New book ms on surface-piercing props and raceboat design

[sandhammaren05]

Thanks Petter, I'll take a look at that web site. Where are you in Norway? I've spent a lot of time there, including on the west coast in rented nutshells with small outboards. Any Norwegian connection for me would be 1000 yrs. old via the Scottish Isles, but I feel very much at home in Norway and Sweden. Best, Joe

Hi Joe,

The Berserk Design (and the web site) is on the back burner for the time being. At Berserk Design I exclusively do high performance boat design, stepped hulls calculations, aerodynamics CFD etc etc, I am still serving existing customers but actively seeing new ones.

Lately I have been focusing on commercial boat design with www.ekersandvik.no

Previously I worked many years in England developing a controllable pitch surface drive, then on to designing CPP’s with Servogear for relatively fast boats, including the latest Palmer Johnsen 48 Supersport.

Do you have a Norwegian connection Joe?

Norway is a boating paradise when the weather is good

Cheers,

Petter
petter@berserkdesign.com

 

[sandhammaren05]

http://www.forbes.com/sites/deborahljacobs/2014/04/25/how-to-self-publish-your-book-through-amazon/

Thanks! We'll be starting to get ready for Port Neches in a few weeks. How did your SST45 project in Singapore work out?
Joe

 

[sandhammaren05]

Yeah, I have a file of the full set of open-water curves for that Escher-Wyss prop and it had very nice efficiencies.

It also had that trick upstream ramp that was used to control the prop immersion by changing the position of the free surface (as opposed to changing the position of the prop shaft, as in Levy / Arneson / etc.)

The data on surface-piercing props by Hadler and Heckler are dead wrong when I apply them to SST45, SST60, and F1-type outboard racing. I'm pretty sure that I know what's missing there. Can any of you guide me to newer data on efficiencies, torque and thrust coefficients for surface props, please? Rolla Propeller, on their website, claims to have data from the Potsdam water basin that they use to calculate the above. I tried to arrange a visit with Rolla (made contact with Phil Rolla) but it's not possible before summer, at best.

 

[PetterM]

Did the CP surface drive become a product?


And just an aside....I was involved in the construction and trials of catamaran ferries built in Mandal (Batservice a.s.) that incorporated some of the early Servogear CPP drives. Early 1990s...I believe the gentleman from Servogear that was directly involved was Endresen? Was that during your time with them?

It not become a product for many reasons, but the technology had significant potential gave nice mix of high-speed efficiency and low speed manoeuvrability for the narrow market sector that needs this.

Leif Magnus Endresen has retired by the time I joined Servogear but he still came around about once a week to discuss technical issues and get updated on projects. He is around 85 now but still sharp as knife, passionate and interesting to talk to. I am still in contact with him.

 

[PetterM]

Yeah, I have a file of the full set of open-water curves for that Escher-Wyss prop and it had very nice efficiencies.

It also had that trick upstream ramp that was used to control the prop immersion by changing the position of the free surface (as opposed to changing the position of the prop shaft, as in Levy / Arneson / etc.)

From memory Brødrene Aa made a SES with an Escher-Wyss prop, but this was before my time.
Would be very interested in seeing the open-water curves if these are shareable.

 

[BMcF]

Leif Magnus Endresen has retired by the time I joined Servogear but he still came around about once a week to discuss technical issues and get updated on projects. He is around 85 now but still sharp as knife, passionate and interesting to talk to. I am still in contact with him.

Good to hear. He is indeed a very sharp fellow, as I recall. I'm sure he will recall the "Sea Lord" cats; I believe they were some of the first built with that propulsion/steering package.

 

[PetterM]

Thanks Petter, I'll take a look at that web site. Where are you in Norway? I've spent a lot of time there, including on the west coast in rented nutshells with small outboards. Any Norwegian connection for me would be 1000 yrs. old via the Scottish Isles, but I feel very much at home in Norway and Sweden. Best, Joe

Hi Joe,

Its all in the mindset.
I am island of Stord at the moment on the west cost

Petter

 

[PetterM]

Good to hear. He is indeed a very sharp fellow, as I recall. I'm sure he will recall the "Sea Lord" cats; I believe they were some of the first built with that propulsion/steering package.

There was a recent series Sea Lord being built, this time also by Båtservice in Mandal, but this time in carbon fibre sandwich:
http://www.batservicemandal.no/vessels/item/35-m-carbon-catamaran-sollifjell

 

[BMcF]

Familiar with those...very. They had a rather bumpy beginning...

 

[PetterM]

Familiar with those...very. They had a rather bumpy beginning...

Hehe, that’s quite an understatement
Think they work well now though.

 

[Roflhat]

Hi Joe,

I spoke to you via email,
I will take a copy as soon as it's available.

Thanks,
Seumas