470 Layout

LaLi

Well-Known Member
#21
My Jib and main halyards are fashioned out of rope. Should they be wires/cables and not rope?
The main halyard can be of low-stretch rope, but the hook on your mast indicates that the original was wire. Also, there wasn't really good enough rope for this purpose available in the early 1970s.

The jib halyard has to be of wire, as thick as the shrouds but more flexible. It tensions the rig against the latter and carries typically between 130 and 180 kg worth of static load on boats built in the 1980s and later. Older hulls probably flex too much to reach those levels, so you have to settle for some lower value. You still need a good purchase system for it.

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Thread starter #23
Among the other things that I'm sorting out is the rudder assembly. My tiller slips into the rudder brackets but it seems that it could slip right out. Is there something that should be holding it in there?

Rudder and Tiller 3.jpg

Also, there are no blocks or fairleads for raising and lowering the rudder blade?

Rudder and Tiller 2.jpg
 
Thread starter #24
...and then there's the little openings in the transom. Right now they have little rectangles of plywood in there. They are fastened with caulking with little holes cut in for draining. Not very elegant at all. I assume that they are supposed to be able to open fully in order to empty the cockpit quickly?

Transom Openings 3.jpg
 

LaLi

Well-Known Member
#26
Jib halyard: I hope it's the luff of your jib that has a wire in it :D
(Fun fact: in my native language, every edge of a sail is actually called a "leech". A jib has a forward, aft, and a bottom leech.)

But seriously, I suppose one could use a very high-tech (and expensive) rope for the jib halyard, I just don't know if anyone has actually tried it. David surely knows if there are any developments in this area. But a wire is reliable, robust and traditional. The line that's in your mast now is a three-strand rope, the kind that's been widely used as a tail, simply to pull the "real" halyard in place. In no way is it acceptable as a load-bearing halyard by itself.

Rudder: basically, the 470 rudder can be held down (and up) by friction alone, but a downhaul is standard and and uphauls are used, too. The classic Vanguard rudder also relies on them to keep the tiller in place! Are there any cleats, or screw holes left by them on the tiller? The lines are probably intended to pass between the two bolts just below the tiller near the forward edge of the rudder head, no other fairleads are needed. A 2:1 purchase along the tiller is standard to keep the downhaul tight enough. The attachment holes for the lines on the blade look like an afterthought; small saddles on the square part of the edge are standard.

As a side note, you need a stopper to keep the rudder in place in case you capsize. Bolt a standard Laser retaining clip to the transom above and inside the lower pintle and you're ok.

Transom flaps: yes, please remove those ugly pieces of plywood! The four filled screwholes above the opening indicate that there's been a working flap there. Now those can be made of numerous different materials, and attached in many different ways. I've made a few myself. But for your purposes I'd recommend leaving the holes open after cleaning the area, and simply using tape (on the outside) to close them before going sailing. Transom draining is needed very rarely in a 470, and if you really do fill the boat, you can just rip the tapes off. (Or punch through them with the spinnaker pole.) Colourless packaging tape or wide white electrical tape look the coolest :D

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Thread starter #27
Jib halyard: I hope it's the luff of your jib that has a wire in it
Yes! The luff, thanks.

I guess I can try and have a wire halyard made for the boat. I suppose that it has to be assembled with the wire already through the mast. I guess I could fabricate my own and "swage" my own ends on it. I'm used to using cables to hoist sails, but always with a winch. What happens to all of the extra cable as the sail is hoisted on the 470?

the 470 rudder can be held down (and up) by friction alone, but a downhaul is standard and and uphauls are used, too. The classic Vanguard rudder also relies on them to keep the tiller in place!
Ah, yes, of course.

Are there any cleats, or screw holes left by them on the tiller?
Yes, there are a pair of cleats on either side of the tiller.

Bolt a standard Laser retaining clip to the transom above and inside the lower pintle and you're ok.
Gotcha, I'll order one of these today.

those can be made of numerous different materials, and attached in many different ways
I was thinking of making some plastic or fiberglass flaps and try and spring (or bungie) load them somehow. Certainly, the tape method will get me by.
 

LaLi

Well-Known Member
#28
What happens to all of the extra cable as the sail is hoisted on the 470?
What "extra"?
The wire attaches at one end to the jib (or more accurately, the top of the luff wire) and the at the other to the tensioning system. There's no "extra" wire... the "lazy" part of the halyard consists of the tail, which can be very low-tech rope.

The hard thing about making a new halyard wire is getting the length right. It doesn't have to be exact, but even getting to the right ballpark requires some rough pre-tuning and measurement when you don't have the old one as a benchmark. But we'll come back to that later.

I was thinking of making some plastic or fiberglass flaps and try and spring (or bungie) load them somehow. Certainly, the tape method will get me by.
I've used acrylic sheet and hinged them from the top edge with different materials (I'll try neoprene the next time) which act as a seal against the transom as well. They keep closed with an elastic rope attached to a horn cleat on the centreline.
But these have been all on Lightnings, which can take on huge amounts of water when things go wrong. On all 470s I've used tape, or no holes at all.

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LaLi

Well-Known Member
#30
kind of all over the place with this rigging.
That's what it's all about... trying to concentrate on 20 things at once :D Just the vang would need its own, endless thread...
I'm thinking of modelling something like #8 in this schematic.

VANG SYSTEMS | Ronstan Sailboat Hardware World
That's a 12:1 rigged as a 2x6. Not bad, but it would make things too crowded at the mast end of it. The problem with almost all systems on that page is that they're drawn as single-ended, and the 470 vang is double-ended. (Ok, it could be rigged single-endedly, but that would be very pointless as your boat already has the needed, standard fittings for the double-ended system at the back.) They all need one more block to lead the other tail down and back.

The standard 470 vang is a 16:1 as a 2x2x4 cascade. The boats I've raced or rigged have had that, or 12:1 (both 3x4 and 3x2x2) which I think is definitely sufficient. The block closest to the boom needs to be a bit stronger than the others, and the primary line of a low-stretch kind. The main mechanical challenge is arranging the sheaves at the lower end in a way that everything runs smoothly. It might actually make that easier if you added a second attachment point to the mast, some 10 cm above the old one. Just something to think about.

This what today's leading builder Mackay uses (and I think it could be improved at the mast end, but this is more to show the 16:1):

Vang_NoTakeUp.jpg

That's from their 470 order form, where you can look at all kinds of interesting technical options :rolleyes:
Their German dealer has a good view of the whole boat:

McKay 470 Ausbau.jpg

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Thread starter #31
Thanks, these pictures are a help, for sure. I noticed that vang setup on the Harken site. I think I'll buy those blocks and rig it up from there. Is something like a Dyneema rope a good option? 8 or 9mm?

I'm going to try and sort out some of these smaller rigging challenges (vang, spin pole lift/downhaul, jib, main, spinnaker sheets, etc) as I explore the main and jib halyard situations.

I have noticed that the jib sheets have an interesting set-up. There is a sort of bridle thing with looped ends that each sheet runs through on the way to each block. My current setup has a similar setup and the bridle has a loop tied in the middle, near the mast. What is the purpose of this gizmo?

After I have completed this I think I will post some detailed pictures of the final set up, just in case others have similar struggles.

I'm having trouble finding a suitable replacement for the brace that also serves as the traveller track. Mine is seriously bent. I think I need to find someone parting out an old hull.
 

LaLi

Well-Known Member
#32
I noticed that vang setup on the Harken site. I think I'll buy those blocks and rig it up from there.
If you're actually going to order stuff now, I can give you a smarter (and cheaper) list :D
A few questions: what kind of vang attachment is there on the boom? (Picture!) What make and model is the current vang key (boom) block? (Picture)

Is something like a Dyneema rope a good option? 8 or 9mm?
Rope that thick is only good for the mainsheet. 3 or 4 mm single-braid Dyneema is good for the primary part of the vang, and 4 to 5 mm double-braid polyester for the cleating part.

I'm going to try and sort out some of these smaller rigging challenges (vang, spin pole lift/downhaul, jib, main, spinnaker sheets, etc) as I explore the main and jib halyard situations.
I'd do it the opposite way: more fundamental, "big" things first. One gets easily stuck in the shackle-and-pin level details and getting nowhere. Been there countless times. My advice is to prioritize the things you completely lack:
1. Straight traveller track
2. Jib halyard system
3. Mast puller (if you have chocks hiding somewhere, forget this for now)
4. Spinnaker bags

After those you can concentrate on the vang, centreboard and spinnaker pole systems, and after those you can go sailing!

I have noticed that the jib sheets have an interesting set-up. There is a sort of bridle thing with looped ends that each sheet runs through on the way to each block. My current setup has a similar setup and the bridle has a loop tied in the middle, near the mast. What is the purpose of this gizmo?
It's a sideways jib lead adjustment system. I already commented on it:
7: The track and the line are apparently for a sideways jib lead system. It's completely unnecessary and it would be best to remove it altogether.
Frees at least two blocks for something actually useful, like the vang :rolleyes:

I'm having trouble finding a suitable replacement for the brace that also serves as the traveller track.
That sort of I-track should be widely available. For example, wouldn't this do: Ronstan 3/4" I beam track 3'3

Couple more things that we haven't touched on yet: how's the trapeze equipment? (Picture!) And what about the centreboard gaskets?

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Thread starter #33
So, I just went up to my club to have a look at my boat (I wish I had brought it to my house) and as it sometimes turns out, my jib halyard IS a cable, not a rope. Faulty memory. So, that is no longer an issue. I'll put a new rope tail on it and use it as is for now.

what kind of vang attachment is there on the boom? (Picture!) What make and model is the current vang key (boom) block? (Picture)
I'll take some pictures of this. I plan to go up and raise the main and jib later today to better see state of those halyards.

That sort of I-track should be widely available. For example, wouldn't this do: Ronstan 3/4" I beam track 3'3
I'll give mine a measure and see how they compare. This looks promising.

3. Mast puller (if you have chocks hiding somewhere, forget this for now)
Mast puller? Chocks?

Couple more things that we haven't touched on yet: how's the trapeze equipment? (Picture!) And what about the centreboard gaskets?
I haven't looked at the underside of the hull so I don't know what the condition of the gasket is at this point.

I do have some trapeze hardware (cables, a pair of figure eight-looking fittings, blocks, etc.) but I know little about how to set them up.

Shroud and forestay tension is another issue...

Thanks for the help!
 

LaLi

Well-Known Member
#34
my jib halyard IS a cable, not a rope.
Yes :rolleyes:

Mast puller? Chocks?
In the pictures, there's nothing that limits mast bend at deck level. I commented on this earlier:
3: Here's where the spinnaker pole downhaul goes through the mast gate. No idea why there's a second fairlead, and a block on the mast.
No visible mast puller (deck-level mast bend adjustment) either. You need to rig one but we'll come back to that later.
The vang won't work properly if it bends the lower mast uncontrollably. The old-school way to limit this was to insert t-shaped chocks of plywood or plastic in front of the mast. They were certainly used on your boat when it was new.
The post-1970s way is the mast puller, which is a rope/wire that wraps around the front of the mast and cleats on the mast gate. This what the Mackay version looks like:

mast_puller.jpg

New rules allow it to be have more purchase, but I don't know if anyone's tested anything yet. Would be interested to hear David's views on this.
You can have a forward puller, too, but it's not needed for recreational use.

I do have some trapeze hardware (cables, a pair of figure eight-looking fittings, blocks, etc.) but I know little about how to set them up.
Pictures!

Shroud and forestay tension is another issue...
...which gets solved the moment you have a working jib halyard system. That's what tightens the shrouds.
The forestay is always slack when the jib is up, and exists solely to keep the mast up when the jib is down. This why you rarely lower (or hoist) the jib on a 470 on the water.

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LaLi

Well-Known Member
#37
Mast puller: a very simple one can be set up with just a piece of low-stretch 5 or 6 mm rope with a relatively hard cover, and a small (short!) Clamcleat. The cleat should be mounted as far back as possible on the mast gate (starboard side is standard for some reason), and the other end of the line can be simply deadended through a hole on the opposite side. A big bowline can be tied to the free end as a handle. Tried it and it works for club-level/recreational purposes.

(Have you looked for any possibly existing chocks yet? They usually hide at the bottom of a sail bag :D )

Vang: I see in an earlier picture that you have a standard Laser vang key; if it fits nicely in the boom slot, fine. I'm thinking that you might use the old key block as well (for a 12:1 system), if it's strong enough.

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Thread starter #38
Mast puller: a very simple one can be set up with just a piece of low-stretch 5 or 6 mm rope with a relatively hard cover, and a small (short!) Clamcleat. The cleat should be mounted as far back as possible on the mast gate (starboard side is standard for some reason), and the other end of the line can be simply deadended through a hole on the opposite side. A big bowline can be tied to the free end as a handle. Tried it and it works for club-level/recreational purposes.
I can rig up such a thing.
(Have you looked for any possibly existing chocks yet? They usually hide at the bottom of a sail bag :D )
No, no evidence of any chocks. This boat was not used in a serious way for many years. Recreational sailing with bare bones, very patched together rigging.
 
Thread starter #39
So, playing around with the rig yesterday, I raised both sails and the trailer and was able to hook up my mail halyard on the little hook but the jib halyard hook (or hooks) appear to be missing.

Main Halyard and Hook.jpg
Jib halyard and missing hooks.jpg
I assume that there were once a hook or two below where the halyard exits the mast, yes/ I see sets of drilled holes there.

As a side note, my mast looks like it has some serious dents. This could be interesting under stress.
 

LaLi

Well-Known Member
#40
There's supposed to be only one hook for the jib halyard, moving at the sail end of the purchase system. It hasn't been (directly) screwed or riveted anywhere.

It's strange with all those holes between the boom and the deck. It's possible that there's been a "magic box" there, at two different positions. That would have been a 1970s-typical solution for the jib halyard system. They fell out of fashion pretty soon after people realized that regular, free-floating blocks actually provided less friction.

From the 1980s on, the purchase system has been running mostly along the centreboard case/cockpit floor. However, on modern 420s it's all on the mast, and I think that would make the most sense on your boat, too. This is how it's on a Mackay 420:

424005.jpg

The cleat doesn't have to be integrated with a block; the control line tail can be led via the mast step to the centreboard case, for example.
(Also note the blue chock in front of the mast!)

Where are the dents on the mast? It's hard to see from the picture, but it looks like the mast has been pushed hard against the sides of the mast gate. Could be the result of way too low rig tension + dipping the mast in whatever there was at the bottom of the lake/sea...

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