Starting Rescue Minor in Plywood HELP

[Ricardo42]

Wes, I am interested in building a rescue Minor with the same setup that your father used. Have you got a photo that you can place on the Forum so that we interested paties can have a look? I live in Australia in a Lakes area and the shallow draught is very attractive

[cshire]

All these ideas of belt drives, hydraulic drives, maybe diesel electric, and other conversion/innovations are interesting.

However the consensus seems to be that additional weight may be needed to have RM sit on her lines properly with our lighter modern engines.

Why not stick with a tried and true Velvet Drive or similar inboard transmission? Direct drive Velvet Drives are just under 100 lbs and reduction drives are around 125-130 lbs. Used Velvet Drives can be found on e-bay and boat salvage yards for maybe $250.

They are fairly simple transmissions, parts for rebuild are readily available, etc. Why re-invent the wheel when a usable and affordable solution is already out there?

[Sal's Dad]

It's not about the weight - it is finding the appropriate gearing and geometry. RM needs a fast-turning prop, with a perfectly horizontal shaft, about 5" above the flat bottom. And a powerplant of about 20hp. I am not familiar with Velvet Drives - but it looks as though current models wouldn't work in this application.

Suggestions are welcome.

Sal's Dad

I got a little Hurth (current version is ZF10M) on EBay, but it's going to be tough getting the engine (Kubota 722) low enough to get the shaft positioned properly.

[cshire]

If you want your prop shaft to spin at 2000 rpm and your engine makes it's max torque at 2000 rpm and has a max rpm of 3000 you want a direct drive transmission - no reduction or overdrive. Any fine tuning is accomplished with the prop.

I don't have the full plans for RM but the lines drawing on the Atkins website appears to show the shaft at a shallow angle not untypical of inboard power boats. This should get the engin up off the floor a bit.

One option to mount the engine lower may be to modify the oil pan (and pickup if needed). Many powerboat applications use a different oil pan than automotive use to allow lower mounting of the Ford and Chevy V8 engines. For a Kubota you would probably need a custom fabricated sheet metal pan.

[Tylerdurden]

I am running a Yanmar in mine, in mock up the shaft is almost parallel.
I am using direct drive using a powerflex belt for reduction. As Wes says Robb White found he didn't need reverse and I have been chasing the dragon with my kitchen rudder idea. I am going to build conventional and leave in place where I can mount the kitchen rudder at a later date. I had some major issues with the rudder prototype so I will finish that idea later.

[pipefitter]

Where I launch my boat at,it is too shallow to put the outboard down to use reverse and I don't like sucking all the sand thru the water pump so I use a push pole to move the boat to deeper waters.I could see where you could easily get away without reverse.Airboats have no reverse either. I doubt you will miss it unless you launch from ramps with strong tides and then it's just getting handy with the boat hook upon returning.

[mcdenny]

Lots of folks use reverse for "brakes" when docking. Makes me cringe to watch.

[Clarksound]

I have thought about building the Rescue Minor but I needed to see some photos of the construction. I did run across a professional builder who has a pretty good website with pictures of the Rescue Minor. If anyone needs a visual of the construction of the Rescue Minor take a look at www.seaislandboatworks.com They have a pretty extensive photo gallery.

[Philip Maynard]

I see there are photo's of a model now on atkins site which I do not recall seeing in the past and it confirms their description:
"The form of the hull is simple and therefore comparatively easy to build using waterproof plywood planking"
http://boat-links.com/Atkinco/Photos...nor/index.html

With regard to "Nobody has ever built Atkins' Rescue Minor"

Atkins says he built many of these, "And added to these straightforward features one can rest assured that because I have perfected the design by slow development over many years and by the production of many boats of this particular model"
- did none survive?

[Spokaloo]

I know of one thats been built, has been used, and is being fine tuned now, trying to play email tag with the guy.

E

[kengrome]

... a professional builder has a pretty good website with pictures of the Rescue Minor at www.seaislandboatworks.com

Well what do you know, it looks like there is a "genuine" Rescue Minor being built in modern times!

Robb White built something very similar of course, but he made his very light, he gave it softer chines, and he made some other changes too I suppose. Then people whined that his boat was not a "real" Rescue Minor ... but to tell the truth I don't know what that has to do with anything ...

If a boat has a tunnel-stern that is similar to the original Atkin plans, and if it works as efficiently as Robb White said his did, then who cares if it's a "real" Rescue Minor or not?

I'm designing one myself that is certainly not a real Rescue Minor, nor is it a Shoals Runner, nor is it a Tolman Seabright -- yet it has what I think are the best attributes of all these boats, and a few other features that should make it even better:





This is just a preview, the rest of the images are here:

http://www.bagacayboatworks.com/link...bb19/index.php

length = 19 ft 0 in
beam = 5 ft 9 in
draft = 6 in
waterline length = 16 ft 4 in
waterline beam = 4 ft 5 in
height at bowstem = 3 ft 0 in
height at midship = 2 ft 1 in
height at transom = 2 ft 3 in
displacement @ 6 in = 1000+ lb
displacement @ 12 in = 3000+ lb
displacement at flood = 7800+ lb

If I can keep the weight down to around 600 pounds or so for the hull and engine, this would meet my target design displacement of 1000 pounds for two people plus fuel -- and allow the boat to run full speed in 6 inches of water. With only one person onboard this boat will probably draw only 5 inches ...

[kengrome]

An Onan twin cylinder with 18 to 24hp is light, smooth and very reliable. Usually under $1000 NEW.

I just found a web page that says Onan engines are no longer in production, so it looks like the only ones available any more are in used equipment.

[Tom Lathrop]

Well what do you know, it looks like there is a "genuine" Rescue Minor being built in modern times!

The owners/builders of Sea Island Boatworks in Charleston, SC are friends of mine. I did not know they were building a Rescue Minor though. Rest assured that I will get the straight scoop from them about this boat and its performance.

[erster]

Tom, when Steve was here last week, he also stated that at the Perido [sp?]boat show this year there was a finished on exactly like the late Mr. White, built strip planked. But he state that the guy has never shared anything on any internet forum.

[Spokaloo]

Another REAL Rescue Minor:



E

[Sal's Dad]

"Bingey" afloat - in this picture with temporary 6hp power.


About 8 or 10 kts, with 25 hp temporary power. Note water in well.


Careened for finish work. (note Diablo at left - she misses the 25!)


The way life should be...


Anybody in the Bath, Maine area want to help me with sea trials? I'd like to get some photos at various speeds. There are significant performance issues (porpoising and loss of control over 12 kts!) that need some attention. I'll be mostly offline this summer, but can be reached at 2O7 65O 3235.

Curtis (aka Sal's Dad - see McCloskey's books...)


Just nobody ask what kind of wood it is!

[Sal's Dad]

I forgot to mention - the most disturbing incident so far was running up on a mud bank on a falling tide. With an outboard, the lower unit digs in and stalls, then you pull up the motor and row/push/pull (think "African Queen) back to deeper water. But I had run it up into 3" of water before it stopped, with the tide falling about 1/2" per minute. A few minutes of frantic efforts, then a 3 hour wait . . .

Makes you think twice about hot-dogging around in the shallows.

Sal's Dad

[kengrome]

Hi Sal's Dad,

It's GREAT to see your Rescue Minor pix! It looks like all your effort was a success. I see that you'll be offline most of the summer but maybe I will catch you before you leave cyberspace, and if not then perhaps you can reply and post some more news when you're online again.

I'm curious about the water level in your outboard well. In your second picture it looks like the water is only an inch or two below the top of the well. Am I imagining things or is this really how high the water gets in the well?

Your porpoising and loss of control issues may be the result of your temporary power system. If all that water is being sucked or pushed up into the well it seems like it might not lift the stern as effectively as it should. Once you finish the boat according to plans it will probably perform more like the way Robb White described his boat.

How much does Bingey weigh empty with no engine, did you have a chance to weigh her before getting out on the water?

Congratulations!

[Sal's Dad]

Ken, Yes, the water fills that well right up, at 12 kts it is full to the rail and streams out through the deck scuppers, despite maybe 2 square inches of scupper at the bottom of the transom. I'd guess the water gets 16" or 18" high, better than 20 gallons, with the motor and fuel tanks lashed on top, that puts maybe 350-400 lbs right aft. Even with this, the bow still pushes down if I try to go a bit faster. This is exciting - solid water up the bows, forced up into the gaps in the pipe rail, then streaming down in sheats from the inside of the rails. Meanwhile stearing gets wild, and the crew starts to panic...

There is a bit of "hogging" in the sheet metal, as a result of weld distortion. Before trying to fix that, I'll try sealing up the motor opening. The prop is pretty much right where the plans say, but the exhaust runs out through the center, so maybe that has an impact.

Weight of hull is about 550 lbs, and so far gear is pretty minimal. I have some heavy cargo to transport, maybe that will change the dynamics.

Sal's Dad

[Pericles]

As in most cases, there are additional designs to be considered when trying to create a craft for running safely in shallow waters. Some months ago, this company was brought to my attention and you may find some of their ideas inspirational. http://www.flatscat.com/

If nothing else, their videos are instructive and entertaining.

Regards,

Pericles

[Eric D]

any updates from those building these? Tom any news from your buddies who are building them?

Thanks