Tabernacle conversion?

[JonnieFlamingo]

Morning all, Work on Flamingo progresses.... just, and while I seem to have very little time to actually work on her I do have lots of 'thinking' time. I've been considering where I might sail her and wondering whether it might be worth converting her mast to a hinged one in a tabernacle. I would keep it keel stepped to save massively reinforcing the deck, and put the 'hinge' in just below the boom. Does this sound feasible, desirable, or a madcap idea sure to end in dis-masting. The reason to do it would be so that if I want to cruise up rivers, or down the French canals then I could do so without boatyard, mast lifting out expenses.
Jonathan

 

[drew silverwitch]

You do not need to reinforce the deck, simply replace the section of the mast between the deck and keel with a compression post to take the strain.
I had a tabernacle on my last boat, a great idea you would think until it comes to getting the mast up and down. You either need a counter weight arrangement similar to those used on the Broads
Werries, on an a gin pole arrangement to allow the use of a winch or blocks, otherwise it is just a pain to do anything with the weight of a wooden mast.
Look forward to seeing finished project by the way. Well done for saving a fine looking yacht.

 

[Wooden Boat Fittings]

I'd agree with Drew's comments (except make it a tension-and-compression post). If you expect to be raising/lowering the mast often, then consider redesigning your chainplates so that the point of attachment of the shrouds and the mast pivot on the tabernacle are in a horizontal line -- this will save a lot of detensioning/retensioning and fiddling with loose shrouds when lowering/raising. And in any case, a gin pole arrangement will be worthwhile manufacturing and storing on board (maybe as a pulpit or bumkin if you intend using it only occasionally).

Mike

 

[Wansworth]

If I recall correctly in many ports that give access to rivers and canals have municipal dockside cranes that have been uses for eons.Certainly a deck stepped mast will be easier to instep but look to how the cabin can be kept square maybe with steel knees.

 

[DownWest]

One our OZ forumites was talking about the local racing fleet that has to pass under a bridge every time they go out. They weld in hinges to their ally masts and lower and raise them on the go. These are not small boats either. The Norwalk Island Sharpies also have hinges in their freestanding masts, as do some US catboats.
Closer to home, I built a tabarnacle for a friend's small gaff cutter. He trailer sails and keeps her fully rigged with sails bent on furlers. Both forestays are on tackles and the whole lot goes up in a matter of seconds.

 

[Easticks28]

Here is a very good illustration of how it's done on the Norfolk Broads http://blog.scruffie.com/the-more-things-change/ The correct ammount of lead on the foot counterbalances the mast perfectly, allowing for the mast to go up and down with the minimum of effort.