Mel operates," adds Swiber. More shipbuilding activity is on the horizon for Diamond Services. The company built the world's largest jet-drive crewboat at Swiftships Inc. Kristin Grace measures 185 ft. (55.5 m) long and 30 ft. (9 m) wide, and is capable of carrying cargo up to 330 long tons on deck, nearly twice the amount of Mr. Mel. She will be designed to transport 64 passengers and five crewmen. The quad-screw vessel will be powered by Cat 3508 Series B electronically controlled engines, each rated 1,300 bhp (975 bkW) @ 1,835 rpm, driving Hamilton water jets