FAQ

This is helpful for many reasons, including GZ stability curves and trailers. Clearly it is in detail specific to an individual boat, but generally it will be approximately the same for all Corbin 39s. a. I don`t have any drawings of the Corbin 39 left. Maybe someone in the group has and could locate the center of gravity on the drawings. The center of gravity should be between 6″ to 1′ in front of the longitudinal center of the keel and about 1′ above the bottom. This was a theoretical center because not all Corbins had the total ballast of 9000 lbs of lead. That should be enough info to build a trailer. Have a great day. Marius Corbin b. I should imagine the centre of gravity is near the middle of the keel along its length and somewhere between 2 and 4 ft above the bottom of the keel, depending on how much of the interior has been finished. Our lead ballast was 23″ deep, I believe, sitting on the bottom of the fibreglass which was probably about 1.5″ thick Regards, David Salter (#050, Opportunity). c. In the Longform Articles section of the website, a variety of analyses are made of stability using various Centres of Gravity (Zg). See especially the static stability and GZ studies (summarised here), and the STIX dynamic stability studies (summarised here).

a.  http://www.corbin39.com/qanda/#050, Opportunityinwinter.jpg

This is helpful for many reasons, including GZ stability curves and trailers. Clearly it is in detail specific to an individual boat, but generally it will be approximately the same for all Corbin 39s.

a. I don`t have any drawings of the Corbin 39 left. Maybe someone in the group has and could locate the center of gravity on the drawings. The center of gravity should be between 6″ to 1′ in front of the longitudinal center of the keel and about 1′ above the bottom. This was a theoretical center because not all Corbins had the total ballast of 9000 lbs of lead. That should be enough info to build a trailer. Have a great day. Marius Corbin

b. I should imagine the centre of gravity is near the middle of the keel along its length and somewhere between 2 and 4 ft above the bottom of the keel, depending on how much of the interior has been finished. Our lead ballast was 23″ deep, I believe, sitting on the bottom of the fibreglass which was probably about 1.5″ thick Regards, David Salter (#050, Opportunity).

c. In the Longform Articles section of the website, a variety of analyses are made of stability using various Centres of Gravity (Zg). See especially the static stability and GZ studies (summarised here), and the STIX dynamic stability studies (summarised here).

I am planning to put my Corbin in my backyard for a year or so to dry out and do some updating. I owned her since 1987. My boat is going in my back yard, not a boatyard. I know that 8 should do the trick. I also know where to place them. The reason I emailed the group is I plan to buy jack stands [aka acrow props] , but they come in short and long sizes. so how many shorts and how many longs??? I don’t want a cradle because I plan to strip the bottom to the gel and re-epoxy it and make it like new. Stands can be moved around. A cradle is stationary. I guess if any of the owners have a photo of theirs on stands would do the trick. I have talked to many yards here and they say, well when the boat comes out we decide then how many longs and short stands are needed. I have lived on her for 16 years and the boat has never been out to dry. I plan to let her dry out for a year and then really do a number on her inside and out, now that we have some land and a small house with no restrictions. Beaufort NC is famous for boat building, so it works out great. THANKS. CHRIS STOYAN (#096, GULLIVER)

a. Chris– My boat is out of the water right now and on jack stands. I will take some digital pictures Friday 11/26 or Saturday 11/27 and email them to you. I will also have to do some bottom epoxy work in next year or so (1984 hull with very little out of the water time!) so will be seeking some input from your process. Doug Archibald (s/v #158, Chaos !!)

b. When I bought my jack stands ( Brownnell ) they shipped me 6 footers after I told them what the draft was. I used 7 all together, three on each side and one V type on the bow. I did need to cut down the bow one to get it under the bow so I would advise you to get a 4 footer for the bow. Whatever you do, do not get too short of ones because you should not put them under the boat but up near the waterline. They do not support the weight of the boat but just shore it up. Use plywood under the stands too to prevent them from sinking. Check them often also, if the ground freezes it rises and will indent the hall when they get too tight. Make sure you line them up properly across from each other to load the chains right. Point the short legs towards each other. Gene Whitney

c. Hi Chris, We had our boat bottom totally redone. We had it in a cradle during that time as the concern was that jacks WILL MOVE. We found that we could remove any one pad at a time to access the area without compromising stability. As far as short / long goes ???? I will attempt to attach a pic. of our boat in the cradle. Consider the draft and how far from floor that may give you an idea ???? Good luck, Frank Bryant, (s/v #186, Visitant)

d. I think we have pictures of our Corbin on the stands. We will look for them and email you when we find them. We live in Oriental, so we can mail them (send us your address), or you can use it as an excuse to drive to Oriental. Donna and Dick Mannion (#173, Wind Melody)

e. Why bother with jack stands that are unsafe and flimsy and after using them what or how do you dispose of them. Why not use a system that gives you TOTAL access to the hull below the water line and after use can be stored on the boat for use in any tidal waters to keep your boat upright instead of having to careen your boat on its side in a falling tide to do one side and then repeat the process again to do the other side! Also, if you happen to ground on a falling tide, just assemble and pop these items into their sockets on each side of the hull, wait for the keel to sit solidly on the bottom and adjust the legs for an upright boat. Sit back enjoy the view, have a drink in comfort and wait for the rising tide! I am referring to a product manufactured in the UK known as Yacht Legs which I have been using now for many years with great success for dry dock storage (see http://www.corbin39.com/sealegs.jpg ). Two small castings are attached to the hull P&S which are the sockets for the Legs. The legs are dismantled into one metre sections and are stored in my cockpit seat locker. They can be assembled in about 3 minutes per leg and are great at haulout as they do not take much time to set up. Hope this helps J. Priedkalns (s/v #023, Simmerdim)

f. I have used 4×4 lumber (about 11 ft long) for this purpose quite satisfactorily when painting the hull and avoiding any obstructions. The lumber is clamped in a pair of brackets made of 1 1/4″ x 1/4″ flat bar that bolt to the slotted toerail. Obviously these pieces of lumber cannot be carried on the boat routinely. David Salter

g. Hello David The correct name of the company manufacturing these legs is: The Yacht Leg & Cradle Company and is based in the UK. [edit: 2019, I have stripped out the older names & addresses of this company. Best to look on the internet for https://www.yachtlegs.co.uk/ . As it happens I know the factory in the UK that is actually the subcontract manufacturer of the legs themselves, and I can vouch for the good standard of workmanship. The legs themselves are a very well thought through design, and well thought of by users.] The company is very responsive. Also, see my article on these legs in DIY Boat Owner magazine dated 1997- #3 page 40 & 42. These legs are semi custom. They have my specs for the Corbin, so it should be quite easy to obtain current pricing. We now have several other members at our yacht club sporting these legs including a C&C 44. Janis Priedkalns ( #023, Simmerdim).

At some point we will be hauling our boat and plan to trailer it to our shop. We need any information from those who have experience moving this heavy boat. Our trailer builder needs to know the center of gravity of the boat. Best regards”, Tim and Vicki Baggett (#154, Brillo del Sol).

a. I moved my Corbin (Jakatar) from the storage area where it was being finished to the marina about 50 miles away by contracting a specialized boat-transport truck with a hydraulic trailer. If my memory is correct, it cost 300 Canadian dollars for a highly professional job (but that was 14 years ago). My point is that it may be cheaper, and less hassle, to truck it rather than build a trailer unless you plan to use the trailer a certain number of times. Best regards, Horacio Marteleira (#073, Jakatar, Peniche, Portugal).

b. I have moved our boat twice, once a long distance and another a short one. In each case the boat, in a cradle, was placed on a flatbed by the Travel Lift and the issue of center of gravity never came up. Regards, Frank Bryant (#186, Visitant).

I need construction drawings for a Corbin cradle? Can anyone assist ? Boris Steipe (#131, Two Crows)

a. Yes, see drawings below (Submitted by Guy LaRoche, s/v Sarbacane, Hull 192), (file opens as a pdf or as a .xls, zoom in to see the detail and dimensioning).

SarbacaneCradle1(xls)      SarbacaneCradle1 (pdf)

b. Here’s an inexpensive, though temporary, way of supporting a Corbin on the hard, Yacht Legs (https://www.yachtlegs.co.uk/index.pl ).

c. Here’s Cap Ocean’s fixed cradle:

   

    PDF PLANS : capoeanecradleplans

d. Here’s #050, Opportunity’s fixed cradle: Pic 1, Pic 2, Pic 3, Pic 4, Pic 5, Pic 6, Plans Sketch (we have yet to locate the photos)

e. Here’s CAD plans, minus the pads: CAD (we have yet to locate the CAD file)

f. Here’s a commercial source. Most cradles in this area come from “The Cradle Shop”. I don’t have the coordinates but am sure they can be found online or in “Boat for Sale” magazine. It’s a very popular source. They have the design for a Corbin since that is where I bought mine from. Jack Verheyden

g. Here’s #145, Saw-Whet’s cradle: Pic 1

h. Boris Steipe, I have a CAD drawing for a cradle for the Corbin. I will dig it out for you. Mike Cashin