How to Install a Jib Where it Hurts Most

Incredibly, Prout Catamarans did not only construct a weak foredeck at best, they decided to add another load to it: the second jib. This jib is not very large but it is anchored in the roof section between the two forward saloon windows. There is little to no support running down the middle between the windows nor much of anything to absorb lateral forces on top of the windows.

The roof of the cat is mounted on such thin stringers that it will deflect as a result of forces being applied to the second jib. These forces work the windows (since they have to be a part of the weak monocoque) and eventually lead to leaks via two mechanisms: window destruction and hole enlargement.

The former symptom has been treated in the previous article. The latter is much more insidious and difficult to handle. For while windows may only partially break, the 20 or so fasteners attaching each to the hull will work the hull as the windows work against the hull flexing. Subsequently, the thru-holes in the window-frame of the hull become enlarged to a point where substantial amounts of water can enter the boat via the bedded window bolts.

The second jenny as installed on the coach roof in the middle of the saloon

A close-up of the base on which the second jenny is installed. Note the interesting attachment method. I have not yet checked to see if the "U" is actually a threaded bolt that has been welded into place (thus increasing the number of fasteners holding this point to 4 and decreasing the bending moment of the Jenny above) or if it just gives the impression of being solid. I will assume however that this Jenny is bedded in Silicone and that the fasteners will probably require replacement.

This section of the roof is scheduled to be reinforced in the winter of 2001-2002, along with the foredeck. We are planning on running stringers both up and down as well as side to side in order to increase the overall strength of this area. I expect good adhesion/bonding to be our most likely challenge.