SLIPWAY AND STERN ENTRY SYSTEMS WITH SINGLE WHEEL DRIVE UNITS
The hydraulic-powered, semi-automatic slipway system consists of a number of single wheel drive units in parallel rows. The tilt, height and distance between the wheels can be manually adjusted to conform to a range of daughter craft hulls.
Daughter craft can engage the slipways at a range of speeds up to 7 knots higher than the speed of the mother vessel. When a boat enters the slipway, the overrunning clutches allow free rotation of the wheels in the recovery direction until the boat speed and wheel drive speeds match.
At that point the hydraulically powered wheel drive units will take over under single-operator control and dock the daughter craft safely inside the slipway. End stoppers automatically set the craft in parking and stowage positions and engage the fail-safe brakes on the drive wheels.
MAX. SEA STATE FOR SLIPWAY OPERATIONS
Test and operational use of this slipway system have been performed in Sea States 3 with mother vessel steaming ahead with low speed.
Safe operations at higher Sea States may be possible but is highly dependent on:
- Stern entry arrangement
- Mother vessel heading and speed
- Mother vessel responsiveness (RAO Profile)
- Waves and wind pattern
- Boat driver’s skills
SINGLE WHEEL DRIVE UNITS
Wheel drive unit configuration: 1 wheel on each wheel drive unit
Wheel angle and transverse spacing: Manually adjustable
Brakes: 1 for each wheel
Hydraulic motors: 1 for each wheel
Over-running clutches: 1 for each wheel
Number of single wheel drive units: Depending on length of slipway
Wheel diameter: Ø 434 mm (Foam filled)
Max. freewheel speed, inlet: 0-240 m/min (0-7 knots)
Drive assist speed, in and out: 0-25 m/min (0-0.8 knots)
Max. slipway slope angle: up to 12°
Max. payload for slipway: up to 12 tons
Max load, each wheel: 2 tons
Weight (each wheel drive unit): Approximately 420 kg