The Land and Water Speed Records Thread

[Life Saab Itch]

For a bit of history which is happening as we type and read, here is the Bloodhound SSC website.

http://www.bloodhoundssc.com/

[dr_gn]

Life Saab Itch said:

DJC said:

Im always wary of "revolutionary" designs, even from within inside the industry because they are always always always an absolute bh to actually develop. There are sound principle and you dont need to be too revolutionary with the current hull knowledge. The aero work is where Im more interested as its keep the boat on the surface and not a flying deathrap that Id want to concentrate on. I can line up any number of RR/AEC engine/FADECs to provide more than enough grunt for the speeds needed.

I have often wondered why the planing shoes were on the inside of the sponsons on Bluebird, I would have thought that the outside would provide a more stable footprint, not that that was a problem as DC seemed to be able to make the 180 degree turns on Coniston at speed.

Wouldn't have made much difference. A line drawn between each sponson planing shoe and transom of the hull form two roll axes (around which the boat 'tramped'). Because these axes are angled to an apex at the rear of the boat, any roll about these axes also produces pitch, which, at a critical value, caused the boat to flip due to the air getting under the hull. In addition, the engine thrust also played a part because the thrust line was quite high, and this to an extent countered the pitch induced by tramping. An engine failure (or sudden closing of the throttle) removed this additional stabiling force and made matters even worse. The water brake on the other hand caused a pitch down moment. In other words, engine failure or closing the throttle at speed *before* deploying the water brake was extremely dangerous.

If K-7 had been a four point design rather than three, or if the sponsons had been at the rear, it would have been far less prone to these effects.

[Life Saab Itch]

dr_gn said:

Life Saab Itch said:

DJC said:

Im always wary of "revolutionary" designs, even from within inside the industry because they are always always always an absolute bh to actually develop. There are sound principle and you dont need to be too revolutionary with the current hull knowledge. The aero work is where Im more interested as its keep the boat on the surface and not a flying deathrap that Id want to concentrate on. I can line up any number of RR/AEC engine/FADECs to provide more than enough grunt for the speeds needed.

I have often wondered why the planing shoes were on the inside of the sponsons on Bluebird, I would have thought that the outside would provide a more stable footprint, not that that was a problem as DC seemed to be able to make the 180 degree turns on Coniston at speed.

Wouldn't have made much difference. A line drawn between each sponson planing shoe and transom of the hull form two roll axes (around which the boat 'tramped'). Because these axes are angled to an apex at the rear of the boat, any roll about these axes also produces pitch, which, at a critical value, caused the boat to flip due to the air getting under the hull. In addition, the engine thrust also played a part because the thrust line was quite high, and this to an extent countered the pitch induced by tramping. An engine failure (or sudden closing of the throttle) removed this additional stabiling force and made matters even worse. The water brake on the other hand caused a pitch down moment. In other words, engine failure or closing the throttle at speed *before* deploying the water brake was extremely dangerous.

If K-7 had been a four point design rather than three, or if the sponsons had been at the rear, it would have been far less prone to these effects.

That is a very interesting post.

Could gyroscopes help stabilise the vessel?

Without reading through the Bluebird website to find the right part, did the air intakes collapse before or after impact? I know that they were in a mess, but I'm not sure whether it was because of the impact. I remember seeing something about the engine not producing thrust when the craft was halfway through flipping, because of the lack of disturbance on the water on the film footage. The water brake was applied though. That was one of the first discoveries of the wreckage.

[dr_gn]

Life Saab Itch said:

dr_gn said:

Life Saab Itch said:

DJC said:

Im always wary of "revolutionary" designs, even from within inside the industry because they are always always always an absolute bh to actually develop. There are sound principle and you dont need to be too revolutionary with the current hull knowledge. The aero work is where Im more interested as its keep the boat on the surface and not a flying deathrap that Id want to concentrate on. I can line up any number of RR/AEC engine/FADECs to provide more than enough grunt for the speeds needed.

I have often wondered why the planing shoes were on the inside of the sponsons on Bluebird, I would have thought that the outside would provide a more stable footprint, not that that was a problem as DC seemed to be able to make the 180 degree turns on Coniston at speed.

Wouldn't have made much difference. A line drawn between each sponson planing shoe and transom of the hull form two roll axes (around which the boat 'tramped'). Because these axes are angled to an apex at the rear of the boat, any roll about these axes also produces pitch, which, at a critical value, caused the boat to flip due to the air getting under the hull. In addition, the engine thrust also played a part because the thrust line was quite high, and this to an extent countered the pitch induced by tramping. An engine failure (or sudden closing of the throttle) removed this additional stabiling force and made matters even worse. The water brake on the other hand caused a pitch down moment. In other words, engine failure or closing the throttle at speed *before* deploying the water brake was extremely dangerous.

If K-7 had been a four point design rather than three, or if the sponsons had been at the rear, it would have been far less prone to these effects.

That is a very interesting post.

Could gyroscopes help stabilise the vessel?

Without reading through the Bluebird website to find the right part, did the air intakes collapse before or after impact? I know that they were in a mess, but I'm not sure whether it was because of the impact. I remember seeing something about the engine not producing thrust when the craft was halfway through flipping, because of the lack of disturbance on the water on the film footage. The water brake was applied though. That was one of the first discoveries of the wreckage.

The details and calculations are all in here:

"The Bluebird Years" by Arthur Knowles.

http://www.amazon.co.uk/Blue-Bird-Years-Campbell-P...

If you haven't got it and are interested in all this stuff, for the sake of less than £10 buy it - you won't be disappointed!

ETA there's some intriguing stuff here too:

http://www.quicksilver-wsr.com/the-craft

...although the design of that thing has changed so many times in the past few years I've lost count. Can't figure out if this project is serious or not. Seems to have made a start though at least.

Edited by dr_gn on Saturday 22 January 16:53

[Life Saab Itch]

Dr_gn, if you were to design a WSR capable craft, do I take it you would have either a single plane at the front and two at the back, or four planes?

How much extra resistance would an extra plane create? The front sponsons on Bluebird had blades that it rode on, did it have a single blade at the rear or something different.

I'll go and dig out my Bluebird books.

This thread has got me sketching. For some reason, I'm designing a two person craft...

[dr_gn]

Life Saab Itch said:

Dr_gn, if you were to design a WSR capable craft, do I take it you would have either a single plane at the front and two at the back, or four planes?

How much extra resistance would an extra plane create? The front sponsons on Bluebird had blades that it rode on, did it have a single blade at the rear or something different.

I'll go and dig out my Bluebird books.

This thread has got me sketching. For some reason, I'm designing a two person craft...

I've no idea. As I said, the Quicksilver project has gone through loads of concepts (most of which were presented on their website as definitive at various times IIRC), and the people involved with that aren't stupid. Nor were the designers of K-7, but any contemporary craft that is designed to the fastest of it's type is pretty much guaranteed to be on a knife edge (or it should be).

I guess there may be a trade off between inherent stability and potential speed. Also, it's bound to be some form of hydroplane, so aerodynamics will play just as great a part, if not greater, than hydrodynamics. I expect the advances in control engineering and materials technology over the past decades would in theory make any WSR challenger safer, but it's always going to be risky. IIRC, a lot more people have died attempting to set a WSR that an LSR.

Having said that, the current record is over 30 years old, so I'd imagine it would not be too difficult to design a craft using 2011 technology with record-breaking speed potential, but that is still well within it's inherent safety margins. I think the real challenge and danger comes when you have serious competition pushing you to the limit of the machine. I'm sure it can't be that simple or someone would have done it...but then again, is anyone really bothered about heroes and engineering these days?

[Markytop]

How critical are the aerodynamics on the boats? I would imagine (as a purely casual observer) that the comments above around getting F1 team aerodynamics involved would be fine if the water was constantly flat and smooth. But given water is anything but flat and smooth, the opening and closing of air pockets (for want of a non-technical term) underneath the vessel as it rides the waves would lead to a very inconsistent platform to enable small differences in aerodynamic trims to make the fine tuning gained with F1 or aerospace aerodynamics as effective on water as the speed increases?

[Scuffers]

you should tale a gander at the unlimited (yes I know!) hydroplanes, they use a movable rear 'wing' as a stabiliser...

[DJC]

There was a reason I said initially that my emphasis was more on the aeros.

The CFD for the hull design isnt a major issue really, the principles are well understood and relatively easy to apply. I can think of 3 designs off the top of my head which would satisfy the hydro side of things, esp combined with a decent propulsion side. Its all on the aeros and control system side.

[friederich]

Bringing this back to the LSR....

Must be the only LSR holder currently licensed and driven on the road:



25litre 1905 200hp Darracq, rebuilt and raced by Mark Walker. First car to hold the record at greater than 2 miles per minute in Jan 1906. Road legal and driven to VSSC events, this photo taken at Mallory Park last year.

[chevronb37]

And from Goodwood FoS 2010. That embodies the spirit of the VSCC for me.

[chevronb37]

Golden Arrow meets London traffic, 1929.



And again in 2008.



While the art of the record breaker may have improved over the years, on this evidence I'm not sure you could say the same of the photographer...

[kiteless]

This is the only clip I could find of the LSR holder in my formative years:

The Blue Flame

What is interesting, in comparison with Thrust II and Thrust SSC, is the immediacy of its rocket propelled acceleration.

[HereBeMonsters]

My Mother knew Donald Campbell, working in the hotel where he and his crew stayed during the final attempt on the water speed record. She had run away from home aged just fifteen and was working as a waitress and chambermaid.

[Life Saab Itch]

DJC said:

There was a reason I said initially that my emphasis was more on the aeros.

The CFD for the hull design isnt a major issue really, the principles are well understood and relatively easy to apply. I can think of 3 designs off the top of my head which would satisfy the hydro side of things, esp combined with a decent propulsion side. Its all on the aeros and control system side.

To follow that, without significant "gifts" or grants, the control systems side would be prohibitively expensive.

With the systems (if I am following the discussion in the right direfction) that you are talking about, you are effectively designing a small aircraft that happens to plane on water.

The speeds we are talking about, we are probably somewhat above Cessna technology levels.

[Nick M]

Life Saab Itch said:

For a bit of history which is happening as we type and read, here is the Bloodhound SSC website.

http://www.bloodhoundssc.com/

Worth signing up for their supporters club too.

Last year I went to one of their talks about the current development of the car - the aero configuration, 'fuel pump' (at the time it was a V12 Superleague Formula engine), suspension (passive not active), wheels and how they could test them, etc., etc. Was fascinating !

They also spoke about the support they were getting from US companies rather than UK ones !!!

Was also interesting to hear that they had a sort of 'epiphany' and which had changed their philosophy from building the *best* 1,000mph car to building the *first* 1,000mph car - apparently they had spent a lot of time trying to get to the perfect configuration but were running the risk of never actually building the car, so settled on building a car which would set the benchmark for others to come and beat with 'better' cars.

It's also really inspiring in terms of the reasons why they're doing this - it's very much not just about the record, and it's definitely not about the people involved with the project. It's ALL about engineering, with this project being the ultimate showcase for engineering skill and talent and is being used to inspire kids in schools to take up engineering. They were talking about the 'Apollo' effect in terms of how they wanted to inspire the next generation of engineers.


The other really interesting bit of the day was the talk by Don Wales about his involvement in the Steam-powered LSR, which he added to his Electric LSR. Really interesting bloke and the family resemblance to his grandfather is very clear !!

[DJC]

Life Saab Itch said:

DJC said:

There was a reason I said initially that my emphasis was more on the aeros.

The CFD for the hull design isnt a major issue really, the principles are well understood and relatively easy to apply. I can think of 3 designs off the top of my head which would satisfy the hydro side of things, esp combined with a decent propulsion side. Its all on the aeros and control system side.

To follow that, without significant "gifts" or grants, the control systems side would be prohibitively expensive.

With the systems (if I am following the discussion in the right direfction) that you are talking about, you are effectively designing a small aircraft that happens to plane on water.

The speeds we are talking about, we are probably somewhat above Cessna technology levels.

Yes it might help if you have experience in flight control computers, software and systems...

[yoof full chav]

DJC said:

Life Saab Itch said:

DJC said:

There was a reason I said initially that my emphasis was more on the aeros.

The CFD for the hull design isnt a major issue really, the principles are well understood and relatively easy to apply. I can think of 3 designs off the top of my head which would satisfy the hydro side of things, esp combined with a decent propulsion side. Its all on the aeros and control system side.

To follow that, without significant "gifts" or grants, the control systems side would be prohibitively expensive.

With the systems (if I am following the discussion in the right direfction) that you are talking about, you are effectively designing a small aircraft that happens to plane on water.

The speeds we are talking about, we are probably somewhat above Cessna technology levels.

Yes it might help if you have experience in flight control computers, software and systems...

Might help??? I should think it would be a serious advantage if you did have relevant experience

Edited by yoof full chav on Sunday 23 January 18:41

[Life Saab Itch]

yoof full chav said:

DJC said:

Life Saab Itch said:

DJC said:

There was a reason I said initially that my emphasis was more on the aeros.

The CFD for the hull design isnt a major issue really, the principles are well understood and relatively easy to apply. I can think of 3 designs off the top of my head which would satisfy the hydro side of things, esp combined with a decent propulsion side. Its all on the aeros and control system side.

To follow that, without significant "gifts" or grants, the control systems side would be prohibitively expensive.

With the systems (if I am following the discussion in the right direfction) that you are talking about, you are effectively designing a small aircraft that happens to plane on water.

The speeds we are talking about, we are probably somewhat above Cessna technology levels.

Yes it might help if you have experience in flight control computers, software and systems...

Might help??? I should think it would be a serious advantage if you did have relevant experience

You still have to bolt the control systems to an impressive piece of structural engineering...

[yoof full chav]

Yeah, true, but a basic understanding of aerospace systems and guidance stuff would be beneficial. Also, who's he sacraficial lamb who's going to attempt 400mph on water??