Dinghy Hoist - added winch
Posted: Thu May 30, 2019 10:08 am
I don’t know about the rest of you, but my dinghy and 9.9 four-stroke engine have gotten quite a bit heavier over the 9 years I have owned them. Hoisting the after end of the dinghy with the weight of the engine got progressively harder over time, but putting brand new line on the 6-part tackle made a big difference in reducing friction, for a year or so. It, again, became harder than I want, so I looked to a solution.
While some will argue it is not the best idea, I have always carried the dinghy with the engine mounted because I am not interested in the extra hassle of dismounting and remounting the engine each time we need to launch the dinghy for use. For one thing, each time you do that, it is a chance for something bad to happen (like dropping the engine overboard). For another thing, if something is a pain to do, you are less likely to do it. I would not hoist the engine on the dinghy if I had doubts about the integrity of the davit system, and I always take those few extra minutes to secure the dinghy with cross-tied ratchet straps. I don’t want to test the davit strength by adding any dynamic loads. We have cruised over 16K nm so far and sometimes in pretty rough seas, so my confidence continues to be rewarded.
As to the solution, I decided to add a small drum winch to handle the (estimated) 50 lbs. of tension in the hoisting tackle. Even though the tackle is 6:1, the friction reduces its mechanical advantage by more than you think. I knew that without a self-tailing winch, I needed to move the current cam cleat in-line from the upper lifting block on the davit to the winch drum. This way it would hold the line even when I stopped grinding or tailing the line. I fabricated some sturdy brackets and attached it securely to the top of the thick Starboard bench seat backrest.
The winch itself is secured to the port armrest of the bench with a Starboard base. It was available in custom-cut sizes (length and width) up to 1 inch thick, so I needed to get two to raise it up enough for a fair lead of the line over the bench seat backrest. Cutting the angle (needed to ensure the line fed onto the drum properly) was not easy with a hacksaw, but I was able to true it up sufficiently with a belt sander that with the cut side down, you cannot tell is was not milled.
The bolts holding the winch are perpendicular to the upper surface of the base block, of course, so they exit the bottom of the armrest at an angle. I was able to cut some angled shims from the Starboard so that the fender washers and nuts seat properly. I positioned the winch so that an 8-inch handle with a meaty hand would clear the davit arm while grinding.
My dinghy is on the dock for probably a few months while I attend to other things on the boat (seasons here in southwest FL are backwards – not much cruising in the often brutally hot summer). To test it, I stood on the beefy spreader bar that attaches to the dinghy stern and let my wife hoist me a few feet. I even bounced a few times and was very pleased with how solid it all is.
Now that I have gone to the expense ($162) and effort, I am counting on some of you to suggest much better ways that I never thought of.
While some will argue it is not the best idea, I have always carried the dinghy with the engine mounted because I am not interested in the extra hassle of dismounting and remounting the engine each time we need to launch the dinghy for use. For one thing, each time you do that, it is a chance for something bad to happen (like dropping the engine overboard). For another thing, if something is a pain to do, you are less likely to do it. I would not hoist the engine on the dinghy if I had doubts about the integrity of the davit system, and I always take those few extra minutes to secure the dinghy with cross-tied ratchet straps. I don’t want to test the davit strength by adding any dynamic loads. We have cruised over 16K nm so far and sometimes in pretty rough seas, so my confidence continues to be rewarded.
As to the solution, I decided to add a small drum winch to handle the (estimated) 50 lbs. of tension in the hoisting tackle. Even though the tackle is 6:1, the friction reduces its mechanical advantage by more than you think. I knew that without a self-tailing winch, I needed to move the current cam cleat in-line from the upper lifting block on the davit to the winch drum. This way it would hold the line even when I stopped grinding or tailing the line. I fabricated some sturdy brackets and attached it securely to the top of the thick Starboard bench seat backrest.
The winch itself is secured to the port armrest of the bench with a Starboard base. It was available in custom-cut sizes (length and width) up to 1 inch thick, so I needed to get two to raise it up enough for a fair lead of the line over the bench seat backrest. Cutting the angle (needed to ensure the line fed onto the drum properly) was not easy with a hacksaw, but I was able to true it up sufficiently with a belt sander that with the cut side down, you cannot tell is was not milled.
The bolts holding the winch are perpendicular to the upper surface of the base block, of course, so they exit the bottom of the armrest at an angle. I was able to cut some angled shims from the Starboard so that the fender washers and nuts seat properly. I positioned the winch so that an 8-inch handle with a meaty hand would clear the davit arm while grinding.
My dinghy is on the dock for probably a few months while I attend to other things on the boat (seasons here in southwest FL are backwards – not much cruising in the often brutally hot summer). To test it, I stood on the beefy spreader bar that attaches to the dinghy stern and let my wife hoist me a few feet. I even bounced a few times and was very pleased with how solid it all is.
Now that I have gone to the expense ($162) and effort, I am counting on some of you to suggest much better ways that I never thought of.