Joystick control for shaft-drive boats - the Twin Disc game changer

by Denby Browning on 20 Apr 2010 Twin Disc has unveiled its new Express Joystick System (EJS), describing it as the smoothest, most cost-effective slow-speed manoeuvring system for leisure and commercial boats.

EJS offers seamless docking and slow-speed handling on traditional shaft-drive boats by combining Twin Disc's patented QuickShift gearbox technology with hydraulic bow only or bow and stern thruster systems.

The system will debut on a Maritimo C60 Sports Cabriolet at the Sanctuary Cove International Boat Show in late May.

The Managing Director of Twin Disc (Pacific), Glenn Frettingham, said the boat would be available for active demonstrations throughout the four-day show.

At the heart of EJS is a joystick installed beside the standard engine controls at the boat's helm with optional joystick stations available for other locations. At the press of a button on the control, the EJS is activated and all the boat's movements are managed completely from the joystick. The secret to the smooth, seamless operation is the patented clutch design of the QuickShift gearbox and express mode. The engines maintain a steady high idle rpm throughout every part of the operation and the boat movement is precisely controlled by transmission direction, slipping clutches and the proportional speeds of the thrusters.

'Standard electric thrusters cannot be run constantly,' explained Frettingham. 'Our proportional hydraulic thrusters offer variable speed and can run continuously through the manoeuvres.'

The EJS joystick combines directional control and rotation. Push the stick in any direction around 360 degrees and the QuickShift transmissions combined with the thrusters to push it in that direction. Twist the knob on the top of the joystick and the boat rotates. Pressure on the stick controls speed of operation.

The QuickShift technology ensures that changes in direction and speed are smooth and instantaneous – no lag, no clunk or jerk of gear switching. The system can be installed on any boat that has QuickShift gearboxes and can even be retrofitted with relative ease.

Frettingham said the EJS is a more cost-effective method to achieve precise joystick control than any of the current pod drive systems.

'With EJS we don't significantly alter the original design of the boat,' he said. 'If an owner already has standard QuickShift transmissions and controls installed an upgrade to EJS joystick control is relatively simple when compared to upgrading to pods. Basically all you would require is the joystick itself, an additional electronic controller module in the engine room, extra harnesses and the installation of compatible hydraulic bow/stern thruster system.'

He said pods require a uniquely designed hull structure and positioning.

'Part of that structure sacrifices a keel on the boat that can compromise tracking,' he said. 'With EJS there is no sacrifice.'

Maritimo's General Manager and chief engineer Martin Lewis confirms the smooth and simple operation of the new EJS.

'On the boat I tested, the joystick generated immediate and smooth response,' he said. 'There was no delay.'

The Twin Disc Express Joystick System will be available from January 1, 2011.

'We are taking orders for the system now,' said Mr Frettingham. 'We can begin installation on all new boats immediately. Final commissioning will be available from early next year.'

The Maritimo C60 equipped with the Express Joystick System will be on display at Stand F29 at the outer end of F arm throughout the Sanctuary Cove International Boat Show. Demonstrations will be conducted by appointment.