The Pickle Fork
After our tales of woe about our experiences with the Sea Wise davit system, which we unceremoniously ripped from the yacht several months ago (see "An Un(Sea)Wise Purchase," July 21, 2002, and "Sea Wise Bites (the Dust)," May 29, 2004, you might be wondering how we solved the dinghy problem. The answer is, with a pickle fork.
Now, I thought a pickle fork was kitchen hardware in a Jewish deli, but turns out they show up on boats, too. This, I learned from J.R. Means, III, president of the nearest Carver dealer, Bayport Yachts of Newport Beach, CA, in one of my few productive conversations with that organization.
J.R.'s pickle fork was a davit system designed by Nick Jackson Company, of Redmond, Washington, that mounts directly to the transom of a yacht, or, if you have room, to the swim platform. Rather than a set of fixed arms on stanchions with hoists to raise the dinghy up to the arms, the entire davit assembly pivots down right to the water, with hinge pins at the base of the stanchions, whereupon you snap a fixed bridle to each of those arms. Then everything pivots back up, and the dinghy ends up in the familiar horizontal orientation, well off the water, and secures snugly. This classical orientation is an order of magnitude more seaworthy than the "edge" securing scheme that proved so disasterous with the Sea Wise.
The only problem for us was that twice burned, we wanted to make sure that the dinghy and davits stayed with the boat, through hell and high water.
An inspection of a Nick Jackson installation on a sistership, shown here, revealed a potential flaw: Although the amply-built davit system could easily carry the weight of the dinghy in the vertical axis, there was essentially no structural rigidity when the yacht would pitch – for example, when powering into large seas. The entire pitch load – which we calculated could rise to over 3000 lbs of compression force in a tenth of a second – was being carried by a 1/2" diameter, welded stainless steel rod.
This wouldn't do; fundamentally, one wants the davit system to form a box structure with the yacht, so that everything – dinghy, davits, and yacht – pitch, roll, and yaw as a unit. Working with Nick Jackson himself, we were able to re-design the davit legs to accommodate structural members of our own design, which securely and rigidly bridged the gap between the davit's legs and the transom of the yacht. Both ends of the arms were fitted with stainless steel gudgeons and pintles that could be removed allowing the davits to be lowered. The finished result is shown here.
Although it was a tedious, painstaking installation, requiring 1/2" x 1 sq. ft. stainless steel threaded backing plates to be fished inside the swim platform, and the inside of the transom to be reinforced with a large aluminum plate surrounding the transom window, in the end, we got what we had hoped.
The only disadvantage is that carrying so much weight this far aft has forced us to add 700 lbs of internal lead ballast forward, and has rendered the trim tabs nearly ineffectual (we are contemplating changing out the tabs for much larger ones). This probably has taken a few knots of cruising speed off the top end.
Before signing off, it's worth mentioning that we also considered, and then rejected, mounting the dinghy on top of the fully-enclosed aft deck, as was done on another sistership, shown here. Although Carver provided us with an engineering "OK" for such an installation, we realized that working so high off the water, in any kind of a swell, would be quite tricky, and potentially dangerous. No, we're happy with the pickle fork.
For Nick Jackson, his davits, cooperation, and custom changes, an "A". For Carver's timely engineering advice, an "A". For our fellow skipper who opened his yacht to us, allowing us to photograph and measure his cabin-top davit installation, an "A". To Mack's Yacht Services in Marina del Rey, an "A" for a superb installation. And to Bayport Yachts: an "A" for advice, but a "D" for the design flaw on our sistership (described above). We seriously think you should retrofit this installation, and we sent you our engineering drawings, no strings attached.
Now, I thought a pickle fork was kitchen hardware in a Jewish deli, but turns out they show up on boats, too. This, I learned from J.R. Means, III, president of the nearest Carver dealer, Bayport Yachts of Newport Beach, CA, in one of my few productive conversations with that organization.
J.R.'s pickle fork was a davit system designed by Nick Jackson Company, of Redmond, Washington, that mounts directly to the transom of a yacht, or, if you have room, to the swim platform. Rather than a set of fixed arms on stanchions with hoists to raise the dinghy up to the arms, the entire davit assembly pivots down right to the water, with hinge pins at the base of the stanchions, whereupon you snap a fixed bridle to each of those arms. Then everything pivots back up, and the dinghy ends up in the familiar horizontal orientation, well off the water, and secures snugly. This classical orientation is an order of magnitude more seaworthy than the "edge" securing scheme that proved so disasterous with the Sea Wise.
The only problem for us was that twice burned, we wanted to make sure that the dinghy and davits stayed with the boat, through hell and high water.
An inspection of a Nick Jackson installation on a sistership, shown here, revealed a potential flaw: Although the amply-built davit system could easily carry the weight of the dinghy in the vertical axis, there was essentially no structural rigidity when the yacht would pitch – for example, when powering into large seas. The entire pitch load – which we calculated could rise to over 3000 lbs of compression force in a tenth of a second – was being carried by a 1/2" diameter, welded stainless steel rod.
This wouldn't do; fundamentally, one wants the davit system to form a box structure with the yacht, so that everything – dinghy, davits, and yacht – pitch, roll, and yaw as a unit. Working with Nick Jackson himself, we were able to re-design the davit legs to accommodate structural members of our own design, which securely and rigidly bridged the gap between the davit's legs and the transom of the yacht. Both ends of the arms were fitted with stainless steel gudgeons and pintles that could be removed allowing the davits to be lowered. The finished result is shown here.Although it was a tedious, painstaking installation, requiring 1/2" x 1 sq. ft. stainless steel threaded backing plates to be fished inside the swim platform, and the inside of the transom to be reinforced with a large aluminum plate surrounding the transom window, in the end, we got what we had hoped.
The only disadvantage is that carrying so much weight this far aft has forced us to add 700 lbs of internal lead ballast forward, and has rendered the trim tabs nearly ineffectual (we are contemplating changing out the tabs for much larger ones). This probably has taken a few knots of cruising speed off the top end.
Before signing off, it's worth mentioning that we also considered, and then rejected, mounting the dinghy on top of the fully-enclosed aft deck, as was done on another sistership, shown here. Although Carver provided us with an engineering "OK" for such an installation, we realized that working so high off the water, in any kind of a swell, would be quite tricky, and potentially dangerous. No, we're happy with the pickle fork.For Nick Jackson, his davits, cooperation, and custom changes, an "A". For Carver's timely engineering advice, an "A". For our fellow skipper who opened his yacht to us, allowing us to photograph and measure his cabin-top davit installation, an "A". To Mack's Yacht Services in Marina del Rey, an "A" for a superb installation. And to Bayport Yachts: an "A" for advice, but a "D" for the design flaw on our sistership (described above). We seriously think you should retrofit this installation, and we sent you our engineering drawings, no strings attached.
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10:26 PM
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