Forward jumpers

[mikereed]

I have a 46' cat with a fractional rig that is supported by 2 sets of diamond stays on swept back spreaders with matching forward jumpers/struts and a set of jumpers at the masthead. The mast is held up by 2 shrouds and a forestay, no lower shrouds. Very similar to the older Fontaine Pajots. The mast is a fairly beefy section, 7 x 11" and 1/8" thick with thicker areas on the sides and front.

My question is, are the forward jumpers and struts really necessary? I understand that they prevent the mast from bending back, but I notice a lot of similarly rigged boats with lighter masts that do not have them. I would love to get rid of them as they add a lot of weight aloft and the leech of the jib gets hung up on them whenever I tack. On the other hand, it would be embarrassing to have the mast fold back into the cockpit. Any thoughts before I bust out the angle grinder?

[Brion Toss]

Hello,
Those jumpers might indeed by decorative, but before performing a jumperectomy, get a detailed analysis of loads and geometry. In addition to keeping the main from pulling the top of the mast aft, the jumpers also keep it from going to leeward, the proportion of effort being related to the angles that the jumpers form to the mast. Depending on how much of the mast extends beyond other supports, those jumpers could be vital. Note also that the lower ends of the jumper stays interact with the diamonds and forward struts, especially the lower ones. If you do decide to remove the jumpers, watch out for effects lower down. Got any pictures?

Fair leads,
Brion Toss

[mikereed]

Thanks for the reply! Here is a photo. I am interested in getting rid of the 2 forward struts that can be seen below my wife who is painting the upper lateral jumpers. (I would have gone up myself, but it looked a little dangerous).

[Brion Toss]

Hello,
Thanks for that picture. Actually, those forward struts don't so much keep the mast from folding back as they keep it from buckling forward. The aft-swept lateral struts impose compression on the mast, and the forward struts oppose that. True, there are boats that have aft-swept struts without the forward ones, but (a) some of them have other wires doing the same job, like aft-led intermediates and/or lowers, and (b) your mast, despite what seems like beefiness, might have been designed to be light enough that it needs those forward struts where others don't. Removing them doesn't seem like a good idea. But you might try installing rollers or other devices to help get that jib across....
Fair leads,
Brion Toss