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 Author  Topic: Question for PT Boat Experts
QM

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Post a Reply To This Topic    Reply With Quotes     Edit Message   Posted on: Jan 7, 2009 - 1:35pm
This reply is a little off the subject but also a bit related. A former Chief Motor Mac once disagreed with me when I said that the boats would "plane" upon reaching a certain speed. He said that the boats did not plane. He gave me another word which I have completely forgotten. The boats certainly would level off upon reaching a certain speed and the rooster tail would flatten. Can any old hands give me a word for this leveling other than "plane"?

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Drew Cook

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Drew Cook  Posted on: Jan 7, 2009 - 2:19pm
"On step?"


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TED WALTHER

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of TED WALTHER   Send Email To TED WALTHER Posted on: Jan 7, 2009 - 8:11pm
QM;
ON STEP is the correct term.
TED


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Dick

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Dick   Send Email To Dick Posted on: Jan 7, 2009 - 10:59pm

Jeff - - Can you see the EGG on my face . . .

You are correct; the lighting has made the louvers appear nearly invisible. I had read your earlier email about photo 2 but just couldnt make out what you said you saw. This time I downloaded the photo and enlarged it in PhotoShop and applied some filters, changed levels settings, then with the burn tool darken up each area. Low and behold there they were louvers, not brackets. I even outlined lightly the second to the last. To better define the object.

This angle shows the exhaust ports (the very dark spot) on the backside of the louvers where either air, bubbles, spray, water or the combination of one or all are guided from the step planes and ported out of the louvers. From this photo the lovers are clearly fixed to the boat and not adjustable. They are clearly meant to vent but for what exact purpose Im not really sure. Below is a partial doctored copy of photo 2. He best I can do with the resolution and size of the original then again lowered for posting for web viewing.






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Jeff D

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Jeff D   Send Email To Jeff D Posted on: Jan 8, 2009 - 4:49am
Cool Dick, nice Photoshopping!

I dug up the plan but it pretty much just lays out the steps. There is some historical information though:




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victorkchun

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Post a Reply To This Topic    Reply With Quotes     Edit Message   Posted on: Jan 9, 2009 - 3:04pm
Hi David Buck,
I studied your reply of Jan. 7, 2009 in great detail. By George! I think I
got it. However, in your first sentence you wrote, as the boat moves
forward "the water is sucked out of the steps, thus creates a vacuum
within the steps." Do you mean " behind" the steps instead of "behind"
the steps. I assume the step is a solid piece of wood. Please advise.
Thanks for all your knowdedge.
Victor

Victor K Chun

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TGConnelly

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Post a Reply To This Topic    Reply With Quotes     Edit Message   Posted on: Jan 9, 2009 - 4:32pm
Jeff,

Please contact me offsite at PTConsultingNHR@aol.com. Thank you.

Garth


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David Buck

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of David Buck   Send Email To David Buck Posted on: Jan 13, 2009 - 3:43am
Hi Victor, in my reply to you i was following the line of thougth that you put foward in your post of Jan 7. "that the louves provided a layer of air under the boat". I should have explained that my thougths had a vent of some kind on the rear face of the step under the boat.

This vent could be either holes drilled into the face with a chanel leading to the chine and thence up to the louvers via the afore mentioned connection or, the rear face of the step may be hollowed out a small distance into the step and then a checkout would lead down to this hollow again from the chine connection.

Or nither theory is correct and the Elco steps as fitted were just solid pieces of timber and took advantage of the turblance they created to break the surface tension acting on the hull.

The reason i considered the chine cutout was the placement of the louvers which start a good 2/3 to 3/4 along the length of the steps and would allow the joining of the louver and the step with plenty of material to work with.

Another thing to think about is while there were a number of stepped hull designs around at the time not many of them carried the step up the sides as Elco did.

Steve Tuhy did bring up a good point and i agree with him if i owned a brand new boat i would not let anyone cut holes in it either, however we must remember that Elco had made 200+ boats at this time and they were always looking for ways to make them go faster and any hole in a timber boat could be repaired quickly if needed. This was proved when they had to remove the steps and louves and plug the screw/bolt holes that were left behind.

Just a point of interest there are a number of stepped hull designs that are currently in use today that use a system very close to the one i have described. Air is channeled down through the boat and exits at the rear of the step thus creating a layer of air under the boat for it to ride on. With the use of computers very fast boats are being built with differant forms of this system fitted.

Cheers David.

D.buck

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