Cape George Cutter, righting moments

[GRIT]

Hello all.

A friend is preparing a 1988, 36 foot, Cape George cutter, for the Golden Globe Race. The owner would like to install a new mast, so they would like to get the righting moments for the boat. The manufacturer seems to be hesitant to share this information with them, so I'm asking here if anyone has the information at hand.

They would appreciate either: the righting moments for the boat, or the moments of inertia for the mast. Even a brand and model number for the mast would be helpful.

The present mast is wooden, so there isn't the option to replace like for like.

Thanks in advance.

Cheers.
Paul.

[Orion Jim]

You may require the expertise of a naval architect to obtain a value which satisfies the Golden Globe Race requirements. Robert Perry has offered his consulting services for a reasonable fee in the past so this may be within his realm of services.

[GRIT]

Thanks for your suggestion.

If this thread doesn't give us what she needs, she plans on doing just that.

Cheers.
Paul.

[Benz]

There is a Cape George owner's forum, or was: someone over there will be able to answer the question. There's several home builds.
If she's buying a stick from a mast manufacturer (Selden? Zspars?) they should be able to make recommendations if they know displacement, length, beam, SA etc.
For what it's worth, my Cape George 31 was spec'd for a mast section moment of inertia of just about 5lbs/ft. I'll bet the 36 isn't much bigger...

[GRIT]

Thanks for that.

I'll search out that forum.

Cheers.
Paul.

[barnakiel]

Originally Posted by GRIT

The present mast is wooden, so there isn't the option to replace like for like.

Btw why is this? Suhaili masts were wooden (or so I thought?)

[GRIT]

I should rephrase that. The owner does not want to use a wooden mast. Neither would I, nor most people planning a non-stop race around the world.

I said most, not all. Wooden masts have their merits, but since the owner doesn't want one, then that's that.

Cheers.
Paul.

[Pauls]

You can measure the righting moment of your boat directly and cheaply. It is called an inclining test.

Suspend a plumb bob from the cabin top so that it is just above the cabin sole. Measure the length of the bob and line, and make a mark to show where it hangs above the sole. This is your zero mark.

Rig the boom out, ideally to 90 degrees. Hang a reasonably heavy weight to the boom. This can be large buckets filled with water, a tender, people, etc. You need to know the weight of whatever it is you are using. This weight will heel the boat. Measure the distance from the point on the boom to the centerline of the boat. Weight times distance = moment.

Make a second mark showing where the plumb bob is now suspended above the sole. The length of the bob and the distance between the two marks are used to calculate the degrees of heel.

Moment divided by degrees of heel = moment /degree heel. Multiply by 30 and you will have a reasonable value for RM30 which is used for rig sizing. In addition to the mast, use this value to ensure the wire sizes used have a large enough safety factor to stand up to what the boat will see in the Golden Globe.

[GRIT]

Thank you Pauls.

The boat's out of the water, and they're hoping to get the mast on before launch. Though, if they don't manage that, then we'll calculate the moments ourselves, and order accordingly.

I appreciate you sharing.

Thank you.
Paul.

[roverhi]

The Cape George 36's I've seen have had pretty tall aluminum sticks so they seem to be able to stand up to a lot of sail area. A benefit in light air for a boat with a ton of wetted surface. I'm surprised that Cecil Lange's son who inherited the business wouldn't help you as they should have the dimensions in their files. Failing that riggers in Port Townsend should be familiar with the boats as they probably rigged most of them.

Wood has many good qualities but maintenance, light weight, and custom hardware needed aren't them.

[GRIT]

Thanks Roverhi, for your comments.

I hadn't thought of contacting the local riggers. I'll get on that right away. Best advice so far.

Thank you.
Paul.

[Cadence]

Originally Posted by GRIT

Hello all.

A friend is preparing a 1988, 36 foot, Cape George cutter, for the Golden Globe Race. The owner would like to install a new mast, so they would like to get the righting moments for the boat. The manufacturer seems to be hesitant to share this information with them, so I'm asking here if anyone has the information at hand.

They would appreciate either: the righting moments for the boat, or the moments of inertia for the mast. Even a brand and model number for the mast would be helpful.

The present mast is wooden, so there isn't the option to replace like for like.

Thanks in advance.

Cheers.
Paul.

I would imagine if the same length aluminum mast were used the CG might change slightly. It might make her a little stiffer.

[Tortuga's Lie]

Not sure if you've opened this up or not:
Homepage - Cape George Marine Works

[CarinaPDX]

Originally Posted by roverhi

I'm surprised that Cecil Lange's son who inherited the business wouldn't help you as they should have the dimensions in their files.

You are quite a bit out of date I fear. It hasn't been in the Lange family for a long time. I don't know who owns it now, but the first (and possibly current) non-family owners acquired the Bristol and Falmouth Channel Cutter molds. They also started an owners' website that seems to have passed into history. Of course Cecil had the original blueprints and specs and so should the current owners. They really have no excuse for not providing the righting moment specs - very odd behavior. BTW the Cape George 36 was the last boat that Ed Monk Sr. laid down the lines (he did not do the interior - his son finished the commission).

Greg

[Panope]

Originally Posted by GRIT

Hello all.

A friend is preparing a 1988, 36 foot, Cape George cutter, for the Golden Globe Race. The owner would like to install a new mast, so they would like to get the righting moments for the boat. The manufacturer seems to be hesitant to share this information with them, ..............

Originally Posted by CarinaPDX

.............Of course Cecil had the original blueprints and specs and so should the current owners. They really have no excuse for not providing the righting moment specs - very odd behavior............

The current owner of Cape George Marine Works is Todd Uecker. Todd is not withholding ANY information. In fact he is helping this effort to the extent possible. The reason he has not provided the righting moment is because he does not have the data. No one does.

I have known Todd as a friend for 25 years and he is now my employer.

Steve