Bluebird K7

[Mark Poole ModVP]

The Bluebird was the earliest successful outrigger style hydroplane. He evidently understood that this design would be well suited to the huge power output of the jet engine. The biggest benefit of the outrigger hydro is that it does not trap air under the entire front of the hull like a conventional three point hydro. There have been attempts to use this design in unlimited hydro racing, but even with turbine engines, a prop driven U hydro does not have the power to weight ratio to make it work properly.

I have no doubt that Don Pinckert, the man who built the first RC outrigger hydroplane, was inspired by the Bluebird. The design is the ultimate RC speed boat because the power to weight (and size) ratio is off the chart.

But every design has a limit and Campbell pushed Bluebird past it on that day.

As for Lee Taylor, if you go to YouTube and watch the vids of Hal Needham's Budweiser rocket car driven by Stan Barrett, you see where Taylor got the idea to build his radical boat. His boat used a hydrogen peroxide rocket engine the same as the rocket car. His idea was to have a boat with the same 'footprint' of that tricycle rocket car. But the angle of all three ride surfaces had far too much AOA which was the main contributing factor of why the boat flipped over like it did. The water conditions on Tahoe that day did not help either.

[kelvin523]

... The biggest benefit of the outrigger hydro is that it does not trap air under the entire front of the hull like a conventional three point hydro...

Thank you, I missed this part until i looked closer. Academic question; from what i gather the K7 did not have a propeller and is in essence a full in-ground effect design with six pressure ridges, three on each side? Thanks again

https://www.thingiverse.com/thing:5263550

[mach351]

None of the record attempt boats we are talking about are propeller driven. Thrust only.

[Instigator]

20 yrs ago I was in Ken Warbys basement/bar and among videos we watched was the one of of Arfons attempt.

Ken thought he ran out of fuel.
This got my attention.
He also thought there was possible, personal issues at play that he didn’t go into.

As stated though, these boats are propelled by thrust which I’ll be the first to admit I know nothing of.

Propeller driven, has effect on lift.

Thrust driven, once flying, they are 100% aerodynamic controlled/effected w/angle of thrust being the limiting/controlling factor.

On Arfons, I clearly remember his design.
It was a stretched out Top Fuel Hydro design. Like, 10’ longer.

I remember seeing Arfons pre-attempt press on it and saying TFH was already running 230.
And I was screaming at the TV screen saying, “yeah for the last 100’ of their pass and 3 drivers die every yr trying”, and your going to go 100 mph faster?

I gave him 0% chance of succeeding.

Kens take was, under power/thrust, that thrust angle keeps the bow down.
Run out of fuel/thrust, aerodynamic lift stays the same, mechanical thrust/angle goes to zero and…..

These guys are the men of men.

Like the first guys to challenge the world is flat.
OK, but how do we know?

I remember Warby bitching about the APBA trying to institute safety rules for their future record attempt and laughing at them.

No one, I mean no one, knows ANYTHING about going 300 mph in a boat!

Well, one guy does.
But the man tells him the rules they’re going to instate?

[Jimboat]

20 yrs ago I was in Ken Warbys basement/bar and among videos we watched was the one of of Arfons attempt. Kens take was, under power/thrust, that thrust angle keeps the bow down. Run out of fuel/thrust, aerodynamic lift stays the same, mechanical thrust/angle goes to zero and…..

The dynamic balance of these hulls is ever changing, with changes in aero lift/drag, thrust, hydrodynamic lift/drag, etc. The many force contributors to the dynamic balance all change quickly, particularly as velocity changes quickly too. Propulsion force from propeller vs jet engine is definitely quite different in the respective contribution to dynamic balance. it's difficult to maintain the changes needed to keep the boat in dynamic balance, and once it's just slightly off, the changes come increasingly faster. it's tough to stay on top of, with some designs.

[kelvin523]

Real-time pressure differential telemetry is a fantastic opportunity; these are in ground effect craft imo\. The plywood, 60$ jet engine and > 300mph is nothing short of genius, passion and fortitude. I'm not sure I would have enough courage to even start it up; let alone push the throttle to the wall. What these folks accomplished is legendary.

[Lake X Kid]

The Bluebird was the earliest successful outrigger style hydroplane.
He evidently understood that this design would be well suited to the huge power output of the jet engine. The biggest benefit of the outrigger hydro is that it does not trap air under the entire front of the hull like a conventional three point hydro. There have been attempts to use this design in unlimited hydro racing, but even with turbine engines, a prop driven U hydro does not have the power to weight ratio to make it work properly.

Top Fuel Drag Boats have been using outriggers (safely with stability) in the bow for years. Their prop driven, but surely the aerodynamics are in play, similar to the record attempt boats like Bluebird and Lee Taylor's boat.

[Lake X Kid]

[Lake X Kid]

Outriggers in the bow saved his bacon.

If the Outriggers were in the back, then surely his needle nose front would have dug into the water, and pitched the boat out of control.

[techteam]

Campbell and Warby's hull configurations were pretty different. Warby used an aft stabilizer which kept the 3 point "planted" on the water where Campbell did not. All Warby had to do was "power thru" to get the speed he needed. The K7 never really gave a hint before lifting off. Having blown over myself I can tell you the ride always is smoothest and fastest right before going skyward.

I don't agree, if you watch the video closely you can clearly see the sponsons lifting well before she actually goes. Now they think they know why it blew over and are carrying out some tests to prove their theory. I think they will announce it next year sometime.

[Instigator]

As a friend/fan of Warbys, he is a bad ass.

For proof, watch the documentary about his record attempt.

They were struggling to get through the 280/290’s and couldn’t figure out why.
They knew they had the hull and the power but couldn’t get there.

He had a professor (I think) on his crew who was running calculations on their set up.
He determined the rudder was too deep and causing to much drag.

Said if the removed 4” it equaled a reduction of x thousand lbs of drag.

Ken decided 6” would be better!

They had a cutting torch on site but no goggles.

Ken wouldn’t let his crew do it because of the risk to their vision so he did it.

While cutting the bottom of the rudder off, he kept one eye covered.
When asked why he covered one eye he said, in case it blinded him he would still have one good eye so he could still drive!

It worked and they went 317!

To remind myself of how important that record is, I am reminded that every attempt since then has ended up killing that person!

Real-time pressure differential telemetry is a fantastic opportunity; these are in ground effect craft imo\. The plywood, 60$ jet engine and > 300mph is nothing short of genius, passion and fortitude. I'm not sure I would have enough courage to even start it up; let alone push the throttle to the wall. What these folks accomplished is legendary.

[Instigator]

Just found these on my phone, from 20 yrs ago!

[mach351]

The water speed record is the most dangerous of all speed records. I read that since 1900, it has had an 85% mortality rate

[kelvin523]

Really great thread; worthy of creating an "In-Effect" forum imo\

https://www.youtube.com/watch?v=0RPdEiI_foI

[Brad Zastrow]

85% chance of dying. Who on earth would even think about attempting a speed run with those odds?
Top fuel drag boat record is around 265 mph. But they get to that speed in a few seconds and shut it down. I think the long runs and the little higher speed is the line being crossed.