Prompted by the failure of my second Dutton Lainson electric winch, the desire of the owner of another P275 at our club to replace his Dutton Lainson manual winch, and the interest of Peter Copsey, the owner of a Parker 27 at the club, who has a specialist metal machining company, I developed some ideas I had for a hydraulic keel hoist to replace the Dutton Lainson electric winch.

The completed hoist has just been successfully tested on my boat, and the second system will be installed on the other boat as she completes her current refit.

The hoist uses a hydraulic ram to extend a 4 part purchase, the tail of which is attached to the keel. This means that the 390mm stroke of the ram will raise the keel from fully extended to retracted. The line used is 8mm Dyneema.

I did the design using 3D CAD software, from which Peter Copsey was able to machine the fittings that carry the sheaves, hold the ram, and secure the assembly to the front of the keel box. These parts are made in a marine aluminium alloy, and following the successful test they have been hard-anodised. The hydraulic power unit is a standard unit from a firm called Fluidlink, and the hydraulic ram was made by a local hydraulics company, Atom Hydraulics.

There are some photographs and video of the new hoist here, together with some of the old Dutton Lainson electric winch for comparison:-

https://www.dropbox.com/...hKggF0-0qXN0dLK90ma?dl=0 

My apologies for the tractor being parked nearby while I took the external video!

The new hoist intrudes much less into the fo’c’sle than the Dutton Lainson winch. It should also need less maintenance, and should eliminate the issue with the lower wraps on the winch drum having the outer wraps pull through them.

The hoist raises the keel in about a minute, and lowers it in about half a minute. I have incorporated a limit switch, so that the keel will stop before it runs into the top of the keel box, the switch is also adjustable to compensate for any stretch or creep in the Dyneema.

I’ll be sorting out a casing around the hoist in due course.

If anyone is interested in further details, please get in touch.

Dick Garside

P275 No 36 - Dark Star

Thanks

Marv Kowalewski

P 27 The Happy Seal # 135

WOW

My Strongarm winch gave up the ghost only a few weeks ago and I am completing the remainder of the season with the good old fashioned block and tackle

The brand new electric winch only lasted 2 1/2 seasons (Fitted When i bought her ) before the light metal holding the rope drum wore the hole from round to oval thus causing the drum to rock and chewed up the teeth on the cogs

Luckily I was able to run her up the beach at our club and allow the falling tide to push the keel up enabling me to replace electric for the manual

your hydraulics looks fab and definitely the way forward

Perhaps you could give the forum an idea of cost etc --- as this may be of great interest to many who like myself had electric and are now manual but always thinking about that magic up button !!

cheers for now

Peter Lowry

Sophia 275 #53

Dick - most innovative and thank you for sharing. I will spend the evening studying the photos 🙂.

Ken, P275

Hi Dick

WOW

My Strongarm winch gave up the ghost only a few weeks ago and I am completing the remainder of the season with the good old fashioned block and tackle

The brand new electric winch only lasted 2 1/2 seasons (Fitted When i bought her ) before the light metal holding the rope drum wore the hole from round to oval thus causing the drum to rock and chewed up the teeth on the cogs

Luckily I was able to run her up the beach at our club and allow the falling tide to push the keel up enabling me to replace electric for the manual

your hydraulics looks fab and definitely the way forward

Peter,

That's exactly how my Strongarm winch failed at the end of last season. I had the older one in the garage, it was just rusty, and held together to get me to the end of the season. The problem is that the rope drum is meant to rotate on the 0.5 inch pin, which has a "D" shaped hole in the frame at one end to stop it rotating. So when the steel drum seizes to the steel pin, it tears the "D" hole out and wears away the end of the pin and the frame. There is no way to lubricate the drum and pin without completely stripping the winch, and the maintenance info in the manual only mentions oiling the external gears and bearings [I guess that keeps the demand for replacements up].

We've done the hydraulic hoists for the two boats at the club on a prototype sort of basis to iron out any bugs and make sure it works ok, so I'm actually not sure what the cost is at the moment!- it would depend on the number being made at a time. We'll be thinking about that over the next few weeks.

I have added some illustrations from the CAD model to the pictures on dropbox. The original link should get you to the right folder.

Regards

Dick

We had a rally this weekend to Gosport and had 10x26/27 and 275 along with 2x325s

Several of were chatting about your ram idea..

all very impressed and awaiting more info

so it could be in big demand !!!!

keep us informed please

cheers for now

Peter

I managed to fit in a fair amount of trips up and down the coast locally. The new keel hoist has performed very well, and I’ve had no problems with it. As the home mooring dries on soft mud, a fair amount of it gets into the keel box, but this hasn’t stopped the keel going up or down.

With the boat ashore, I removed a couple of the sheaves to see if there were any signs of wear - as the attached photos show, they both look very good. Number 1 sees the most revolutions while number 4 experiences the highest loads. The plain Delrin sheaves, running on stainless steel bushes, with a bit of PTFE grease, seem just fine for this application.

https://www.dropbox.com/...2y98v6/PA180321.jpg?dl=0 

https://www.dropbox.com/...bwwmg1/PA180322.jpg?dl=0 

Watermark, the second boat that had the hoist fitted, has also come ashore. The conversion from the manual Dutton-Lainson winch that she had has made her much easier to sail, especially short-handed.

So the hoist seems to work well in practice. I hope to build a casing around the hoist during this winter.

The costs incurred for the system were in two parts:-

1) The power pack, ram, electrical and hydraulic fittings around £800

2) The machined alloy components, sheaves, bushes, axles, base plate, etc.

- These parts were done on a “prototype” basis by Copsey Engineering.

- If they were done as a normal production job with a run of, say, 10 sets the cost would be around £900 a set.

Kate Parker 275 Beeline no 21

Is that £800 plus £900 or is the £900 including the £800?

Regards

Martin

Hi Dick

Is that £800 plus £900 or is the £900 including the £800?

Regards

Martin

£800 plus £900

Click to View Image72 View(s)

Click to View Image86 View(s)

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There are 3 pictures of the enclosure, they are also in the dropbox folder here:-

https://www.dropbox.com/...hKggF0-0qXN0dLK90ma?dl=0