Novel gearbox installed in Brixham boat

Newage Transmissions' first production StepDrive unit - an automatic two-speed marine gearbox that dramatically improves the performance of boats equipped with Volvo Penta diesel engines - has been installed in a 25ft Lema Clon motor boat based at Brixham. The installation marks the new gearbox's successful completion of exhaustive rig testing and sea trials designed to simulate many years of normal pleasure craft operation. StepDrive units are self-contained gearboxes that can be retrofitted to Volvo Duoprop 290 drive legs.

They are installed entirely within the centre section of the Duoprop unit and are ideal for use with turbocharged engines such as Volvo Penta AD31 and 41 series; as well as supercharged units up to the KAD44.

In operation, StepDrive gearboxes automatically change from low to high ratio at a predetermined engine speed.

This is optimised during installation to the individual boat and engine combination.

When the boat decelerates again, low gear is engaged as the engine speed falls below 1500rev/min.

Installed on the Lema Clon with a 150hp AD31 engine and DP-E driveleg, the Newage StepDrive unit has fully justified its makers claims that it typically increases boat performance by 25%.

"In timed test runs, some vessels have achieved massive 40% improvements in 0-20 knot times", reports Newage's Marine Sales Manager, Jamie Pratt.

"However, by providing an additional reduction ratio of around 25%, StepDrive units not only boost overall performance, but provide the benefits of reduced creep speed, emissions and noise when manoeuvring in busy marinas or restricted waterways".

"In some cases, they will also enable the original propellers to be replaced; so that the vessel's improved handling and fuel economy characteristics can be combined with an even higher top speed".

StepDrive installations will normally be completed in a day, with further in-water commissioning required to set the optimum gear change point.

All units carry a two-year warranty and are available nation-wide through the following six regional installations centres: DB Marine of Cookham, BA Peters in Chichester, Maldon-based Volspec, Marine Engineering Looe of East Looe, Southampton-based RK Marine, and Abersoch Land and Sea in Pwllheli.