[Replace life line covering]

Hi all,

 

I need to replace my top lifeline covering, it's aged and started to crack and split.

 

As I can't replace the covering without cutting the wire, I thought now might be a good time to switch to Dyneema top lines.

 

On other boats I have always found Dyneema life lines to suffer from abrasion and constantly needing replacement, therefore my thought was to use Dyneema inside the plastic lifeline covering.

 

Subject to no one saying that this is a ridiculous idea (and giving a reason why)

 

Where in Auckland (or online) can I purchase the life line covering?

 

Thanks folks!

 

 

 

 

[Engine sea intake]

Might be a stupid question, but do I need two engine sea intakes?

 

The Saildrive has one and there is a thru hull fitting under the berth next to the engine. The hose for that one loops through the "condensor fridge thingie" and then loops around to join the intake from the Saildrive.

 

I am replacing the Engine driven fridge compressor with an electric one so the "fridge condensor thingie" (what ever it is) will be coming out...

 

Thus the thru hull fitting seems possibly surplus to requirements....

 

Thanks as always.

 

 

 

[How to repair gooseneck]

Hi all,

 

Looking for some more advice please.

 

My Gooseneck has gained a bit of a wobble over the years, the centre piece that attaches to the mast has more oval than a circle hole for the bolt.  Any recommendations on how this could be repaired?

 

Thanks

 

 

 

[Volvo 2003 Cooling Pipe Manufacturing]

Hi all,

 

I am in the process of replacing my Volvo Penta 2003 raw water exhaust mixer.  The previous one had been modified to take BSP pipe fittings.  I am hoping to find someone who can manufacture the original pipe parts.  To me these just look like tri clamp connections...

 

The part I want made is #26 in the diagram:

 

 

Here is the old exhaust mixer, with a brass BSP hose fitting that has been tapped into the cast steel.  Not a bad solution and I might go back to this (if I can find an engineering shop to do the drill/tap) if I can't get the pipe made.  But keeping brass out of the system would be preferred...

 

 

Any ideas appreciated....

 

Thanks

 

 

[Hot water cylinder to hot]

Thanks all. I don't have a radiator. The water from the ocean is just pumped through the engine. That same water is pumped through the heat exchanger in the hot water cylinder.

 

I have followed the hoses and there is no pressure release valve anywhere. So it's not surprising that the cylinder blew its outlet hose off.

 

I am guessing that I need to fit a pressure release valve in the circuit, but I am not sure where to release the pressure too...

 

Thanks for the responses all.

 

Rowan

[Hot water cylinder to hot]

Is there supposed to be something in the engine hot water circuit that stops the temperature in the cylinder from reaching explosion levels?

 

I started using our hot water cylinder the other day for the first time in two years and since we have had the boat and the freshwater outlet blew off after motoring for a couple of hours.  The engine temperature was sitting around it's normal 90degC.  The boat became a bit of a steam room for he next half an hour while the remaining water boiled off.

 

I haven't tried exploring the water pipes to see if there is something in the circuit, like a temperature regulator that isn't working, but given this has happened I would kind of expect something to exist?

 

Thanks

[What's my mechanical advantage]

Instead on finishing on the boom is it an option to finish at the top triple block?

 

Are you looking for less or more purchase?

 

I can build it anyway I want, I just kind of want to know what the advantage is, cause it's got me stumped.  My guess was it's somewhere between 24:1 and 28:1...

 

Thanks

[What's my mechanical advantage]

So it makes no difference that the compound 7 is linked to the load as well?

 

I don't understand this, why doesn't some of the force from the 7 get distributed away from the 4 and directly to the load.

 

What if the dotted line was attached to the second pulley from the top, would it still be 7 x 2 x 2, or would there now be some equal or unequal distribution of the 7.

 

I totally get that if the dotted line was attached to the block of three, then it would deffinitely be 7 x 2 x 2, but I am not understanding why it would be still 7x2x2 when one leg of the 7 is connected to the to load.

 

Thanks

[What's my mechanical advantage]

Hi folks, I am rebuilding the vang on a Cookson 47 that I am racing on out of Australia occasionally.  The vang was repaired after a breakage and I am trying to calculate what the current mechanical advantage is of this setup.  I don't know how the formula works when a compound pulley system is connected to an intermediate cascaded system.

 

In the attached diagram the dotted line is confusing me and I don't know how to calculate it.

 

I am probably not going to rebuild it like this, I just want to know what the advantage is, because it's adequate and I don't need more or less.

 

Thanks

[Impact of Shortening Spinnaker Pole]

The number to look at is the max width of your kites.  Ideally the kite pole should be minimum of about 55% of the max width of your bigger kite, or rule of thumb kite width = 1.8 times pole length.  Guessing you probably don't want to cut any more off than you absolutely need to.

 

Thanks for this @markm, very interesting rule. So my sail maker advises that the SMW (maximum width) of the largest spinnaker is 7.6m.  I assume that is the right number?

 

So have I worked out correctly that my Spinnaker pole could be a minimum of 4.18m (7.6 * 0.55)?

 

And going the other way if I cut off 150mm from my 4.35m pole, my kite should be 7.56m SMW. (4.2 * 1.8 )  (So the kite will be just a bit wider than the rule of thumb).

 

Thanks

[Impact of Shortening Spinnaker Pole]

Hi all,

 

I have some damage to the end of my Spinnaker pole and I am toying with the idea of shortening it rather than replacing it.

 

I need to lop off about 100 - 150mm.

 

The pole at 4.35m is already quite a bit longer than "J" which is 3.85m.  The boat is a 10.6 Fractional rig (if that is relevant).

 

Obviously my existing spinnakers (MH and Frac) were both "made to fit" this Spinnaker pole.

 

So what impact would I notice or see if I just shortened it?

 

Thanks

 

 

[Calculate main sheet load]

Hi all,

 

I am wanting to replace our mainsheet with a 6:1 with a cascaded 4:1.  It's currently a very difficult to manage 3:1 that goes back to the mast, down to the shroud and then comes along the deck to the cockpit.

 

I have tried to use the Harken Calculator http://www.harken.com/MainsheetLoading/ to calculate the load, but the technical notes say that it shouldn't be used for sails with large roaches and we have a square top.

 

I tried contacting Harken NZ for support, but it's been a week now and I have had no response.  Which is kind of disappointing because I was intent on using Harken blocks at the time, since then I have found a few other neat solutions by Ronstan and Lewmar.  But I am still stuck with calculating the load.

 

My Sail maker says that the sail is 48m2

 

The measurements are:

Luff: 13.5

Foot: 5m

Distance from aft of boom 1.8m

Max wind speed: 20knots - once over 20 knots we should of reefed 2 knots ago so this has a bit of fat in it

 

Is anyone able to assist me with calculating the mainsheet load?

 

Thanks

 

 

[Snap shackle on an adjustable bight]

No. I am in Auckland. Never been in Whangarei longer than a few hours.

[Snap shackle on an adjustable bight]

The prod is retractable. I will launch all sails on the 2:1. I plan to leave the Tylaska LB on the bight for non furling sails.

 

I looked at the fairlead but I don't like it because it has a screw pin (like a d-shackle) which is prone to going over the side when changing sails or setting up when underway. If all my sails were on the furler then it would be perfect as it could be left on permanently when underway.

[Snap shackle on an adjustable bight]

Ok, lets see how I go explaining this to get to the question...

 

I have a need to put a Ronstan shackle on a prod tack line.  The non opening side of the shackle will be attached to a continuous furler.

 

Currently my Tack line runs parallel to the Prod, passes through a block attached to the end of the prod, and then ends at an eye splice with a Tylaska T8 attached.  We simply haul on the tack line at the cockpit to tighten the tack line.

 

What I am wanting to do is create a 2:1 at the prod, the reason for this isn't for the extra purchase, it to create a solid platform that won't rotate so that the continuous furler cannot rotate.

 

The solution I have come up with, is to take my existing Tack line, leaving it exactly as it is now, but attaching the end of the tack line back to the same point that the block is attached to.

 

So now I have a bight in the tack line, one end is fixed, the size of the bight can be adjusted from the cockpit.

 

Now what I want to do is take the snap shackle on the continuous furler and connect it to the bight.  I can now pull the luff tight, pull the furler all the way down to the end of the prod, and the bight creates a solid platform so the furler will not rotate on the tack line.

 

So, my question, is it a good or bad idea to use a snap shackle in such a way?

 

My concern is that the friction of the tack line being pulled through the snap shackle will cause issue for the shackle, and the tack line making a sudden 180deg turn will also cause an issue for the shackle.  I have never seen a shackle used in such a way, which usually means it's not such a great idea.

 

I had also considered putting a non rotating block on the bight, and then attaching the shackle to that block, but we use the tack line for non furling sails as well and the thought of a 60mm block flogging around when the tack is released plain right scares me.

 

Hopefully that makes sense.

 

Thanks

[PHRF Application Measurements]

Thanks for that. Yup the zero is a head sail.

 

So reading the IRC rules which PHRF references there are several many other rules which I presume don't apply to PHRF. eg:

 

* use of stored power to adjust rigging must be declared.

 

* more than three Spinnakers must be declared and will give an increase in rating

 

Not that these are an issue for me, am I correct that these don't apply to phrf and that the reference to IRC rules is purely for the measurements definition?

[PHRF Application Measurements]

Trying to find some details on the PHRF measurements but have come up short...

 

Can anyone confirm if the "Largest Headsail" measurements should be done against a "Code 0" or the largest Genoa?

 

I am guessing Code 0, but can't find this documented anywhere....

 

Thanks