Bronze pulley block

[Old Forum]

Adrian Swenson
   
Posted on Friday, January 18, 2008 - 09:33 pm:      
Continuing to refurbish WB100. Re the starboard bronze pulley block fitted to the cabin roof At some time one of the 3 white pulleys has siezed but a previous owner obviously never noticed because it was continued to be used and the line has nearly worn away one side of the pulley. What to do as the pulleys do not seem to be replacable. Any advice dear friends?

[Old Forum]

Julian Swindell
Username: Julian_swindell

Registered: 03-2007
   
Posted on Saturday, January 19, 2008 - 06:00 pm:      
Hi Adrian,
The pulleys on my boat are very conventional plastic/steel affairs. They should be easily replaced. Are your blocks solid bronze?

[Old Forum]

Adrian
   
Posted on Tuesday, January 22, 2008 - 08:38 pm:      
Sure are, bronze block with 3 pulleys x 2. The axle for the pulleys appears to be welded at the ends into the block. Yours look as if the do the job. I don't know if mine are a 1 off as WB 100 was built for a London Boat Show.

[Old Forum]

Phil Shimmin
Username: Philshimmin

Registered: 11-2010
   
Posted on Monday, November 29, 2010 - 03:13 am:      
The centre pins of the solid blocks on WB100,can be simply driven out,and the sheaves replaced with new ones.I actually made new pins for both blocks, faired the ends, repolished and lacquered the block..looks fine.

[Ken]

Hi Phil (and anyone else who's replaced sheaves in the bronze block)
I'm about to change my sheaves and am wondering how much driving is needed to shift the pins. In particular is it ok to knock them out in situ on the boat or does the block need to be taken to my workbench ?

[Rick]

Just read your post on the website..No wonder I cant quite remember ..its 9 years ago!.....you could try and tap one out and see if it moves...I may have drilled thro to weaken the pin before drfting it out.  Best do it on the bench and rebed with a squirt of sikoflex sealant.  At 75 the old memory has been damaged by years of Rum drinking. Rgds Phil

On Mon, Jan 14, 2019 at 11:16 PM phil shimmin wrote:

    Hi, are you referring to the sheaves on the cabin top front?  When I renewed all the nylons, I removed the bronzes, polished them up and lacquered them, before fitting the new sheaves in the workshop vice.  I cant really remember how tight the pins were.... and if I " tapped over" the pin ends a bit.  I remember thinking at the time that the whole arrangement was rather sticky for them to revolve.They had previously been a bit solid and worn down unevenly. Hope this helps..I may have a few spares. Rgds Phil.

(sent by email by error, so reposted by admin)

[Ken]

  I'm impressed !  Post a Q one day and get a same day response.

Thanks Rick and Phil !

…. and yes it is the two sets of three on the roof front I'm replacing.
I just started loosening the nuts when I thought - the fixing is fairly solid so maybe the pins would drive out on the boat … but only having done that job on mild steel I thought I'd ask the experts about how easy or otherwise bronze was to shift so thanks again both for your inputs.

And, Phil, if you find any spares you're happy to see getting used do let me know.


Ken

[Ken]

More on the pulley blocks:

I managed to tap the bronze pins out and "temporarily" loaded new sheaves into the blocks on ss bolt with nylock nut. They work fine except ....

I soon noticed the lines were all trying (and the dyneema one succeeding) to ride onto the edges of the sheaves. No wonder the old ones had lost their edges and ... no doubt the life of the lines were being significantly shortened as well.
1st thought: tie a loose pulley to one block for the dyneema line allowing it to align itself to the best direction for the strains it was dealing with( i.e. angle inwards towards the mast top instead of outwards because of the coach-roof slope).
2nd thought: Swap it for a loose block of three like Julian Swindells pic above ... operationally a great improvement.
3rd thought: But I quite like the bronze block. Can I make it work better ?
4th thought: I've just made some angled blocks to direct the new jib sheet cleats down towards where I'm sitting in the cockpit. These have worked well (for the two days use so far this year  grrr to cv19) maybe I'll try something similar for the bronze blocks. I'd need a trianguar bronze plate to tip the pulley block towards the mast and a new resin mount for it to rest on.
I'm letting that idea marinade in my head for a bit while I wait to see if you guys have more possible solutions to suggest

May you all have a happy, Covid free year of sailing.
Ken

Oh dear. The pics I tried to send were 2020 size so got blocked. May try to shrink them when I get time,

[John Burton]

I am certainly no expert, but looking at photos of WBs it seems earlier examples didn’t have the bronze triple sheave arrangement, but instead had an identical plate as the shroud plate that served as an attachment point for whatever blocks were needed. Whilst the triple block arrangement looks nice, from a functional point of view, as you point out, it is not efficient. I have tried mock ups of various ways to mount the fitting using backing plates and wedges, but whatever I do looks Heath Robinson. I have temporarily threaded a short strop around the inner sheave and attached a block to that so it aligns itself with the pulling force. I use this for the running jib halyard that is used for raising the mast and it has made an enormous difference. It would obviously be good to have all the sheaves aligned correctly so I will be very interested in any solution you come up with. This all helps to while away lockdown, I have been nicely occupied with painting and varnishing, almost as good as sailing!

[Rick]

I've usually found that the blocks line up reasonably if you use the central sheave for the tightest line - which is usually the main throat halliard and the jib halliard - depends exactly how you run the lines. That way the lines hold the blocks reasonably correct

[Ken]

Thanks for responses guys. No time to shrink the pics tonight as I'm off for my third days sailing tomorrow ... oops ... when it gets light. If I remember I'll switch phone to "little pics" and bring back some that will load here.
Don't hold your breath (John) for the final solution ... think it took at least 18m to get idea to reality for the jib sheet blocks as I tend to let sailing get in the way of fettling
Ken

[David Bone]

Hello Ken,

Your query stimulated me in to doing something, so here is my take on realignment:
David

[John Burton]

David, that is a very neat and elegant solution and I am unashamedly copying it at present. I have also been able to purchase 6 replacement Barton sheaves as mine had worn down considerably. Not sure when I am going to be able to test it all out!

[Ken]

Hello Ken,
Your query stimulated me in to doing something, so here is my take on realignment:
David

Great to see David.  I was intending to try virtually the same apart from one or two variations.
I've just done something similar for the jib cleats to angle the lines down and towards the cockpit to make their release, in
particular, easier.

That having worked fairly well I was intending to make the wedges for the front pulley blocks of the same resin filler (if the jib ones last the season I'll smooth them off and paint them).
I notice your pulleys  have ended up horizontal which I imagine will work fine and looks sensible ... I may still cant mine a tad further to "aim" at the top of the mast in the direction of the tension unless I decide that makes them look too odd for the minimal advantage.
I'm going to look for bronze plate first and if I get fed up failing I'll follow the stainless route. Did you finish the edges with hand or power tools ?

Must go. Things to do before day 6 sailing tomorrow