From: TBPNews [webnews@aeromarineresearch.com]
Sent: Sunday, April 27, 2003 10:27 AM
To: jimboat@aeromarineresearch.com
Subject: TBPNews #39 - April 27, 2003

TBPNews #39 - April 27, 2003 
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>>>>>> Tunnel Boat Performance News >>>>>>>>>>>>>>
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In this issue: 
1) Bernie Little, "King of Boats" Dies at Age 77
2) FREE Powerboat e-book
3) Special! 2003 U.I.M. F1 World Championship entries
4) Bombardier: Competitors spreading fear
5) Outboard engine pioneer O'Brien dies
6) Campbell's Bluebird Jetstar For Sale
7) Future Boats to have air bags?
8) Russell 'Tunnel Vision' article in Extreme Boats Magazine
9) ** Feature Article - "The Short Course on Tunnel Boats", Part II
******************** TBPNews *******************

1)Bernie Little, "King of Boats" Dies at Age 77

LAKELAND, Fla, April 26, 2003 - One of the most recognizable faces in motor sports history, Bernie Little, owner of the Miss Budweiser unlimited hydroplane team passed away April 25 in Lakeland, Florida as a result of complications related to pneumonia. He was 77. 

A force in hydroplane racing since 1963, Little completed 40 consecutive seasons of competition after entering 354 Unlimited hydroplane races. Little's Miss Budweiser finished in the top three a total of 230 times. At the conclusion of the 2002 season, the Miss Budweiser team was presented with the first Bernie Little World High Points Championship Trophy, which was renamed in 2001 in Little's honor.  In addition to Little's unprecedented racing accomplishments, he had received several honors both in and out of the sport of Unlimited hydroplane racing. For those who knew Bernie Little, he'll always be remembered as a hard charging, dedicated individual.

http://www.hydroprop.com/news/030426.htm
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2) FREE Powerboat e-book!

Join the Tunnel Boat Performance News subscriber list, and receive a FREE gift. ALL new subscribers will receive FREE e-book: "History and Design of Propellers", by AeroMarine Research.

http://www.aeromarineresearch.com/popup.htm
******************** TBPNews *******************

3) Special! 2003 U.I.M. F1 World Championship entries

We are now approaching the start of the 2003 U.I.M. F1 World Championship.  The opener is at the Grand Prix of Portugal in Portimao on the weekend of May 3/2003.  Here's who will be there:

Italian Guido Cappellini the current World Champion and 7-time holder of the
title in the past 10 years, has won in all 4 previous events in Portugal. The lead driver of the Zepter Team has added a new teammate in Russian pilot Stanislav Kourtsenovsky for
the upcoming season. Cappellini will be debuting his new radical boat as a designer who has set the trend that past 5 years in the sport.

Another Italian Francesco Cantando is finishing testing on his new Blaze catamaran boat. The 28 year-old head of the Singha F1 Racing Team has named as a replacement for his last year partner, (Torta) with the youngest driver in the series in 19 year-old Massimiliano Max Moreschi.  

Veteran driver Andy Elliott of GB joins Saudi driver, Laith Pharaon on Team Green. Pharaon, who stated a year ago that 2003 would be his year to run for the title, will be looked upon as a driver to challenge Cappellini for the top rung. Elliott, who has pushed for the title in the past maybe a serious runner this season joining one of the most respected teams on the tour.

Australian Bob Trask will be joining new teammate Massimo Roggiero on the newly formed Baba Seaquest Racing Team. Trask is a long time participant in the domestic Australian series. Roggiero picked up two wins and finished 3rd in the championship a year ago.

The Rainbow Corona Extra Team will stay put this season with one-time World Champ Fabrizio Bocca who was 10th in the series in 2002 with 3 top-5 finishes and 5 top-10 results leading the effort, while Swedish driver Pierre Lundin running his first full campaign after picking up a top-5 finish last season.

Portuguese driver Duarte Benavente will lead the Atlantic Team in his English built Burgess hulled boat. Dutch driver Marcel Meiberg will join him in his first F1 campaign, while fellow Portuguese pilot Luis Figueiredo will join him in Portimao.

Another new team Danita Racing will be led by Danish driver Gert Ladefoged who made more improvement than any other driver during last seasons competition, finishing 13th overall will add rookie Belgian Julius Leysen who comes over from the F1 Waterski Racing World Championship tour as one of there leading drivers.

Team Ligier Sport could be one of the most exciting to watch with a fully French flavored effort with lead driver Philippe Dessertenne, 4th in the championship a year ago coming off a win and 4 podium finishes. Joining Dessertenne will be fellow countryman Philippe Chiappe who joined the team last season in the final two events.

A pair of Finnish drivers will make up the Velden Racing F1 team led by Sami Selio who continues to show great promise in the Johnson powered 3.0 litre effort put together by multi-time world titleholder Cees van der Velden. Joining Selio will be Michael Weckstrom who had 1 top-10 finish on his way to 18th place in limited action in 2002.

2-time World Champion American Scott Gillman will once again lead the Emirates Team. Gillman, who finished 5th in the championship in 2002 struggled with 4 different boat hulls and hopes to find his first victory in 2 seasons. Tany Al Qamzi the talented United Arab Emirates driver from Abu Dhabi, looks to improve on his 5 top-10 finishes having run a strong F2 series during the winter months throughout the Middle East.

Fabio Comparato of the Comparato Racing Team looks for his first win in a boat he and his family are building in the boat factory near Venice. Joining the Italian will be Luigi Roberto who was 5th last season in the Italian F2 championship in his first full taste of F1 racing.

Team Maremagnum is expected to join the circuit at the seasons 3rd event at the Grand Prix of Hungary. Veteran Italian Franco Leidi will head the team with fellow Italian Marco Gambi comes from the sport prototype series.

So a full field of drivers is ready to start the 22nd edition of the U.I.M. F1 World Championship at the Grand Prix of Portugal in Portimao on the 3rd and 4th of May. The new drivers and a few wildcards throughout the season along with new boat manufacturers will make this a good possibility that this season will be a one to remember for excitement on the water in the quest for a new World Champion of the sport.
******************** TBPNews *******************

4) Bombardier: Competitors spreading fear

Bombardier has sent out letters to Evinrude and Johnson Friends to stave off rumors that have emerged since its parent company announced plans to spin off the recreational business.  The letter accompanied a three-page frequently asked questions answer sheet addressing the rumors. This includes speculation that Bombardier Recreational Products is going the way of the former Outboard Marine Corp. Lambert says the recreation unit is not going bankrupt, nor is it in any kind of financial trouble.  He says there is no resemblance to the OMC situation, and that the company is operating in a business as usual mode. All warranties and extended protection stand, and all program benefits and credits are processed as usual and will be honored, says the company.  He says Bombardier Recreational Products has a very bright future, and while the next few months will be a period of transition, in the end, we will be stronger than ever.
******************** TBPNews *******************

5)  Outboard engine pioneer O'Brien dies  
  
Outboard engine pioneer Harry E. O'Brien Jr., 89, of Indianapolis, died on April 9, 2003.  O'Brien, founded custom roller skates manufacturer Special Engineered Products Co. in Indianapolis in 1953, but during the 1960s, the company switched to manufacturing outboard engines for hydroplane and runabout racing. During the next 30 years, O'Brien's engines won more than 150 national titles and set runabout and hydroplane speed records.  O'Brien was a member of the U.S. Title Series outboard racing association and he published the series' monthly newsletter, Promotion, for 10 years.  He also was a past president of the Indiana Outboard Association and sponsored the race team lead by his son, Mike, who won multiple national championships and along with other hydroplane and runabout racers.
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6) Campbell's Bluebird Jetstar For Sale

A rare boat will be going under the auctioneers hammer on 25th April when the late Donald Campbell's Jetstar 1 will be seeking a new home.  A boat with an unusual history, Jetstar was the prototype of a range of sports boats produced by Bluebird Marine. Jetstar 1 was Campbell's personal craft, used to take journalists for promotional trips on Lake Coniston prior to his ill-fated record attempt. Campbell had planned to promote the Jetstar 1 alongside Bluebird K7 at the 1967 London Boat Show but his death on 4th January ended that dream. However, the Jetstar concept lived on and went into production. The prototype was unused until Villa restored the craft in the early 1970's and after his death Jetstar 1 remained in the 'family' as Ken Norris co-designer of Bluebird K7 inherited it. It was passed to John Ackroyd, designer of Richard Noble's land speed record breaker 'Thrust' who got the craft up and running and used it to take the family out.

http://members.ebay.co.uk/aboutme/ljnorris1/. 
******************** TBPNews *******************

7) Future Boats to have air bags? 

Dr. Willy Johnson, a British inventor, has come up with an idea for an air bag for boats, called the C-Bag. The invention works like a car airbag and is designed to stop a vessel from sinking, according to the newspaper. Once a boat gets a hole in it, water flows into the boat, setting off sensors, which activates the airbag, keeping the boat afloat.  The Evening Standard London newspaper reported that the idea has been patented and that Johnson is in discussions with a major pleasure boat builder.
******************** TBPNews *******************

8) Russell 'Tunnel Vision' article in Extreme Boats Magazine

Check out the April 2003 issue of Extreme Boats Magazine to read author Jim Russell's first in a 3-part series on Tunnel Boat Design.

http://www.extremeboatsmag.com/home.shtml
******************** TBPNews *******************

9) ** Feature Article - "The Short Course on Tunnel Boats"

The Short Course On Tunnel Boats, Part II (by Jim Russell, P.Eng.)

In TBPNews #38, March 14, 2003 we looked at a brief history of tunnel boats, including "Where did tunnel boats come from?"  This issue, in Part II, we will look at the design and types of tunnel hulls.

- Boat or Aircraft? 
The Tunnel Hull is a strange 'bird'. It is part boat and part aeroplane.  The hydrodynamic lift and drag forces are generated by sponsons, center-pod, water appendages (such as lower unit, propeller, trim tabs, etc.) similar to the behavior of a vee-hulled boat.  Aerodynamic forces are significant also, with lift and drag generated by the 'wing' formed by the deck surfaces and tunnel design.  These forces must always be balanced, and the relative significance of aerodynamic and hydrodynamic forces changes throughout the velocity range of the boat.  The combination of these forces is what makes the tunnel hull the super-high performance machine of its day; and the balance of these forces is key to keeping it on the water.

- The fine edge: 
As we have noted, the hull weight (including engine, driver, fuel, etc.) must be EXACTLY equaled by the lift forces generated.  This is true for any boat (or aeroplane, too) in stable flight.  The tunnel hull must however always be in 'stable flight', and so this balance is critical.  Too much lift and we take-off like an aeroplane - too little and we sink! 

- Two kinds of Lift: 
There is lift generated in two ways.  The planing sponson bottoms create 'hydrodynamic' or water-lift (lift due to forces on and reactions with, the water surface).  The aerodynamic lift is generated by the relative air flow over the tunnel and deck surfaces (lift due to forces on and reactions with the air, itself).  

It is important to note here, that the relative significance of these forces changes as the speed of the hull increases.  At low velocities, the aerodynamic lift may account for less than 5% of the total lift, the sponsons supporting nearly all of the weight of the boat.  At the speeds now attainable by conventional racing catamarans, the aero-lift can account for well over 80% of the total lift.  For every pound of aero-lift we get, the sponson (hydrodynamic) lift (and drag) is reduced accordingly, which gives dramatic improvements in the performance of the tunnel boat.

- Ground Effect: 
Tunnel Height - this is the height of the tunnel at the aft-most location.   It is this height at the aft most (trailing) edge of the tunnel that is important.  The aerofoil of a tunnel hull is really a wing, flying in what is called "close-proximity ground-effect."  This means that the aerofoil is actually influenced by its proximity to, in our case, the water surface.  A smaller tunnel height will increase Lift/Drag ratio of the tunnel hull "wing", improving lift characteristics.  Regrettably, it also brings the tunnel roof closer to the water surface, risking increased (abrupt) wetted surface if water conditions (waves) cause "splashing" to the tunnel roof and sides.  The design of this feature is, as most are, a compromise of different performance factors.

- Vee hulls dont have a tunnel: 
Tunnel Width - The width of tunnel measured from inside sponson to inside sponson. A wider tunnel creates a wing of larger "aspect ratio" (width/length relationship), which creates Lift that is more efficient.  A wider tunnel will also place the outboard sponsons further apart, improving stability of and handling of the hull.  So there are multiple advantages of increased tunnel widths.  Generally there are only the practicalities of construction and user operating needs that limit the tunnel width.

- The wing and the prayer: 
Wing Chord - The length of the "wing" or aerofoil, measured from the leading (front) edge of the deck to the trailing (aft most) edge of the deck.  A longer Chord will increase the overall area of the "wing", and hence, more lifting surface.  Unfortunately, increasing the chord will also reduce the "aspect ratio," which will reduce the efficiency of the wing somewhat, and will also increase aerodynamic drag.  A reduced length can also relocate the Center of Pressure (C of P) of the wing, to a position further aft.  This should also be a consideration.  There's a trade off in the benefits of increasing Chord length.

- Deck design: 
Deck Width - Width of the hull deck at the widest point.  Just as with the width of the tunnel, a wider deck creates a wing of larger "aspect ratio," increasing Lift efficiency.  Generally, there are only the practicalities of construction and user-operating needs that will limit deck widths.  We will discuss the shape of the deck further in the 'Aerofoil' section below, but it's worthy to note that the deck will perform best when designed to be smooth and flat across its width.  The 'spill' of airflow off the sides of the deck surface (referred to as 'wing-tips' in the aircraft world) can be reduced when the surfaces are not 'canted' or sloping to from side-to-side.

- Fatter is better: 
Wing Thickness - The maximum thickness of the aerofoil, measured from the top of the deck to the tunnel roof, at the thickest point along its length.  If we were to slice a tunnel boat in two, from bow to stern, we'd see the cross section of a wing or aerofoil that is made by the deck and tunnel roof.  This aerofoil provides the tunnel boat with much of its lift.  "Thicker" aerofoils - especially those in "ground-effect" - have higher L/D ratios, and thus are more efficient at creating lift.  So a thicker aerofoil is better.  Moreover, there is an added benefit of thicker aerofoils - that is the structural advantage of the deck-to-tunnel roof thickness - the boat is stronger when it's thicker.  So, this means that we can actually decrease the hull weight, by making the wing thickness greater.  We win twice - what a great way to improve performance!

- The shape of things to come: 
Aerofoil shape - The shape of the aerofoil and its influence on the performance and stability of the tunnel hull is the subject of a complete book all in itself.  (The details are currently discussed in the 12th edition "Secrets of Tunnel Boat Design" book, based on the research that we have done on the subject).  Since the lift and drag forces CHANGE throughout the speed range of the boat, "balancing" your boat by "weight" while it's on the trailer will only help stability while it's on the trailer at zero mph!

The impact of aerofoil shape on tunnel hull aerodynamics and hydrodynamics is quite different than the impacts of shape on airplane wings.  The "camber" of an aerofoil can change both overall Lift/Drag (L/D) characteristics and change the position of the "dynamic center of pressure" (C of P) of the 'wing'.  The C of P is the location of the aerodynamic lift, and it changes for each speed that the boat is traveling.  The effect is a dramatic influence on the dynamic stability of the hull.  This is one of the key design features that can optimize the performance of a tunnel boat.  The shape of the 'wing' can be designed to position C of P further fore, or further aft, depending on the performance needs of the hull and its application.  

- Sponson Design: 
Sponson Pad Width - The width of the sponson running surfaces (bottoms), measured from the keel (inside) to effective chine (outside).  Wider pads give higher aspect ratio (relative width to length) and thus, generate more efficient lift.  This can be an advantage during acceleration.  At higher speeds, however, there can be a greater pad surface exposed to extraneous water drag, resulting in less top speed.  It is a design tradeoff.  

- Speed or Comfort?: 
Sponson Pad Deadrise Angle - The angle of sponson running surfaces, measured from keel to chine is called the deadrise.  A very shallow deadrise (less than 8 degrees) will provide the most efficient lift.  Deeper deadrise angles (like 12 to 20 degrees) will make a much cleaner presentation to the water surface in rougher water conditions, exhibiting a much more comfortable ride.  Again, a design tradeoff.

- Three sponsons?: 
Center Pod - The additional lifting surface in a "modified tunnel hull" or "Mod VP" design can improve handling and even acceleration under certain circumstances.  The "center pod" is really a "third sponson" located in between the two sponsons of a traditional tunnel boat.  Boats that are heavier or carry increased payloads can benefit from having a center pod design.  The center pod can be purposely designed to become effective or non-effective at certain speeds, thus getting the advantages of both a conventional (twin-symmetrical sponson) design and the center pod design.

- Conclusions:
Tunnel hulls can be the fastest powerboat design.
The tunnel boat is part airplane and part boat.
The designer must recognize that he is designing a hull with both aerodynamic and hydrodynamic dependencies - or results can be disappointing.
Properly balanced design can be more stable, more comfortable and faster than any other design.

(The complete history and design of tunnel hulls is detailed in Russell's book, 12th edition "Secrets of Tunnel Boat Design").  

http://www.aeromarineresearch.com/stbd2.html
******************** TBPNews *******************

See you next time!

/Jimboat
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>>>>>> Tunnel Boat Performance News >>>>>>>>>>>>>>

Let us know any ideas you have, requests for articles, questions or comments on our TBPNews.  Send your comments to TBPNews@aeromarineresearch.com
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Also, the publications "History of Tunnel Boat Design" book, "History of Propellers" e-book, the "Tunnel Boat Design Program for Win98" software, and the "PropWorks2" software for speed prediction and propeller selection at the Aeromarine Research web site.  
GO TO: http://www.aeromarineresearch.com

"Secrets of Tunnel Boat Design" book
"History of Tunnel Boat Design" book
"History of Propellers" e-book
"Tunnel Boat Design Program" for Win98 software
"PropWorks2" software for propeller selection and powerboat speed prediction

GO TO: http://www.aeromarineresearch.com

>>>>>> Tunnel Boat Performance News >>>>>>>>>>>>>>
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AEROMARINE RESEARCH - Tunnel and High Performance powerboat specialists
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