Suppose a Hard Carbon Crackdown

Discussion in 'Boat Design' started by sharpii2, Jan 28, 2021.


What would happen to the planing powerboat hulls?

  1. They would simply be used less.

  2. Most of them would be scrapped.

  3. Some of them at least would be converted into displacement powerboats.

  1. wet feet
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    wet feet Senior Member

    I haven't been on too many motor boats,built in the the last fifteen years that didn't have a pretty full complement of power control modules,chargers,inverters and sometimes three battery banks (engine,domestic and thrusters).So they won't be gaining those and will be losing some stuff.It may not be too obvious just yet but Tesla and Nikola are on the verge of launching full size trucks for long distance hauling.Volkswagen,GM and Ford are moving away from IC denying the inevitability doesn't mean it won't happen and we should be observing and adapting.The alternative is to go the way of the dinosaurs.
  2. clmanges
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    clmanges Senior Member

    What supplies are you talking about? The slower one still makes the trip in less than eight hours, so you need to pack, what, a few extra sandwiches?
  3. Will Gilmore
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    Will Gilmore Senior Member

    For my ocean passage, I choose a displacement hull. I think most would. To get from point a to point b on the water takes more into consideration than fuel economy and ecology. Displacement boats are what any boat is when traveling under planing speeds, as has already been pointed out, and those are the speeds one travels in large ocean waves. Humans don't have backbones or brain padding to take planing speeds under common ocean weather and wave conditions for very long. Foils may be changing that. Fuel economy would certainly play a roll in choosing an ocean cruiser.

    However in the recreational boating world, getting from point a to point b, for many boaters, isn't the point at all. Getting there at fuel efficient rate also isn't a consideration.

    Water-skiing and wake-boarding, taking the family out for a run across the lake or just getting to a favorite fishing spot without having to spend the night on the water are all legitimate and very common reasons to choose planing hulls over displacement hulls. Then there is the most compelling reason of all, speed and power impresses us and we choose to pay I obscene prices for boats, just to show that off.

    -Will (Dragonfly)
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  4. KeithO
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    KeithO Senior Member

    I'm not forced to use an engine from the 50's in my 50's truck, whereas with my 2008 F250 with the 6.4 I cant just drop in a pre-emissions Cummins 5.9. I'm pretty sure your reliability problems don't apply to the Cummins 5.9 mechanically injected engine, nor the CAT 3116 engine found in the M35A3 deuce.

    How about the GM 3400 V6 vs its new variant with direct injection, variable valve timing and all manner of chains that have to be replaced after 75k miles lest the engine grenade. BMW turbo 4 cylinder that replaced the time proven straight 6 and also grenades because of various weak chains and guides by 70k miles. The fix costs $3500-$5000 and comes out of your pocket. Read Newer is not always better. There are plenty of lemons, especially when new regulations apply.

    My own Ford 6.4 engine (Navistar made it, the last engine), just try to have a service done at a Ford Dealership... They are usually backed up for months on warranty work. Cab has to come off the truck for any serious engine work. I know a lot of people in the hole from $7000 to $18000 with trucks that had between 70k and 150k. I bought my truck with 70k miles and have only put a little over 30k miles on it in 10 years. Hardly severe service. Yet the DPF was cracked within a couple of years of owning it, so it no longer stops soot from exiting the tailpipe. Yet in winter, the thermal loss from the exhaust is so high that a regen cycle will run every day for more than a tankful of fuel. 10mpg is all you get, just driving 55mph belching out huge clouds of smoke and smelling like a mis-adjusted kerosene heater. Ford / Navistar doesnt care. Not their problem.

  5. sharpii2
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    sharpii2 Senior Member

    There is one major flaw I see in your reasoning:
    You assume the planing boat can make a very lengthy voyage nonstop. It can't. It must travel at a mininum speed to stay on a plane. Once off a plane, it experiences horrible drag. And to stay on a plane, it must consume a minimum of fuel, which much higher than that of a displacement boat, even considering the much longer run time of the displacement boat. And this is even before the displacement boat is run at a slower S/L rate, which can improve its range considerably. To get greater range, the planing boat must carry more fuel. And, depending on the range expected, that amount of fuel can become substantial. It can quickly crowd out the boat's payload capacity to the point the boat needs a greater displacement just to carry all the nonfuel things it could before. Then it needs more power. And that means greater fuel consumption. Eventually, you end up with a giant fuel tank and little else.

    Of course, the same rules apply to the displacement boat. But it has more operating options. It can travel slower when the tank is full, then speed up some as the fuel load gets lighter. Or it can keep going slow to get the maximum range. I doubt my 18 ft example could carry enough fuel and stores to cross an ocean. But I'm absolutely sure my 16 ft planing example couldn't.

    So, for a very long trip, they would both have to make refueling and/or resupply stops.

    Suppose I add 90 lbs of fuel to both boats (about 15 gallons) but remove no other weights.

    The displacement boat will go just a little slower. The planing boat may not be able to continue planing. I know from experience that they can be that weight sensitive. This is one reason you see huge engines on their transoms. Not only to go faster, but to insure they can still plane if some unexpected weight is added.

    In my example, I deliberately sloped the game to favor the planing boat. I gave it an engine which was a little more than 30% more efficient, and I assumed it could get about 7 mpg while planing. I challenge anyone to find a planing powerboat, that displaces a ton, that can get that kind of mileage.
  6. wet feet
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    wet feet Senior Member

    All of which reinforces my point about the things we may be able to lose.I've also seen the amount of technology needed to reliably get an engine ECU to communicate with a gearbox control module that operated a gearbox.The engines were German and very good, The gearboxes were American and had some clever features which required the controller to mediate.The tech said that in effect they were both having to learn a common language and then use it and his laptop installed and configured the control language.It worked well because all the parties were extremely competent.How much simpler to have a slider or lever to just modulate speed of a motor?

    I think we may have outlived the era of planing hulls for leisure use.With the advent of low cost airlines we can get to distant places without the expense of berthing a boat and annual maintenance.If simply being at sea away from everyday life is the aim,we can go more slowly and still achieve our aim.
  7. gonzo
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    gonzo Senior Member

    It depends on your budget. 300 foot yachts are getting a Green Certificate and tax breaks because they reduced their carbon footprint with some solar panels.
  8. fallguy
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    fallguy Senior Member

    I decided to check back to see if this thread had any worthwhile content. It looks like chicken little was here which offers as much comedic value. Beyond that, not much.

    Before we had any fuel standards, the Saudis had the world on a plate. King Saud fathered 108 children. Oh, the horror of a Prius. Might put those guys on a lower plane down to say 60 offspring.

    Any reason to get a flow meter on a semi-displacement catamaran? Isn't it always faster burns more fuel?
  9. fredrosse
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    fredrosse USACE Steam

    Sharpii2 did an analysis for a one ton displacement boat requiring 5 horsepower to make hull speed. In my experience, making displacement hull speed requires something less than 2 horsepower per ton. Many displacement hulls are overpowered to allow for wind and waves, but his analysis should consider less than half the fuel consumption he has used.
  10. sharpii2
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    sharpii2 Senior Member

    That may be more about politics than actual efficiency. We have a problem with the wealthy dominating politics, here in the USA. I wouldn't be surprised if there's a similar problem elsewhere.
  11. sharpii2
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    sharpii2 Senior Member

    Thank you Fredrosse.

    Most of the design books and articles I have read recommended that level of power if not more. That's where I got that number from.

    Maybe this is why Robert Bebe insisted on what he called the "A/B ratio", a concept that got pilloried on this site.

    A/B stands for "above" / "below". This was a measurment of how much of the boat's profile above water divided by how much that was below. If the product was too high, he considered the powerboat to be unsuited for ocean voyaging. This didn't mean he considered it unseaworthy, just unsuited for ocean voyaging.

    I suppose his reasoning was, that to cross an ocean in a relatively small powerboat of say 45 ft or less, one needed a small engine and a very large fuel tank. A small engine usually burns less fuel than a larger one with the same hp, if the smaller engine is not over worked. And for this reason, the smaller engine could keep the size of the large fuel tank more within reason.

    But it did limit the boat's ability to deal with winds. If the boat had as much or more of its profile underwater, there would be a greater amount of lateral resistance to prevent the wind from blowing the boat every which way. So, more of the engine's limited power would be used for overcoming friction and limited wave making drag, than used for overcoming cross wind vectors.
  12. sharpii2
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    sharpii2 Senior Member

    I hear you.
    I'm driving a '98 Chevy S10 extended cab with a 4.3 V6 engine. It has over 340k miles on it. The body is starting to fall apart. And my family is trying to convince me to buy something newer. I have entertained that thought.

    But when I look at the economics of my situation, it just makes more sense to keep the old boy on the road, even if that means a rebuilt trans or engine.

    My income is extremely limited, and I need a vehicle to get to my job. If I buy something newer, I will have to go into debt to get it. And that means higher insurance costs along with the payments. And if it breaks down, I will have to go further into debt to fix.

    I am now an eco-criminal, driving a two ton dinosaur which gets less than 20 mpg. It probably puts out far more than its share of other pollution too. But it's what I can afford on my limited income.

    What I need is a small car that won't fall apart in five years (or even 10) with a small engine (about 40 hp/ton) and a 4 speed manual transmission. Nobody makes such a car. It's not profitable. And most don't want to drive such a car, because its performance is low.

    So, now I feel stuck with what I have.

    Even though I am an environmental firebrand, I understand the auto-maker's position.

    The C. A. F. E. rules are a ruinously inefficient way to get people to use less fuel. I read books where Lee Iaccoca and DeLaurean bitched about them endlessly. And that was back in the '80s.

    The more efficient way is to put higher and higher excise taxes on the fuel, which will push consumer demand in right direction. But it would screw me.

    Even if the electrics came out tomarrow, people like me would still be driving the now unwanted ICEs until we got taxed off the roads.

    I expect the ICEs to still be on the road up into the 2040s. Hopefully by then, we will have halfway decent mass transit, and I can hang up my keys for good.
    Will Gilmore likes this.
  13. Rumars
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    Rumars Senior Member

    Manufacturers make such cars, they just don't sell them in the US, the customers don't want them.
    Now is you take a look south of the border, you will find Renault sells the Kwid and the whole Dacia range in Mexico. What would you rather buy for 14k, the Chevy Spark or the Dacia Duster?
  14. goodwilltoall
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    goodwilltoall Senior Member

    I had 82 toyota celica 32mpg, 84vw gulf get 44mpg, 87 Nissan 3 door Sentra 47mpg, friend w 84 Honda crx 58mpg, friend w 84 vw diesel pickup 57mpg.
    Absolutely preposterous how tyrants keep talking about going green but actually r regressing.
    Cars r old technology, if I wanted I could build a simple straight frame w a 40 hp kubota diesel n driveline that would last 70yrs and get 70mpg.
    Half the nations on earth build cars but in US people r limited 2 buying from monopoly players that have rigged epa regulations to keep out competion forcing buying average cars costing $25k rather than $7k.
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  15. missinginaction
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    missinginaction Senior Member

    I can tell you from personal experience that planing boats can be pretty fuel efficient. A lot of you know who I am and the story of my little cruiser. Here's a picture for those who don't. Small boat, not fast, over the past seven years I've done some fairly extensive trips. I've kept track of my fuel consumption.

    Pearl Aft.jpg
    Inside this boat is a small block Ford V8. At displacement speeds (8 - 9 knots) it burns a little less than three gallons per hour. My fuel economy in calm conditions is about 2.9 MPG.

    See that little outboard there on the swim deck? That's a Yamaha 9.9 high thrust. That little outboard will push my boat along at a leisurely 5 knots. I typically run it a bit slower. At 4 - 4.5 knots (5 MPH or so) that little outboard will literally run all day on a 3 gallon gas can. More than once I took a measured trip and found that the outboard achieved 8 miles per gallon running on it's own. That's right, 8 MPG.

    That little Honda generator that you see on the starboard side is their smallest. Rated at 1Kw. Weighs less than 30 pounds. Burns 8 ounces of fuel per hour. A battery charger can be run off the generator (40 amp) that feeds the batteries, which runs the 5000 BTU air conditioner, refrigerator/freezer and other house loads. If my "red neck" air conditioner breaks a replacement is about $200.
    Pearl Profile Photos 2014 002.JPG

    Gas is relatively inexpensive right now and I almost always use the main engine. Should fuel prices double, I'll certainly lean more on the outboard/generator. I won't be setting any speed records but I'll be out there, the AC will be running and the beer will be cold.

    Maybe going forward new boats will be designed something like this. But in order for them to sell, people will have to change their attitudes, here in the US at least.

    Back in the 1970's I owned a car powered by Buick's mighty 455 v8. It was pretty fast but it burned a ton of fuel. Literally. We used to say "Speed costs money. Now, how fast do you want to go?"
    Last edited: Feb 2, 2021
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