morning all,
 
Could someone / does anyone have a reference to the length of rope I'd need for a 2:1 main halyard, on our EZ roller.  
 
i presume 4mm dynemma, any advice always greatly appreciated :)
 
thanks 

4mm is fine.
 
21m is my standard length 

Chris, how do you terminate this on the mast tip? Do you run it through a shackle on the head or??

Cheers


Andy

On a Chipstow the neatest solution is a large D shackle through the hole occupied by the pin for your turning block. The other was is a P clip bolted through the same hole.
 
I used to use the D shackle method. 
 
 

Chris.

On my 400 I used a spare hole in the mast head. I've got a selden mast on my merlin. I presume it's some sort of plastic/composite and unable to be drilled or too soft?

Thanks for other info also 

With the Selden head fittings i've seen various ways of terminating the halyard, the neatest is to simply splice a loop that goes over the head fitting but is too tight to slip over the shoulder and down the tube itself. If that wont work (I think it will) then either of the methods above will.
 

Sorry if it is a silly question but what is the perceived advantage of 2:1?:
- Less halyard tail floating round in the boat?
- quicker to pull up?
 
I guess countered against more stuff to jam up inside mast? 

Hi Jeremy,
 
I use it on my boat to stop the halyard from slipping especially when i use the cunningham and kicker in windy weather, before with a single rope it used to slip quite a lot. 

Hi Jeremy, 

Never a silly question.
We are talking of a 2:1 not 1:2.

We want to double the length of the halyard.

This reduces halyard tension and thus reduces slip or creep of the halyard whilst sailing.

Easier to pull up the mainsail as every 2m of halyard pulls 1m of sail. It is a labourious task.

Thanks Andy ..  the 2:1 rather than 1:2 makes sense .....  I was confused as to why the halyard end would therefore be at the top of the mast ... unless the 2:1 bit is external?  (I was imagining it to be internal  Many (albeit singlehanded e.g. OK, Phantom, RS100 etc.) classes use a short strop and lock fitting at the top of the mast to avoid any stretch or slippage or mast compression / tension and then a very light 2mm halyard externally.   Has this been tried on Merlins?   Perhaps it would be considered an extra external piece of string that will just cause more knots?  
 
 

I felt the differance in the 2:1 it was definitely better.
 
12 months later I went for a lock and did not notice a differance from the 2:1. I think a significant reduction in compression gets you 90% off the way there and while there may be a benefit to eliminating the compression completely you are now talking very slight differences. 

Thanks Chris and makes sense.   I am sure an extra bit of rope flapping around outside the mast would find lots of things to get tangles with!   Likewise trying to put 2:1 inside the mast i.e. ending at the foot, ...  would likely be asking for trouble  :-)  
 

When we did a bit of testing last Friday we plotted the mast compression by computer on photos taken by northsails Uk. In 15 knots on a skinny Selden, Chris G’s old boat the mast was 40mm to windward mid section