Kit_L
Guru
- Joined
- Mar 12, 2016
- Messages
- 510
- Location
- Australia
- Vessel Name
- Suu Kyi
- Vessel Make
- Custom 40' catamaran
The current vessel is a 40' ply and fibreglass power catamaran. Its displacement is unknown. She carries 1,200 litres of fuel in two tanks, and the same amount of water. She is fitted with a generator in the port hull. We assume she's around 12 tonnes, but she could be more.
The boat is powered with a pair of Volvo Penta KAD-300s (285 hp), with stern drives, driving Duo-props. At 1500rpm, she makes 6.5kn using 10l/hr; at 1900 around 8kn, using ~24l/hr. At 2250, she does 9kn, using 31l/hr.
At 3250, she's well on the plane, and making 15–16kn, using 70l/hr.
I would be happy to run her at displacement speeds only, which is around 8kn. My question to the gurus is would a pair of petrol 60hp heavy duty ('hi-thrust') outboards (with the 3:1 reduction gearbox and larger props, used by oyster punts in this area) be enough to push her to these speeds?
This is just a thought experiment at this point, but I'm curious. The modern four-stroke outboards are quiet and very reliable, and being able to lift the legs completely out of the water in this area is a big, big plus. The last time the boat was slipped, I spent two hours on each engine getting all the barnacles out of the 10,000 crevices that legs have!
The boat is powered with a pair of Volvo Penta KAD-300s (285 hp), with stern drives, driving Duo-props. At 1500rpm, she makes 6.5kn using 10l/hr; at 1900 around 8kn, using ~24l/hr. At 2250, she does 9kn, using 31l/hr.
At 3250, she's well on the plane, and making 15–16kn, using 70l/hr.
I would be happy to run her at displacement speeds only, which is around 8kn. My question to the gurus is would a pair of petrol 60hp heavy duty ('hi-thrust') outboards (with the 3:1 reduction gearbox and larger props, used by oyster punts in this area) be enough to push her to these speeds?
This is just a thought experiment at this point, but I'm curious. The modern four-stroke outboards are quiet and very reliable, and being able to lift the legs completely out of the water in this area is a big, big plus. The last time the boat was slipped, I spent two hours on each engine getting all the barnacles out of the 10,000 crevices that legs have!