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Re: Blue Bird K4

Posted: Wed Feb 27, 2019 3:50 pm
by f1steveuk
I'd refute canard or reverse three pointers are "bad" design or unstable. Ones without dead rise do have problems though, but there are many that have been successful, even going around corners!!

Ted Jones DID invent prop riding, he approached Sayres with the idea before he had built a boat to test it, the idea was as he said "in my head". And bare in mind, Ted Jones was not a boat designer or builder, although his idea was to have the CoG quite far forward to get the stern up and out, supported by an air cushion, but as luck would have it, the prop hub did the job.

Miss England II. I pilot, Segrave, and two mechanics, Wilcox and Halliwell, one for each Rolls-Royce R type. After Segrave's deaath, as Ernie says, refurbished for Donn to use and destroyed when the storage warehouse was hit by an incendary bomb, so NOTHING left. The science museum has a propeller, but only because it was a spare. The Windemere Steamboat museum has Segrave's wicker seat from his accident, and the steering wheel is in a private chapel in Italy in all it's bent up glory. Though Bugattis have been "restored" from a wheel nut found in a pond before now!

I'm signed to secrecy on Crusader and it's successor but I can answer the point regarding materials and how the Vulcan was flown for the first time when Crusader was built, yet I stated it was ahead of the materials and construction techniques of the time. It was 1950, post war Britain. Vospers had to get a construction license to build Crusader. Materials were still short and there was only so much that could be made available. The Vampire was built in a similar way to Crusader (or vice aversa) with wood and alloys. The Vulcan was a goverment project, so an all ali airframe wasn't going to be a problem really was it!!

I have letters where requests for some special materials for Crusader, and some construction help is turned down by the Ministry of Supply, so I stand by my remark, as it's researched and has documentation to prove it, Vulcan or not!

Finally, did you know that once the first model tests of K7 were proved successful, the idea was to move the forward sponsons to the stern and the rear shoe to the bow? Wasn't done because of the lack of money. Again, I have this is someones own handwriting, someone involved in both Crusader and K7.

Re: Blue Bird K4

Posted: Wed Feb 27, 2019 6:20 pm
by Ernie Lazenby
Surface drives, part of the prop out of the water, were first tried by Albert Hickman on his sea sleds in 1916 -1919. Used on a boat called Rainbow in 1924. The roostertail is evident in photos of rainbow in 1924.
'Prop riding' boats really became evident in 1948 with Miss Canada 1V then Slo Mo then Bluebird K4. It can reasonably be argued that it all goes back to Albert Hickman but what do I know.

Re: Blue Bird K4

Posted: Thu Feb 28, 2019 1:33 am
by Renegadenemo
Fascinating stuff, guys. Keep it coming. This is all new to me, I enjoy learning this stuff these days.

Steve - can you also record that I was first to want to build a new Crusader. Not my fault the good folks of the BBP thought I was off my pot, again! :lol: :lol:

Re: Blue Bird K4

Posted: Thu Feb 28, 2019 11:20 am
by Ernie Lazenby
Bill, you may find this book very interesting. Loads of technical and engineering stuff. 'High speed small craft' by Commander Peter Du Cane. One of the reprints has an exploded view of Crusader in the back. Copies are available on Amazon or ABE Books. Massive amount of real heavy information about boat/ prop/rudder design and a whole lot more. BTW The title can be misleading, its not about model boats.

Re: Blue Bird K4

Posted: Thu Feb 28, 2019 11:47 am
by Ernie Lazenby
Steve posted 'Ted Jones DID invent prop riding, he approached Sayres with the idea before he had built a boat to test it, the idea was as he said "in my head". And bare in mind, Ted Jones was not a boat designer or builder, although his idea was to have the CoG quite far forward to get the stern up and out, supported by an air cushion, but as luck would have it, the prop hub did the job'.

Ted O Jones was an aircraft engineer working for Boeing of Seattle He did indeed make it his speciality to convert Ventnor three pointer boats into prop riders but...... back in the 1930's several power boats including Horace Dodges 'Delphines' had lifted the back end up and thrown out a rooster tail. The crew put weight into the back to put the prop back under the water! In the 1940's the Champion boat company of California had accidently fitted an engine too far forward only to find that not only did the boat throw up a big rooster tail it was much faster. All that is correct but it can all go back to Albert Hickman and his concept of surface piercing props for his sea sleds. Much much earlier than Ted Jones foray into prop riding. I think I am factually accurate but can stand to be corrected if I am wrong. In truth, prop riding as we know it evolved, it was not invented by a deliberate design thought. (just my opinion based on facts available)

Had Ted Jones and Stanley Sayers not entered the history of WWSR with 'Slo Mo Shun' when they did K7 may never had been built.

BTW loads of controversy surrounding 'Slo Mo Shun' but that's another story.

Re: Blue Bird K4

Posted: Thu Feb 28, 2019 5:27 pm
by JfromJAGs
Very interesting information about the Hickman Sea Sled. That was new to me. I found some pictures showing how these boats looked, see attachments. There were single and twin drives. In a discussion why Sea Sleds are not more common, I read it was because Hickman had filed many patents around his ideas, so he might have held patents for such a props configuration. Anyway, these props were just bigger conventional props of the time. But in case you don't consider paddle steamers as surface piercing drives, then it was probably Hickman who used them first.

In Peter du Canes book (from which I own a copy) there is some good information on surface piercing props. Todays race props are not only big conventional (subsurface) props, they also incorporate pretty much all the design principles of super cavitating props - props which run submerged at high speed, and thus in their own gas cavity due to the pressure dropping below the boiling point of water on the suction side. These props are build to mainly push on the pressure side, as the suction side is just facing vapour - or air, when used surface piering. The air follows the blade on the back/suction side when it enters into the water.

While submerged props use pretty much airfoil profiles, so almost flat on the pressure side and an airfoil camber on the suction side, super cavitating prop profiles have a) a wedge shaped thickness distribution and b) are spoon like cambered on the pressure side. The key to efficiency of surface piercing props lies in this camber - very little (and if, then only very old) information can be found about this. Most of the time such cambers are "optimized" by adding cup, which is an additonal bent at the trailing edge. Anyway, super cavitating props were a major research area of Vosper for their torpedos - which closes the circle to Peter du Cane who worked for Vosper. I found an interesing Amazon review of Peter du Canes book from a Houston Professor of Physics: see here

Surface piercing props are my hobbyhorse as these are the key element for going faster with a given amount of input power.

The 2 pictures of Sea Sled ads come from ebay - the ads are sold there. The other picture comes from an italian website.

Re: Blue Bird K4

Posted: Thu Feb 28, 2019 6:45 pm
by Ernie Lazenby
I too have a copy of Du Canes Book. Bought it 25 years ago.
Joerg, best you and I keep away from mentioning how to alter Octura surface drive props to get the best from them we will send folks to sleep. :lol: ! Some of mine are so thin its a wonder they work at all. That's not to mention 'tipping' and 'cuping'. Its all a black art!

Re: Blue Bird K4

Posted: Fri Mar 01, 2019 9:36 am
by f1steveuk
It is all interesting stuff!!

Sea Sled, I was informed that it was more to use the air cushion between the two hulls, maybe I have been mis - sled!!?

It is pretty safe to say, whenever you think you have found the origin of something, you find some bugger did it 20 years before the date you thought!!

I have unearthed some very interesting letters between Railton and @@@@@@@ about how Railton came to a reverse three pointer, and it threw me (all in a forth coming book of course, so I'll keep that to myself!!!), but it wasn't what I was expecting.

I can confirm that I sent drawings of Crusader to Bill over two years ago so he could see the construction methods, and to be honest, you'd be daft to try and follow that system today, but in carbon etc I could see that. All I will say is there are no plans to build a full size working replica of Crusader that I know of.

I'm in two minds about Du Cane's books. They don't have the authority of say Uffa Fox, but those that worked him speak very highly of him. I have ALL the communication between Du Cane, Railton and Cobb, as well as others involved, and I can at best describe Du Cane as distracted, he was after all trying to keep Vospers going in very difficult times, but hhe certainly didn't seem focused on Crusader, though I'm not convinced it was him that "dropped the ball" over three key aspects.

As an aside, would those with those books (I cannot find mine, house move) give me a list of Du Cane's qualifications, I fear I may have sold him short !!

Re: Blue Bird K4

Posted: Fri Mar 01, 2019 9:57 am
by Jordangbr
Have you read Uffa Fox’s biography Steve? It’s absolutely superb and very funny.

Re: Blue Bird K4

Posted: Fri Mar 01, 2019 12:52 pm
by Ernie Lazenby
This has turned into a very interesting thread.
Maybe of interest; Henry Fauber, a pioneer of powerboats, in 1908 submitted patents for a stepped hydroplane powered by a totally enclosed paddle wheel, essentially a drum with blades on it, in the centre of the hull. The boat was never built. 15 years ago I obtained the full patents and set about building a large model to see if his idea would work. I got it to work as a displacement hull but it would not lift onto the step. I burnt out a lot of motors attempting to get the thing to lift. I gave up on it too early, I now believe the wheel/drum, whatever one calls it, needed more ventilation to prevent hydraulic lock up. I am going to have another go from scratch because I sold the first one. Making the drum and blades in accordance with the patent drawings was, and will again be, a challenge.
The early pioneers had lots of ideas and command respect.