Gaff Conversion

[windchaser360]

I just purchased an Island Trader 37 ketch and was wondering how difficult it would be to convert to a gaff rig. There is a website with some specifications on the original rig at http://www.eskimo.com/~martinm/itrader/wires.htm . Full keel, 18000lbs, and 600 sq feet of sail. I was hoping that in addition to enhancing the traditional look of the hull that it might also increase sail area and performance.

[Brian Duff]

difficult, no. A LOT more expensive than just going sailing. yes


(are you doing this yourself or hiring someone) OR rather

how much money are you willing to spend?

The conversion will mean some pretty big changes to be done right. Like a new mainmast and all its rigging. probably a longer bowsprit (maybe not) and different headsails (maybe)

Maybe a good place to start is with a copy of Chappelle's 'Yacht Designing and Planning' and a copy of 'Skene's Elements of Yacht Design' and then - before you buy or build anything, get into Brion's 'Riggers Apprentice' and Leathers 'Gaff Rig Handbook'. Probably add Cunliffe's 'Hand Reef and Steer' to that list.

And A lot of specific questions posted here.

goodluck!

[Ian McColgin]

I'd think this expensive conversion through with great care as not all hulls can take all rigs. For example, you'll be without a fixed main backstay and depending on the gaff and mast height perhaps the triadic. Even if you really can't live without the excitement of adding running backs, are the partners through that high trunk strong enough? Is there room for the greater diameter mast. What's the bury for the mizzen to keep it from racking backwards too much? Will the lower weights and CE result in a whippy motion at sea or will it actually be better?

The advice above on preliminary reading to see if this makes even a little sense is a good start. Sooner or later you need the original designer or another NA to do the correct engineering.

This is something I'd contemplate only if I had a large budget and if the existing rig - spars, sails and stays - was total unsalvagable trash. Even then, I'd stick to her as designed as it's hard to see how a gaff rig on this hull would enhance her.

G'luck

Ian

[windchaser360]

Thanks for the input. I already have the books Riggers Apprentice, Hand, Reef and Steer and the Gaff Rig Handbook. I actually just got them to start the research, that's how I ended up on this site.

I actually have two of these boats and parts of a third. One new wooden main mast and an older wooden mizzen, two aluminum masts, booms and sails that replaced the originals on one boat. Three sets of standing rigging. In other words I pretty much have one boat to go sailing on and the other to play with. We are attempting to revitalize our downtown waterfront and these boats are part of the effort to pay homage to our maritime heritage. I was hoping to convert to a more historical rig. Even replacing the winches and using blocks, etc.

I'll proceed with caution, most of the work will be done by myself and interested parties in the area. I'll seek the advise of a NA to get the proper size of spars before I get too deep into this.

[Brian Duff]

If you are thinking that you can use all of those parts from similar boats, then rig it as it was inteneded. You will probably not find any of those parts will work for a gaff rig.

If you have a municipality backing up the project, hire someone to do this for you ?

[windchaser360]

No, I'm not looking to use the existing stuff for the project boat. I would use some of it to get one on the water so I can go sailing while I'm experimenting with the other. We would build from scratch. We are a small town and there would be no money from the city so I'll have to go it alone $ wise. Lots of volunteer labor though.

I'm still in the planning stages and trying to determine what would be involved. I understand that all the spars would need to be sized for larger sail area and the rig. Rigging (standing and running) would need to be reconfigured as well.

My main concern in the early stages is if the design of the hull would benefit from the change, or at least not suffer from it, without reconfiguring decks etc. In other words is the CE close to what it needs to be or would the deck and mast steps need to be repositioned.

So before I get to far I'll have a NA do the math for me and see where it leads.

[Brian Duff]

you can easily do the math for CE and learn about how hull shape affects that , to determine if the change is worthwhile, by reading through 'Yacht Designing and Planning' and skenes.

Probably would be a great change and the boat will make a stiking image along your waterfront!

[windchaser360]

I'll look in to the book and see what I can make of it. If all goes well and it looks doable I'll attempt to document and publish on the web.

There is another great project going on here in Washington to build a replica of Edward Teach's sloop "Adventure" and the NC maritime museum is considering a replica of the "Queen Anne's Revenge" to be built in Beaufort as part of a new Pirate Exhibit. Hopefully I can contribute to some of these projects as well....

Michael