A Frame design for a 4.8m RIB

TomKat · 22 November 2011, 20:19

Hi

I get a fair bit of SS fabrication work done and am very friendly with the them, they will rattle me out an A Frame (I'll buy the metal!).

Any handily made tidy looking designs about? A pic would be useful if anyone can point me in the right direction. They are making me a jockey seat frame out of 1" 316 SS, I'm guessing that would be too flimsy for an A Frame, any opinions?

(Primarily want one cos they look cool

but will stick nav lights on in case I end up working on my DT55 in the Irish Sea in the dark!)

Downhilldai · 22 November 2011, 21:53

1" OD would be ok for a braced double frame, or 2" OD for a chunky single section also looks good.

Make sure you design it tall enough to allow enough room to remove the outboard lid with the motor trimmed down, if you plan on doing any at-sea maintenance.

Downhilldai · 22 November 2011, 21:56

hamster · 22 November 2011, 21:59

Also make sure your nav lights are high enough not to be obscured by the bow if the boat, console or people stood driving etc.

On a lot of boats you can't see the nav lights when they are coming towards you half on the plane with the bow in the air and people stood up. Kind of defeats the point of having lights in the first place of people can't see you coming towards them!

Sent from my iPhone using Rib.net

TomKat · 22 November 2011, 22:32

cheers chaps - good tips there!

jyasaki · 23 November 2011, 02:30

If the guys you're working with can do some bending, you can flare the bottom of the A-frame out over the tubes. That will put your lights further out to the sides, and give you more room to lean over the transom, should you need to replace or clear a prop while on the water.

jky

Jizm · 23 November 2011, 07:18

This is the double one I had for my 4.8m Tornado.

Jizm · 23 November 2011, 07:19

From the stern with electrics fitted....

Nick Hearne · 23 November 2011, 09:06

I had one made up to my drawing & I'm very happy with the result

TomKat · 23 November 2011, 09:24

like all of those! Decisons decisons! I am calling in to see them later about some paid work so will print a few pics out and see what is easiest for them. I like the ways yours just mounts on the transom Jizm as avoids any deck issues.

Do you tow skiers etc from the tow ring on yours Nick?

Nick Hearne · 23 November 2011, 09:37

Quote:

Originally Posted by TomKat

Do you tow skiers etc from the tow ring on yours Nick?

Yes I can ski from this no problem & I have towed other boats from it too!
I have not tried it but recon you could pick the whole boat up by the Aframe it is that well built

TomKat · 23 November 2011, 09:51

cool - looks pretty solidly made!

9D280 · 23 November 2011, 10:29

Quote:

Originally Posted by jyasaki

If the guys you're working with can do some bending, you can flare the bottom of the A-frame out over the tubes. That will put your lights further out to the sides, and give you more room to lean over the transom, should you need to replace or clear a prop while on the water.

jky

...and allows space for an Aux!

TomKat · 23 November 2011, 10:50

forgot about the aux! flared is the way to go!