When the U-95 turbine-powered unlimited hydroplane sank in the north turn of the Sand Point Lake Washington course after scattering one of its two engines during the 1974 running of the Seattle Seafair event, there were those who thought this sounded the death kneel for a turbine-powered hydroplane.
But not Dave Heerensperger.
Heerensperger saw the potential of the idea and in late 1978 when he was ready to return to the sport, he had made up his mind that he wasn’t coming back to the hydro wars without a turbine-powered boat.
“In the first place there wasn’t that much Rolls (Rolls Royce engines) equipment available and Jim (Crew Chief Jim Lucero) wanted the challenge of putting the package together.
“We knew that we needed a single engine installment and when the engine became available there was never any doubt about the direction that we would be taking in getting back into racing,” Heerensperger said.
After a year of research on the engine and its characteristics, Lucero and his team began the process of “putting together the package.” Prior to that Heerensperger had asked for and secured a moratorium from the Unlimited Racing Commission on any rule changes against the turbine power plant for four years from the time the boat ran in its first race.
Putting together the package entailed designing and building a hull and simultaneously acquiring the surplus turbine engines and then rebuilding them to make them race ready.
Design and building of the hull was perhaps the most familiar task to the Lucero team since this newest Pay ‘n Pak would be Lucero’s fourth hull. The power plant for the hull was an area where the team would be breaking new ground, however.
Chosen for the job was the Lycoming T-55 L-7 turbine, an engine that was used in the Chinook helicopters during the Vietnam war. Stan Hanauer, father of Squire Shop driver Chip Hanauer, was hired to be responsible for the detailing and maintenance of the engines. Together, Lucero and Hanauer spent two weeks as the turbine engine school learning about their new engines.
Putting the package together was no easy task. Before any construction could begin the Pak’s shop had to be fitted with the proper equipment, no small chore in itself when you consider that housed within the walls of the Pak shop are a complete machine shop, a fiberglass shop, the engine room and the boat building area.
Outfitting of the shop began during the summer of 1979 while Lucero was still working with the as Van Lines and continued through early 1980 when the last piece of the machine shop was put into place. Construction of the hull actually began in October of 1979 with the crew working simultaneously on finishing the outfitting of the shop.
Although the crew had hoped that the hull would be ready for the first race of 1980, construction and outfitting of the hull, complicated by outfitting of the shop and the building of special tools for the Pak’s turbine engines, took longer than anticipated. It wasn’t until July of 1980, after nearly two weeks of exhaustive round-the-clock work, that the crew dropped the boat into the water for its “maiden voyage”.
The new hull was christened at Stan Sayres pits with the traditional bottle of champagne by Dave’s wife, Jill Heerensperger, and Arlene Walters, wife of driver John Walters, on the Thursday prior to the running of the Tri-Cities, Washington, Columbia Cup. After the short ceremony before almost 3000 unlimited fans, John Walters took the newest ‘Pak out for its shakedown cruise.
Although the boat never went over 125 mph, the initial test runs at Lake Washington were impressive even by the critic’s harshest standards, and by Saturday the boat was in the Tri-Cities, Washington pits to attempt to qualify for the Columbia Cup.
Word of the Pay ‘n Pak’s success spread rapidly to the Tri-Cities area and the new craft caused quite a stir among local race fans. Radio stations in the area were breaking into their regular programming with progress reports on the boat’s trip on the way down from Seattle.
The excitement created in the pit area on the arrival of the new Pay ‘n Pak reminded may old-time observers of the sort of excitement that was generated by the Slo-Mos some 30 years earlier when the thunderboats first came to Seattle.
The boat not only looked fast on the trailer, but Walters and the ‘Pak proceeded to turn in a qualifying lap just a few ticks of the clock shy of 125 mph, which considering it was just the second time the boat had been in the water, was a remarkable feat.
Even with that speed, however, Lucero indicated that the team really didn’t come to the Tri-Cities with the intention of racing.
“We simply want to get some test time in race-like condition. We certainly did not come here with the idea of knocking off the Budweiser, Atlas Van Lines, Circus Circus or the Squire Shop.
“We want John to get some time in the boat and see what will happen running against other boats. If we finish third or fourth that will suit our team just fine,” said Lucero.
But Heerensperger, Lucero, Walters, and the rest of the Pay ‘n Pak team never got a chance to get the boat into competition. In a pre-race test run of the boat with Walters at the controls, the boat flipped in a spectacular 165 mph, one-and-three-quarter loop, that severely damaged the boat, injured Walters, and brought an early end to the 1980 Pay ‘n Pak racing hopes.
Just exactly what caused the accident will probably never be known. But there is evidence to support a theory that the flip was caused by several factors acting together. Any one of these factors acting by itself probably would not have been enough to cause the accident.
One of the factors was the loss of the microphone from Walter’ helmet on Saturday. That happened when Walters and the ‘Pak crew were virtually mobbed by fans and media people on the dock after the first test run. The microphone was inadvertently knocked off his shoulders and into the water.
What that meant was during the Sunday test run, instead of relaying information to Lucero via the radio, Walters had to keep track of all of the systems so that they could be charted when he got back to the pits.
Not a big thing in itself, but just one of those minor distractions that may have caused John to loose track of how fast he was going.
Another factor that should be considered was just the fact that Walters and the rest of the crew had not had much rest getting the boat ready for its first race during the previous two weeks.
“Saturday night I got out of the pits early, had dinner and tried to go to sleep. But I was really excited and really didn’t sleep all that well,” he said.
For Sunday the game plan was to try and run just a little faster than Saturday and one of the things that Walters was doing when the boat got airborne was making his timing run on the starting clock.
Still another factor hat may have contributed to the accident was the failure of the rear wing. It appears that excessive head from the exhaust pipe may have caused the wing to become weakened and then in a stressed state, it failed.
Walters recalls, “I was making a run on the clock to time my start and I had put down a throttle setting of what I thought would give me 150 mph. I check the instruments and tach just like it was a real start.
“About 50 yards before the starting line the boat rattled over the wake of a patrol boat. I looked up and the boat recovered from that easily. I glanced back at the speedometer and I was going faster than I wanted to be – just above 155 mph.
“Then the nose got high and hung up there. I didn’t think it was a problem, but I realized that I was going faster than I wanted to be and I got slightly off the pedal. The boat climbed more, the speed was close to 160 mph, and I was just kinda coasting along.
“The boat pitched up some more, but it still didn’t seem like it was any big problem. Then all of the sudden it seemed like someone kicked a jack stand out from underneath the back of the boat. The bridge disappeared, the horizon disappeared and I tried to bury myself as far back in the cockpit as I could,” he recalled.
The “jack stand” being kicked out from underneath the boat is what many think is the rear wing failing. That wing functions to hold the tail of the boat up; and in doing so keep the nose down. When the wing failed at such a high speed there was only one thing that was going to happen – and it did spectacularly!
It was a long fall and winter for Walters and the Pay ‘n Pak team as they regrouped to put the ‘Pak back together. Walters broke his hip in the accident and had multiple minor injuries.
The boat broke the right sponson as well as stripping the deck of the cowl, uprights and horizontal stabilizer. The crew stripped the boat of the deck before repairs begin to ascertain whether there was any other damage to the hull.
“Surprising enough, the boat came through the accident quite well. There was some minor damage to the superstructure, but with the exception of the sponson the integrity of the hull remained pretty much intact.
“We beefed up several sections of the hull and made some other minor modifications to the hull, but other than that the boat is pretty much like it ran at Pasco,” Lucero said.
“Modifications that were made to the ‘Pak include a set of wings in front of the boat. It was hoped that these wings would allow adjustment to be made in the riding attitude of the boat at high speeds. Although they were taken off the boat during testing prior to the season, Lucero said there was a chance that they might return to the hull later in the season.
Pre-season testing has been extensive for the Pay ‘n Pak as the team has patiently worked the bugs out of the hull and engine, trying not to go too fast too quick.
“Working under the pressures that we were last summer, I think that one of the things that led to the accident was that we went too fast too quickly. Testing during the winder has allowed us the luxury that we didn’t have last summer time,” Lucero said.
And whether or not the Pay ‘n Pak is a winner – only time will tell and as Lucero notes, “That’s why we go racing.”
Nevertheless, there are still those who are skeptical about the use of a turbine engine in an unlimited hydroplane and while Lucero and the rest of the ‘Pak crew are quite certain that there is enough power in the turbine (the L-7 is rated at 2650 hp) to make the boat a contender, there are some questions that Lucero thinks will only be answered through running the boat in competition.
“We are concerned about the reaction of the boat to being hosed down. Quite frankly we are not sure what is going to happen if John has to drive through a roostertail.
"The air intake is designed so that any water that might be taken in must go through three 90-degree turns to get to the motor, so it shouldn’t be a problem. But there is always the chance that we might take in more water than the system was engineered for and in that case it is conceivable that we could break a blade on the turbine - which probably would cause us to scatter a motor and could lead to the same kind of problems that the U-95 had,” he said.
Another worry of Lucero’s is the possibility of “foreign object damage.” That is the sucking into the turbine of something other than air or even a little water.
“The turbine is much more sensitive to balance and if we had that kind of problem there is again a chance for serious damage to the engine and boat,” Lucero said.
However, even with all of those worries face fans should remember that the T-55 turbine that the Pay ‘n Pak is running has some 3.3 million hours of airborne experience (if you will pardon the phrase), many of those under combat conditions.
And there are some other factors which make the turbine power plant a very enticing proposition for an unlimited hydroplane.
Like power-to-weight radio. The turbine will weigh about 500 pounds less than the Rolls or Allison engines which are being turned at rpm’s that are almost double that for which they were originally designed.
The turbine engine on the other hand was designed to be turned at between 15,000-16,000 rpm’s and then geared down, so it will be operating under normal factory specifications, even when the boat is performing at top speed – of about 170 mph.
And this is perhaps one of the best things about the engine, in terms of long term operating costs, the engine should require a great deal less maintenance, last longer, and in the long run make the cost of racing less expensive.
In fact if there is one thing that has drawn Heerensperger to the engine, it is the fact that it is not only a proven power plant, but in comparison to a reciprocating piston engine they are a great deal more simple and more efficient.
The gas turbine, as a generic engine, has been around since 1791 when John Barber proposed and patented the first one. However, it has only been within recent years that the gas turbine has attained a state of development as a power plant where it has become practical as a primary power source.
During the years between 1792 and 1950 many scientists attempted to refine gas turbine principles with little or no success. The idea of obtaining continuous rotary motion directly from a combustible mixture without utilization of a steam boiler or reciprocating mechanism was always intriguing, but one that defied practical realization.
To really understand the way a turbine works, one has only to understand Newton’s third law of motion which states, “For every action, there is an equal and opposite reaction.”
Picture a garden hose without a nozzle. Water at normal hose pressure flows freely from the open end of the hose. Attach a nozzle, preset the nozzle to spray at the greatest distance possible and turn on the water. The reaction of the water flowing through the nozzle can be felt as a force at the nozzle in a direction opposite to the water flow.
If you’ve ever been squirted by your own garden hose when you have turned it on with an open nozzle, you have directly experienced Newton’s third law of motion.
In thinking about the above model there are three stages to keep in mind: First the system is charged, in this case by turning the faucet. Second, the gas in the system (and in this case our gas is water) is compressed. This is done by keeping the hose nozzle closed. Third, the nozzle is opened to release the pressure, and there is a reaction in the opposite direction of the water.
With the turbine that drives the Pay ‘n Pak there are basically the same three stages.
When the engine is started, it is started much like a car engine in that a battery-run starter is used to initially spin the compressor.
Like turning on the faucet, the compressor sucks in air and compresses it to approximately 100 pounds per square inch, or roughly seven times normal. When the boat is running, the two scoops that are adjacent to the driver’s compartment assist the compressor in sucking air into the engine. Remember, the faster you want to turn the engine, the more air that is going to be required.
The compressed air could be used by itself to power a turbine wheel, but to make the system more efficient, the compressed air is combined with fuel and ignited. The product of this combustion is a gas under significantly higher pressure than before combustion. At this point, like our hose whose nozzle has not been opened, we have a pressured system.
Remember in the turbine engine there is no nozzle to open. The escaping gas is directed through a series of three power wheels or turbines. The first of these three wheels drives the compressor so that the battery can be disconnected. The second and third power wheels provide the power to turn the propeller.
The greatest difference between the turbine engine and the reciprocating engine is that the piston powered engine takes up and down motion and turns it into circular motion, while the turbine engine simply generates circular motion. This in itself is one of the chief reasons that the turbine is a comparatively more efficient engine.
The efficiency and simplicity of the turbine are the things which lead the aircraft industry to use it. It has been proven over and over again as a power plane for helicopters and airplanes.
And if things go according to plan, it will be proven as a power plant for a hydroplane in 1981.