Hydraulic pumps save Hong Kong yachts from damage

Parker Hannifin hydraulic pumps and motors are at the heart of a marine hydraulic drive system supplied to Hong Kong yacht clubs for use on their Yanmar diesel powered harbour taxi ferries.

Parker Hannifin hydraulic pumps and motors are at the heart of a marine hydraulic drive system designed by Anglian Diesels and supplied to Hong Kong yacht clubs for use on their Yanmar diesel powered harbour taxi ferries.

The Hong Kong Harbour Authority has, over many years, had to deal with "accidents" involving moored yachts and harbour taxi ferries under the control of inexperienced captains.

Members of the four yacht clubs based in Hong Kong harbour have to use dedicated water taxi ferries provided by the clubs to transport them and their crew members to and from their yachts.

The yachts are moored on swing moorings (attached to a buoy in the harbour, not moored alongside a jetty or pontoon).

The problem with this arrangement is that due to harsh operating conditions (inexperienced captains changing gear too quickly and crashing the manual gearboxes), accidents occur, leading to damage to moored yachts.

When a manual transmission breaks, the water taxi ferry cannot easily be stopped.

The captains then rely on hitting other vessels to come to a standstill.

Following a visit to the Anglian Diesel stand at the 2003 London International Boat Show, a Hong Kong Harbour Authority official reported back to the yacht clubs that he had seen an impressive "unbreakable" hydraulic drive system that might solve the clubs' problems.

The Anglian Diesel system has been used and abused on Norfolk Broads hire boats for over 30 years.

The Anglian Diesel hydraulic drive system comprises a Yanmar 30hp (at 3600rev/min) variable speed engine driving a Parker F12/30 pump boosted by a Parker BLA 4 160 boost unit fitted to a 15-litre reservoir.

The control valve is a Parker F130 single motor spool (modified for cable control) with three-position detent and 250bar pressure release valve.

This drives a Parker F12/60 motor, using the motor's twin taper roller bearings to directly couple, via a flexible coupling, to the boat's propeller shaft.

Engine speed and forward/neutral/astern is controlled by "single lever" Morse cable.

Cooling is achieved by circulating the drain line and boost drain to a sea water cooler attached to the engine's cooling circuit.

"We specify the Parker F12/30 pump/motor for two main reasons", says Anglian Diesels' Sales Director, John Lurkins.

"Firstly, because it is a high efficiency piston unit and, secondly, because of the ability of the twin taper roller bearings to take full propeller thrust in both directions.

Most of competitive products available only have one of these features not both".

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