What boatspeed should I expect, as a percentage of True wind?

[Tupaia]

Originally Posted by 44'cruisingcat

If you choose to ignore VMG when talking about sailing upwind, you're basically wasting your time.

10 knots in 10 knots at 45 apparent sounds good right?

No one is disagreeing that VMG is important but for the context here the velocity made good to destination or waypoint, that may not be directly to windward, in fact maybe at right angles or even downwind is more important.

[jmh2002]

Originally Posted by GRIT

I may just buy double cheek blocks, for in front of the daggerboards, in lieu of the singles we have in waiting. And double blocks for the aft sheet blocks too. If I can leave all the sheets in place, I'll be more likely to use the sail.

I would do this anyway if buying/mounting new equipment as the double blocks will give you flexibility for different setups, either now or in the future.

Obviously I don't have a layout drawing of your boat, but for example see @fxykty's and @Tupaia's notes about downwind sails:

Originally Posted by fxykty

On a cat there’s no need to pole out a blade jib, but it will be necessary to pole out an overlapping genoa. In both cases you’ll need a way to rig a block for outhaul/downhaul on the rail a couple of metres back of the front beam.

So you will have both a sheet and this outhaul/downhaul, and if twin headsails DDW (or even on a symmetrical spinnaker downhauls can be useful too to get the right sheeting angles) then possibly on both port and starboard too. So 4 lines.

So think about how that integrates with your deck layout and your forward cockpit. Does it work better to run the outhaul/downhaul from it's fwd block aft to the cheek block too? And then to your cockpit? Or?

Additionally, if things are getting busy in your cockpit I have also seen cheek blocks with integrated jammers. Don't forget low friction rings as part of the overall setup too.

NB: since @fxykty also mentions "the jib out hauled with or without a main is our 25+ knots TWS DDW rig" - I can say that offshore in a big breeze and seas I have sometimes rigged a second sheet on the same side as a safety back up.

Because having a sheet let go (for whatever reason) is no fun when shorthanded in the 'plus' type of conditions (and always in the middle of the night too, right?). But having a second sheet rigged on a long leg is nothing if you already have the blocks for it.

All food for thought maybe.

Originally Posted by Tupaia

I'd never heard of Code D before but it would appear it is a cross over between a Code 0 and Asym.

Yes, Code D is a term particularly used in France/Europe. The term was invented by Delta Voiles (sails) France in 2010, and is in fact their registered trade mark.

Here is some technical info on their specific sail: https://deltavoiles.com/wp-content/u...code-D-ENG.pdf

Originally Posted by GRIT

I believe tangon is a pole, as it says "avec tangon au vent" which I assume means poled to windward.

Yes, this is correct in French.

[fxykty]

Just a caution on stacked cheek blocks based on our experience with an original 57mm Harken Black Magic double foot block - the working load of the upper sheave is about 30% lower than the rated safe working load due to the leverage. In our case the upper sheave bearings were crushed and the frame distorted, despite seeing the same loads as the lower sheave.

We replaced that double foot block with a double deck organiser - fortunately we had enough room for the unit and now both sheaves are full strength. The unit has enough spacing to allow for soft shackles or loops for mounting LFRs above it (though watch the loads).

[Dave_S]

It is an interesting thread.

But it's all about VMG, optimising your speed to a heading regardless if you can achieve that on one heading or by tacking or gybing.

VMG upwind
VMG to marker
VMG to destination
VMG downwind
VMG on any point of sail

[jmh2002]

Originally Posted by fxykty

Just a caution on stacked cheek blocks based on our experience with an original 57mm Harken Black Magic double foot block...

Yes good point. In fact the entire double footblocks are always rated less than the singles. And 'double stacking' singles to create doubles causes a similar problem.

57mm Single: Maximum working load (kg) 1134 kg
57mm Double: Maximum working load (kg) 750 kg

Just out of interest, do you think that the 57mm size was correctly spec'd for your boat size and it's loads? That seems a little small to me - but that's just by eyeball, I didn't calculate anything.

57mm Double: Maximum working load (kg) 750 kg
75mm Double: Maximum working load (kg) 1572 kg
100mm Double: Maximum working load (kg) 2250 kg

To save @GRIT having to search here are is the whole range of footblocks all together:

Black Magic: https://www.harken.co.nz/productcate...spx?taxid=4514

Cruising ESP: https://www.harken.co.nz/productcate...spx?taxid=4515

Deck Organisers: https://www.harken.co.nz/productcate...spx?taxid=4504

Also to note is that the loads double if it's a 180deg turn on the footblock.
For reference here's a chart of Loads vs Angles.



https://www.harken.com/gallery/3c692...ff55c2f9d4.pdf

[fxykty]

Originally Posted by jmh2002

Yes good point. In fact the entire double footblocks are always rated less than the singles. And 'double stacking' singles to create doubles causes a similar problem.

57mm Single: Maximum working load (kg) 1134 kg
57mm Double: Maximum working load (kg) 750 kg

Just out of interest, do you think that the 57mm size was correctly spec'd for your boat size and it's loads? That seems a little small to me - but that's just by eyeball, I didn't calculate anything.

57mm Double: Maximum working load (kg) 750 kg
75mm Double: Maximum working load (kg) 1572 kg
100mm Double: Maximum working load (kg) 2250 kg

To save @GRIT having to search here are is the whole range of footblocks all together:

Black Magic: https://www.harken.co.nz/productcate...spx?taxid=4514

Cruising ESP: https://www.harken.co.nz/productcate...spx?taxid=4515

Deck Organisers: https://www.harken.co.nz/productcate...spx?taxid=4504

Also to note is that the loads double if it's a 180deg turn on the footblock.
For reference here's a chart of Loads vs Angles.



https://www.harken.com/gallery/3c692...ff55c2f9d4.pdf

Great sleuthing and digging up that loading chart.

A few of the original components on our boat were low spec’d, while most thankfully were over spec’d. A bit frustrating. For the remote cruising we plan on we are slowly upgrading the under-sized components and wherever possible replacing with LFRs rather than blocks with bearings. That 57mm double foot block was for our jib sheet and obviously undersized, though also 16 years old.

For anyone building a boat, or specifying it with a boat builder, or refitting, for your sake and that of any subsequent owners, please pick parts and components for which the expected loads are at the low to midrange of their working loads, and not near the top. You’ll have bigger and more expensive gear, but it will work and last so much better.

[GRIT]

Thanks guys for your thoughts. And thanks Jmh2002 for the charts too.

We have cheek blocks (with integral jammers) for the jib sheets, but they don't actually "jam" very well. They're ok for small loads, but not very good at all for medium to high loads, and this on a 37m2 jib, which I'd consider fairly small. Harken Element 80mm cheek blocks (2200kg mwl) I may upsize the sheets to 15mm, just to see if I can get the jammers to bite properly.

Great points about the smaller loading on doubled cheekblocks, I'd not thought of that. I'll have a good look at your chart, and calculate the loads properly before purchase, but you've talked me out of the double cheek blocks. I still have an extra pair of 80mm Harken Elements, which I'll use, but I'll stay away from the doubles.

Cheers.
Paul.

[GRIT]

For Dave_s and 44C.

We're strictly talking about what boatspeed one gets at certain wind speeds, and angles. No matter how useless you may think that is. It's the specific purpose of this thread, as mentioned in the very first post.

This thread is intended to help me understand, in a general sense, how I'm doing; as regards learning to sail this boat. Sail trim, and expected raw speed.

I understand your experienced cat sailors, but let me learn, as you did, step by step. Starting out by ignoring VMG. VMG is tactics, this thread is just about sailing fast.

Add smileys wherever you think is appropriate.

Thanks guys.
Paul.

[GRIT]

I talked about Cheek blocks, but I guess they're now called foot blocks.

In any case, these are what we have:

https://www.harken.co.nz/productdeta...752&taxid=8956 one left and one right, for the jib sheets.

These for the Code 0 sheets, at the back of the boat:
https://www.harken.co.nz/productdeta...774&taxid=8959

And these for the code 0 sheets, at the front of the daggerboards, to lead the sheet to the cockpit.
https://www.harken.co.nz/productdeta...770&taxid=8956


We're also getting clutches for the Code 0 sheets.

We're still sorting out the uphaul and downhaul, blocks and hardware for the daggerboards. They'll be led to the same winches as the sheets.

We only have three winches aboard. Two are Harken 46 electric winches, for the halyards and foresail sheets; one on each side of the mast. We also have an electric Harken 46 reversing winch, used for the mainsheet (in and out), and reefing lines.

We also use an Antal line driver (1000W) for the traveller, which works a treat.


Cheers.
Paul.

[arsenelupiga]

Originally Posted by GRIT

For Dave_s and 44C.

We're strictly talking about what boatspeed one gets at certain wind speeds, and angles. No matter how useless you may think that is. It's the specific purpose of this thread, as mentioned in the very first post.

This thread is intended to help me understand, in a general sense, how I'm doing; as regards learning to sail this boat. Sail trim, and expected raw speed.

I understand your experienced cat sailors, but let me learn, as you did, step by step. Starting out by ignoring VMG. VMG is tactics, this thread is just about sailing fast.

Add smileys wherever you think is appropriate.

Thanks guys.
Paul.

That is very important to get your setup for optimum sailing. There are fine points in all points of sail for any boat. You will have to find strongest points for your boat and then sail only using these strongest setups when it matters.
Remember I was 'racing' against other 40 feet cats including L 400, identical sails and hull and we were ~ 20 % faster. So there is lots of performance meat available if you want to grab it. But will not happen overnite and will not be jsut set sail and it is done.

It is most satisfying when one sails boat near full potential.

[Dave_S]

Originally Posted by GRIT

For Dave_s and 44C.

We're strictly talking about what boatspeed one gets at certain wind speeds, and angles. No matter how useless you may think that is. It's the specific purpose of this thread, as mentioned in the very first post.

This thread is intended to help me understand, in a general sense, how I'm doing; as regards learning to sail this boat. Sail trim, and expected raw speed.

I understand your experienced cat sailors, but let me learn, as you did, step by step. Starting out by ignoring VMG. VMG is tactics, this thread is just about sailing fast.

Add smileys wherever you think is appropriate.

Thanks guys.
Paul.

We are in agreement. Sorry, I was just pointing out what you want to know is your best speed in all conditions and headings which is your best VMG on those courses in those conditions.

[Jim Cate]

for all the contributors in this thread:

Thanks for an interesting discussion, one that has been informative to this heathen monohull person. It's good to hear such talk when free from bombast and self-admiration.

Please carry on...

Jim

[jmh2002]

Originally Posted by Jim Cate

for all the contributors in this thread:

Thanks for an interesting discussion, one that has been informative to this heathen monohull person. It's good to hear such talk when free from bombast and self-admiration.

Please carry on...

Jim

I think many of the contributors to this thread have sailed a lot of different types of boats, both mono and multi, and whilst there might now be a preference for a certain type, enthusiasm for a good outcome seems to be the primary goal here

[GRIT]

Thanks for your comments Dave_S.

You're right, of course, and that's what I'm trying to learn; maximum speeds for each heading, in each wind condition.

Once I know that, I'll be ready to talk about VMG.

Your comments are appreciated.

Cheers.
Paul.

[GRIT]

Thanks Jim. We have a good group here.

Lots of knowledgeable folks on this thread, and I'm learning from each one.

Jmh2002's comment is spot on, in my opinion.

Cheers.
Paul.