Changing mast from keel to deck step

[vickers41]

I am building a 41 Vickers GRP Racer/cruiser which is designed for a keel stepped mast. The mast is about 60'' long. The spreaders are designed to be in line with the mast ie not swept back.
However I would like to be in the position to be able to take down the mast as I would possibly want to travel up rivers and canals.
The opening for the mast through the coach roof has not yet been made.
Does anyone have information as to what is involved in such a change, how to go about it or where to look up information.
Thanks Steve

[Jeff_H]

It is not that hard to do. My favorite detail for this is the one used by Farr on my Laser 28. This detail uses a piece of mast that runs from the original mast step location on the keel or a transverse frame to the underside of the deck. This short length of mast has a large to flange welded at the top. There are welded stiffening plates at the four corners of this top plate creating a stiff moment connection. The deck in this area is solid fiberglass and is stiffened ut into the deck. Above the deck is a flat plate that has the mst hinge on it. This plate has two small bolts that through bolt through the deck to the top flange below deck stub mast. The mast itself has a flange that is similar to the flange on the below deck stub that is attached to its bottom. The mast hinges up into place (not very easily). The flange on the bottom of teh mast then through bolts through the flange below deck creating a moment connection between the two halfs. In the end you have the advantage of both mast step options with none of the disadvantages of either.

Jeff