Ideas for Alberg 30 mast step beam support!

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Windcall
Bottom Paint Application Technician
Posts: 22
Joined: Sun Jan 12, 2020 6:19 pm
Boat Name: Windcall
Boat Type: Alberg 30 1969 Hull 397

Ideas for Alberg 30 mast step beam support!

Post by Windcall »

I am completely refitting Alberg 30 1968. I have just completed the 4 bulkheads, re tabbing, New mast step beam.

I would like to before I start the v-berth construction. and construction of the head and clothes locker. I am thinking of preparing a mast beam support, My idea is to make it a easy to lock into place, probably of Aluminum construction, I have come up with a plan to have a locking mechanism top and bottom, easy to place and remove,
I am looking for ideas about how to support the base, I have looked into as much as I could in to the construction and used a Walbot and have used a deep wall scanner
The attachment 20200115_194959.jpg is no longer available
Although I cant see what is what.. the above photo shows what I can decipher, the object with the ? in it is dense and has no registration on the thermo-scanner. I am guess it is metal possibly.. this is the location in line were the mast support beam would be located.

Any ideas about how to apply the support base in this area.. if at all possible. I have heard and read about others having used one for emergency.

My idea is to place a custom support made out of fiberglass and G10 to the floor building it up so that the whole fiber glassing area would spread support around the hull area about 2' in all directions, slowly building to a maybe 12x12 g10 plate. My thought being the pressure on the g10 plate would distribute all the pressure to the surrounding areas. More or less making a fiberglass molded platform laminated to the hull.

Maybe this is over kill or maybe its a bad idea...

The other option was. Once I finish the v-berth. I would place a attachment to the plywood between the bulkheads, being about 2' high that would when the support was placed in place would hold the base of the beam support and being all fiber glassed in would spread the downward pressure to the port and starboard bulkheads just as the bulkheads support the existing beam pressure. Or would this being counter what i am trying to do and be better supported by the base of the boat above the keel.
20200115_194959.jpg
Any ideas would be appreciated. This is something I really want to have available to me for mental sake! Thanks for your ideas and comments.

Windcall
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atomvoyager
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Re: Ideas for Alberg 30 mast step beam support!

Post by atomvoyager »

All those options you mentioned can work but since you already have a new solid mast beam, it is overkill. The removable beam support brackets I've seen were for boats with much wider spaced bulkhead beam supports or boats lacking a bulkhead in that area but yours are relatively narrow and strong. Unless I'm missing something in what you want to achieve, then once the beam is strengthened, as you've done, check the bulkheads the beam is attached to for it's weak points and then the attachment of bulkheads to hull and other cabinetry and possibly cabin sole and how that transfers loads to the hull in the bilge. You have a plan to add knees under the beam. If concerned about the strength, I would just add bigger, longer knees until its obvious it can't move. Full length knees or stringers not only support the beam they also effectively add thickness to the bulkhead to prevent it crushing or bending if that is your concern. If concerned about how the bulkhead is supported at the hull or sole, add some support there. At some point, and you are probably already there, the mast will buckle before anything below it fails.

A removable bracket in this case is more unneeded weight and stuff to find a place for when not installed and restricts the opening when installed, all with no benefit. Once fit out for cruising you will have plenty of gear and provisions to find a place for in an already very limited space. To sum up, identify the weak point and then give it permanent strengthening. If you think the unsupported section of the beam isn't strong enough, then I would add to the beam. But maybe I'm misreading your plan and purpose?
Windcall
Bottom Paint Application Technician
Posts: 22
Joined: Sun Jan 12, 2020 6:19 pm
Boat Name: Windcall
Boat Type: Alberg 30 1969 Hull 397

Re: Ideas for Alberg 30 mast step beam support!

Post by Windcall »

I tend to agree with you that I am over thinking and over building, I don't see any weaknesses in the main bulkhead to be honest, I added made large fillets and fiber glassed tabbed both sides all the way around. Base Bulkhead tabs have 7 layers both sides at hull. and 4 layers across the top with dbl bi axial cloth.
The attachment tabbing.jpg is no longer available
I added 8" ply to the bulkhead along the hull, both sides! Main bulkhead is filleted and 5 Layers of bi-axial then the 8" ply, then filleted again and 2 layers of bi-axial mechanically attached with fiberglass fiber! This is done both sides of mast step bulkhead, I will then fasten it or sandwich it together with SS Bolts.
Now that its completed, the bulkhead walls are extremely stout and firm, Along with the modifications to the step beam supports by thickening them up, This wall will not go anywhere. So you are probably right!

The with the new beam bolted in place with thickened supports and tabbed and glassed in.. now that i think about it.. I am worried I did to much!
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tabbing.jpg
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Nomad
Bottom Sanding Grunt
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Joined: Fri Mar 27, 2020 2:18 pm
Boat Type: A30

Re: Ideas for Alberg 30 mast step beam support!

Post by Nomad »

Although my A30 did fine without it the last 53 years or so, i also figured some support wont hurt. So i deemed it sufficient to get some 2.5x3.5x8 planks, and i believe 1/4 x 7 in bolts and washers. I angled the base and top of each of the 4 support beams so they would fit as snug as possible into their designated positions, each bolted with 3 bolts to the original support struts attached on the bulk head. Now i will tab it all in place and call it the day. Cheap and easy fix that should do its job, if this is what you was talking about.
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IMG_20200324_131121514.jpg
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