Gas turbine

When will this nonsense end?

Every single time a CPP is mentioned, somebody comes out of his wood and makes the same, wrong statement.

We both Fred, had this discussion several times now, and you really should now better, now after having read all the related text!?:!:


To the Jet:

we had the Finnjet in Germany for about 30 years. She served the Lübeck Helsinki route all year round and could hold her 30kn cruising speed even in light ice conditions.
Her class was: 1A1 ICE-1A* Car Ferry A MCDK E0
She was the fastest Ferry in her entire life, and driven by two Pratt & Witney Turbines of 27.500 Kw each. The consumption was 360 tonnes in 24 hrs! For the turbines only!
She later got two diesels installed to make slower passages (especially in winter) more economical.
She had two KaMeWa CPP´s
Two years or so ago, she was wrecked in India.

Regards
Richard

 

Tom,

I don't know enough about their application and use to venture a guess as to why they would convert to diesel, but a couple of things come to mind.

It could have to do with capacity and cost of overhaul. If they had run out the turbines they could be facing a big overhaul bill, and this is particularly true if they had already done a couple of hot section overhauls and were staring at the cost of essentially new engines. With a big tab for the turbines, they could make a case for diesels if their load factor was down and they didn't need the lighter engines. Also, some older turbines aren't that reliable, and are expensive to maintain with their hydromechanical control sysems, and the issue of support comes into it, how good was the support they were getting and how good were their mechanics? These kind of operators aren't like an airline, they just don't route in another boat...... Finally, two hour runs aren't the best thing for large turbines either. You see a lot of start/stop cycles in that usage and overhaul periods on some engines are based on stop/start cycles in addition to hours of use. I'm sure it comes down to the support and economics (and that could be short term economics as opposed to long term), they ran the numbers and made a decison.

The reason you don't see many turbines in general use is primarily because turbines cost a lot, and secondly that most yachts don't run fast enough for a long enough time for them to make sense. Most yachts putt up and down the ICW and seldom run over 15 or 20 kts outside even though the owners like to brag how fast they can run. Even big Bertrams typically cruise in the mid 20's so that they save fuel, even when they can run over 30 if they want to. At those load factors turbines burn more fuel than a diesel every time. Why spend more to burn more fuel?

While the next generation of turbines will have fuel consumption close to that of a diesel, they won't be cheap. About the smallest turbine you want to design, for a number of reasons is about 500hp, and you can buy a marine 500 hp high performance gasolline engine for about $20,000. Expect that a turbine of similar power will cost 8 or 10 times that. At 500hp per engine we are talking about roughly a 40 ft boat, and when the first cost is that much higher (and considering that they get used a dozen times a year) there isn't enough price elasticity to make it work. You still see a good number of gasoline engines in this class just because the cost is low and the boat doesn't get used that much (although buyers now are thinking resale value and buying the diesels even though they cost more than gas).

If you go bigger, and as I said, once you get over 1500 hp per engine, and if you want to go fast, turbines start to make a lot more sense. But really, ask yourself how many owners actually cruise a 75 to 80 foot boat at 35 or 40 knots and want to run about 100 gph of diesel thru each engine? The answer is really, precious few. They would rather make the salon bigger or outfit the boat with a nicer interior than have big speed. The reason there is a niche market in this power range is that if you are spending $3 mil on a boat, you can afford a $400k more to put turbines in there if you want them. The next gen of turbines will have first cost parity with diesels in this size class, so that may result in more sales, but really, how many fast eighty foot planing yachts get built each year? Not that many is the short answer.

For these reasons, while there is a niche market for a small number of big fast yachts, most of the marine applications for turbines will be in the military, where speed is life and the ability to haul butt out of a bad situation or carry a much bigger mission payload is a lot more important than the higher first cost or some wasted fuel. Patrol boats and special ops boats are where you will see them first and then they will filter down into the general public.

Will we see turbines in the 40 ft class? The answer is a few, but not many.

 

Yellowjacket,

Interesting, thank you.

-Tom

 

As an aside I was fortuneate enough to go onboard the Wally 118 with a relative who knows Luca, the owner.

All I can say is stunning-I was so befuddled by it that 30 minutes later I dropped my camera into the drink.

I think there's about 16,000 hp from turbines and 800 from diesels.
From memory it uses 16 usg per mile,or about 40 litres per km at top speed.

 

20 some years ago a guy made a set on some herring and got the whole damn quota. He took that money and built one damn fast seiner. Triple motors if I remember correctly with the center one being a turbine. The mast folded down at speed to provide air to the engine room. That seiner did 50 mph. The fastest fishboat that ever came out of Pt. townsend, The Order Of Magnitude.

 

Atta boy! Nice post.
Tolly, Ray Wadsworth had it built. He lives here (well, Seldovia 12 miles away). The thing was a disaster. Cooked his fish, burned a $30,000 net, broke his mast, couldn't easily transform from cruise to sprint to fish, couldn't afford it. He's still around - with diesels. Yes, seiners can make some money, even today. Check out this vid http://www.youtube.com/watch?v=DV-Eju09Ios - kinda dorky but wait to the very end of the show. That's my friend Tom Stafford (F/V Infinite Glory) with 1,400 tons. This fishery is the first thing they do in a season and all of his crew quit immediately after offloading. He's building a new boat with the proceeds (that's the way seiners are!) and no turbines. Speed is incredibly important in this fishery, tho about once a year. Hard to justify those big MANs (or turbines) when you putt around 99% of the time...

 

The fast catamarans in my area are all turbine powered. I try to avoid public transport for various reasons, but the few times I went to the mainland with one of these 350+ passengers ferries, the absence of noise and vibrations kept surprising me.
There also used to be a "slow" car ferry with turbines, but after it was docked for maintenance, it never returned and was replaced by a Japanese boat.

But the original post mentioned a helicopter engine. That can never be a good idea because the amounts of air needed to keep the output section from burning out simply are not available in a boat's engine bay.

 

http://www.youtube.com/watch?v=gWSXJBE6iWY A perennial favorite, This Callan used the Italian Tencara hull - it would be smokin' fast if the output section were not burning out! The best of the vid is near the end when it imitates a router bit binding. I couldn't find the company that did the engines, but for interest, this company marinizes and does installs;
http://www.turbinemarine.com/turbine_extreme.html
One can shove more air into an engine bay than you can imagine - more air to the turbine than if it was mounted on the aft deck. Please check out scoops at end of vid.

 

A helicopter turbine is simply a turboshaft engine. No different than any other turboshaft other than that some have magnesium gearboxes and you wouldn't want that in a boat. The Turbine Marine engines are surplus helicopter engines that have been marinized and they work just fine. Also some of the Vericor engines were maranized helicopter turbines, so where the engine came from isn't an issue, it is how it has been modified for marine use that is what is important.

All turbines need a lot of air to run. That is the nature of the beast. Making sure there is sufficient air without a large inlet loss is an important aspect of the turbine installation. Having too much inlet restriction will simply reduce the power available, it won't cause the turbine to burn out. No different than running the engine at altitude, where there is less air to start with.

You burn out the turbine if you run it too hot (which is easy enough to do if you are greedy or stupid and trick the fuel control) and ignore the turbine inlet temperature limits that are prescribed for the engine. If you ran a reciprocating engine above redline speed, would you expect it to last for very long?

The only bad thing about surplus helicopter engines it that they are cheap. That sounds silly, but they depress the market for new products that would be a lot better in terms of fuel consumption or reliability. With relatively inexpensive engines out there it is harder to bring new products into the marketplace. Right now it does appear that the supply of some of the Lycoming/Honeywell engines is starting to dry up and used engines as well as replacement part prices for those engines are climbing.

 

I didn't know that guy lived in Seldahoovia, I thought he was a Washington boy. I've always enjoyed Seldovia. It's a lot more than 12 miles away from Homer, it's a world away.

I know those herring seiners are that way about boats. There was a clan whose name escapes me now that had 3 high speed seiners built by Modutec. They bought the mold and Modutec built the boats. The only boat name I remember of the 3 was the Gore Point which I think was also a triple screw.

LOL it always had extra fuel drums lashed on deck. I have fond memories of an incident offloading in Seward. That boat came in and met the fuel truck, the skipper laughed and yelled up to the driver about being his favorite customer. While he was fueling a russian came in in their ignorant rude fashion and waked everyone at the dock. When the Gore Point left he did this tricky triple screw pirouette, got his stern right next to the russians beam and blasted him into the pilings. Didn't disturb the rest of us a bit.

 

The Cabana clan. I fished for blackmouth with Larry on the Silver Beach a couple days ago.
By the way, the one that had triples (it was the Gore Point) was hardly faster than the ones with twins. They are all three just twins now with tiny John Deeres.
'it's a world away" - kinda like Fox Island to Gig Harbor. Kick Dixie when you go by!

 

there are a few dozen turbine pleasure boats in the US now, mainly 50' cats and as a replacement for a pair of 1000+hp big blocks they are a proposition.
Google Al Copeland Jnr, he's building a 4 engined big cat to claim the prop driven record which is about 220mph which the boat will do easily or should I say capable of..

 

Yes, there have been several turboshafts 'marinized' over the years including the (somewhat hated) Lycoming T-55 (think Chinook & Bell 214B) and the (definitely hated) T-53 (think Bell 'Huhey' series and USCG Dauphins), and the venerable Pratt & Whitney PT-6, to name the more common ones

Google "Andy Granitelli Turbine Indy Cars" to see a real world case of intentional restriction of the inlet to reduce power. (Even with only 24 "^2, he was still lapping everyone, that's when Indy pulled the plug on turbines )

'Hot Starting' is the usual way turbines get overheated
though that is easy enough to avoid most of the time by making sure the starting battery and motor are up to snuff, and the operator allows the engine to obtain sufficient RPM before adding fuel and spark. The auto start systems avoid all this, though which is more than likely to be part of a marine installation.

Over heating through straight-up overloading is an issue with helicopters, though as the FCU will respond to an overloaded (too heavy) vehicle by adding fuel to keep RPM in range. Digital engine management (mostly) prevents this kind of thing now. Probably less of an issue with a propeller in water, especially fixed pitch.

I bought a Allison 250 C-18 for $1200.00 (Mil. surplus auction) in 1995. It just had a slipped O-ring in the gearbox and was pulled and mothballed with only 50 hrs, TSO. A friend helped me split the gearbox and then all was good. I intended to put it in a Fiero, and had just about all the engineering worked out.

But then a guy with an airboat came along and offered $10K, and I really needed the money at the moment so...

Now there's this really cool turboshaft powered airboat that runs around on Central Florida lakes

Jimbo

 

Hell Jimbo that turned out well. Sold for a profit when you needed the $ and LOL who knows, might have saved your life. I can only imagine my life would be hanging by a thread toolin around in a turbine powered fiero. Sounds like the batmobile!

 

gas turbine for a backup generator

Yellowjacket, you say that gas turbines are only better than diesels in high-speed applications, but what about other applications where small size, light weight and low maintenance are more important than fuel economy?

For example, Rick is planning to build a boat with wind turbines and electric motor. If I were doing this, I would want a backup generator that is capable of driving the boat at good speed when there is no wind. But a diesel generator has several disadvantages --not only size, weight and maintenance, but also the fact that the fuel shouldn't be allowed to sit for too long. Would it be reasonable to make a very small gas turbine that runs off of propane?

I would want a fossil-fuel backup for cooking, heating, and water heating, and propane is better than diesel for those purposes. If you could run your generator off of propane, you could get by with one backup fuel system instead of two.
Also, propane has an unlimited shelf life.

You can modify a gas engine to run on propane, but the savings in weight and maintenance (over a diesel) is not that great. I'm thinking that a gas turbine engine would take up no significant weight and space and that the engine could be mostly ignored when it wasn't in use. You would expect lower efficiency but it is only for occasional use so that is not a major concern.

Just idle speculation. Any thoughts?