Some sad pics from Windermere (from Bren)

[Louise]

From what I've heard, stepped hulls require a bit of getting used to and the driver needs to understand thoroughly how they work if he is to avoid accidents. Not saying the guys above didn't know what they were doing though! Everyone gets caught out from time to time, especially when you're pushing the limits!!

Glad to hear everyone was OK.

[Cookee]

Originally posted by Admiral P. Brain
Are Stepped hulls dangerous??
The evidence above seems to indicate this...

Hate to disagree with you Admiral but it doesn't! The batboats go over rarely and no more than race boats in general - if you went to an OCR race you often see boats getting dragged out after rolling and stuffing but there are no steps allowed in that class.

I believe all the above PROVES is that race boats go over, although it is allarming how often the Hondas flip but I believe that it is a combination of factors including the steps, the narrowness of the hull and the general hull shape that contribute to the boats "unforgiving" nature.

The above comments have nothing to do with the fact that I make a stepped hull RIB!

[Slacko]

Originally posted by Cookee

The above comments have nothing to do with the fact that I make a stepped hull RIB!

Or the fact that you have a very limited knowledge of boat design.

Stepped hulls are not new, but became a must have for a large amount of builders a few years ago. Many american manufacturers built boats that had suspect handling, brought about by the adding of steps to what was once a very competent non-step hull.

Cookee is correct in saying that a true Mannerfelt stepped hull rarely inverts, unlike the Cougar which has inbuilt instability, brought about by an obvious design flaw.
What's strange about the Cougar is Honda's acceptence of what is obviously a very poor design, I wonder what they would do if a model of Honda car fell over at every roundabout.

Cookees argument about OCR's going over is pretty poor, as if you try hard enough any thing will fail.

[Cookee]

Originally posted by Slacko
Or the fact that you have a very limited knowledge of boat design.

Cookees argument about OCR's going over is pretty poor, as if you try hard enough any thing will fail.

Certainly don't claim to be an expert or a boat designer - all the above is just my opinion.

As far as OCR is concerned that is my point (maybe not very well put!) race boats go over - Pascoe and Revenger RIBs go over as well in race conditions but it doesn't make them bad or dangerous.

[Admiral P. Brain]

but arent these stepped hulls too!!!
I read a articule from a respected boatbuilder/racer in the states that anything sub 34ft should not have steps!!

[Cookee]

Originally posted by Admiral P. Brain
but arent these stepped hulls too!!!
I read a articule from a respected boatbuilder/racer in the states that anything sub 34ft should not have steps!!

They are stepped hulls but there are lots out there in the leisure market and to my knowledge they don't turn over.

That means he is saying that respected European designers Lorne Cambell and Ocke Mannerfelt are wrong then - everyone has an opinion!

[Admiral P. Brain]

yes true you never know if they are talking the truth or just promoting their hulls.....
here a quote from Sonic who refuse to put steps in their hulls....

""In the USA, higher tech consumers are no longer enticed into the market with stale design offerings with "quickie" design tricks and ever higher stressed gasoline engines and traditional drives. The former has resulted in dramatically decreased handling and control and hence occupant safety and the latter has resulted in almost routine major component breakdown during the first 300 hours of boat ownership. For today's consumer this is an unacceptable combination.

Sonic USA decided to take this divergent path by not embracing a hull design regimen that purposely undermined handling and hull stability for a few extra calm water miles per hour and instead embarked on a higher technology approach to gaining performance"

[Jon Fuller]

Originally posted by Matt
Well that's not a sweeping generalisation then is it!

It's utter rubbish!
There are few boats as fast, sure footed and exellent in rough water as the Mannerfelt B28 bat boat, I'd love this running surface under my P28!..and well under 34'.

(this comment goes foe Pleasure use, as well as racing)

all IMHO

[Admiral P. Brain]

so Jon you reckon its the individual design thats flawed ?

what actually happens when a stepped hull turns tightly?
i know they say you must not trim in (like a nonstepped hull)
is it that the front can dig and the stern losses grip due to lack of hull and air trappment??

[Jon Fuller]

I'm not really saying anything's flawed, the B23 (roy smiths boat..C54) is a highly competitive race boat, Roy is an extremely experienced driver. Once in a while, when pushing to, and mebbe a little beyond the limit, things go wrong, the steps and pad-ish type keel of todays racing mono's definitely require a great deal of respect when cornering hard, as they do seem more likely to spin out than a conventional 'V' hull, but all this is just the compromise you have to expect to make if you want that level of performance from a mono.

The Honda 225's do seem to go over quite frequently given their performance (considerably less than a 3-C batboat), but I've never driven one, so wouldn't want to lay blame anywhere.

[dbe1]

Originally posted by Johnson
I'm not really saying anything's flawed, the B23 (roy smiths boat..C54) is a highly competitive race boat, Roy is an extremely experienced driver. Once in a while, when pushing to, and mebbe a little beyond the limit, things go wrong, the steps and pad-ish type keel of todays racing mono's definitely require a great deal of respect when cornering hard, as they do seem more likely to spin out than a conventional 'V' hull, but all this is just the compromise you have to expect to make if you want that level of performance from a mono.

The Honda 225's do seem to go over quite frequently given their performance (considerably less than a 3-C batboat), but I've never driven one, so wouldn't want to lay blame anywhere.

Not sure that stepped hulls are any less stable than conventional hulls, as Jon said they certainly need to be driven differently, many years ago when power boat racing was at its highest I was a member of Allhallows Yacht Club, in those days Allhallows put on many power boat races, quite a few boats over the years turned over Phantoms included, I ski raced a Phantom 21 for many years and only on 2 occasions did I nearly lose it, both times on flat water, Loch Earn and Strathclyde Park, (Scotland) both times nearly flat out (70MPH) on a tight turn with the skier waving up for more speed, kept the power on probably to much trim and engine lift to high, luckily with ski racing the pull of the skier behind does help to settle the rear end, on both occasions the back stepped out.

It is probably the quest for speed that is the route cause, badly set up boats, erratic driving and inexperience and more importantly when the red mist comes over you and all reasoning goes out of the window in the quest for more and more speed.

Hated racing on Windermere, each time I raced there we found more holes in the water than offshore, flat one lap dam great holes the next.

[Jon Fuller]

Originally posted by dbe1
Hated racing on Windermere, each time I raced there we found more holes in the water than offshore, flat one lap dam great holes the next.

When we were racing, it was the flat calm races that worried us most! (everyone else seemed to love em) at least if it's dog rough, your speed is dictated by the water, and is generally lower, and your trim/settings are set for pitch stability across the un-even surface. When driving flat out in calm water, trimmed way over the 'stable' line, trying to ring every last ounce out of it, this is when the slightest unexpected swell, or wake is fkkn dangerous!
I'd rather crash-n-burn at 50 summat in a rough sea, than have the big whoopsee @ 80!

[dbe1]

Jon

Did you race the Phantom 28.

I have just found a couple of photos of Peter and Jan's Faberge Turbo Phantom on its trailer at Allhallows, also Clarke Group Racing (Phantom) and one of Agfa Bluebird (Phantom) being crane in by Tower bridge for the Putney Calais Race.

When the scanner plays ball I will post the photos.

[Captain Chaos]

Originally posted by Matt
a non stepped hull is, generally accepted as being more forgiving to poor driving.

well thats a result!

[glen76]

i asked cougar outright why they kept showing their arses off and they admited they are a sensitive boat because of mailnly the steps (obviously) and originally they had spray rails in the pad area but due to the number of flips etc they removed em to eliminate some of the excess lift.

Another reason mentioned was the lines of the boat mean there is no hard outside chine and the hull just slopes into an almost bath tub shape giving it no stoping point (a bit like trying to float a tennis ball only one way up)... have a look at the side profile of the hull to gunwale, its just to round... dont alot of boats have a hard negative final chine to give side stability?

Oh yeah and the last reason given is drivers technique, the 225 drivers that have previously been in the 150s are just to enthusiastic as the 150s corner on rails and as we all know you have to have respect for any stepped hull.. ocke included.

Still i hope i never have to drive one!!

[Jon Fuller]

Given the above statements by Cougar, mebbe Steve (Curtis) could tell us how HE came to involuntarily 'exit' a 225 Honda during testing

(sorry Steve!)

[Numb Nuts]

I must agree with Jon the B28 hull is absolutely awesome and very versatile, it takes any thing you put in it or on it from twin 300 X outboards to Volvo diesels with 280 hp. I think all this business of stepped hulls being unpridictable is unfair as anything can bite you if you f*&ck it up. The problem, in my opinion in corners in the flat is the fact that, particularly with outboard race boats is that the prop can break away leaving you with no power to try and rectify the situation. Same deal with cars no power very little control. If you do start to slide in the turn instinct tells you to try and stop it from happening and thats when, again in my opinion can bite you.

[BREN]

it must be down to the drivers as well.iv'e never seen james Sheppard in king of shaves go over and he really pushes his boat

is'nt there any honda boat drivers who are members on here maybe if there was they could explain the reason maybe

[simon johnston]

is the wieght of the motor a factor ???

[BREN]

i wouldn't think so