what does a 40,000HP catamaran look like?
96 metre Incat has about 36,000. Here’s Incat hull 050 (ex Devil Cat, now Mananan) on acceptance trials with the Navy in Tasmania. My brother is driving and he’s just pissed off the OZ and NZ vessels. They used this photo as the basis of the embroidered badge on their baseball caps.
water jet powered, so when going down hill and you back off nothing happens
Whats the powertrain configuration in them?
Two CAT engines each side with solid shaft to two individual pumps. To go slower than 15 knots you had to use the thrust reverser buckets. Minimum sustained speed to keep the engines happy 27 knots.
Had a joystick at the after end of the bridge – if you pushed the button it would take fifteen seconds to align the jets through the CLR for translation mode (and another 15 to get back if you changed your mind).
In usual ferry service the navigation crew was Master, Navigator, Engineer sitting upstairs and a roving fire watch. Keeping her at sea as the Navy and Army did took a crew of 35.
what model is a 10,000hp Cat?
Back to the Cats, the Incat 86 metre ones would run at 42 knots at 985rpm.
The engines started off as V12 (I think) locomotive units that ended up stretched to V20 with a 10,000hp rating at max chat of 1050rpm.
Ours were downgraded to 985rpm and then 940 due to crank bearing failures ($1/2 million a pop) but this was later traced to lubrication contamination.
Put the throttles down at harbour speed and they would accelerate up to 27 knots and then go dynamic and launch themselves out of the water with a real shove.
Slowing down was even more impressive; ‘take the tops off’ for 60 seconds for thermal protection and then chop them to tickover (15 knots) and they just drop in the water immediately.
1000 litres per hour per (4) engines.
Utterly appalling in bad weather, hence the name ‘Vomit Comets’; like being on a 3 hour train crash sometimes.
3618 is the biggest Cat I think?
The dump truck engine is a v20 but its lots smaller
anyway all of them can be operated from shore for our autonomous ship
Don’t forget that CAT owns MAK, a medium speed engine builder, so the power range goes quite high. Cat’s own design large engine is/was the 36 series, but MAK’s line goes to higher power levels. These catamarans usually have “high speed” (>1000 rpm) engines but as the catamarans get larger they are branching to medium speed engines by CAT/MAK and MAN. https://www.ship-technology.com/news/man-energy-austal-incat-tasmania/ Note that in the engine biz there isn’t really a black and white definition of what is medium speed vs. what is high speed, so the 1000 rpm value is somewhat arbitrary.
I phrased that wrong. There’s a reduction gear on each shaft, but the shaft turns whenever the engine is running.
050 went back to Incat with a few wrinkles amidships. Dunno if it happened on the Navy’s or the Army’s turn with her. Phil seemed to think that the best thing about bad weather (the way they were using her) was being fast enough to be somewhere else when it happened.
Incat say 7200 kW at 100% MCR on the 3618s.
The 86 metre ones had clutches so the jets only operated when clutched in.