Converting a bermudian rig into a gunter rig

Hello I have a project in mind with a newly acquired sailboat ( it's already a project boat so why not take the time and Make it a real project boat !).

The boat is a tanzer 16 and I would like to change the rig from the classic bermudian sloop to a Gunter rigg
(and keep a front sail, so I guess a smaller front sail since the front sail will be attach to the top of the mast and not on top of the spar !?)
The main reason for the change of rig is based on the use I want to do with the boat and I want to be able to rig her alone easily on and off the water and mostly I want the whole mast to fit in the boat while I am on the water (as well as for trailering since I will drive it in forest roads alot)

So Ive done some work on sailboats before and I enjoy it (crazy rigth?!) But I am by no means a boat builder (yet) and I am unsure of where to start to be honest.

I am wondering if I could use the tanzer main without too much modification ( I am willing to learn sewing sails if I need to change the shape a little ) ?! I don't think I would need to change it much since I guess i would keep close to the same amount of sail to keep the boat balance as intended.

Could I keep the mast step in the same position ?! What length should the mast be compare to the spars ?! And lots more question comes to mind at this stage of the project !

Anyone have a few links or even maybe a book where they describe Gunter rig in details and I could make myself a better idea of where to start and figure where to put the stays etc...

Any tips/idea/pointers are welcomed thank you very much !

 

It's fractionally rigged so the best case scenario is you cut the mast above the forestay attachment point and the remaining mast fits into the boat. If not, you need another jib. The topmast slides on the mast with two rings, google sliding gunter photos. The main needs no modifications, you lace it to the topmast and fit longer lacings for the mast. The small gap will not be a problem.
Examples: Duckworks Magazine https://www.duckworksmagazine.com/06/columns/nichols/index1.htm
Duckworks - Projects https://www.duckworksmagazine.com/05/vintage/sbj/2/index.htm

 

I wouldn't cut the existing spar. Not everyone finds sliding gunter rigs quite as congenial as their enthusiasts. Rigging the boat with a gaff waving round can be unpleasant, and if you decide that you don't like it after hacking up the spar then that's a bit irritating.
For the sake of an experiment the sail will do as is with the addition of some eyelets for lacings and so on. You need to decide whether you want wood or metal spars. Metal spars can be a bit clanky and noisy for this game, wood of course needs maintenance and fabrication.
For a quick and dirty test of the concept you might want to see if you can source a secondhand metal mast from something else for not much cash. Many sailing clubs will have a scrap pile. It wants to be at least three feet longer than the current one. You'll need to be able to saw, drill and rivet metal. Basically what you'll want to do is to cut the spar to the length of your mast above where all the shrouds attach, and move the fittings for the shrouds and forestay - the hounds - down to where they are on the other spar. You'll probably need to move the gooseneck too. What you're aiming for is exactly what you'd have if you did cut the top off the other mast. That should leave you with the piece you cut off, some 3 feet longer than the top mast. There are neater ways to do this, but for a trial a set of jaws like the first link will do. Just screw them on the spar with self tapping screws. The sail will need a set of smallish eyelets, I suppose about 6 inches apart in the bottom half. The top half of the sail slides into the track on your yard/gaff, the bottom half is *loosely* lashed to the mast.
There are better ways to do both the lashing and the jaws, but don't worry about that until you find whether the idiosyncracies of the gunter rig suit you or not. An alternative you might consider is whether you could construct a two piece spar with the top simply telescoping into the bottom. This is difficult to get the right metal for though.

 

The complication of a Gunter is not justified in such a small boat. To start with, the mast will need to be of larger section, therefore heavier. Further, Gunter and other rigs that use jaws on the spars require a circular section mast to work properly. The original mast is only 31 lb., so it is not much of an effort to push it up; especially with a hinge like the early ones had. You can simply cut the mast a few inches above the deck and install the hinge.

Tanzer 16: Tanzer 16 Hinged Mast Step --early models had them http://jimslittleboat.blogspot.com/2014/05/tanzer-16-hinged-mast-step-early-models.html

 

Dinghy sized sliding gunters were popular in the mid 20-th C. One of the appeals was indeed fitting the spars in the boat. Unlike a gaff rig a dinghy sized sliding gunter doesn't mandate a round spar - indeed even square spars were perfectly conventional. Whereas with a gaff rig the gaff is free to rotate round the spar - and indeed must do so - with the sliding gunters on dinghies of the 50s and 60s the yard is sweated up as tight as possible and is locked against the mast so that it definitely doesn't turn with the sail. One common implementation was to have the lower end of the yard and sliders for the luff all running up a track on the back of the mast, which brought the sail very close to a Bermudan, except for the gap between mast and sail. The rig has its place, but as mentioned I don't like swinging the spar up. Given the requirement I would much rather have a two piece bermudan rig with a removable topmast. More of a project to build though.

 

thank you very much for your replies I understand it migth not be the best rig in our time but I also forgot to mention i like the look of it aswell and to me it makes the more sense to make this instead of a telescopic mast with the resource and time I have to complete this project !
thank you very much for your opinion/tips and keep them coming I am really glad i had some answer I am studying everything that has been said in this thread yet and I am starting to have a better idea of how to do it

I also think converting a rig is a great first ''design'' project with sailboat so thanks again !

i migth also ask precise question on the answer you guys gave me in a few days onces my plans are more set in stones!

In the mean time I am sanding and preping the whole boat for a new paint and some fiberglass repair if you guys wondering !!

 

1. I've never seen a Tanzer in the flesh so to speak, but I have pictures.
2. I've done a fair bit of sailing with a gunter rig - it's the traditional rig for small cruisers where I live (Norfolk UK) - although most of that experience was in dinghies.

Converting to gunter isn't quite as easy as you might think.

You have essentially two options -
a) a sliding gunter, which is effectively a telescopic bermudan mast, where you can use your existing sail and maybe your existing mast cut down (if it's strong enough)
b) what we call a gunter round here, which is like a very high peaked gaff rig.

If you go for (a) then the yard is secured parallel to the mast by a couple of fixings, which might be a couple of batten cars running in a track, or a complicate framework of a pair of mast hoops held apart by battens (a.k.a. gunter irons). The problem with this is that it's not easy to get the yard down horizontal (at best it's a PITA casting off the top fixings - which may be 7ft above the deck on a cruiser!). It's probably better therefore to leave the yard vertical at all times and use an outhaul (uphaul? "halyard"?) to take the top of your sail to the top of the yard before you hoist the yard up the mast. That outhaul needs to cleat on the yard, and the fall goes up with it. (So make sure you can cut it if something jams.)
Personally, although I've never tried, I wouldn't want to sail with a sliding gunter in anything bigger than a canoe (which can be rigged/de-rigged on the beach). YMMV!

(b) is just like a standard gaff rig, just very high peaked; (angle between the mast and yard of the order of 10 - 20 degrees). Uses two halyards - throat and peak, jaws on the bottom of the yard, and hoops or a lacing to hold the luff to the mast. The mast needs to be circular in section so things slide around it readily, and stiff enough to stand without spreaders, and short enough to take the stays to the masthead and still have a decent angle on the shrouds. Well tried and tested, but you'd most likely need a new mast (alloy tube?) and certainly need the top of your sail recut, otherwise it will set horribly.

Either way you will be able to have a mast shorter than now by between a half and two-thirds of the length of your yard. (NB with a sliding gunter the yard is about 40% of the length of your luff, so that when it's down the top just sticks up above the masthead, thus minimising the chance of it getting caught on shrouds.)