PeterL
  • PeterL
  • Advanced Member Topic Starter
2018-11-22T19:35:18Z
Opinions please re. the role of the cable.What is it really for ?
If it is fitted as a limit to the downward travel of the keel, then presumably it would need to be of the length required to halt the keel before the 'square' shoulders of the keel sliders reach the small 'shelves' at the bottom.In that case the keel would always be hanging on the cable,with some movement,rather than resting firmly on the shoulders. And if the keel fell because the lifting line failed,it might prevent damage to the bottom of the slot,although at the quoted 130/160 kgs you might think that the top housing would fail first as the stopper hits it,and that it would still strike the bottom 'shelves'.If it were to do so at speed then there could conceivably be damage to the hull/box junction.
I apppreciate the secondary use of the cable,coupled with a length of elastic as a tensioner, as an indicator of the current position.
I am about to replace my cable so this has become of interest.Does it's length require a degree of precision since anything more than 10/20mm will give a sloppy fore and aft fit.
What do people think ?
Peter
Parker Seal 27 #131
Ken Surplice
2018-11-22T20:39:54Z
Hi Peter,

Do you have an electric keel winch in the forepeak? If so, and the keel is supported in all positions by the winch, except when fully down, the value of the wire is a) depth indicator b) failsafe way to ensure the keel stays up, by placing a pin through the cable loop and across the keel box on the deck.

My keel is raised and lowered manually by a line to a coachroof winch. The wire performs three functions for me.
- First, I can pin the keel fully up, with no strain on the lifting rope.
- Second I have an additional loop halfway down the wire. In combination with the pin across the top of the keelbox, this allows me to hold the keel halfway up on the wire. I do this rather than hold it on the rope and jammer because my pulleys have delrin plastic bearings. They might deform if they were always supporting the keel weight. I often sail with half keel unless beating hard into wind.
- Third, as a keel depth indicator, it allows me to slow up when winching up and nearing the fully up position. This avoids the two pulleys in the keelbox crunching into each other.

I hope this makes sense. Happy to chat via phone if you need further clarification.

Ken
Ken
Ken Surplice
2018-11-22T20:42:30Z
By the way, it is normal to lower the keel so it rests on the bottom of your keelbox, leaving the wire strop to flop about.
Ken
PeterL
  • PeterL
  • Advanced Member Topic Starter
2018-11-23T10:36:18Z
Thanks Ken for your reply.
In fact the 27 has significant difference to the 275 due to the additional weight of your keel and of course the later development of your series.So no I don't have the electric winch and rely on the coachroof winch.But the same anomaly seems to exist ref. the wire strop.Yours has a function of retaining the keel at mid or full height - I hadn't heard of this 275 feature before - whereas ours has a hole clear thro the top housing and head of the keel to take a hefty securing pin and has no mid height lock.
But if the keel is resting on the lower box 'shoulders' then the strop can clearly do nothing to provide a safe lower stop point should the keel 'run-away'.Admittedly the keel may not be lost but damage will be caused in a very difficult area.

I have meanwhile turned up the keel description in the manual specific to my hull which was an early Parker build in the developing 27 series.
' it should be emphasised that the keel must not be allowed to drop out of control as this would damage the fore and aft bearing shoes.To avoid this problem we are now fitting a secondary wire strop,the length of which is set to control inadvertant dropping of the keel.'
So,when setting the cable length,dead reckoning it does have to be.
Peter
PeterL
  • PeterL
  • Advanced Member Topic Starter
2018-11-23T11:58:56Z
So perhaps a length (75/100mm).of crushable sleeve/rubber tube would be useful over the cable under the stop bead/washer at the top,to make this more practical,since it would be hard to install any easily renewable buffers at the bottom.
Marvin Kowalewski
2018-11-26T15:46:44Z
Hello Peter, just saw your note regarding the keel drop safety wire. Long ago I had to replace it because of corrosion, mine stops the keel from "bottoming out" and 'drop through" . Since I was racing and wanted all the keel down I could get for pointing, the length is right at the full down position.
On another topic, have you modified the keel lifting pulley and added another to make it 3:1 purchase? ... I finally got around to doing that job and it took a day but really easy to do and yes..if the boat is in the water I can grasp the keel halyard and pull up by hand..on the winch I can just go round and round one handed.

If you do the job..be sure to get a 28 foot halyard to allow for the added pulley. (allows 3 ft tail over the winch when full down)

If you want info on this mod let me know......also see page 5 1990 newsletter RHL ? is the source writer.


Marvin Kowalewski, Ph.D
Ken Surplice
2018-11-27T10:57:30Z
Peter,
About the additional loop halfway down the strop, that was an idea of mine, not standard. With your keel weighing much less than mine it would probably serve no useful purpose for you.
Ken
Ken
PeterL
  • PeterL
  • Advanced Member Topic Starter
2018-11-27T19:48:56Z
Hello Ken,
I hadn't intended to add such a loop,my arrangement being so different,but I do have a broad technical interest in how others deal with issues arising on their vessels.As you say there is a much lighter keel ( 50% ish) on the 27 and I have a lot of confidence in my clutch,the 10mm braid on braid line and the new Antal tailing winch I have used to replace the original Gibb, so I rely on these for an intermediate setting.
As it happens I have the keel out for inspection this winter,particularly the hard to view wear blocks at the bottom of the slot-so this is all gripping stuff.
Peter
PeterL
  • PeterL
  • Advanced Member Topic Starter
2018-11-27T20:15:30Z
Hi Marvin,
Coincidentally I am also refinishing the fibreglass cover to the slot and planned to replace the original tufnol upright block with a new Barton size 4 that I have had for a little while, in a campaign to reduce friction.The antal winch fitted last winter has already made a great improvement.Looking at the cover,which sits here in my office,I have already sketched out a 3:1 system so your message is timely.I have found the sketch that you refer to,thank you, and that's pretty well what I intend ,using another similar upright block on the other side and terminating the line through the top of the keel.I believe this gives an assymetric lift but I assume that it is not a spoiler as the keel is so long and narrow.
I am happy to take the modest improvement of 3:1 having decided that I don't want to be chopping holes in the keel body.
Had the side slider blocks been 1" instead of 3/4" there might have been more scope to add cheek blocks to the side of the keel rather than through it.
I am very impressed that you can hoist the keel by hand at 3:1,I am expecting to continue use of the winch!
I trust that you are still sailing in this season ! whereas we have too much time on our hands (in 7 degC) for idle conjecture.

Peter
Marvin Kowalewski
2018-11-28T00:42:01Z
HI I was anxious to hear your reply..especially about the 3 to 1 pulley. Yes..if in the water.. so buoyancy counts here..I can pull it well...up..but the winch is much much easier . I know you will be very happy with the change.

As for your wire strop? when we raced we taped it around the mast so as not to foul the crossing of the 155 jib.
If it's rubber coated..(nice idea) it may hang your jib. keep it close to the mast after all it's only a make shift stopper.

As for your keel... I would hose it out and spray the sliders with dry lube. I use it on sail tracks etc. non sticky and effective.

I have only lifted my keel out once by the halyard...and that was not a good idea so now... all I do is unscrew the 4 wing nuts on the box..and use a 2X4 under the boat placed in the keel slot and in contact with the ground...then I lower the lift and the keel just slides up. Do it slowly and work the box as it comes up...so once the box is off....you can work on your keel safely. Since you are on ground...you can use a jack under the keel..?

Now for the way to attach the keel lift line.... I didn't like the idea of an "earth plate" the top knot would stop me from using the keel peg. I went to the marine consignment shop and found an L shaped stainless piece about 1 3/4 inch on the lower L x 2 wide. the idea is to turn the L upside down and rest on the top of the keel in the position where the line will follow to the keel....now pre drill a hole for your line through the stainless (use a vice) then mount it in place on the top of the keel aligning with the pulley and drill a hole into the keel at an angle ...and exit out the opposite keel side .screw the stainless plate down ...run your line through the top of the keel through the side hole and make a knot..now the line is very secure and you can use your keel stop peg...otherwise I found that the earth plate and top knot precluded me from using the stop peg....and I don't worry about screws coming loose.

I am not too good with explaining..but when you are ready to do it give me a call or email 941 740 0171.. marvfl@comcast.net

Marvin Kowalewski, Ph.D