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February 6, 2001

"There’s No Such Thing As A Drop-In" Repowering Navy RIBs

Mine sweeping is no longer solely reliant on wooden hulled mine sweepers. The U.S. Navy has developed a method that involves a Sokorski helicopter towing a catamaran sea skid equipped to detect and detonate mines. Each helicopter and sled unit is accompanied by a pair diesel-powered rigid-hulled inflatable boats. The RIBs tow the sled when disengaged by the helicopter and act as general support vessels.

The 24-foot RIBs had been powered with 165 HP diesels powering Duo-prop out drives. Complaints of frequent breakdowns and complexity of auxiliary systems making service difficult were brought to the attention of the people at the Saunders Engine Company in Panama City, Florida, who in turn consulted with their associated company Saunders Yachtworks in Orange Beach, Alabama. With the collective experience garnered over the years since the firm’s founding in 1959, they proposed a repower solution using Navy-recommended Cummins BT5.9M1 and Konrad 520 outdrives. "In our experience the Konrad drive is the most heavy duty on the market and allows the largest diameter propeller," explained company president Andrew Saunders, "it matches well with the Cummins engine which is simpler in design and has a higher record of dependability than the original engines." With an order in hand the company completed a prototype installation. "There is no such thing as a drop-in," said Saunders, "We had Murray Loper from Yachtworks designing the layout and fitting the auxiliary components and wiring into the existing space. We also refurbished the operator’s console and installed new gauges. The result is one of cleanly balanced form and function from lay-out to performance." The prototype demonstrated superiority in vessel speed, manoeuverability and handling throughout the operating range, quietness of operation and bollard pull. Shortly after the test of the prototype in early 2000, Saunders received orders for 13 additional repowers. By early February 2001 they had delivered seven units and work is progressing on the balance of the order, two boats at a time.

The following are the specifications of the boats before and after the repower:

 
BEFORE
AFTER
Vessel weight 4700# 5550#
Vessel operating speed 31.8 knots 34 knots
Engine HP 165 260
Engine operating speed 3600 RPM 2600 RPM
Propeller Duo-prop 16 3/4 x 20" (3 blade)
Bollard pull @2000 RPM 1060 lbs 2170 lbs

A note to editors: This is an interesting project on a number of fronts. It is a good clean repower by a quality company that understands form and function. On another level it is a mating of diesel and outdrive that has been proving successful and meets a wide range of commercial marine needs. Finally the naval application of these boats is a dynamic story in itself.

For further information contact:

Andrew Saunders or Murray Loper
Saunders Yachtworks Division
27075 Marina Road
Orange Beach, Alabama
Phone: 334 981-3700
Fax: 334 981-3919
Web Page: http://www.saundersengine.com/

or:

Larry Neff
V/P Marine Marketing
Cummins Alabama Inc.
3422 Georgia Pacific Ave.
Moblie, AL 36617, U.S.A
Work: 334 452_6426 Fax: 334 473_6657
Web Page: http://www.cummins.com/na/pages/en/index.cfm

or:

Ken Konrad
Konrad Stern Drive Specialists
1421 Hanley Rd.
Hudson, Wisconsin 54016_9376, USA
Phone: (715)386_4200 Fax: (715)386_4219 Toll Free: 1 800 927_3545
Web Page: http://konradmarine.com

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