T830 Canting

[tdan 0]

Hi SA community,

i think it is now time to publish a few details of our T830 canting project. We finished the boat approx. 2 month ago and tested it a few times. Due to problems with the canting keel purchase (a few Ronstan blocks exploded) we have taken the boat out of water. So no more sailing this year...(it is getting f..... cold here in germany)

The first test were very promising. The boat was extremly fast even without the optimal trim. Here are some pictures: Please take into account that we only had 3 month (after work and weekends) to build the boat (without the foils) - so don't expect a perfect finish and a clean shed.

The specs:

carbon airex, draft 2,6m; approx weight 750kg; bulb 330kg;

[attachment

=86955:DSC01082_Kopie.JPG]

[barnone 0]

Boat looks awesome. Really like the cabin top. Too bad there's no wind in the sailing photo.

 

Also good to see some cases of Pilsener (beer) in the shop. Can't make proper design decisions without it.

[Schoonerman 6]

That is ONE awesome sporty you have there!

 

Did you sort out the canter issues?

[CapsizeKing 0]

Hey Dan,

 

finally some pictures

saw you on the water during the Herbstwoche in Flensburg...and there´s a thread on the german SA hier klicken. Maybe you could shed some light (and pictures) there as well! Awesome boat you have there, mate.

 

cap

[Squevil 0]

what a weapon!

[andrewlachlan 0]

i want that one!

[ratchamatic 0]

i want that one!

 

hey frayedsheet,

 

by the way ... the moulds are still available and ready for collection in hamburg (germany)! Don't miss it!

[andrewlachlan 0]

i want that one!

 

hey frayedsheet,

 

by the way ... the moulds are still available and ready for collection in hamburg (germany)! Don't miss it!

 

this may be true, but ill have to make do with the 8m non canting version

[fullsail 0]

Really nice, I want one too.

 

Christian

[Christian 72]

i want that one!

 

hey frayedsheet,

 

by the way ... the moulds are still available and ready for collection in hamburg (germany)! Don't miss it!

 

Hmmmmmmmmmmmmmm - can you give a little more detail: what moulds are actually in existence hull? deck? Keel? rudder? other?

[ratchamatic 0]

Hmmmmmmmmmmmmmm - can you give a little more detail: what moulds are actually in existence hull? deck? Keel? rudder? other?

 

hull and deck: frames for female battened moulds

keel: female mould

rudder and canard: no moulds ... blades are made of carbon layers over a male CNC-shaped foam-core

[ultaracer613um 2]

i want that one!

 

hey frayedsheet,

 

by the way ... the moulds are still available and ready for collection in hamburg (germany)! Don't miss it!

 

 

The 830 tooling?? Say it ain't so.. i'd damn sure be interested! I miss my 830 something fierce.

[Speedwatch 6]

Mmmh, with a strong Dollar as today buy / ordering a T830 in Germany would make sense for someone who quit the market 3 months ago ...

[t-8 0]

there is also a T8 for sale in Aus for those in the northern hemisphere. The AUD has tanked in the last couple of months, off nearly 40% from its highs! Its like a stock take sale!

[Christian 72]

Mmmh, with a strong Dollar as today buy / ordering a T830 in Germany would make sense for someone who quit the market 3 months ago ...

 

Wouldn't exactly call the dollar strong - just not as shitty as is has been recently

[revo 0]

Hi SA community,

i think it is now time to publish a few details of our T830 canting project. We finished the boat approx. 2 month ago and tested it a few times. Due to problems with the canting keel purchase (a few Ronstan blocks exploded) we have taken the boat out of water. So no more sailing this year...(it is getting f..... cold here in germany)

The first test were very promising. The boat was extremly fast even without the optimal trim. Here are some pictures: Please take into account that we only had 3 month (after work and weekends) to build the boat (without the foils) - so don't expect a perfect finish and a clean shed.

The specs:

carbon airex, draft 2,6m; approx weight 750kg; bulb 330kg;

[attachment

=86955:DSC01082_Kopie.JPG]

boat looks anreal, is your tube shape for keel in stainless ? have you got a casset, what sort of purchase for canting ? any more pics? great job , well done , hope you win many races.

[tdan 0]

to answer the questions concerning the canting mechanism:

we use a ss tube as bearing for the keel. a carbon casette is glued in the tube. we first used a 1:8 purchase - but the blocks exploded. No we try a 1:16 purchase using ronstan orbits. We hope they'll do the job and keep the friction at a reasonable level. i have attached a few pics of the canting keel tube+casette. FYI the plastic parts you can see on the pics attached to the first post is the pivoting canard bearing.

[revo 0]

to answer the questions concerning the canting mechanism:

we use a ss tube as bearing for the keel. a carbon casette is glued in the tube. we first used a 1:8 purchase - but the blocks exploded. No we try a 1:16 purchase using ronstan orbits. We hope they'll do the job and keep the friction at a reasonable level. i have attached a few pics of the canting keel tube+casette. FYI the plastic parts you can see on the pics attached to the first post is the pivoting canard bearing.

thanks for the pics so the teflon bearing are at the top and bottom of the casset so the keel is just clear of the stainless tube ? on the sports 8 xx we got 4 to 1 purchase going to a 32 winch wich make pretty qwick to tack but you got extra 100 kg in keel and lower! what sort of winch ? or may be you got none ? we also cant 50 deg its very hard to get !

[tdan 0]

No - the keel is directly bolted to the carbon casette. We use a Harken 16 Winch.

The POM bearing has nothing to do with the keel. It is for the canard.

the tacks are not very difficult as one man can lower the keel down and pull the first 20-30° to the other side without using the winch.

the keel fully canted is like 4 massive lads on the rail - the gain in RM is high.

[tdan 0]

Here a few more details of the build:

as mentioned we used a female battend mould, with airex as sandwich core and carbon.

deck and hull moulds:

internals fitted:

deck and hull joined:

deck laminated:

boat turned:

fairing:

boat ready for paiting:

primer sprayed:

topcoat sprayed:

then it was time to make the foils:

we used vacuum infusion to build the keel, the rudder and the canard. The canard and the rudder were infused over Cnc-milled foam cores:

picture of the infused rudder halfes:

The keel was also made by infusing each halfes seperately and then glueing them. Here is a picure of the infusion in the female mould:

The keel is 40mm thick and about 300mm wide. The laminate is about 12mm thick. Hope it is thick enough .

I almost forgot to say thanks to Jan Myslik from Prague for his help. Without his experience of the T830 our project would have ended in a disaster.

[mathewgj 1]

are these euro t830s (canting or non) faster than stealth 8 / sports 8 ? maybe on light air lakes? maybe not in heavier breeze?

[tdan 0]

yes that would be interesting to know. How does the T8 compare to Vivace and co.?

[mathewgj 1]

aussie t8 rates a good bit slower than stealth 8 or sports 8 - but the euro t830s are quite a bit different than the t8

[dachopper 20]

Don't forget the "Turbo" t8 aswell

[tdan 0]

Turbo T8? I thought it is stuck in the drawing/construction phase. Are there any photos of it?

[t-8 0]

Turbo T8? I thought it is stuck in the drawing/construction phase. Are there any photos of it?

[dachopper 20]

what are those smudges in the pictures ... oh wait thats' just my drool !!

[tdan 0]

nice boat indeed. Will you soon start building or are still some drawings missing?

[jacobsen1 1]

very nice!

 

I bet the canter solves the issue we had with our viper 830: it wanted 7 big guys on the rail, but the perfect crew was ~5...

 

how many do you plan on racing her with? Nice job!

[GybeSet 19]

then you get another issue or two, cost premium .. and the non-canter will beat you

 

there are 2 non-canter t830s in GER/SUI to prove whats already known in aus, in the light conditions there I know which one I'd have my money on.

[revo 0]

then you get another issue or two, cost premium .. and the non-canter will beat you

 

there are 2 non-canter t830s in GER/SUI to prove whats already known in aus, in the light conditions there I know which one I'd have my money on.

sorry but the canter prooved at airlie there are quicker that the none canter ! for the none canter to have the same speed as us up wind in 20 , 25 knt they had to carry an extra 200 kg of crew weight, but as the wind drop of we where quicker up wind, and really took of down wind lower and faster because the weight saving !!canting keel make a lot of sence in big boat and worck less and less as the boat get smaller , but it still worck, well done guys with the t 830 great job, and dont warry about all the wingers full off critics !!

[ratchamatic 0]

very nice!

 

I bet the canter solves the issue we had with our viper 830: it wanted 7 big guys on the rail, but the perfect crew was ~5...

 

how many do you plan on racing her with? Nice job!

 

We always are short on crew members. 3-4 guys (250-300 kg) on the rail, that's all. But enough for good boat handling. Now, with canting keel, we get the option in medium and heavy air of about 330 kg "rail meat" extra without raising boat weight at all. And on the other hand that will pay off in lighter conditions (despite more drag because of the canard) ... hopefully!

To handle the canting keel in tacks and gybes quickly, we still need some training sessions ...

[dachopper 20]

Turbo T8? I thought it is stuck in the drawing/construction phase. Are there any photos of it?

 

 

Has it started construction ?

[GybeSet 19]

it's an interesting looker, and would be good to see 'eh,

In true t boat style the alternative is only cms away, the t830 !

 

reckon the ratio of computer renderings actually turning into physical baost is about 50:1 on Anarchy, even worse at the mo with the stock market

 

calling BS

[tdan 0]

i really can't understand the discussion about the canter. If it is a sportie with only a few kg lead - ok than it isn't worth the effort. But if you take a heavy bulb sportie like the t830 with 500kg lead and use a canting setup it is very reasonable. Our boat has about 40% more RM and 30% less weight than the non canting T830. I really can't understand why the canting version shouldn't be clearly faster than the non-canter - only because of the drag of the canard upwind? On the other hand the canting keel can be designed that it has less drag than the non canting keel as it needn't create any lift.

[Kestrahl 6]

With 500kg of lead and moderate beam it is reasonable to assume a canting keel will be faster, although reducing the lead to 250 and putting wings on would be faster because wings and people provide more righting moment than a keel canted without the extra drag of the canard and bigger bulb. Both have a extra risk of capsize, canting is good for shorthanded.

 

The Elliott 30 canter did pretty good in the coastal classic the other weekend.

[dachopper 20]

With 500kg of lead and moderate beam it is reasonable to assume a canting keel will be faster, although reducing the lead to 250 and putting wings on would be faster because wings and people provide more righting moment than a keel canted without the extra drag of the canard and bigger bulb. Both have a extra risk of capsize, canting is good for shorthanded.

 

The Elliott 30 canter did pretty good in the coastal classic the other weekend.

 

Don't forget that although you don't have a canard in your fixed keel example, you need more crew weight, causing the entire boat to sit lower in the water giving more drag ( probably an extra 3 people on board for that example )... Needing more people in the Non-canting version to keep the boat flat would mean downwind.... the canting version would weigh considerably less, the canard is all but out of the water, and therefore it will go a lot faster....they are designed with the optimum crew weight AND keel size AND cant AND rig size before hand so unless you go from 3 or 3.5 to 4.5 metres beam.... the crew weight is not making a huge difference....

it

Otherwise vivace would be faster upwind all the time that 79xx ... looking at ABRW it would appear to say that 79xx is .01 to .02 faster than vivace? ..... you would have to increase vivace beam Further to 4/ 4.5 metres to make up for the non cant

 

also assuming you can get a 45 degree cant, the entire bulb weight is at roughly 1.5 Metres to windward ( 2.2 draft ) ( on the rail for a 3 meter beam boat... 250kgs on the rail = 3 people........ )

[Turkey Slapper 55]

Turbo T8? I thought it is stuck in the drawing/construction phase. Are there any photos of it?

 

 

Looks alright for a Winged Shitter eh!

 

Must be a Tboat thing!

[tdan 0]

terminology is incorrect....the inertia of water at 17PSI is greater than that at 16 PSI

 

 

As water is incompressible it doesn't change its density. So the inertia should be the same.

[Cheesy 0]

terminology is incorrect....the inertia of water at 17PSI is greater than that at 16 PSI

 

For all intensive purposes water is in-compressible, the density will be the same at different depths for a given temperature

[Cheesy 0]

The pressue in water DOUBLES every 10 metres......its a fact.

therefore to move through "double" the pressure with the same force you will go slower...

 

Its on of the reasons aircraft fly at high altitude to go fast where the pressure reduces... to 1/3 of what it is a sea level.

 

 

I think the drag you are talking about is something along the lines of:

 

Fd = -1/2 * Ro * v^2 * A *Cd

 

where

Fd = drag

Ro = density

v= velocity

A = frontal area

Cd = coeficient of drag

 

Your example with the plane is correct, as the height increases the pressure decreases and because air is compressible the density of air decreases, which from the equation will decrease Fd (note that Cd may also be different as this is usually plotted against Reynolds number which in turn has a density term). However because water is not compressible the density does not change with pressure or therefore depth, so Fd also remains the same.

[revo 0]

i really can't understand the discussion about the canter. If it is a sportie with only a few kg lead - ok than it isn't worth the effort. But if you take a heavy bulb sportie like the t830 with 500kg lead and use a canting setup it is very reasonable. Our boat has about 40% more RM and 30% less weight than the non canting T830. I really can't understand why the canting version shouldn't be clearly faster than the non-canter - only because of the drag of the canard upwind? On the other hand the canting keel can be designed that it has less drag than the non canting keel as it needn't create any lift.

 

 

the sports 8 xx canter have less weted area ( keel and canard ) that the kell on the first boat non canter vivace . so far all the race result we got are on w/l and that s not the best for a canter. your t830 gana fly.

[tdan 0]

our keel and canard have also less wetted surface than the original keel design. But the wetted surface is not the only reason for drag. Also improtant is the projected area (thickness x length of the foil) - so we decided to build the foils as thin as possible. When we thought about the canting keel, we also considered a non canting keel and wings, but to have the same weight and RM, than the Canter the boat needs approximately 5m width.

So we decided to increase the draft and to decrease the thickness and chord length of the keel, to keep the drag low.

But there are serious drawbacks: The price, the complexity and the reliability.

[andrewlachlan 0]

The pressue in water DOUBLES every 10 metres......its a fact.

therefore to move through "double" the pressure with the same force you will go slower...

 

Its on of the reasons aircraft fly at high altitude to go fast where the pressure reduces... to 1/3 of what it is a sea level.

 

 

I think the drag you are talking about is something along the lines of:

 

Fd = -1/2 * Ro * v^2 * A *Cd

 

where

Fd = drag

Ro = density

v= velocity

A = frontal area

Cd = coeficient of drag

 

Your example with the plane is correct, as the height increases the pressure decreases and because air is compressible the density of air decreases, which from the equation will decrease Fd (note that Cd may also be different as this is usually plotted against Reynolds number which in turn has a density term). However because water is not compressible the density does not change with pressure or therefore depth, so Fd also remains the same.

 

This drag question made me curious so I asked a friend... but to simplify I asked him if a submarine at 1m or 20m depth would need more force to push it forward... so even though I didnt intend hm to, he got even more technical and started talked about propellers!

 

"water is an interesting substance, it behaves quite differently to all the others.... due to its molecular structure..... Ever notice how water expands when solid, compared to everything else which contracts???? This is a fundamental principal when answering your question....... But for the time being, the molecular mechanisms at work here don't really matter.... I'll just give you the consequences.

 

 

When studying a submarine through water, we must look at liquid viscosity. Now just about every liquid known to us will get thicker (increase viscosity) with increasing pressure. Water, however, is an anomaly, it get's thinner (decreases viscosity) with increasing temperature, due to its unique structure. Water is at its thickest, and most dense at around 4 °C. The liquid water grows ever more thin until the first crystal of ice forms, at which point it cannot flow any more. As long as the water is at constant temperature, and the only difference in your scenario is depth (pressure), than we can infer that the deeper submarine is in "thinner" water.... The effect of adding salt to the water (as in the ocean) actually eccentuates the effects im describing here.... You get freezing point depression and boiling point elevation.... so our subs could travel at a vast range of temperatures, but again, the deeper sub would still be in the "thinner" water.....

 

 

So is it better to be in thinner or thicker water? I asked myself this question during the last olympics, while watching the swimming. Thinner water means less resistence to push through, but your rotors/turbines wont be able to get as much "purchase" on the liquid to propel you forward. So it basically comes down to this trade off.

 

 

I'd say it's better to be in the thin water - you have less resistence on the front of your submarine as it travels forward, and less resistence on your propeller blades. While the increased resistence on the prop. blades in the thick water might help, it will require more energy a) to even turn the propeller through the thicker water, and way more resistence acting over the entire body of the sub as it cuts though the water. Propellers these days are really well designed, i doubt whether small changes in viscosity will affect thier efficienc too greatly.

 

 

In summing up...... By this rationale, thinner water means an easier to turn propeller and way less resistence over the body of the sub, which is where the biggest savings in energy will be achieved. Since water viscosity decreases with increasing pressure...... I have to say that the deeper submarine is more energy efficient to operate.

[jonsailor 1]

The pressue in water DOUBLES every 10 metres......its a fact.

therefore to move through "double" the pressure with the same force you will go slower...

 

Its on of the reasons aircraft fly at high altitude to go fast where the pressure reduces... to 1/3 of what it is a sea level.

 

 

I think the drag you are talking about is something along the lines of:

 

Fd = -1/2 * Ro * v^2 * A *Cd

 

where

Fd = drag

Ro = density

v= velocity

A = frontal area

Cd = coeficient of drag

 

Your example with the plane is correct, as the height increases the pressure decreases and because air is compressible the density of air decreases, which from the equation will decrease Fd (note that Cd may also be different as this is usually plotted against Reynolds number which in turn has a density term). However because water is not compressible the density does not change with pressure or therefore depth, so Fd also remains the same.

 

This drag question made me curious so I asked a friend... but to simplify I asked him if a submarine at 1m or 20m depth would need more force to push it forward... so even though I didnt intend hm to, he got even more technical and started talked about propellers!

 

"water is an interesting substance, it behaves quite differently to all the others.... due to its molecular structure..... Ever notice how water expands when solid, compared to everything else which contracts???? This is a fundamental principal when answering your question....... But for the time being, the molecular mechanisms at work here don't really matter.... I'll just give you the consequences.

 

 

When studying a submarine through water, we must look at liquid viscosity. Now just about every liquid known to us will get thicker (increase viscosity) with increasing pressure. Water, however, is an anomaly, it get's thinner (decreases viscosity) with increasing temperature, due to its unique structure. Water is at its thickest, and most dense at around 4 °C. The liquid water grows ever more thin until the first crystal of ice forms, at which point it cannot flow any more. As long as the water is at constant temperature, and the only difference in your scenario is depth (pressure), than we can infer that the deeper submarine is in "thinner" water.... The effect of adding salt to the water (as in the ocean) actually eccentuates the effects im describing here.... You get freezing point depression and boiling point elevation.... so our subs could travel at a vast range of temperatures, but again, the deeper sub would still be in the "thinner" water.....

 

 

So is it better to be in thinner or thicker water? I asked myself this question during the last olympics, while watching the swimming. Thinner water means less resistence to push through, but your rotors/turbines wont be able to get as much "purchase" on the liquid to propel you forward. So it basically comes down to this trade off.

 

 

I'd say it's better to be in the thin water - you have less resistence on the front of your submarine as it travels forward, and less resistence on your propeller blades. While the increased resistence on the prop. blades in the thick water might help, it will require more energy a) to even turn the propeller through the thicker water, and way more resistence acting over the entire body of the sub as it cuts though the water. Propellers these days are really well designed, i doubt whether small changes in viscosity will affect thier efficienc too greatly.

 

 

In summing up...... By this rationale, thinner water means an easier to turn propeller and way less resistence over the body of the sub, which is where the biggest savings in energy will be achieved. Since water viscosity decreases with increasing pressure...... I have to say that the deeper submarine is more energy efficient to operate.

 

Well that was an interesting piece of information, not sure if most keel variences of depth will come into play but thanks for the story.

As we do not want propellors to work at that depth, that side of the equation dosent effect the outcome

 

Well done

Thank you

[dachopper 20]

Can you put some new pictures of the T830 on the thread?

 

maybe of the canting setup, deck layout, etc etc

[tdan 0]

Here are a few more pictures.

The finished rudder (total 5kg)

the hydraulic mastram

the canting keel case and bearing. Unforunately without the purchase as we plan to install a new one. It runs from the keel casette to the tubes. The canting angle shoud be about 50to 55°. We installed a new sealing to allow a larger angle.

very comfortable sandwich bunks...

pivoting prod:

hydraulic pump

mastpost and stringer

[Turkey Slapper 55]

This drag question made me curious so I asked a friend... but to simplify I asked him if a submarine at 1m or 20m depth would need more force to push it forward... so even though I didnt intend hm to, he got even more technical and started talked about propellers!

 

"water is an interesting substance, it behaves quite differently to all the others.... due to its molecular structure..... Ever notice how water expands when solid, compared to everything else which contracts???? This is a fundamental principal when answering your question....... But for the time being, the molecular mechanisms at work here don't really matter.... I'll just give you the consequences.

 

 

When studying a submarine through water, we must look at liquid viscosity. Now just about every liquid known to us will get thicker (increase viscosity) with increasing pressure. Water, however, is an anomaly, it get's thinner (decreases viscosity) with increasing temperature, due to its unique structure. Water is at its thickest, and most dense at around 4 °C. The liquid water grows ever more thin until the first crystal of ice forms, at which point it cannot flow any more. As long as the water is at constant temperature, and the only difference in your scenario is depth (pressure), than we can infer that the deeper submarine is in "thinner" water.... The effect of adding salt to the water (as in the ocean) actually eccentuates the effects im describing here.... You get freezing point depression and boiling point elevation.... so our subs could travel at a vast range of temperatures, but again, the deeper sub would still be in the "thinner" water.....

 

 

So is it better to be in thinner or thicker water? I asked myself this question during the last olympics, while watching the swimming. Thinner water means less resistence to push through, but your rotors/turbines wont be able to get as much "purchase" on the liquid to propel you forward. So it basically comes down to this trade off.

 

 

I'd say it's better to be in the thin water - you have less resistence on the front of your submarine as it travels forward, and less resistence on your propeller blades. While the increased resistence on the prop. blades in the thick water might help, it will require more energy a) to even turn the propeller through the thicker water, and way more resistence acting over the entire body of the sub as it cuts though the water. Propellers these days are really well designed, i doubt whether small changes in viscosity will affect thier efficienc too greatly.

 

 

In summing up...... By this rationale, thinner water means an easier to turn propeller and way less resistence over the body of the sub, which is where the biggest savings in energy will be achieved. Since water viscosity decreases with increasing pressure...... I have to say that the deeper submarine is more energy efficient to operate.

 

 

So thats why the big yachts have such deep keels now!

[Speedwatch 6]

our keel and canard have also less wetted surface than the original keel design. But the wetted surface is not the only reason for drag. Also improtant is the projected area (thickness x length of the foil) - so we decided to build the foils as thin as possible. When we thought about the canting keel, we also considered a non canting keel and wings, but to have the same weight and RM, than the Canter the boat needs approximately 5m width.

So we decided to increase the draft and to decrease the thickness and chord length of the keel, to keep the drag low.

But there are serious drawbacks: The price, the complexity and the reliability.

 

Hallo Dan,

da du offensichtlich nicht in Deine PM-Box hier bei SA.com reinschaust melde ich mich jetzt auf diesem Weg: Ich würde mich sehr freuen, wenn wir Deine / Eure T830i auf SailingAnarchy.de vorstellen könnten. Hier auf der englischsprachigen Site geht natürlich sehr viel mehr ab, was den Austausch mit den Segelfreunden von AUS & NZ betrifft, aber auch wir freuen uns, wenn Du uns mit Infos aus erster Hand zu Eurem Selbstbauprojekt fütterst. Bitte einfach mal eine E-mail an info ätt sailinganarchy.de und ich melde mich so schnell als möglich.

Gruß aus Berlin

Joachim

[CapsizeKing 0]

Jou! Da bin ich auch dafür! Gruß aus W´mnde

 

Götz

 

p.s. Speedwatch, how about your little boat? Already finished the season? I could imagine little Xmas cruise with some Glühwein!

 

cap

[Speedwatch 6]

Jou! Da bin ich auch dafür! Gruß aus W´mnde

 

Götz

 

p.s. Speedwatch, how about your little boat? Already finished the season? I could imagine little Xmas cruise with some Glühwein!

 

cap

 

Off topic so quick: The T680 Sport is still in water and I hope it will stay there until mid of december as in 7 of 10 years there are good weather conditions for sailing in Berlin. Maybe I can push the boys for a pre Xmas cruise with Grog or Glühwein instead of lifting in out and move it into the shed until March / April.

And if so, I will give you a call for sure

Joachim

[jonsailor 1]

Jou! Da bin ich auch dafür! Gruß aus W´mnde

 

WTF...your spelling is as good as mine????

[dachopper 20]

How long until you have finished the block / new cant angle mods....

 

must have been like 4 guys on the rail for sure with 330kgs in the keel !

[tdan 0]

we wil install the new purchase next week.

 

By the way, does anybody now good high-load ball bearing blocks that are affordable?

How about the orbits? our last ronstan blocks exploded under are load that was far under the specified SWL and the german importer doesn't want to take them back. Maybe i should ask ronstan, maybe they are more cooperative...

[Christian 72]

we wil install the new purchase next week.

 

By the way, does anybody now good high-load ball bearing blocks that are affordable?

How about the orbits? our last ronstan blocks exploded under are load that was far under the specified SWL and the german importer doesn't want to take them back. Maybe i should ask ronstan, maybe they are more cooperative...

 

You have to think about the dynamic loading you get on the blocks (just think about pounding a bit into chop).

 

The Karver blocks are really nice.......but not cheap.

 

Interesting way of keeping the water out - how long do you anticipating before having to replace that rubber? How much does it bulge up when the boat is in the water - especially when on a screaming plane?

[tdan 0]

the sealing has to be replaced every year. but it is thick approx 1mm so it is very hard to stretch.

The karver blocks are nice that is for sure. But they are extremely expensive here (80€+).

[TocToc 2]

the sealing has to be replaced every year. but it is thick approx 1mm so it is very hard to stretch.

The karver blocks are nice that is for sure. But they are extremely expensive here (80€+).

 

Did you check the new ronstan lashing blocks: http://www.ronstan.com/marine/range.asp?RnID=024

[tdan 0]

Yes the ronstan lashing block are indestructable, but also very expensive (even more expensive thatn the karvers). i think we will go for the ronstan orbit 55 blocks. If we take a 1:12 pulley the load is approx. 200kg each block and they have a SWL of 500kg. i think that is enough safety margin. We will see...

[Christian 72]

Yes the ronstan lashing block are indestructable, but also very expensive (even more expensive thatn the karvers). i think we will go for the ronstan orbit 55 blocks. If we take a 1:12 pulley the load is approx. 200kg each block and they have a SWL of 500kg. i think that is enough safety margin. We will see...

 

If I were you I would seriously think about staying away from Ronstan. My experience (as well as many other people's) is that Ronstan is definitely lower on the rank than Harken and also be aware that when marking blocks with load limits - Karver and Harken uses safe working loads with a safety margin of at least 2 where Ronstan doesn't. I don't know the newest Ronstan blocks so they might be fine - I would just be weary due to past performance of the brand. Lewmar is another brand to avoid.

 

What is your total load for the system (boat on the side with keel out of the water)? How do you calculate your dynamic loads? - I think most designers are thinking shockloads in the 10x to 20x range compared to static load - naturally deppending on venue and boat type

[MR.CLEAN 3,842]

Yes the ronstan lashing block are indestructable, but also very expensive (even more expensive thatn the karvers). i think we will go for the ronstan orbit 55 blocks. If we take a 1:12 pulley the load is approx. 200kg each block and they have a SWL of 500kg. i think that is enough safety margin. We will see...

 

If I were you I would seriously think about staying away from Ronstan. My experience (as well as many other people's) is that Ronstan is definitely lower on the rank than Harken and also be aware that when marking blocks with load limits - Karver and Harken uses safe working loads with a safety margin of at least 2 where Ronstan doesn't. I don't know the newest Ronstan blocks so they might be fine - I would just be weary due to past performance of the brand. Lewmar is another brand to avoid.

 

What is your total load for the system (boat on the side with keel out of the water)? How do you calculate your dynamic loads? - I think most designers are thinking shockloads in the 10x to 20x range compared to static load - naturally deppending on venue and boat type

We've tried almost all of the small boat Ronstan blocks - the Orbits have taken some serious abuse with no problems to loads beyond the SWL, in waves. The old-style bearing blocks not so much, even the high-load ones.

[tdan 0]

the maximum static load of the pulley is 1300kg (keel 90°). i don't think the dynamic loads on the pulley will be more than 2-3 times of the static loads - but i don't know. The keel fin is desgined to withstand a dynamic load that is 3-4 times the static load. The MaxFun that lost its keel only had a safety factor of 1.8. - Ok it obviously wasn't enough but i think a safety of 2 with respec to the static worst case scenario is usually enough. But if we hit the ground at high speed - that will be the end of the Tboat...

[Christian 72]

the maximum static load of the pulley is 1300kg (keel 90°). i don't think the dynamic loads on the pulley will be more than 2-3 times of the static loads - but i don't know. The keel fin is desgined to withstand a dynamic load that is 3-4 times the static load. The MaxFun that lost its keel only had a safety factor of 1.8. - Ok it obviously wasn't enough but i think a safety of 2 with respec to the static worst case scenario is usually enough. But if we hit the ground at high speed - that will be the end of the Tboat...

 

Well - I hope you are right but it seems like walking on edge and if the blocks explode it could be a BAD situation. The keel fin blade will have an easier time to take static loads as it has some give in it - maybe the stretch in the line in the purchase system will also save your bum by stretching as opposed to peak loading the blocks. Wish you the best. It's a cool boat. I have a Viper 830 and can definitely see how a canting ballast could improve performance a great deal - not that it's a slowpoke in the first place............

[tdan 0]

you're right it is bad when the blocks explode, we had it one time and don't want to have it a second time . But i'm confident that the orbit blocks will do the job.

[psyclone 12]

just a thought.......why not buy the "tried and tested" ones? so what if they are "more" expensive at least you have peace of mind.....i dont know about you but a)having your board swinging freely aint my idea of fun or cool

b)if cheap ones keep exploding and you have to keep replacing them then they actually become more expensive!! especially if they fail the boat capsizes and you break a rig or worse drowns someone then they will be very fcuking expensive then

just my 2 cents worth

[Christian 72]

you're right it is bad when the blocks explode, we had it one time and don't want to have it a second time . But i'm confident that the orbit blocks will do the job.

 

The very nice thing about the Karver blocks is that due to the design - even if a block were to explode the lines will still be kept captive so you wont have a free swinging keel...........just consider it. You can do somewhat of the same if you use the Harken tie-lite blocks or the heftier ones made for loops

[t-8 0]

question to all... who is quicker around the cans.... The T830i or the Cone? I see she is for sale.......

[Teaky 143]

Cone's not the best cans vehicle.

[GybeSet 19]

question to all... who is quicker around the cans.... The T830i or the Cone? I see she is for sale.......

 

especially if 2.6mtr draft, a non-cant t830

 

also I think the early t30 protos could beat the Cone on W/Ls

[pete 0]

agreed

[Heaven can wait 0]

question to all... who is quicker around the cans.... The T830i or the Cone? I see she is for sale.......

 

especially if 2.6mtr draft, a non-cant t830

 

also I think the early t30 protos could beat the Cone on W/Ls

 

 

Yup.

 

The Cone and the T980 were head to head similar uphill, the Cone wins out downhill, the Foundation T30 was and still should be quicker than both, uphill and down.

 

I'd say that in my humble opinion that the Foundation T30 and the T35 "Woodstock" are the quickest designs Thommo has ever designed.

[dachopper 20]

I would have thought that the full carbon fibre thompson T920, would be faster than the glass T980 as it probably weighs half as much ?

[GybeSet 19]

the comparison was 'T30-Protos' . similar-ish ( but not the same ) as the 920, more extreme

[t-8 0]

has the 920 found a new home?

[window 0]

has the 920 found a new home?

 

yep still based out of hobart. a young guy bought it, is enjoying saiing it with his mates.

btw. your inbox is full cam

[GybeSet 19]

that doesn't surprise me with the wait on the TCF variations

 

how can we get YV to be more responsive ? $$$

[Flatbag 51]

Cone's not the best cans vehicle.

 

Assume you mean "racing around" type cans rather than the "liquid container" type cans.

Cone was unsurpassed in Oz with regard to the latter

[Flatbag 51]

I would have thought that the full carbon fibre thompson T920, would be faster than the glass T980 as it probably weighs half as much ?

Except in very light stuff, 5-8 knots, the T980 is a fairly ordinary performer as it is also full of heavy furniture unlike the T30 Protos. Couldn't see a T980 beating The Cone upwind or down outside of that narrow wind range. The T920 was no-contest faster than the T980s up & down when Bruce (RIP) had it over here for Skandia Week a while back. Some of that differential would have been down to his sailing ability but nevertheless the T920 is a bloody fast and very impressive machine. Probably the only Thommo you could legitimately call an offshore sporty.

 

The Cone still gives me wood but today I would have a T920 for preference.

[The Advocate 113]

Cone's not the best cans vehicle.

 

Assume you mean "racing around" type cans rather than the "liquid container" type cans.

Cone was unsurpassed in Oz with regard to the latter

 

Oh yeah, and Jamies previous boat, great memories of twilighting in Pittwater on the wire doing main with a tinnie in the other hand. Not sure which was more comfortable, ESP or the Cone.

[t-8 0]

has the 920 found a new home?

 

yep still based out of hobart. a young guy bought it, is enjoying saiing it with his mates.

btw. your inbox is full cam

ahhh so its is..... nothing like a full box...

[Flatbag 51]

Cone's not the best cans vehicle.

 

Assume you mean "racing around" type cans rather than the "liquid container" type cans.

Cone was unsurpassed in Oz with regard to the latter

 

Oh yeah, and Jamies previous boat, great memories of twilighting in Pittwater on the wire doing main with a tinnie in the other hand. Not sure which was more comfortable, ESP or the Cone.

 

He's moved on from those wild and primitive times. On the Crone of Silence you can do a twilight with a can in each hand!

[dachopper 20]

ON the subject of new t-boats, noticed a couple more pics of the T780 t780 blogspot

[lausl 0]

Hi SA community,

i think it is now time to publish a few details of our T830 canting project. We finished the boat approx. 2 month ago and tested it a few times. Due to problems with the canting keel purchase (a few Ronstan blocks exploded) we have taken the boat out of water. So no more sailing this year...(it is getting f..... cold here in germany)

The first test were very promising. The boat was extremly fast even without the optimal trim. Here are some pictures: Please take into account that we only had 3 month (after work and weekends) to build the boat (without the foils) - so don't expect a perfect finish and a clean shed.

The specs:

carbon airex, draft 2,6m; approx weight 750kg; bulb 330kg;

[attachment

=86955:DSC01082_Kopie.JPG]

 

Hi TDan,

 

kannst Du Dich mal melden bei mir, danke.

klaus

08158 258633