National 12 - find out more...
 

Are masts shorter from 60s -> 80s?

Started by Interested Party, 02 May 2013, 09:46

« previous - next »

Interested Party

From designs like Squids, Starfish, Smugglers and Sparklets (last of the clinkers), through the 70 to 80's, to designs like Crusaders and Baggys etc.
The hulls are getting wider, but they are also getting less deep?
Is this why measurements pertaining to the mast and fittings are taken from the sheerline?  An imaginary line across the boat from gunnel to gunnel, marked on the mast?
This implies that in real terms, masts can vary in length quite considerably between designs.  depending on the distance between the hog and the sheerline.
Therfore an alloy mast from a later design might not be appropriate for an earlier design?
ho hum
Steve H
Steve Hawkins <br />N12 - Planet 672 -1948 (Holt modified 500 series)<br />N12 - Spider 2523 - 1971 (Spider) <br />N12 - Sparkle 2383 - 1967 (Starfish)

Chadders

This is indeed true and of course a boat with a double floor will have an even shorter mast which is why I had to add 6-8 inches to the mast that came from my brothers Feeling Foolish and is now in my Starfish. 8)

Interested Party

Chadders,
How do you add inches to a mast?
Cheers
Steve Hawkins <br />N12 - Planet 672 -1948 (Holt modified 500 series)<br />N12 - Spider 2523 - 1971 (Spider) <br />N12 - Sparkle 2383 - 1967 (Starfish)

Interested Party

Well its a C section mast and it looks like I will have to add a section to the bottom.
After having a quick chat with Tim Gatti, I need to go back and measure my existing mast sheer line to see how it measures up.
Then I will have a better idea how much I need to add.
But it looks to be more that 8 inches.
Cheers
Steve h
Steve Hawkins <br />N12 - Planet 672 -1948 (Holt modified 500 series)<br />N12 - Spider 2523 - 1971 (Spider) <br />N12 - Sparkle 2383 - 1967 (Starfish)

Chadders

Having got an extension piece of the same section and correct length I used another piece of the same section and cut darts into it so that it would compress and fit inside the the mast and extension with some gentle easing (big hammer but take care)  I pop riveted both halves through the sleeve and finished it off with a carbon wrap.  It has sailed in all sorts of winds and the Hayling waves etc and never moved.  My mast is actually a Kappa and as Solo's use sleeved C sections for the lightweight helms I assume that you can by a sleeve section for a C section?  That would be much easier than the creative dart cutting technique that I had to use.  I went into the mast about 6-8 inches if I remember correctly I extended by about 6 inches.  Sorry not home at the moment so I cant actually check that.  Hope that helps.  Howard C aka Chadders. 8)

Interested Party

Okay a little background.
Being a bit of a Noob, I rushed out and bought a recently advertised spare C section mast from a later boat (Crusader) expecting to fit it to my Starfish with only some adjustment to the shrouds, etc.:X
Only to find when I laid it next to my old mast, there was a significant difference to length of the two masts (33cm - 13inches) :-/ 
I now understand that this is going to be a more tricky operation than I first thought.
The sheerline for my old mast is about 51 cm on the starfish,
Where as, extrapolating down from the top black band on the C section, the sheerline would be about 30cm.
The difference is 20cm (8inches).
So I need to extend the mast by 8 inches at the least.
The old mast is a little longer and the boom height is 13 cm (5 inches) higher than that on the new.
Ho hum.
Cheers
Steve H
Steve Hawkins <br />N12 - Planet 672 -1948 (Holt modified 500 series)<br />N12 - Spider 2523 - 1971 (Spider) <br />N12 - Sparkle 2383 - 1967 (Starfish)

Confused (Guest)

What's wrong with the existing mast. Seems a lot of hassle to swop ::)

Interested Party

Just wanted a more modern, lighter, mast with Spreaders, rather than a diamond.
Although I am just bringing a late 60s boat into the 70s.
But you are right, its a hassle, more hassle than I originally envisioned.
But it has been done before.
Cheers
Steve
Steve Hawkins <br />N12 - Planet 672 -1948 (Holt modified 500 series)<br />N12 - Spider 2523 - 1971 (Spider) <br />N12 - Sparkle 2383 - 1967 (Starfish)

Chadders

Are you sure that you are not swapping an old C section for a newer one?  If this is the case then you could just fit the one you have with swinging spreaders.  It could well be a C section already on Sparkle, Andrew Dawson may be able to confirm as he had her for many years before Tim bought her. :)

johnk

Proctor C is 65mm x 54mm
Proctor D is 73mm x 57mm

Interested Party

It would seem that the old mast is in fact a very old Proctor C.
It used to have a wheeled kicker, and still has a diamond plus a lot complication around the slot at the lower part of the mast. It is however considerably thicker above the hounds than the newer mast I have aquired.  Probably due to the way the sheave is mounted at the top.  Makes it look beefier than its more modern counterparts - which is probably what had me fooled.
The newer mast, the sheave for the main halyard is a part of the top mast fitting.
So I could just transfer the spreaders across.  After removing the Diamond, etc.
To complicate maters, I have just been offered an abandoned Lark (Parker 1900 and something) to strip and dispose of, for a donation to club funds - not my club, but another one local (they have another as well).  It comes with a straight Proctor C mast, of very similar dimentions to my original - with adjustable spreaders, etc.  The distance from the base of the mast to the 'for triangle height' on the Lark mast is exactly the same as that on my original N12 mast.  In theory, I would only have to move the top band down by 7 cm and the boom mount up by 9cm and Bob is your mother's brother.  plus I get a bucket full of stainless doodads for the trouble.  Oh and I have to take the old hull to the tip.....
I will have to give it some thought.
Cheers
Steve H
Steve Hawkins <br />N12 - Planet 672 -1948 (Holt modified 500 series)<br />N12 - Spider 2523 - 1971 (Spider) <br />N12 - Sparkle 2383 - 1967 (Starfish)

Interested Party

I acquired the Lark.  Stripped it of spares.  Sold some spares that covered the cost of the original purchase.  Dumped the hull - only suitable for a planter. 
The Lark mast only needed the new bands painted on, the goose neck moving and the shrouds remounted - I used the stainless steel chain plates off the lark riveted to the mast to attach the shrouds.
I sailed it today.  All seems well.
The spreaders are mounted lower than seems to be the norm with N12s, but I am not sure it will make much difference - so I did not move them.
So I have a older 60's type Proctor C section mast with a single diamond up for grabs as well as a later, shorter mast, possibly of a Crusader (6480mm length).
Cheers
Steve Hawkins <br />N12 - Planet 672 -1948 (Holt modified 500 series)<br />N12 - Spider 2523 - 1971 (Spider) <br />N12 - Sparkle 2383 - 1967 (Starfish)

n12 Bottom Banner