[Public-List] Mast beam-- photos of a repair

[Randy Katz]

Greetings, All,

   The repairs I did were typical-- see photos and description at the
Alberg website at
http://www.alberg30.org/maintenance/HullDeck/MastBeam/SimpleGifts/

    Concern over the doors not closing initiated my interest in making this
fix. It wasn't too complicated and has held steady since: the doors have
fit consistently since the repair, and it's nice to have them functioning.

Regards,
Randy Katz
#249
Bellingham, Seattle





Message: 1
> Date: Fri, 31 May 2013 07:40:02 -0400
> From: Mike Lehman <sail_505 at hotmail.com>
> To: "Alberg 30 Public List -- open to all"
>         <public-list at lists.alberg30.org>
> Subject: Re: [Public-List] Mast beam
> Message-ID: <BAY170-DS44D34D86D915A373E3DD1B7920 at phx.gbl>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>         reply-type=original
>
> Glenn
>
> You may not like the appearance of the aluminum sister plates...but they
> have never failed. We have had boats racing in 50 knot winds with large
> waves and driving hard without a beam failure once the beams have been
> properly reinforced.
>
> On all of the boats the bulkheads support the beam and the deck, the
> vertical oak pieces along the bulkheads are stiffeners that prevent the
> bulkheads from buckling under high loads. The main problem is the beam is
> not well supported under the aft end and the mast sits on the aft side of
> the beam which causes the beam to twist back. The solution to this is to
> add
> knees to the existing oak supports to prevent the twisting.
>
> On the liner boats the problem is a bit different. I you carefully inspect
> the bottom of the bulkhead you will see that is rests on the floor liner
> and
> there is not adequate support under the floor. This is the problem that
> George mentioned in an earlier post on this subject. Adding extra support
> under the floor to transfer the load to the hull solves this.
>
> One main problem with ALL the boats is the bolts that Whitby used are 1/4"
> threaded all the way to the head of the bolt. These bolts were used on the
> chainplates and the main beam. When these old bolts are removed they are
> often bent, especially the main beam bolts. They should ALL be replaced
> with
> 5/16" shoulder bolts. The increase in strength is almost 3x because of the
> increase in diameter and especially because of the shoulder.
>
> I don't think push the sag out of a beam in the liner boats, but you can
> stop its progress.
>
>
>
> ~~~_/)_/)~~ Mike Lehman ~~_/)~~~
>