Fuel Consumption

[Rod Kelly]

I am the Sales Director for a firm that had developed a rather impressive new hull design for crafts from 18' to 60' that both eliminates wake and diffuses the impact of waves to provide a very stable ride. We have created an interest from the U.S. navy, and we are looking for some back up information concerning fuel consumption.

The prototype of our craft is 24' with an approx. weight of 5,000 lbs. It is powered by a 225 Honda 4 stroke engine.

The information I am looking for is the fuel consumption figures of similar sized and weight craft with the same motor. If you have a comparable craft,I would love to hear from you, and the fuel consumption figures in gallons per hour at a sustained speed.

I would greatly appreciate any information you can provide for me. The website for our craft is www.waveskimmer.ca

Thank you for your assistance

Rod Kelly

[FAST FRED]

I WOULD HAVE ASSUMED TO CLAIM THE RESULTS PROMOTED ON YOUR WEB SITE 40% FUEL SAVINGS , YOU HAVE DONE THE TESTING!


1800# Boat (deep "V" hull) 3000# Boat ("WAVE SKIMMER")
30 mph. Cruise Speed 30 mph. Cruise Speed
135 Horsepower Mercury outboard 175 Horsepower Mercury outboard
12 gal. / hr. (0.40 gal. / mile) 7.5 gal. / hr. (0.25 gal. / mile)

"The information I am looking for is the fuel consumption figures of similar sized and weight craft with the same motor. If you have a comparable craft,I would love to hear from you, and the fuel consumption figures in gallons per hour at a sustained speed."

Would not the results you desire be more realistic/useful/honest if you simply installed a Flow Scan on your own motor , and ploped it on similar boats for a real life comparison?

FF

[Leo Lazauskas]

Originally Posted by Rod Kelly

I would greatly appreciate any information you can provide for me.

You will continue to be viewed as a charlatan until you can provide independent confirmation of the 40% fuel reduction you claim on your web site.

HTH.

[Frosty]

But you must already know the fuel consumption of a similar vessel. How could you quote a 40 % saving.

10% savings would have raised eyebrows ,--40% has probably attracted unwanted attention.

[mydauphin]

Darn, that is scary looking boat. Can I fit a giant vacuum cleaner to clean lakes with it.... All kidding aside.
Fuel consumption at what speed?
Obviously, all boats work differently at different speeds.
Is this a displacement hull??? Or a trihull planning?

[gonzo]

You claim 40% reduction in fuel consumption without data? I looked at the video, there is a wake as with anything that moves through water. In the post you say "eliminate" in the website "reduce". You did not eliminate it, and what do you compare it to when you say "reduce". This is typical of people that make sales pitches based on false and unfounded claims.

[Rod Kelly]

Thanks for your info... We have documented the fuel savings on a small group of "Deep V" hulled craft.. It was also confirmed by the Canadian Coast Guard's advise as a reasonable fuel saving figure based upon their assessment of the prototype.

It had been recommended that we look for a larger base of comparison. That's why I have posted his thread.


Thanks again.. your information is most helpful

Rod

Originally Posted by FAST FRED

I WOULD HAVE ASSUMED TO CLAIM THE RESULTS PROMOTED ON YOUR WEB SITE 40% FUEL SAVINGS , YOU HAVE DONE THE TESTING!


1800# Boat (deep "V" hull) 3000# Boat ("WAVE SKIMMER")
30 mph. Cruise Speed 30 mph. Cruise Speed
135 Horsepower Mercury outboard 175 Horsepower Mercury outboard
12 gal. / hr. (0.40 gal. / mile) 7.5 gal. / hr. (0.25 gal. / mile)

"The information I am looking for is the fuel consumption figures of similar sized and weight craft with the same motor. If you have a comparable craft,I would love to hear from you, and the fuel consumption figures in gallons per hour at a sustained speed."

Would not the results you desire be more realistic/useful/honest if you simply installed a Flow Scan on your own motor , and ploped it on similar boats for a real life comparison?

FF

[Stumble]

Assuming this is on the up and up...

Take a look at TwinVee's performance numbers for their 24' powered by twin 115 outboards. Not a direct comparison but in the ballpark, and the boat weight is pretty close.

The attached file is from a 2005 TwinVee hull with new twin 115 Yamaha outboards. The fuel flow numbers and rpm readings were taken strait off of the engine instruments calibrated by the dealer before testing. If the Excel spreadsheet won't come up PM me and I will e-mail it to you. Speed reedings were taken every 500rpm by DGPS, with the boat constantly being accelerated (we didn't back down the throttle once it was on a plane). All testing was done with one person on board and a full fuel tank.

[Willallison]

I suggest you take a look at a few of the us power boat magazine sites - Power & Motoryacht, Motorboating, and Boating all publish quite extensive test results and most are readily available online. You need to be a little selective about some of the test results, however, as some are simply based on manufacturers consumption figures as opposed to actual test results.

And guys, give the fella a break... ok there may be some unsubstantiated claims there, but he only just got here....and was just asking for some guidance...
If the claims prove to be baseless... we can keel-haul him then

[Frosty]

Very diplomatic Will and probably right.

Perhaps the first 5 words of his opening post explains everything.

[Willallison]

Yes - granted, that wasn't the best opening line!

[FAST FRED]

But the first 5 words were HONEST!

FF

[marshmat]

Guys, guys.... let's give the guy a chance. The boat resembles a few SES (surface-effect ship) shapes that have been spotted here and there, many of which have worked fairly well. Maybe this thing is worthless and the claims are bunk- then again, maybe it'll turn out to be the next big thing in medium-speed planing hulls. I'm willing to give him a chance.

Now, on the fuel consumption issue. A big part of the difficulty here is that there is such a wide range of marine engines available. A 1987 two-stroke outboard might very well use two or three times as much fuel as a modern direct-injected model. A brand-new 4-stroke outboard from one manufacturer might be vastly superior to a competitor's two-stroke at some speeds, and noticeably inferior to it at others. At least among small planing hulls, fuel consumption is really only a valid comparison between complete boat/motor packages- not between bare hulls. Now, if you can find other boats, about the same weight and with similar performance and similar engines, fuel consumption could be a useful comparison between them.

If you're looking to differentiate this craft from the existing (and very large) crop of deep-V designs, consider the following points as worthy of investigation:
- At what speed is it really on plane (if that really describes how an SES is running at speed)? Many deep-V hulls simply cannot operate between 9-18 mph or so, they have to be either fully on plane or dead slow. Load the thing up, both bow-heavy and stern-heavy, and see if it can run well in this range. Being able to top 40 mph is great advertising, but most people actually cruise much slower- and slower still in rough weather.
- What happens to the trim as you accelerate? Anyone moving up from an 18' deep-V will be expecting the bow to rise, often above the horizon, as you accelerate. A boat that stays level would be a highly desirable surprise to many folks.
- How does it handle rough seas or chop? Does it pound? Does it cut the waves smoothly? Does it have any new handling characteristics that a deep-V owner would find unfamiliar? Many SES designs can keep up a pretty good speed in bad weather, to a point- at which time they, too, have to slow down. How does this design behave when you do slow down? How does it naturally lie when you kill the engine, beam-on or end-on to the wind and waves? You may find some desirable handling traits that are worthy of marketing attention. Conversely, you may find some undesirable traits that would demand either modifications to the design, or different seamanship techniques for the captain.

Best of luck

[yellow cat]

Hi Rod,
Have you heard about the volvo duoprop ? Playing with the pitch (variable prop pitching would be even better) will reduce rpm hence fuel consumption.
Friction and displacement being the essence of low drag alowing the uplift of the craft untill feasable propulsion (the prop in water ...) . The "new" catamarans designs tend toward reversed bows for wave piercing. The other factor is energy dissipation horizontaly see "hydraplaneur médiatis" from the "redan" shape typically used for hydro planes . The wake left is greatly from the shaft and water propulsion energy. If for instance, the motor would be forward (could even be a front prop traction at low speed ) and move back with increase speed , it could even reduce wake .I am designing my cat with that in mind but other factors will come into play, as you know, the bows have a sink in tendency "suction" from the displacement. Another factor is stability, bouncing up and down increases distance and aerodynamics of the sails and the sink into (surfing not considered unless right direction).
The best fuel economy might just be the regen electric hybrid/gas/H concept.
Sails, kite(s) , elect. regen motor (solar, batteries, surfing).
It is (conceptually) possible that the hovercraft (and not at present technology) may be the choice (when i look at your video going thru dangerous rock islands) for specific use. In canals, the wake is one thing but hitting a manatee or a whale is another.
Just want to reflect on this, got to go.
mike

[Frosty]

Give the guy a chance ---Ok,-- what I saw was an ugly boat but different. The wake did look less but maybe the boat is very light which would give a light wake.

It crossed the wake of another and looked stable as it did so but it was the wake of another wakeless boat.

I got bored after the guys in the canoe fishing bit.

I didn't look fast but film can be speed ed up or slowed down.

Thats what I saw.