My carpenter brain had issues with the asymmetrical layout. Also, the coaming is a great place to sail from.
RonB.
With only some of the winch’s bolts going through the fiberglass, what’s involved in getting enough backing under the coaming to distribute the lateral loads on the winch?
– Bob
It also looks like you may have some difficulty turning the winch handle a full 360 degrees as it may hit the sheet. And in a tack or gybe, the main sheet might catch on the winch handle as the mainsheet passes overhead.
Don
3 out of the 5 bolts go through the coaming and the other 2 are right up against the wall. All are through the thick fibreglass sheet.
RonB.
The sheet lead is off to the side somewhat, even heading upwind. It’s never as shown under sail. There is plenty of room for the winch handle while sailing. Having the handle face forward will be necessary. As it was the sheet was always getting hung up on the stern light or anything else it could find back there.
RonB.
This is structurally inadequate. The upward pull on the block will lever the whole arrangement off of the coaming and the lateral pull when the sail is sheeted way out will want to twist it sideways. And more bolts will only make that easier by weakening the fiberglass. What you need is a tension member leading from the aft end of the platform down through the aft deck. A trapezoidal plate with the narrow side at the top and attached onto the bottom of the base plate and the long side bolted to the deck with three large bolts - one at each end and one in the middle - with backing below the deck would probably fix this.
Here’s a really awful sketch of approximately what I mean:
Other issues such as whether this will really be better or not for sailing are personal and if this works for you, that’s great.
Thanks for your detailed input. I’ll try it as is in light winds and see if there is any movement. Although the further out the sail goes the further forward the pull is. Even sheeted in for upwind the pull is more up than sideways. There is a bunch of dynemma from the original attachment point to the underside of the plate. I feel confident about the upward load.
So, a few ideas… more dynemma off to the sides. That’s going to look complicated.
A plate that is much more triangular in shape.
And from your suggestion a bent stainless bar in an upside down V shape with a wide spot on the top and legs to bolt it to the deck.
RonB.
I’m not sure stability in light winds will actually tell you much about ultimate loads.
I did not notice the dyneema that you mentioned. Dyneema is good in tension, so if it is pulling down wards on the block, that is good. It will give you no off-axis support.
Keep in mind that the upward pull does not only occur while sailing. In fact, the harshest upward jolting that I see on my boat is while motoring in seas with the mast whipping forward/aft and yanking upwards on the clew end of the boom via the topping lift. Likewise, the jolts you get while jibing or long-tacking or even during snappy tacks will put harsh lateral jolts on that block, while sailing is probably much more gentle. It’s those jolts that break things.
A plate like I drew will transmit the tension in almost an direction from up/down to sideways. It’s kind of a belt and braces approach. I think lateral dyneema hold downs at an angle, like you mentioned, would probably be adequate, as would your inverted Vee bar.
Ron
However you support the back end of that plate it needs to be supported. Perhaps you could install some attachment hardware from the corners of the plate to the lower pushpit rail. That would not be as solid as what Brian sketched out but it will give the end of the lever you have created with the sheet pulley way out there some solidity and save your coaming fiberglass from cracking where the plate is fastened.
It may look cleaner also.
Fair sailing,
Brian
Version 2. On the first version the turning block was too low and I was having winch override problems. There was also some torque problems, not severe, but this fix seems to address everything and is still pretty tidy looking. I’m very pleased with the central winch location.
RonB.
V2 looks much better! What are the dimensions and material of that tube that you made the support out of? And where were you able to get such a small piece? (The metal store here in Escondido sells tubing by the 10’ or 20’ length, only.)
Thanks! The tube is 3x6 with a 1/4” wall. It’s an off cut from a boom on a previous boat. Had to buy the 20’er and have been chipping away at the 4’ off cut for years with various projects. Still have a little left!
RonB.
I like version 2 better than version 1. A concern I have is a slack sheet in a tack or gybe might snag the winch on the way past.
Mark
I added the roll bar and it definitely helps but getting the sheet snagged on the winch is something that needs to be paid attention to. There is little else to do so it’s not a big deal. The central winch is much more convenient, especially with the tiller. Sitting on the rail, tiller extension in hand, leaning against the roll bar is very comfortable.
RonB.