bertram31.com

Hi guys,

Thought you might be interested in seein' a few pics of a friend's build. Its been almost 4 years and were finally seeing the light at the end of the tunnel. It was stripped to bare hull and everything was rebuilt using mostly foam core composites. Here are some pics of most recent work, sorry about the quality...the pics were taken with my phone.

Enjoy

Zowie! Of all the great stuff he's doing I'm particularly enamored of the electrical panel. Very nice. Keep us posted as completion nears.

The very first photo shows the rudder set at the furthest possible location aft as it can be for this B31..........over the past couple of years I've noticed more and more B31's being talked about with their rudders / ports located in this aft most position.

Question is what's the history of the aft most rudder location?
Seems like the 'first generation' B31's [1961-?] had their rudders located as far aft as could be [which has posed performance issues for 'generation Y2K' power plants.]

Also of interest is the very old school square prop nut shown as opposed to a hex type nut!

The electrical panel is terrific,fitting a continuous hinge on one side of it so as to allow the entire panel to swing out for easy access behind would be my next step!

Best advise; leave the damn rudder in the original position and go build a fiberglass model is you like playing with F/G!! Absolutely positive the 31bertram will steer/ handle it's very best with the rudder in the OEM position. Don't go there!

Great work! One thing I have never seen before looks like a modification to the stringers. It looks to me like the stringers by the mufflers have been stepped down/reduced. This seems to make the muffler placement easier, but I wonder what the guys who know something about structural engineering/architecture think about what effect this would have on the hull?

Preston let's keep in mind C. Raymond Hunt design the 31 Bertram with the rudder in that original position lets give him the benefit of your doubt because you must maintain the three dimension! The first dimension is the distance from prop. Blade to rudder .we move the rudder back 8" so the shaft and prop. Move further into the water column at a angle of 14 degrees and we have to maintain our 8" (1st dimension.)now with only 1 support on shaft (struct). You have gone beyond max dimention for support on 330 hp diesel.if you wanted to Decrease fuel economy,performance why not leave rudders in stock location and tow 3 five gallon buckets off the transom! In addition to losing steering effectiveness from prop.wash on rudder.

JJ. Good call on the stringer "shaving". Would never have the guts to cut one down myself but if it was to be done this may not be a bad spot to do it. The hull shape with the reverse chine built into the mold adds allot of strength, but only time will tell.

Just think of how big a the kill boxes could be if we just cut the stringers out!?!

Looks like the struts have moved aft as well. Is that to swing a bigger wheel, or to decrease the shaft angle?

Bob:

My comments were questions not doubts as to where the OEM Bertram rudder location was for the 'generation 1' B31's!
Which,per your comments,are in the location as shown in the photos of this B31 - which is where my curiousity lays as to their OEM location being where..... bearing in mind others previous posts as to differences in rudder locations and performance issues being encountered.

Mike:

Good one, I'm not going there!

Preston the rudder was moved back from OEM position you can still see repair area of original location.every FBC I have ever seen has the rudder 7 " + or - . I will leave this to capt. Patrick. However I can supply photo's of a job I did on Blackfin .moving rudder and shaft to match 31 Bertram . Along with some other changes vast improvement 32 Blackfin is very similar bottom .he attained 30 knot plus at wot at 19,000 lbs she ain't light ,rudder relocation created great steering ,handling.

Preston Burrows wrote:The very first photo shows the rudder set at the furthest possible location aft as it can be for this B31..........over the past couple of years I've noticed more and more B31's being talked about with their rudders / ports located in this aft most position.

Question is what's the history of the aft most rudder location?
Seems like the 'first generation' B31's [1961-?] had their rudders located as far aft as could be [which has posed performance issues for 'generation Y2K' power plants.]

Also of interest is the very old school square prop nut shown as opposed to a hex type nut!

The electrical panel is terrific,fitting a continuous hinge on one side of it so as to allow the entire panel to swing out for easy access behind would be my next step!

Preston,

The boat is being refit by Jimenez Boatworks here in PR. I believe the owner wanted more cabin space, so the engines where moved further aft. As a result, the rudders had to be moved. Also the shaft angle was reduced to 12 deg. I know there are numerous discussions here about the consequences of moving the rudders so I won't get into that. I hope that it doesn't bring problems in the future. As to the prop nut, I think it was only used fot temporary fitting & alignment. It should get a hex with the new props.

I agree with you on the panel! Its the best part of the boat right now. Thanks for the comments!

Best advise; leave the damn rudder in the original position and go build a fiberglass model is you like playing with F/G!! Absolutely positive the 31bertram will steer/ handle it's very best with the rudder in the OEM position. Don't go there!

Bob,

I agree 100% with you on this. This wasn't my idea... If I could've talked the owner out of it , i would have but it was too late. Why fix something if it isn't broken!

Thanks for the advise, I trust that you and many more on this board know these boats better than Raymond Hunt!

John Jackson wrote:Great work! One thing I have never seen before looks like a modification to the stringers. It looks to me like the stringers by the mufflers have been stepped down/reduced. This seems to make the muffler placement easier, but I wonder what the guys who know something about structural engineering/architecture think about what effect this would have on the hull?

John,

Good eye! That one slipped right by me. I really don't know if it will have negative effects on the structural integrity of the hull, but JP is right... imagine the fish boxes that would fit in there!

I'll ask Jimenez next time I go visit.

Thanks for the comments!

Mikey wrote:Zowie! Of all the great stuff he's doing I'm particularly enamored of the electrical panel. Very nice. Keep us posted as completion nears.

Thanks Mikey! The owner designed the layout of the panel himself. It's one of the many nice things on the boat.

I'll post progress pics next time I visit.