steps

glen76 · 22-01-2006, 09:37 PM

whats the optimum number of steps on a stepped hull. ive heard single stepped craft can pivot about the step, so shouldnt lots be better? 3, 6, 10??

Burty · 23-01-2006, 12:44 AM

Most seem to have 3 the only one i've seen with more is Adams cat which has 4

JamesM · 23-01-2006, 06:11 PM

Quote:

Originally posted by Burty
Most seem to have 3 the only one i've seen with more is Adams cat which has 4

Think you mean 2 and 3 steps.

CB1 · 23-01-2006, 06:56 PM

Our cat has 4 steps per sponson.

codprawn · 24-01-2006, 09:15 PM

I remember seeing a photo somewhere of a boat with loads of steps - think it was 7 or more!!! Boat was from the 1920s so not much new out there really......

glen76 · 24-01-2006, 10:00 PM

so nobody really knows then huh!

K9 racing · 24-01-2006, 10:05 PM

bat boats only have three and that seems to work well enough

K9 racing · 24-01-2006, 10:06 PM

two even

BluFin · 24-01-2006, 11:16 PM

The key to steps is make sure they vent correctly or the little suckers will actually hold you down, the Idea is basically to redued the wetted area as well as giving a more level attitue. The number & size is dependant on the way a boat would run without them, That is a good base to start Steps are normally added as the breed evolves, or by calculation with those wizz bang comptr cad wotit thingys. In the case of the phantom 21 (Hot Gossip) it had a single but it wasn't really any quicker than the normal 21' Would have been nice to see an experiment on the 25'.
THere are many schools of thought but it boils down to a couple of big ones or lots of little ones. obviously the parasitic drag increases with the number of steps employed. IMHO three is about the max required for most applications, but I talk s**t anyway. A step is only effective when it's a running surface or wetted area so if it's out the water it dont need to exist, cats tend to use them at intermidiate speeds the they be come redundant as as you are running on the last foot of the sponson. Look a t the back of the skaters & various the way it steps up then runs back to the transom. a step hence running on the prop and the tip but with a more forward c of g than with out the step (thats a running c of g) which will make for a more level angle than with out, I'm waffling of topic.

3 Purrrfect +/- 1

rama · 26-01-2006, 08:27 PM

go to [URL=http://www.sharkeymarine.com/]and look at the outerlimits factory tour part1, lots of steps there.