What have you done this weekend...?

Open ocean performance that would melt the tostesterone in most "go-fast-pontificators" into a brown stain at the back of their pants... I have a strong desire to live long, so I will watch from some distance...

Could you imagine frosty's boat doing 150 mph - - - Nah it is a bit big and heavy... These boats are a bit over 4000kg (8818 pounds) and around 40 ft LOA hand made engines that pull in excess of 10000rpm to give a de-rated to 750 shaft hp ready for the 2012 world racing season rules... 5 blade surface piercing screws where the leading edge is fine enough to shave with...

You could almost start and idle the engines in your garage, but once warmed up do not 'blip-the-throttle' as the sound pressure alone, would likely destroy the garage and the house attached thereto....

These boats corner flat and exert more lateral G forces than an F1 racing car by several times...

 

Very good photos.


Has the exhaust tube been extended before the race to get it lower to the hub there?

 

Hi IMP-ish,
That is NOT exhaust, that is to ventilate the propeller... it is a surface drive and must have air to drive efficiently/effectively... When they corner the G forces are so great that much of the propeller ventilation fails, a huge rooster tail is thrown up and the boat seems reluctant to accelerate until it is well aired then the rooster tail disappears and acceleration is visible as the boat succeeds in completing the passing manoeuvre...

The exhaust is dry and comes out the top at the rear (look at previous years images - in my gallery)... http://www.boatdesign.net/gallery/showphoto.php/photo/15578/ppuser/22903 shows the holes in the top of the open engine hatches...

Two images posted on http://www.boatdesign.net/forums/boat-building/my-little-piece-peace-25962-114.html#post487419 before they recovered from the tight U-turn corner...

Here is one just before the corner, full cry, well by the sound, less than 8000 rpm, as there is no point when the race leader... The spray there is mainly from the 'tunnel'...

 

Not as exciting as watching Go Fast boats but a lot of prying, tugging, grunting and strapping goin' on in the boat shed!

 

That looks very interesting... Where are the rest of the build images?

 

http://she-kon.blogspot.com/

 

Well, Mas, that shows how little I know about surface drives. I always thought air and props didn't mix; cavitation and all that.

KB, the progress looks very good. Bon chance.

 

I worked on Saturday till the rain shut us down. Today I am designing and fabbing my truck tailgate frame with 1" square tube. I hope to get it fitted and sandblasted for epoxy tomorrow.

 

Thank you masalai. Very good pictures in your gallery. My preconception was the air needed to be forced down the tube to do anything. Despite the clear photos you posted I tricked my eyes into thinking diverted exhaust gas. In your picture at http://www.boatdesign.net/gallery/showphoto.php/photo/15580/ppuser/22903 are the tops only open pipes? The air is "sucked down the tube" by the prop? I'd like to see how close that tube end fitting comes to the prop blades?

 

I did not measure as on this occasion I did not hang around whilst the propellers were fitted... about an inch or three at a guess... I would guess at air coming down as soon as 5 knot harbour exit speed as without air they start to self-destruct as a consequence of vacuum-cavitation (water boiling in a low pressure area), surface piercing propellers rotate fast and rely on air ventilation (partial submersion only)... I do not know the technical terms but this is generically the principle...

 

I nearly burnt my workshop down.

I cut some steel on my docking saw, went to another shed to weld it to what I was making. Did about 50mm of welding and my welder stopped.

Thought, probably the RCD has tripped. Went out of the shed and noticed smoke coming from the outside of the wall. It was some plastic hose leaning on the wall, then i realised that the heat was coming from inside the shed.

Went around to the front of the shed and there's a fire around the area of the docking saw. Went to the tap to get the hose, not there, hose is on other tap, I have to go through a gate that is bolted up, unbolted gate, grabbed hose, a fairly short one, scxrewed it on other tap, put nozzle on hose to get the distance, threw it over the fence in front of the shed.

By this time there was black smoke coming out of the eaves of the worshop all around and I thought I had lost it.

Grabbed the end of the hose, no nozzle, it's plastic and snapped off when it hit the ground. However the water just managed to reach the fire which was still restricted to the docking saw area.

Phew, the sparks from the docking saw had ignited a small piece of rope under the saw, I had been doing some work on my boat, timber, had saw dust all over the place. Luckily one of the first things that burnt was the cable to the saw which was dangling down near the floor. When that burnt it tripped the RCD other wise I would have kept welding in my other shed not knowing my workshop was going up in smoke.

The weather was crap and I didn't win Lotto.

Had a great weekend.

 

Well you are obviously still alive healthy and happy (could not detect any tears on your post)... Take care and best wishes... I did not win lotto either maybe Manie and others with spotless workshops are on to something - I have been lucky in that respect... No fires yet (note to self - do some tidying up now...)

 

I have just come back home with 2 fire extingishers and 2 fire blankets.

Later I'll get some smoke alarms.

 

Poida you told me you were'nt burning it down till next week when the insurance was paid.

 

I'm glad no one was injured. I hope you did not suffer any major material loss.
I won't suggest you not allow clutter under your tools.
You have already suffered enough.