Sport Hydro Sponson Design

[007clint]

Has anyone had any experience with stepped sponsons or added sponson ride pads?

Are there any Sport Hydro 20 or 40 sponson designs that are doing well?

 

[Mark Anderson]

Most of them have stepped sponsons and ride pads. what specific info are you looking for?

 

[007clint]

Most of them have stepped sponsons and ride pads. what specific info are you looking for?

I am looking for pictures, drawings, (or even names of the hulls so I could maybe find pictures) OR even an article discussing this topic, so I can better understand the dynamics of this type of sponson.

Thanks

 

[Bob Blazer]

The step on the sponsons makes it easier to launch. It breaks the suction and drag that the water creates. Look at the amphibian airplanes sponsons, there is a sharp break a little more that half of the way back. This enables the plane to take off and land without nosediving.

Bob

 

[P THOMAS]

http://www.intlwaters.com/index.php?showto...4&hl=blazer

http://www.intlwaters.com/index.php?showto...8&hl=blazer

http://www.intlwaters.com/index.php?showto...4&hl=blazer

Check these posts there is some good info there

There are many variations on sport hydro design, angle of attack, dieheadral anheadral, offset pads, pads with smaller ride surface on a wider pad, steps.

I think the boat balance of the overall weight and the lift of the hull determines what angle and size the running pads can be.

When you have it all figured out let us know.

Phil Thomas

 

[007clint]

Thanks for the great information. If you don't mind, I am sure I will have a couple questions after I digest it all. Being an engineer is a curse sometimes - I can't just try something without understanding the dynamics behind it. Being new to the sport also doesn't help either since I don't have the experience to pull from.

Thanks

 

[jetpack]

These are pics I took as I was building and painting my Dumas Eagle. It is a 36" long hull and is built for a 40-45 size engine.

Everything was built to stock dimensions, however I feel the planing blocks on the front of the sponsons are designed too low and could cause drag or touch if the transom lifts too much.

Each sponson was filled with expanding foam before the deck was installed to allow any re-shaping changes easier by sanding and re-capping with ply.

The sponson that rides outside of the turn circle has no step lengthwise to it. It is designed to be able to slide without tripping.

http://www.intlwaters.com/index.php?automo...=si&img=837

The inside sponson does have a step along its length on its rise, which reduces the drag at speed.

http://www.intlwaters.com/index.php?automo...=si&img=838