B473 Mast Head Sheave badly worn

[Fadwa Pettit]

We have just been told by my rigger who was giving the boat its pre season check that the main halyard mast head sheave has worn flat on one side and does not allow

The halyard to turn on it, the halyard just rubs against one side, the only choices is to de rig and takes the mast out of the boat, an expensive thing to do and considering the boat is only 2 ½ years old. “Z” spars who design the cast alloy mast cap seem to have made it impossible to replace the sheave any other way. The rigger was also surprised that the pulley wheel was only 1’1/2 diameter for a 180 deg turn and is made of a very hard plastic. The most cost affective   way out to temporarily fix the problem I think, would be to swap the topping lift with the main halyard over so that the main halyard runs up and down the good sheave currently used for the topping lift as we hardly ever adjust the topping lift and pull the mast out in a couple of years when there may be good reason to look at a complete service of the mast. I would appreciate any experiences and comments

 

Thank you

 

Martin Pettit B473 Melbourne Australia

[Nello Angerilli]

Earlier this year I replaced all of the standing rigging on my '85 B 11.5.  The masthead sheaves were still in good condition (unlike those at the aft end of the boom which need to be replaced).  One of the additional things that I did however, at the suggestion of the riggers, was replace the topping lift with a line that will serve as an alternative halyard in the event that the main halyard should fail or otherwise become unavailable.  Therefore the solution that you propose below seems eminently reasonable and saves having to drop the mast.

Most boats in Vancouver stay in the water year round and hence rarely have their masts off.  In my case taking the mast down meant cutting the cable to the radar antenna and subsequent issues associated with getting the radar working again.

Good luck.

Nello
SV Marathon

On 8/14/07, Fadwa Pettit <m.pe...@optusnet.com.au> wrote:

We have just been told by my rigger who was giving the boat its pre season check that the main halyard mast head sheave has worn flat on one side and does not allow

The halyard to turn on it, the halyard just rubs against one side, the only choices is to de rig and takes the mast out of the boat, an expensive thing to do and considering the boat is only 2 1/2 years old. "Z" spars who design the cast alloy mast cap seem to have made it impossible to replace the sheave any other way. The rigger was also surprised that the pulley wheel was only 1'1/2 diameter for a 180 deg turn and is made of a very hard plastic. The most cost affective   way out to temporarily fix the problem I think, would be to swap the topping lift with the main halyard over so that the main halyard runs up and down the good sheave currently used for the topping lift as we hardly ever adjust the topping lift and pull the mast out in a couple of years when there may be good reason to look at a complete service of the mast. I would appreciate any experiences and comments

[Noble, Milner E.]

Nello,

Doesn't your radar cable go through a junction box to prevent the need to cut the cable? 

--Milner

[Capt Brian]

Ahoy Martin,
I have a '95 OC400 with Z spars. When I commissioned my boat 3 years
ago after moving to Lake Lanier I was able to remove the cap plate on
top of the main cap casting and had I needed to I could have pulled
the sheaves out easily. Hard to believe you would have to de-comm to
replace sheaves? Did you go up the mast to look for yourself?

Cap Brian

[Mike McHugh]

Hi, Martin,

I have the same question as Brian. I did pull the mast out of my 40CC
with a Zspar rig. We fully disassembled the mast and put it all back
together with liberal amounts of anti-seize and Lanicote, and in the
process broke parts and had a heck of a time getting recommissioned.
It seems that Zspar stopped making spreader parts for my mast years
ago, and there's no inventory anywhere in the world. But that's another story.

We also had the plastic (actually, are they nylon?) small sheaves. We
replaced them with Zspar aluminum sheaves. However, now that I know
how it all comes apart, I know that the sheaves on my rig can be
replaced without pulling the rig. The top cap comes off, giving
access to the axle for the sheaves. The axles rides in slots on the
masthead casting. You should be able to secure the mast with lines,
such as the jib halyard, spi halyard, topping lift to hold the mast
for and aft. You'll need to tie them on the mast below the masthead
and slack them out of the top of the mast so that the cap can be
removed. Then you'll have access to the sheave. It shouldn't matter
if you have roller furling or not to do this.

Cheers,

Mike
Water Wing
B40CC
Richmond, CA USA

At 08:27 AM 8/14/2007, you wrote:

>Ahoy Martin,
>I have a '95 OC400 with Z spars. When I commissioned my boat 3 years
>ago after moving to Lake Lanier I was able to remove the cap plate on
>top of the main cap casting and had I needed to I could have pulled
>the sheaves out easily. Hard to believe you would have to de-comm to
>replace sheaves? Did you go up the mast to look for yourself?
>
>Cap Brian
>
>On Aug 14, 9:00 am, "Fadwa Pettit" <m.pet...@optusnet.com.au> wrote:
> > We have just been told by my rigger who was giving the boat its pre season
> > check that the main halyard mast head sheave has worn flat on one side and
> > does not allow
> >
> > The halyard to turn on it, the halyard just rubs against one side, the only
> > choices is to de rig and takes the mast out of the boat, an expensive thing

> > to do and considering the boat is only 2 1/2 years old. "Z" spars

> who design
> > the cast alloy mast cap seem to have made it impossible to replace the
> > sheave any other way. The rigger was also surprised that the pulley wheel
> > was only 1'1/2 diameter for a 180 deg turn and is made of a very hard
> > plastic. The most cost affective way out to temporarily fix the problem I
> > think, would be to swap the topping lift with the main halyard over so that
> > the main halyard runs up and down the good sheave currently used for the
> > topping lift as we hardly ever adjust the topping lift and pull
> the mast out
> > in a couple of years when there may be good reason to look at a complete
> > service of the mast. I would appreciate any experiences and comments
> >
> > Thank you
> >
> > Martin Pettit B473 Melbourne Australia
>
>
>

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[Fadwa Pettit]

-Thank you Mike, I have not been up the mast my self but this makes sense I
will pass this on to the rigger and let him go up the mast!! I will also
contact the Rep for "Z" spa in OZ and see if my mast cap is of a similar in
design to yours.

Cheers
Martin

----Original Message-----
From: Benetea...@googlegroups.com
[mailto:Benetea...@googlegroups.com] On Behalf of Mike McHugh
Sent: Wednesday, 15 August 2007 4:24 AM
To: Benetea...@googlegroups.com
Subject: {Beneteau Owners} Re: B473 Mast Head Sheave badly worn

[Nello Angerilli]

No junction box. All of the electronics people out here, including the dealer that sold and installed the radar in Washington St where we used to keep the boat, strongly recommend against a junction box.  There was unanimity that the cable be cut and resoldered if and when the mast had to be unstepped.  In their view (3 dealers sampled), junction boxes result in significant signal degradation.  The riggers on the other hand indicated that they encounter junction boxes reasonably frequently.

cheers

Nello

[Noble, Milner E.]

Interesting.  The Beneteau dealer in this neck of the woods uses junction boxes.  None one here has commented on signal degradation from this type of installation, and the radar image on the 361 that I sail on doesn't appear to be different that other radar images I have seen -- but I don't know if those systems had junction boxes or not.  Having rewired the mast of a 361 twice after it was stepped to travel south and return, I can't imagine soldering all those tiny-gauge wires.  The box makes it a very straightforward process -- if you take GOOD notes.  :-)

--Milner

 

 

-----Original Message-----
From: Benetea...@googlegroups.com [mailto:Benetea...@googlegroups.com] On Behalf Of Nello Angerilli
Sent: Wednesday, August 15, 2007 1:52 AM
To: Benetea...@googlegroups.com
Subject: {Beneteau Owners} Re: B473 Mast Head Sheave badly worn

[Nello Angerilli]

Re-soldering all of the wires was a chore but nothing compared to having to relocate the windlass and drop the radar antenna by several feet on the mast because I also installed an inner forestay.  The chainplate for this stay is now solidly attached to an inner bulkhead in the v-berth and is bombproof. However, the windlass relocation required modifying the anchor locker hatch (cutting it in half, bolting the front half to the hull and then bolting the windlass to the front half). The radar antenna had to be moved down to allow the inner stay to attach at the height of the second spreaders. THEN, the steaming light/deck light had to be moved down so that the deck light would illuminate the deck rather than the top surface of the radar antenna.  I now wish that I had gone for a gimballed mount on the backstay for the radar antenna when I first installed it two years back. It would have saved $$$ and much hassle with only a minor loss in range but greater usability when the boat is heeled.

cheers

Nello

[Noble, Milner E.]

Wow.   Too many boat projects.  :-)