Roostertails Unlimited: [1973]
Chapter 6 - Building A Hydroplane

Ch.1 A Race
Ch.2 A Little History
Ch.3 The Evolution Revolution
Ch.4 The Principle
Ch.5 The Power Plant
Ch.6 Building a Hydroplane
Ch.7 The Crew
Ch.8 The Men With the Money
Ch.9 What's an Unlimited?
Ch.10 Preparing the Race
Ch.11 The Rulebook
Ch.12 The Spectator
Ch.13 First You Get Into the Cockpit
Appendix A Unlimited Class Speed Records
Appendix B National High Point Champions
Appendix C Major Races

Putting all these ingredients together into a working hydroplane requires immense technical knowledge and a certain element of luck brought about by hard work. The job is obviously not a simple one and usually not a profitable venture either. It is usually done purely for the love of the sport.

Few designers and builders have made it to the forefront of Unlimited design. Ted Jones is given credit for creating the first successful 3-point hydro and for the revolution that followed. He has designed many great boats through the years including the Slo-Mos, the Thriftways, the first three Bardahls and the Mavericks. Nearly every boat that has raced since the early 50s is either an obvious copy of a Jones design, or, indeed, was a Jones design.

A church pew builder from Kawkawlin, Michigan, named Les Staudacher, actually constructed many of the early Ted Jones boats but then went into the business on his own. He is given credit for the design of Gale IV and V, Tempo VI, Coral Reef, Miss Seattle Too, Miss Madison and others.

There were other designers but they never were consistently successful — they include: Norm Christianson, Bart Carter, Rich Hallet, Danny Arena, Henry Lauterbach, Chuck Hickling, Walt Kade and Bob Gilliam. In 1958, Fred Wickens designed and built the "ugly duckling" $ Bill and later went on to develop Atlas Van Lines U-35 and U-29. Drivers Lee Schoenith and Bill Cantrell teamed to create the Smirnoffs, Gale's Roostertails, the third Miss Madison and the 1972 National Champion Atlas Van Lines U-71.

Ed Karelson became very popular after he designed the fifth Bardahl in 1967 and was commissioned to develop Budweiser, the 1969, 1970 and 1971 National Champion, the ninth Notre Dame and the second Parco's O-Ring Miss. Ted Jones' son Ron, who had served as a foreman for his father, designed and built the ill-fated fourth Bardahl, the Pride Of Pay 'N Pak (now Miss Budweiser), the tenth Notre Dame and the new, light-weight, Pay 'N Pak among others. His excellence shows much promise for the future of hydroplane design.

Each hydro built is a custom job, no two are exactly alike. In fact, some have tried to use an old successful hydro as a pattern, actually tracing the pieces, and yet it would perform with all the ability of a brick when finished. There are probably twice as many half-boats and quarter-boats lying around this country unfinished than there are actual competitors. Too often, the right combinations do not appear.

Surprisingly, more of the building technique is borrowed from airplane manufacture than from boat building. There are literally thousands of engineering details that must be worked out for each hydroplane. The prop, rudder, skid fin, sponsons, spoilers, gear box and gas tanks must be in harmony with each other and with dozens of additional parts. Little things are vital. The shape, size and location of the rudder and skid fin, the size of the propeller in relation to the gear box ratio and to the position of the fuel tanks, the temper of a particular engine with a particular water condition, the shape of the sponsons, the weight of the spoiler and the position of the driver's seat. The list can go on and on.

They have to be built strong, not only to resist the stress and strain if it should ride out of proper attitude (a popular misconception is that hydros suffer severe impact loads while on a plane - in actuality if it is properly designed and balanced the boat will "dance" or skim over the surface of the water with very little resistance), but for the non-racing life they lead. They travel over bad roads in bad weather and at highway speeds. They are stored in daily contact with fuels, oils and tools...many times in a wrecking yard. They can expand or contract up to a quarter inch in one night due to atmospheric conditions. A hydro must withstand these kinds of stresses.

Perhaps most important in the construction of a thunderboat is money ... it takes lots of it. A typical expense account for a boat's first year could very well look like this: $50,000 for a boat and trailer, trucks, spare engines, gear boxes, props, shafts, etc., most are purchased with spares -none are cheap. There is $1,000,000 worth of insurance for the boat, driver, crews and for public liability, the salaries of the crew and the driver, entry fees, crane rentals, highway transportation costs and living expenses for personnel. For the sponsor, not only does he help pay for much of the campaign, there are the promotion costs: ads, buttons, patches, stickers, hats, picture post cards and matchbook covers. Total cost is near $200,000 - and it does not pay to cut corners ...second-class operators rarely win and rarely keep a sponsor for very long. Still interested? Money no object? Then let's build an Unlimited Hydroplane!

Our designer has had his headaches and sleepless nights and has come up with a blueprint. We can now hire a builder to work closely with him so our boat will be a strong entry and run circles around those other hulls. Where shall the boat be built? To take an easy and cheaper way out we should build in Seattle. Here the wood costs less, about one-third regular prices, and it is in greater abundance. Boeing Aircraft Company has plenty of spare or scrap airplane parts and materials and with these advantages we can finish the construction quicker and will have more of that valuable testing time before her first race.

The builder starts with the 30-foot engine stringers made of special laminated spruce and plywood or oak. These are laid, leveled and tried fore and aft. Rib frames made of oak and plywood are pre-assembled and bolted across the stringers to form the wooden skeleton of our hydroplane. This frame is placed on sawhorses and becomes its own construction jig, or foundation.

The bottom is worked on first. An oak keel is laid with chines (the edge runners) and battens (the bottom planking) bolted to the frame. The transom, the strongest portion of the boat, is covered with metal and fastened in place. The non-trip, sides and sponsons are added, then the entire underside is covered using aircraft type bolts instead of screws. The bottom is -inch thick 5-ply, reinforced, marine-grade plywood using mahogany, with an extra protective Dural plate bonded to the outside. The sponsons and non-trip, formerly planked with plywood, have ?" Dural and the sides are ?" 5-ply mahogany. Aluminum in .90 and .125 thicknesses are sometimes used when the plywood is not available.

The intermediate strut and stuffing box are then connected to the bottom and the prop shaft is inserted through them and into the hull. If spoilers are to be used these are built to the underside then the entire assembly is turned rightside-up so that work on the deck can begin.

The deck frames, made of laminated spruce or of marine plywood, reinforced with white oak, are fastened to either side and over the engine stringers. The fuel tanks are than placed in position followed by oak deck battens which are joined to the frames.

We are now ready for the decking. Carefully selected, knot-free, 5-ply African Mahogany, reinforced marine-grade plywood is screwed into place with great care, sanded, sealed, filled and given a complete final sanding. The entire deck area is then fiberglassed, in many cases, and the edge where the bottom meets the deck is sealed with fiberglass to make the unit water tight.

The hardware is next. The cleat is placed on the bow and engine attachments are inserted, the rudder, water intakes and vents are added. Steel bars are fastened to the frame in the front of the engine compartment and at the back of the cockpit opening on either side so that the boat may be lifted from the trailer to the water and visa versa.

The instrument panel and cowling are positioned, the tail fin is inserted and the engine is put into place and connected. The hull is then painted, final checks are made, she is christened and launched. A new Unlimited Hydroplane is born. From beginning to end it had taken about eight weeks to build.

A trailer must be custom built for the boat. Made of steel, these trailers are sometimes nearly as sophisticated as the boat itself. They must be able to tilt hydraulically from horizontal to about 60 so that they may travel on highways and city streets within the legal limit of width. To tow the trailer is an intermediate size van, the size of a rental truck, which handles the extra equipment. Some of the richer camps have a semi tractor and trailer which contains spare engines, tools and even a machine shop.

(Reprinted from Roostertails Unlimited by Andy Muntz, 1973)

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This page was last revised Thursday, April 01, 2010 .
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Leslie Field, 2000