We supplied two ZF 3070 reversing gears to Pon Power

Recently we supplied two ZF 3070 reversing gears to Pon Power. During the sea trials it became clear that the reversing gears were getting too warm in trolling* mode. In close cooperation with a sister company we came up with a solution. A nice piece of cooperation between ADS van STIGT and Wiegel Transport Equipment.

The vessel is used as a sport fishing boat, and is fitted with two Caterpillar C23 V12 turbo diesel engines.

In the design surface piercing propellers were specified due to their suitability for high speed operation. During cruising speeds the propellers are only partly submerged, significantly reducing the underwater drag.

However during operation at trolling* speeds the propellers are fully submerged and have a much higher underwater resistance, resulting in a much higher power demand. It proved difficult to cool the transmission sufficiently with the available cooling media.

The solution: More oil through the oil cooler during trolling operation. The challenge that arose from this solution was the higher electric power demand to drive the necessary extra oil pumps.

To tackle this, our project engineer Martijn van Kesteren contacted our sister company Wiegel Transport Equipment. Wiegel supplied a compact Voltstar generator system driven by a PTO on the engine.

Wiegel project engineer Richard van Tol explains: “The generator has a special transmission for this specific application, ensuring the supply of the required electrical power over the complete speed range of the engine. Doing so, the separate cooling system with the 400 VAC pump motor will keep the transmission oil temperature reliably under control”. 

Martijn states: “I experienced the cooperation with our sister company as very pleasurable, and our on-site engineer reported that the system we designed works exactly as intended. On top of that the yard complimented us with the quality of the components we used. It was a long and intensive project, and I am very proud we managed to conclude the project in the way we did.

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*Trolling is a fishing technique in which bate is drawn slowly through the water to emulate the swimming speed of a wounded fish. With a fast boat this speed is only attainable by letting the reversing gear multi-plate clutch slip in a controlled manner to have a vessel speed that is below the speed at the lowest possible engine rpm.