West coast trimaran docs from '66, '68 and '70. Brown pamphlets and study plans, Trimaran design Center 1970 catalogue, Cross stuff

Fasterdamnit!

Anarchist
617
34
Charlotte NC
Eric- seeing how these are intended for blue water sailing is really cool. I would love to build a 25, add a sprit and big asso.

V- you are quite welcome. The paper is starting to really age so I’m glad it is now recorded for anyone to peruse or even use. 

 

jhc

Super Anarchist
2,415
260
I have two brown trimaran books. In good condition, if anyone is interested in purchasing.

 

Rasputin22

Rasputin22
14,083
3,618
After all the daydreaming with my Dad about he and I building a Jim Brown trimaran I ended up buying a Cross 42R trimaran on the Gulf Coast and after a quick resto sailed it to the Virgin Islands. I had hoped my Dad would make that trip but he did buy me a cheap plastic sextant and some up to date charts and cast off the docklines for that epic trip. Oh, he did buy 13 cases of DIXIE beer at the Navy commissary which almost lasted for the whole trip!

    This design was very different that the Cross 42 which was more of a cruising boat. The builder had built a Cross 32R for a client who had paid Cross for the design and rights to build one boat. The builder later enlarged the design to 42 foot and called it a Cross 42R (r for race).  There was a Cross 52R named CRUSADER which was the inspiration for the 42' knockoff and all three R designs had much narrower beam to length ratios for the hulls and a twin beam (aka) design with a aeronautical inspired vent between the hulls and crossbeams. All three also had a deep fin keel which was part of Norm Cross's thinking from his day job which was as an aeronautical engineer in San Diego. The strangest and most dubious feature was that he used a constant cross sectional area theory at the keel which was an important part of what let jet aircraft break the sound barrier. The pinched hull in the area of the keel root was supposed to suppress wave making but looked odd to me and didn't really apply as water is incompressible and air is not. Still a pretty quick tri for her era but it seemed to really hit a speed wall around 18 knots when it would start sucking up a BIG stern wave. I lengthened by 4' the overlarge transom with a 'sugar scoop' which lessened the stern wave my extended the run and reduce the rocker but more importantly was great for swimming and dinghy boarding and molesting mermaids. 

    I kept threatening to cut off the unballasted keel to lessen wetted surface but Hurricane Hugo obliged me when getting beached in Culebra! I built a big central daggerboard case and foil but sold the boat before completing those mods. Just got confirmation that the old Cross 46R is now down in the ABC islands and still hauling tourists on daysail charters. 

image.png

     I really regret not having shanghai'd my Dad for that trip from New Orleans to St John. 

image.png

 

Fasterdamnit!

Anarchist
617
34
Charlotte NC
Thanks for the story and great pics. It is great seeing you two together with the Cross. Last time I had a Dixie it had a pull tab! I still have the giant daggerboard Dad built for the hopelessly stuck in displacement mode tri. 

 

illan_voyager

New member
46
11
Pretty cool for me to see the Brown Manta drawings (with fins on amas originally). I had one 10+ years ago and never found any info on the design around that time.
 

stinky

Anarchist
951
166
Thanks for posting all of this, so cool to imagine a time when every other back yard in Santa Cruz had a plywood tri or ferro cement shitter under build. If only there was some magic fairy dust to bring back that spirit of adventure and optimism.
 

illan_voyager

New member
46
11
Manta 34- So how did she sail? What did you like and what needed improvement?
Polyester & ply with all the potential issues there (vs epoxy. Issues could've likely been minimized with above average maintenance over past years- most of my memories are peeling sheets of glass off areas of the decks with no end in sight). Would've preferred a central board of course but not enough to build one in myself at the time. Not too big and not too small, I did like the rear cockpit & simplicity of the boat solo but also it wasn't a big/spacious cabin or layout etc, certainly made me appreciate how much thought went into the center cockpit searunner as an optimized cruising design.
 

Fasterdamnit!

Anarchist
617
34
Charlotte NC
Polyester & ply with all the potential issues there (vs epoxy. Issues could've likely been minimized with above average maintenance over past years- most of my memories are peeling sheets of glass off areas of the decks with no end in sight). Would've preferred a central board of course but not enough to build one in myself at the time. Not too big and not too small, I did like the rear cockpit & simplicity of the boat solo but also it wasn't a big/spacious cabin or layout etc, certainly made me appreciate how much thought went into the center cockpit searunner as an optimized cruising design.
Ugh. I've seen that peelfest on some DIY Opti's.

Jim Brown interviews Mike Leneman
 

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