What size of lines do I need on a 27' yacht

S

SteveSarabande

Well-Known Member
Joined
3 Apr 2012
Messages
1,304
Location
Solent
Visit site
When I bought the boat an older survey said that the lines where too thick and to reduce friction through the blocks and deck organiser the sizes could be reduced. I am talking about halyard, topping lift, vang, etc...

Is there an online resource that would give me an idea of what size these lines should be on a 27' yacht (Sabre27)?
 
Stevev2 said:
When I bought the boat an older survey said that the lines where too thick and to reduce friction through the blocks and deck organiser the sizes could be reduced. I am talking about halyard, topping lift, vang, etc...

Is there an online resource that would give me an idea of what size these lines should be on a 27' yacht (Sabre27)?
Click to expand...

What size are your lines?

My boat is 28ft and we use mostly 10mm lines, the genoa sheets are thicker, but are overdue for replacement, probably with 12mm or 14mm.

The deciding factor in our case is not tensile strength but comfort, thinner lines are better at cutting your fingers off.

We had an 8mm halyard on the mainsail, but it jumped off the masthead sheath a couple of years ago whilst hoisting for a passage from Corsica Tuscany and got jammed, setting in motion a several thousand euro mast refurbishment (it wasn't the halyard's fault, it just helped us to realise it was due).

The point I'm trying to make is, wee lines are probably ok for the forces they'll see in a 27ft boat but bigger is better for the comfort of whoever has to handle them.

As for friction through blocks etc, that is only an issue if the lnes are actually squeezed through blocks etc that are too small. If the blocks are the right size for the lines, there will be no measurable difference in friction.
 
Stevev2 said:
When I bought the boat an older survey said that the lines where too thick and to reduce friction through the blocks and deck organiser the sizes could be reduced. I am talking about halyard, topping lift, vang, etc...

Is there an online resource that would give me an idea of what size these lines should be on a 27' yacht (Sabre27)?
Click to expand...
An "older survey"; so what did your surveyer think and why do you thing the last owner did not change the line size? It's one individual opinion and that individual has no idea what you are using the vessel for.
 
Stevev2 said:
When I bought the boat an older survey said that the lines where too thick and to reduce friction through the blocks and deck organiser the sizes could be reduced. I am talking about halyard, topping lift, vang, etc...

Is there an online resource that would give me an idea of what size these lines should be on a 27' yacht (Sabre27)?
Click to expand...

There are guides among the technical articles on the Jimmy Green website
 
.
It's personal choice. Can't believe that surveyors charge for this sort of rubbish.

10mm is the minimum that is generally comfortable to handle, though our reefing lines are smaller.

- W
 
My boat (Jaguar 27) had a 14mm main halyard when I got it. Nice and comfortable to hold, but so much friction on the sheaves it needed the winch to get the main sail to the top. I reduced to 10mm (based on info in the Jimmy Green site mentioned above) and I can now easily haul the main to the top by hand.

Go for it.
 
10 mm should be strong enough for everything, at least on 30 footer; 12 mm is better for hands (and peace of mind), 8 mm is uncomfortable.
But the right size for the blocks depend on the block. Every block is made for certain diameter line, may be used 1-2 size smaller line in it (ie 8 mm in 10 mm sheave), but not bigger. So best to measure the blocks.
 
I don't like to disrespect the Jimmy Green tables, but...why are "recommended line sizes" always so tight-fistedly economical? The best change I ever made to my dinghy was upgrading from a standard 10mm mainsheet to a soft 14mm which I could grip in any weather...

...and the standard blocks - which I presume were meant to take nothing thicker than 10mm - were perfectly fine with 14mm.
 
dancrane said:
I don't like to disrespect the Jimmy Green tables, but...why are "recommended line sizes" always so tight-fistedly economical? The best change I ever made to my dinghy was upgrading from a standard 10mm mainsheet to a soft 14mm which I could grip in any weather...

...and the standard blocks - which I presume were meant to take nothing thicker than 10mm - were perfectly fine with 14mm.
Click to expand...

You are lucky. 14mm would not even fit through the blocks when I tried it instead of the original 12mm sheet.
So have a nice piece of 14mm doing nothing. Too thick for me, too short for a larger boat
 
Ah! I remember now...I switched to a slightly larger boom-end block...a Barton, which was big enough to carry the 14mm. I don't remember it costing more than about £12, and I never regretted the outlay.

Perhaps yachtsmen, who can cleat their mainsheets, don't suffer much from slender lines, but I've always been repelled by the allegedly necessary minimalism employed by dinghy racers - wiry, high-tech lines carrying substantial loadings, gripped by crews for whom even physical suffering seems to be competitive...:eek:

Sorry...beginning to rant, there. :mad:

I'd definitely recommend getting bigger blocks, rather than making do with narrower lines. Lots of discomfort is unavoidable at sea...no need to indulge in the racers' gleeful asceticism - they really seem to believe they're better sailors because they do it the hard way. :rolleyes:
 
Thanks for the replies so far.

I am back on the boat for the weekend and just measured the lines. I will have to check the blocks next

Topping 10mm
Main Halyard 14mm
Main sheet 12mm
Vang 12mm
Genoa sheets 14mm

I get the point about thicker sheets for comfort, but the halyards could certainly come down in size (and price :-)
 
Stevev2 said:
Main Halyard 14mm

I get the point about thicker sheets for comfort, but the halyards could certainly come down in size (and price :-)
Click to expand...

I reckon you're right! I'm all in favour of indulging in luxuriously thick, braided line, but that halyard is a bit OTT on a 27ft! Especially if it's more than the blocks/sheaves can comfortably cope with.
 
I sail a Folksong here so 25'.

All halyards and sheets are 8mm and it's no problem at all for me - how long do you generally hold a loaded up line for on a yacht? They spend the bulk of their time cleated off.

However, if you want to have bigger lines, go right ahead - it's your boat and you can rig it as you want.
 
Here are some things to consider (some mentioned in other posts:)

The rope
-Must fit in sheaves, blocks and organizers
-Must not slip in clutches, cleats or self tailers

For ropes that is not used on winches thicker ropes give better grip.

For some applications (halyard) low stretch is more important than breaking strength.

If you reduce diameter with same type of rope you get more stretch.

By using dyneema ropes you can reduce the dimensions with the same (or better) stretch and strength properties.
So if you compare price you can not go by diameter alone.

You can increase the diameter of a rope by adding extra cover (for some ropes).
Covered dyneema ropes can be reduced i diameter by removing the cover on parts of the rope (strength is in the dyneema core).

Different rope constructions give different properties & price.
The most common today are
-Braid on braid Polyester (double braid)
"classic" rope for sailboats, most stretch, least expensive

-Dyneema core with polyester cover
It is only the dyneema core that give strength the cover increase diameter, protect the core and give better hold.
Less stretch, stronger, more expensive.
For some applications you will need "over sized" rope to fit in clutches, cleats or self tailers

-Dyneema triple braid
Dyneema core, cover and intermediate layer in polyester.
Better strength/stretch than polyester with same diameter, less expensive than dyneema with cover
For many applications this is a optimal price/performance solution.

-Uncovered dyneema
Used where weight saving is important and cover is not needed

Dyneema ropes are easier to splice than polyester double braid.
 
Last edited:
knuterikt said:
Here are some things to consider (some mentioned in other posts:)

The rope
-Must fit in sheaves, blocks and organizers
-Must not slip in clutches, cleats or self tailers

For ropes that is not used on winches thicker ropes give better grip.

For some applications (halyard) stretch is more important than breaking strength...
Click to expand...

I got a bit lost in your extended explanation, Knutty. Surely the point to stress is that halyards ought NOT to stretch...so whatever line/diameter is chosen, it ought to be the least elastic that is available?
 
Plenty of yachts use wire for halyards, exactly to prevent stretch. Or did I dream that? No, I don't think so. :rolleyes: Nothing looks or performs worse than a saggy luff in a breeze, and it can be very difficult eradicating the last bit of slack.
 
dancrane said:
Plenty of yachts use wire for halyards, exactly to prevent stretch. Or did I dream that? No, I don't think so. :rolleyes: Nothing looks or performs worse than a saggy luff in a breeze, and it can be very difficult eradicating the last bit of slack.
Click to expand...
Wire halyards (with dedicated wire winch) or wire/rope halyards is a bit old school now ;)

Dyneema is a better solution for a low stretch halyard.
 
knuterikt said:
Wire halyards (with dedicated wire winch) or wire/rope halyards is a bit old school now ;)

Dyneema is a better solution for a low stretch halyard.
Click to expand...

I must try Dyneema, as soon as I have a boat to re-rig. Generally I detest ultra-thin lines, but it sounds ideal for halyards.
 
You must log in or register to reply here.

Share this page

Top