Pro Hydro Boat Design - USA vs Europe

[Corin_Huke]

Guys

though my involvement in pro hydros over the years and also from looking at photos on forums, such as Hydroracer.net, I've noted a number of differences between the design of boats used in the US, compared to those we use here in Europe

Obviously, boat designs have evolved over the years to suit the style of racing, what's fashionable at the time and so on. Some of the differences in design I understand, but others leave me scratching my head, so I'd welcome your input guys

My observations regarding European boat designs that are currently in use in the 0-125, 0-250 & 0-350 classes are:-

Sponsons - I believe that the design and depth of sponsons on European boats differ from the US designs. From what I have seen, the depth of sponsons on European boats are deeper and (I gather) sometimes have a different design (eg chines). This is brought about because of the different courses that we race upon - lots of river courses in Europe than can rough up. The deeper sponsons provide greater stability in the rough water and more 'lift' in the front end, when turning tight buoy turns. Also the deeper sponsons and the front end lift helps get the boat up and planing quicker for the lemans starts we have

Length, Width & Weight - I get the feeling that European boats are bigger (in general) all around - again to handle the rough water

Other tweaks - to help with the modified lemans starts, a number of the boats have a centre wedge infront of the foot/prop that runs about 18" to 24" towards the front of the boat. This allows the prop to be run deeper to get better 'bite' from the lemans start

The above I think are pretty much obvious differences, but the one that has me scratching my head is the fact that some of your pro hydro boats do not have perspex screens. I can honestly say, I have never seen this in hydro racing in Europe as all of the boats run a screen made from Lexan or another poly carbonate material.

Can I ask, why some of you guys prefer the 'no screen' approach. I'm guessing that it's a personal choice, as I have seen boats with perspex screens and others without. Invariably, here in Europe the driver either looks through the screen, or half through/half over (as shown in the pic)

I'd welcome any thoughts on the matter, and any other input regarding boats designs

Regards, Corin

[arltralite]

corin

I have a question about the boats you race in Europe. What classes require the kevlar reinforcement on the cockpit sides to meet UIM rules? I dont see any kevlar on the cockpit/deck joint on the boat in your pictures.

[Corin_Huke]

UIM rules on reinforced cockpit sides

corin

I have a question about the boats you race in Europe. What classes require the kevlar reinforcement on the cockpit sides to meet UIM rules? I dont see any kevlar on the cockpit/deck joint on the boat in your pictures.

Hi Arltralite

There's kevlar there alright - just have a look at the pic of the guy, Paul Jillings, fitting something (I forget what) in the front of the boat. Over his left shoulder, all of that dark yellow material is kevlar. It was a brand new boat build by Dickfors in Sweden and as such, all of the kevlar was laid up on the inside of the cockpit sides rather than the outside (far neater that way)

As far as the UIM rules are concerned, it's pretty much all of the hydros that race in international events need kevlar reinforced sides, even OSYs*. Rather than misquote the rules, here's an extract from the UIM rulebook that explains what is required.

* although 0-125 & 0-175 have not been specified, my interpreation was that the UIM pretty much expect the rule to apply to all hydros. Now, here's a question, at the WC 0-175 last year, did all your boats need to have kevlar reinforcement?

Regards, Corin

[David Weaver]

Kevlar

Kevlar is not mandatory in the US for open class hydro's and runabouts.

[Corin_Huke]

Kevlar is not mandatory in the US for open class hydro's and runabouts.

Hey David, but how about UIM sanctioned events such as the Worlds (0-175)? Surely you'd need to abide by the UIM rulebook, so you would need kevlar then to compete in these UIM events?

Corin

[David Weaver]

Well...

....that brings up an interesting point. My guess is that none of the boats conformed in 2005 for the 175 class and that they will not conform in 2006 for the 175 class.

This departure in haul in requirements may bring an end to US particpation in UIM PRO classes, except for US drivers willing to "rent" equipment overseas.

US PRO racing is fairly healthy right now. There is room for improvement with regards to particpation. Mandating reinforced cockpits would probably be a step backwards with regards to particpation. It might make sense to have a rule requiring all boats constructed after 2007 or 2008 to have reinforcement.

Just some thoughts.

[Composite Specialties]

MJR Composite center section complies

Just a note that all of the 2006 MJR composite center section boats comply with all UIM specifications.

Also, according to UIM rule 522.02, all hulls for 0250, 0350 and OSY-400 are required to have this reinforcement. It does not state 0125 and 0175 in this rule. This may have been an overseight, who knows.

[Corin_Huke]

....that brings up an interesting point. My guess is that none of the boats conformed in 2005 for the 175 class and that they will not conform in 2006 for the 175 class.

This departure in haul in requirements may bring an end to US particpation in UIM PRO classes, except for US drivers willing to "rent" equipment overseas.

US PRO racing is fairly healthy right now. There is room for improvement with regards to particpation. Mandating reinforced cockpits would probably be a step backwards with regards to particpation. It might make sense to have a rule requiring all boats constructed after 2007 or 2008 to have reinforcement.

Just some thoughts.

All, I think I may have jumped the gun a little and in fact the UIM rules (as they currently stand) do exclude 0-125 and 0-175 classes as needing reinforced cockpit sides - well spotted MJR. Sorry for the confusion this may have caused. Whether this was by design or an oversight.....it's there in black and white now

Now that's not to say that, in my opinion, the rule should no be looked at for the future, especially when comparing the speeds of the boats in question. As you say, may be something could be introduced for all new builds from year x onwards?

I'm all for safety in hydros, but this needs to be tailored with making sure there are boats on the water to compete in the races....

[Corin_Huke]

One of the things I didn't make clear (when I posted details of the UIM rules) was that as well as covering the cockpit sides, the kevlar needs to extend onto the deck of the boat by a certain amount

What the Dickfors team have done when building the boat in the picture is very neat. They have lapped the kevlar under the deck (see image). So rather than the kevlar being on top of the deck, it's on the underside of the deck - neat eh?

Very clever these Swedes! But you must remember the Swedish people have a history of boat building, going back to Viking times (!), so they have learnt a trick or two over the years. Although I cannot remember King Erik Segersäll having kevlar on the sides of his long ship, but then again the UIM were not about then!

Heja Sverige!!!

[arltralite]

Corin

I did see the kevlar on the cockpit sides, but I was wondering about the deck joint. I agree with having the cockpit sides reinforced with kevlar, but laying it down to the deck doesnt make a whole lot of sense to me. Thanks for the reply.

Matt Arlt

[bh/]

Arltra-Lite ?

Matt; -at the PRO race last weekend in Inverness, the announcer seemed to say one of your boats was in 250cc hydro.
I was not able to identify it.
Was there? How did it do?

[arltralite]

Brian

I only remember building a 125cch for Craig Dewald and Billy Allen. Billy finished 2nd overall.

matt

[arltralite]

Corin

the european boats look very narrow. How long are the boats? How wide are the boats between the sponsons? Are there many builders or do racers build the boats themselves?

[Composite Specialties]

Bottoms

They look narrow because they have steps inside the sponsons that look to be about 4" wide but the step stops just behind the sponson backs and the air traps continue on to the rear pads or shoes. These boats are meant to pack a lot of air and the steps inside the sponsons help to reduce the amount of air that is lifting the front of the boat.

[Corin_Huke]

Corin

the european boats look very narrow. How long are the boats? How wide are the boats between the sponsons? Are there many builders or do racers build the boats themselves?

Matt
I'm not sure about the dimension between the sponsons, but MJR is right about the stepped inner sponsons and the reasons for this (you can see this clearly on the photo on the upside down, soon to be repaired, boat) http://www.hydroracer.net/forums/att...achmentid=6061

In terms of length, an 0-250 boat is circa 4m

Attached are a few more photos that show other design features

Both of the boats in question are built by Dickfors in Sweden (the upside down one is a few years older than the other). In recent years there have been many boat builders from different countries - the ones that stand out are Italy (Popoli & Mostes), Sweden (Dickfors), Estonia (Kala) & Germany (Lucas).

You'll find that in the smaller classes (OSY & 0-125) there's more of a chance of self builders, rather than buying from a boat builder. That's not to say that the others, Mostes, Dickfors, Kala & Lucas haven't been very successful in building boats in these classes.

In the 0-250 and 0-350 classes these are pretty much dominated by Mostes & Dickfors these days, although again there have been manufacturers of one off boats (again very successful). Two that spring to mind which were composite copies of other boat designs - composites are also creeping into OSY and 0-125. If we take the 0-250 class (the one I know best) the field is pretty much split between Mostes, Dickfors and the odd one off and self builds. It's strange, but it's only really the Italians that have been able to extract the full potential out of the Mostes boats, whereas the Dickfors are used by a host of different nationalities

The market for boats is not so large as it is in the US, but in the last 3 years I calculated that the Dickfors guys have built 8 boats - from OSY/0-125, 0-250 (most popular) and 0-350. It is a real family run affair - the two oldest brothers, Olle & Johan both race, Dad (Anders) & younger brother, Åke, crew and they are all involved in building boats, with the help of other relatives and friends. Olle & Johan are very successful - Johan #50 was the 0-250 European champion in 2004 and both of them are always placed very highly in the results. The 'problem' is that they keep on selling their successful boats, so for the last 3 years in the winter they have had to build new ones to race!!

Going back to the design of the European boats, compared to the US, I get the impression that there's more shape (a la aircraft wing) in the decks on our boats - again, going back to the point made by MJR of lift.

Corin