Design Challenge: Trapwing-"on-deck" ballast-12'-22'

Trapwing Prototype

I just received this e-mail from Mark Bryant(www.markbryantsailing.com). He has been extremely encouraging to me and he is an accomplished sailor and Disabled Sailing Coach:

"WOW,
That is way cool... Do you need a builder ? Send along your specs and composite schedule....

Mark"
Thanks ,Mark!

 

Gary, thanks for the comments. The whole wing moves to windward in such a way that it will be very dfficult to bury the lee side of the wing. The pod is designed specifically for high speed contact with the water so that it creates a lot of dynamic lift in such a situation.
As to water ballast: at this size water ballast is probably impractical but if you look at my proposal for a 60' Moth you can see that the sliding on-deck ballast there is water and would work well.
Just as an illustration an 8" X 3" X 12" slug of lead similar to one that might slide in The Wing weighs 116lb. To put that much water in the same wing would require an amount of water in a container that was 8" X 3" X 129"(10.75')--which would clearly be impractical. So, in my opinion, at this size, lead is without a doubt the way to go.

 

Real good idea about the transverse foils (wing )... With this amount of ballast, ( if, I knew sail area ) the boat looks like it would be Kick ***...

MB

 

Here are the details of the prototype:
===========
The following is a detailed look at the characteristics of the new Prototype, as well as the design elements it will encompass and test:
-----
Trapwing Prototype:
LOA 17' 8"
Beam hull-3.25' overall 12'(subject to testing)
Weight- hull 155lb
ballast-wing 80-180lb(variable and subject to testing)
keel 0-80(subject to testing)
SA-upwind 100-180sq.ft. variable
downwind 200-360sq.ft. (variable and subject to testing)
crew-singlehanded-120lb-220lb (variable and equalized under class rules-
subject to testing)
crew position for racing on the centerline inside boat, fixed
athwhartships, variable fore and aft
--------------------
1) Sail area to be between 100 and 180 sq.ft
a-different rigs
b-different amounts of ballast
--
2) Ballast wing to be supported by trapeze wires and unique retention system that allows wing and ballast to slide simultaneously, allows athwhartship pivoting and fore and aft movement.
a-version one will use two aluminum tubes with sliding external tray- the tubes and tray move simulataneously:
-attachment system allows wing- with weight centered-to be levered up and then pivoted from a position 90 degrees to the CL to a position parallel to the centerline for transport and stowage.
-weight can be added or removed in small increments.
-fore and aft pivot/sliding tube is mounted to the boat slightly offset from the CL to allow room to retract board/keel.
-aluminum tubes terminate at outboard ends in buoyancy pods-pods will be changeable as determined in testing.
-sliding ballast tray and structural design of wing to be capable of 180lb max ballast @9' from CL; ballast completely adjustable in the range of 80 to 180lb.
b-version two is a slightly curved(athwhartship), molded and sealed(with sealable access to ballast tray) wing with an internal sliding ballast tray. This version will be the final version and incorporates all the features of version one with significantly increased sealed buoyancy.
c-Wing movement by manual or electric means. Minimum electrical movement speed 4' per second. Minimum electrical "stamina" on single battery-12 hours at a rate equivalent to a approximately 60 (full track)tacks per hour.
--
3) Crew Position
a-version one-racing position-allows crew to sit in an extremely comfortable seat that is fixed athwhartship and slides fore and aft adjustably while sailing.
-extremely wide crew weight range:for racing lower tray attached to seat may contain ballast used to equalize crew weight in the range of 120 to 220 lb.
-seat may be moved manually or electrically.
b-version two-center seat is removed and two fixed carbon seats with backrests are "plugged-in" to each side deck.
--
4) Rigs to be tested are main and jib, main alone, with and without an asymetrical spinnaker.
a-asymetrical will be tested as permanently mounted off a bowsprit(a la Weta tri) or retracted into a trough with roller(a la Viper) and a retractable pole.
b-mast to be sealed with masthead floatation in an endplate configuration. Some buoyancy possible in head of sail.
--
5)-Daggerboard/ keel/rudder
a -boat will be tested with and without a retractable "lifting keel"
which would essentially be a carbon daggerboard with the minimum ballast required(determined in testing) to right the boat from a pitchpole(where the wing buoyancy may not significantly help).
b-self-righting from a knockdown or pitchpole is a required design element for any version of the boat used for disabled sailing.

c-a turbo version of the boat will not use a ballasted keel and may not be suitable for disabled sailing but this will be determined in testing.
d- the daggerboard may include as standard a lifting hydrofoil designed to provide "foil-assist" to reduce wetted surface and in conjunction with the rudder hydrofoil improve the pitch and planing characterstics of the
boat.
e-a fully flying hydrofoil system will be tested as will a fully flying system that allows the boat to fly downwind only(requiring less upwind SA and less ballast).
f-rudder will be retractable with a t-foil.
--
6)-On the Beach
a-the boat will be able to be easily beach sailed with a dolly incorporated into the trailer design to make it very simple to go from trailer to water. A "power assist" dolly may be available.
--
7)-Performance
a- the goal is to develop a high performance planing sailboat that can be safely sailed from a center crew position by disabled or able-bodied sailors. I am hoping to be able to achieve an SCP/total weight of 30% or slightly better though that is just a target and a less powerfull version with numbers and performance more like a Windmill or Tasar may be perfectly acceptable. The use of foil-assist technology will help to achieve the performance goals. Full flying foiling is possible in a selfrighting boat-particularly one with the righting assist this boat has from version two of THE Wing.
-------
The concept has extraordinary potential and it will be a blast finding out just what she'll do.

 

As I thought, I had it wrong, you're moving the whole beam like an International Canoe sliding seat - and I thought you were sliding ballast along it (which would be a lot simpler, I might add) - actually you're doing what the failed speed record trimaran Slingshot attempted many decades ago.
But with all this complexity of moving stuff, Doug, wouldn't it be easier to just build a simple and well proven trimaran with foils?

 

-------------
Gary, the weight slides in the wing as the wing itself slides. This allows twice the RM compared to a fixed wing of the same length.*
This boat can be configured to be self-righting ,Gary. That is a critical element it its potential development. The moving stuff is not, to me, complex: it is actually quite simple and robust and certain configurations using THE WING will beat the foiling tri! Remember the fastest sailboat on the planet uses movable ballast.....

*Example- (rough illustration) : 6' fixed wing-100lb moves 3' from center. 6' sliding wing + internal sliding ballast of 100lb-ballast moves 6' from center with same length wing.

 

Trapwing Prototype-Small Rig

The rig shown is 120 sq. unstayed(except for trapeze wires). A rig about this size will be the first to test the system. Still having some camera problems(or photographer problems).
Also shown is name tag on stand....

click on images:

 

Movable Ballast-of historical interest: "Unit 7"

"Tractor seat on a pole"-

http://bearfacemedia.co.uk/Unit_Dinghy.aspx

 

Doug. I should be the last to make such comments, being a type of Gyro Gearloose myself - but fargo truck mate, the whole concept of yours looks a mess. Maybe you should start from scratch again and simplify .... and simplify radically. At the moment it is belts, suspenders, braces, tangles and trip ups waiting to happen. Just being my usual brutal, but honest self. I mean well.

 

-------------------
Gee, Gary-thanks for the comments. I do think you are way off base in addition to being dead wrong. Luckily for me, your analysis is in the minority of those who might count.....

 

Gary... Why suggest pragmatism when there is a walnut based, self-made trophy with an engraved brass name plate to be built?

 

And he probably has to cut it up to be able to do a lines drawing

 

Let's be positive about this

Come on folks, let's be positive about this. Doug is building a model now, and that is a lot better than building nothing. Next he'll be building a boat, and that is a big step forward as well.

I think that we should all support Doug on his progress thus far, and wish him well. I certainly hope he succeeds in this project. At the root of all the noise around Doug, he does at least have lofty intentions - higher performance for the mobility challenged. I'd be happy if the boat works and Doug can rip around the ICW foiling with a cool one in the gimballed drink holder.

My own clear opinions on the project and Doug's abilities is irrelevant to my wish he succeeds. If he does succeed, great. If he doesn't succeed, he's at least building things and trying out ideas and that is far better than polishing his prodigious troll skills on the Internet.

Every minute Doug spends building things, walnut trophies or not is a minute not spent on the Internet. And that is a good thing for everyone.

--
Bill

 

Full agreement, Bill.

For my part, it was just a bit of humorous interplay, knowing that Doug is a true, avuncular gentleman and would understand the care with which it was posted.

Present tense suggestions of blistering performance aside, I'd really like to see a full-sized, working example, as well.

I do hope that there are some pictures/vid clips this time, as they will go miles to support any discussion in the future.

 

Doug, I would like to see a one meter model of this boat, could it become an AMYA Class? why not.
sailfast