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DavefromNZ · 27-02-2017, 02:35

Yep, done

DavefromNZ · 27-02-2017, 03:05

Can you PM me otherwise I will post a PDF here tomorrow when on my mac.

DavefromNZ · 27-02-2017, 11:36

Sheave sizes attached.

davedindubai · 27-02-2017, 20:01

Thanks Dave.

boom23 · 01-03-2017, 03:47

Quote:

Originally Posted by DavefromNZ

Sheave sizes attached.

Thanks Dave. The sheaves are on order.

DavefromNZ · 01-03-2017, 10:34

Cool. Did you find which one had broken? You need a method if working at the top of the mast with weight off the lifting rope. I used hooks below the sheaves. Standard marine hooks didn't fit so I used ratchet tie hooks. I tied ropes to these for my feet and then used a trailer ratchet tie strap around the mast and ropes to stop them from moving. Still always attach to two halyards.

boom23 · 02-03-2017, 12:08

I'm guessing it's one of the hidden sheaves. Thank you for the info on how to do the sheave replacement. I'll start planning for it.

So, the sheave base is not removable? Why did you decide to drill access holes?

DavefromNZ · 02-03-2017, 14:52

Yes the sheave support, which is called a 'mast crane' would be removable. The options were to take the mast out, $6,000 or get a crane with a cage and 18 hours riggers work. So I went with something I could do myself for $400 [emoji41]

davedindubai · 09-06-2017, 05:45

Quote:

Originally Posted by DavefromNZ

A cautionary note for many Lagoon owners and especially new owners as you can demand a change at purchase.

You can see from the pictures that the standard Lagoon sheave is plastic, with no bearing inset. We shattered one with the gennaker halyard.

The solution to replace the front sheaves is to drill a hole in the mast (40mm dia) on both sides, take a cotter pin out, remove the axle and replace with an aluminium sheave.

I did the main halyard and topping lift sheaves at the same time, which was a challenge as I was hanging from them :-)

It took 4 hours to replace all and NZD 100 per sheave.

PM if you want the sheave sizes for L450.

Attachment 141872
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Hi Dave,
I will be launching in a few weeks so have this on the job list prior to stepping.

Do I need to change all 4 sheaves? Or did you just replace the top 2?

Thanks

DavefromNZ · 09-06-2017, 07:14

Hi, There are 4 sheave blocks at the top of the mast, two forward and two aft:
-main halyard, topping lift.
-gennaker halyard, spare.
I would strongly suggest you do all four at once.
We just sailed Auckland-Tonga return in May, about 2600nm. Only things that broke were a jib halyard shackle, Leisure Furl reefing line outer chaffed, hydraulic ram seemed to get air lock so noisey but still worked.
Cheers
Dave