whikeyjack said:
If the RAN or RNZN goes to Austal and says we want a Cat/Tri that can lift a 500-750t payload out to x miles and return empty without refuelling, they will come up with something. I hope
Its not a hope, it would be done. The key for you as the buyer is not to make unreasonable demands. The only thing limiting that type of build is the size of the facility.
Toby, If you'll recall; I chose the 2000NM figure as an academic capability comparison between an 8 unit C130j-30 fleet and a 1000 DWT fast ferry with a speed of 40 knots (Just as you did with a smaller range).
In short, from that comparison I think you need 2 v/ls to make it worthwhile and allow you to reduce your c130 fleet. Or, one 1000DWT ferry per 4 C130 aircraft
As to whether you would want to reduce your c130 fleet to retain capability for other operations is another question. Certainly running a fast ferry is more economical while giving you comparable capability then eight c130 transport aircraft. Provided (that is) you stick to maritime centric operations.
No one mentioned an existing v/l, just what is possible.
So if you strolled up to the front desk of Austal (for instance) and asked them to build a ferry with the above specs. They would in all probability be able to do it with existing technologies.
This also goes back to a valid reason for injecting cash into NZ businesses like Mace Engineering with their engine technologies. Creating a diesel engine with 2 x the horsepower for the same weight as a high speed 4 stroke?? (such as the ones found on the Austal Auto Express 127 design)... Engines happen to be the heaviest thing on a ship like a fast ferry. Risk is minimal as they already have working engines and have proven the concept.
Going for range might also mean changing the propulsion. You don't
have to use water jets. In fact when I asked Incat to design a vessel for me that had a 10000 NM range, we were seriously discussing contra-rotating super-cavitating props. Super-cavitating means a propeller that works best when it is creating cavitation at the tips, which in turn means a very high speed prop that can deliver more horse power to the water then a conventional prop. This in turn saves weight in gearing and makes for a very fast platform that is more efficient then a water-jet per sa'.
Anyway, to get the range and speed you would start off with the 127 design and probably move to a SWATH as I have suggested before on other threads. Increase the length a little to increase fuel load and work out the details from that baseline.
The forward basing for disaster recovery is an excellent proposal and would make my comments above about 2 v/ls redundant if one fast ferry was operating from a forward base. You just have to get it there for the benefits to kick in.
cheers
W