Monohull verses Multihull powersailers / motorsailers

When it comes to getting from here to there, as fast as possible, with a maximum of HP, 2 hulls or sponsons ( baby hulls ) are used. Any speed records read otherwise? Read that as efficiency. And I love MONO's.

[FAST FRED]

"I suppose that big ships would hardly benefit from the multihull design in terms of speed because they are not constrained by small size proportions or by propulsion mode."

Transports are constrained by hull speed.

If the vessel gets to fast and looses the midshops wave , most will break in half.

20 to 25K seems to work interms of low power required , delivery times and hull structural constraints.

FAST FRED

Since I don't understand a word. O K

[icetreader]

I think I understand :-) and it makes sense to me.
I bumped into serious structural problems when designing the world's smallest catamaran: A polyethylene, roto-molded 122 inches long and 25 inches wide paddlesports boat.
The problem was the the passenger(s)'s weight distorting the boat's shape.

Yoav

[ron17571]

I once talked to my neighbor,an ex navy man and told him of my thinking of cruising with a forty foot catamaran(to many years of reading multihulls magazine)he started laughing and said he wouldnt go on the ocean with a ship less than 600 foot long. But i just think of slowly slogging along at an angle in a monohull.I couldnt hang it.I think a catamaran trawler is my latest idea,I like the workmans boat on the trikini site.

[CT 249]

Originally Posted by Richard Petersen

When it comes to getting from here to there, as fast as possible, with a maximum of HP, 2 hulls or sponsons ( baby hulls ) are used. Any speed records read otherwise? Read that as efficiency. And I love MONO's.

What about the world outright sailing speed record, held by a monohull (sailboard)?

I suppose I could also mention that single waterski is faster than a double, but that'd be silly.

I am a firm beleiver of " the wider the stance the faster we go. ". Look at mono hulled iceboats. They are all tri-hulls or tri-wheels. A delta wing and trike gear is the fastest shape in the air and on the ground. The mono hull has not been seriously attacked by a multi hull yet.

[B. Hamm]

Originally Posted by FAST FRED

"I suppose that big ships would hardly benefit from the multihull design in terms of speed because they are not constrained by small size proportions or by propulsion mode."

Ships generally need weight hauling capability, one of the downsides of multi's is the need for them to be light. Conflict of terms.

B. Hamm

[B. Hamm]

Originally Posted by Richard Petersen

A delta wing and trike gear is the fastest shape in the air and on the ground. The mono hull has not been seriously attacked by a multi hull yet.

The delta wing isn't hardly the fastest in the air, has by far the highest drag vs. lift of any wing platform shape known. It's used only because it's strong owing to it's thickness and it's extreme leading edge angle helps with compressability at the speed of sound.

The trike gear isn't fast either, a conventioal gear (taildragger) has far less drag.

B. Hamm

How many land speed records have been set with a tail dragger compared to a trike. 1-2 - 4 or more points are all unstable for a table or chair or anything. 333333 is the only stable contact points of support of any object. Stopped or moving. Eventually, we will devote serious effort in the right direction. Ice boats do great in all directions and wind speeds. Why?

Do you remember the paper airplanes we made in school? Deltas were always the fastest and longest distance in still air. Straight could sometimes stay aloft longer.

[edaydesign]

Please excuse me but I am new here. After reading for the past 15 or so minutes about the constant argument on weather multihulls are efficient or not, I am getting confused.
I am currently finishing up my final year in Transportation design and began working on my senior thesis this past week. I am considering doing a project which will make the boating industry more sustainable(40-50 motor yachts). My previous research has mentioned that catamarans where a truely more efficient boat. Mainly for less drag and fuel efficiency. Is this Info Correct? Should I be looking into monhulls instead or continue with multihulls?

[terhohalme]

As a rule of thumb: At low speed, well under hull speed, monohulls are more efficient than catamarans, from hull speed to near planing catamarans are more efficient and at planing speed monohulls are again more efficient.

So, the catamarans are most usefull at semiplaning (semidisplacemet) mode.

All the fast powerboats I have seen and tuned were always 3 point hydros or a direct relative. Most boats running at + 200 are a 3 point hydro. 2 sponsons, and a prop are all that touches the water. Some hydos are fast enough to only have the prop in the water down the straightaway. They are for all purposes not a boat. A BOAT has as much of it's hull in the water during a turn, as it has down the straightaway. Any thing else is a FREAK. O K sensitive ones, take your best shot. Richard Petersen

Sorry we wandered Brian, from your original thought. I thought you were right. Tri-hulls are the equivelant of a 3 point hydro. Just going to take a FORCE 5 breeze to prove it.