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rockDAWG · 20-01-2014, 10:14

Quote:

Originally Posted by annsni

Hank having experienced 5 loss of steerings in all his years of deliveries and two dismastings. We were one of the loss of steerings - LOL. This was his first ever abandon ship in LOTS of sailings and deliveries. Wow - crazy!

With Hank's experience of 5 loss of steerings and 2 mismastings, I wonder if he has learned from each incident. Are there any similarities in these cases?

How would others learn from his experience? We are not here looking to blame, but what would he do next to prevent this again? I am sure there is no easy answer, hence this long thread.

**HappyMdRSailor** · 20-01-2014, 10:15

Quote:

Originally Posted by annsni

Yep - We're reading the story of this whole thing and it's so interesting. But again, Hank has a TON of experience sailing and I remember when he got to NY on our boat and was very non-chalant about the loss of steering because he knew how to handle it. I'm sure if there was a way to get this boat to safety, he would have done it.

That said, I LOVE our boat and know it took him through a big storm with only the loss of steering (and one crew who will never sail again - LOL). 10 years later, many things have been updated and we really trust this boat to keep us safe. But I'm a landlubber and fair weather sailor. That's why we hired Hank to bring the boat from Fort Lauderdale to NY.

A sailor "knows" what another salty "I want you in my boat when the crap hits the fan" guy looks like... Hank has the look... and the reputation and skills to back it up...

**Cotemar** · 20-01-2014, 10:23

Quote:

Originally Posted by rickbase1

I decided to go with a Balance 451(14 metres or 44 ft) and my shafts are solid stainless, approx 48mm, which is just shy of 2 inches. The initial travel limits are set to 30% and the load calculations were done based on a working load of 12 knots at full turn. The stocks are easily accessible from a top hatch (where the emergency manual tiller fits over the stock) so they can be hammered out from the top in an emergency.

Hopefully I won't find myself in a similar position as the unfortunate crew of the Alpha 42, but if I do many of the productive comments in this thread will help in ensuring that I will overcome it.

rickbase1

Make sure your Balance 451 has 4 rudder stops.

Some Production catamarans only come with the 2 outside rudder stops for the whole system. The problem with only having 2 stops is that the designer is hoping the rudder connecting rod which is 20+ feet long will stop the other rudder and as we have seen here there is just too much force on these rudder components to hope for that.

Each rudder should have its own 2 rudders stops.

**HappyMdRSailor** · 20-01-2014, 10:26

Quote:

Originally Posted by Cotemar

rickbase1

Make sure your Balance 451 has 4 rudder stops.

Some Production catamarans only come with the 2 outside rudder stops for the whole system. The problem with only having 2 stops is that the designer is hoping the rudder connecting rod which is 20+ feet long will stop the other rudder and as we have seen here there is just too much force on these rudder components to hope for that.

Each rudder should have its own 2 rudders stops.

+100! BINGO!

colemj · 20-01-2014, 11:03

Quote:

Originally Posted by minaret

You're asking a pin or bolt to take a lot of load in sheer, especially if its a spade rudder. And you are repeatedly loading it in opposite directions, the worst kind of stress cycle for metals. Clevis pins simply prevent rotation or extraction of a part, they bear no load. Not the same thing at all.

Our standing rigging will be very surprised to learn it puts no load at all on the clevis pins holding it on each end.

Are you confusing clevis with cotter pins?

It seems to me like a full shoulder bolt or clevis pin through the rudder stock is strong. That is what we have, and it is how Edson provided this system.

Mark

**HappyMdRSailor** · 20-01-2014, 11:10

Rot Row Rastro.... Here we go....

sigmasailor · 20-01-2014, 11:11

Quote:

Originally Posted by rockDAWG

Rick's cat uses 48 mm solid SS stock. 48mm is 1.89". How is that equivalent to a 1.5" pipe? I must miss something here.

Simple: 1.5 inch pipe has the same OD. Just look it up in the table I sent a couple of posts earlier.

Kookaburra · 20-01-2014, 11:21

For all you that love quotes here is one to help you avoid mistakes. It is far too late to hope that it could be applied on this forum.

It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts.

From A Scandal in Bohemia (Sir Arthur Conan Doyle) (Sherlock Holmes Stories)

rickbase1 · 20-01-2014, 11:23

Quote:

Originally Posted by sigmasailor

I'm unfamiliar with 2021; is that an aluminium alloy? The all important factor is the 0.2% yield stress (200 N/mm2 for 316).

Sigmasailor, here is a quick overview of 2101 Stainless product for your review.

LDX 2101® is a lean duplex stainless steel designed for general purpose use. Like other duplex stainless steels, LDX 2101® provides both superior strength and chloride stress corrosion cracking resistance compared to 300 series stainless steels. The use of manganese ensures proper ferrite-austenite phase balance, while allowing a reduction in nickel content.

The combination of a duplex structure and high nitrogen content provide significantly higher strength levels than 316/316L stainless steel. Often a lighter gauge of LDX 2101® can be utilized, while maintaining the same strength as a 300 series fabrication. The resultant weight savings can dramatically reduce the material and fabrication costs of a component.

rickbase1 · 20-01-2014, 11:29

Quote:

Originally Posted by Kookaburra

For all you that love quotes here is one to help you avoid mistakes. It is far too late to hope that it could be applied on this forum.

It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts.

From A Scandal in Bohemia (Sir Arthur Conan Doyle) (Sherlock Holmes Stories)

Heeding this advice can certainly help fend off the notorious "Foot in Mouth" disease some of us have been afflicted with at times !

I am certainly no stranger to its bite!

Cheers to all,

Rick

44'cruisingcat · 20-01-2014, 11:40

Quote:

Originally Posted by sigmasailor

Well maybe you're right. You can also go for aluminium bar (a lot stronger dan 316: Jefa Rudder bearings).

I'm trying to explain here that a large diameter is so much stronger (8 fold from 38 to 76 mm) than a small diameter. The proof stress of aluminium (0.2%) is twice as high as that for 'normal' 316. 316 Is hard to cut and machine but not very strong.

Wasn't there a Hanse yacht with an aluminium rudder stock which sank when the rudder fell off? IIRC in quite benign conditions too. Off the Irish coast.

Then the liferaft failed to inflate, if they hadn't been sailing in company they almost certainly would have been left swimming in the North Atlantic until hypothermia took them.

**Cotemar** · 20-01-2014, 11:59

Quote:

Originally Posted by 44'cruisingcat

Wasn't there a Hanse yacht with an aluminium rudder stock which sank when the rudder fell off? IIRC in quite benign conditions too. Off the Irish coast.

Then the liferaft failed to inflate, if they hadn't been sailing in company they almost certainly would have been left swimming in the North Atlantic until hypothermia took them.

Aluminum and carbon fiber rudder post have caused far more problems than properly designed Stainless Steel rudder post.

SS rudder posts have proven them self’s over time to be far superior to all the other materials used.

**HappyMdRSailor** · 20-01-2014, 12:12

Quote:

Originally Posted by rickbase1

Sigmasailor, here is a quick overview of 2101 Stainless product for your review.

LDX 2101® is a lean duplex stainless steel designed for general purpose use. Like other duplex stainless steels, LDX 2101® provides both superior strength and chloride stress corrosion cracking resistance compared to 300 series stainless steels. The use of manganese ensures proper ferrite-austenite phase balance, while allowing a reduction in nickel content.

The combination of a duplex structure and high nitrogen content provide significantly higher strength levels than 316/316L stainless steel. Often a lighter gauge of LDX 2101® can be utilized, while maintaining the same strength as a 300 series fabrication. The resultant weight savings can dramatically reduce the material and fabrication costs of a component.

Almost sounds too good to be true! Higher nickel is what helps 316 with corrosion resistance.... I must investigate.... Good stuff Rickbase!

(so far anyway... )

Sand crab · 20-01-2014, 12:36

Quote:

Originally Posted by rickbase1

Sigmasailor, here is a quick overview of 2101 Stainless product for your review.

LDX 2101® is a lean duplex stainless steel designed for general purpose use.

The problem was you said 2012 in your first post.