Photos courtesy of the Jensen Motorboat Company
The Jensen Motorboat Company Vessels:
Beginning with the1922 Tony Boy, and concluding in the late 1950s with a mix of military vessels and a “pickle fork” experimental hydroplane for the Boeing Company, the Jensen Motor Boat Company built over 200 vessels. While that number may seem small, it is a substantial output of custom one off wooden boats. Reflective of the company name, the majority of the vessels were motor boats ranging from 30’ upward. While most of the vessels built by the yard were cruising boats, from the beginning there were runabouts and/or speedboats. And it was from fast boats that the yard gained it’s greatest fame.
Jensen family boating really began in 1901 with Tony Jensen's purchase of the Hipp, one of the first motorized pleasure boats in Seattle. Hipp was followed by several others as Tony gravitated toward the emerging sport of boat racing. In 1911 his efforts paid off with the winning of the “Potlach” motorboat race, a SeaFair-Gold Cup race predecessor. By the late 1920s, Tony had designed and raced two 505 class boats, the SAR (Seattle Auto Rebuild) and the Waterdog with notable success. His son, Anchor, began racing as a teenager on Seattle’s Green Lake, learning from his father how to hotrod engines. Yet father and son would never have dreamed that one day they would build the world’s fastest boat!
Tony knew that boat yard bills are paid by pleasure craft, not race boats. He had “backed” into professional boat building when people admired his 42’ Tony Boy, an Ed Monk/Tony Jensen designed craft he built in the backyard of his Victoria, B.C. home. Upon moving to Seattle in 1923, his Tony Boy cruiser so impressed Seattle boaters that he soon found himself struggling to build more cruisers in his spare time.
Working in the old Miller Aircraft buildings near Seattle’s Green Lake, Tony and crew trucked their finished products down to Lake Union for launching. One boat project led to the next until Tony bit the bullet and purchased 100’ of property on the Portage Bay arm of Lake Union in 1926. A year later, with the help of architect Harold Iversen, Tony had designed and built a marine railway and an enclosed boatyard complete with a family apartment.
The new Jensen Motorboat Company, strengthen by partnership investments, soon employed up to 35 men building and repairing boats. A steady stream of Jensen built boats slid down the railway until the Depression years squeezed down the money. Even then, building to the designs of Ed Monk, Ralph Hugg, Frank Strickland as well as Tony, Anchor and George Jensen. the yard remained remarkably busy. In 1932, they built what was to be their largest craft, the 80’ Cadrew. They also built a few sailboats, including the beautiful 55’ staysail schooner Vavachi, designed by University of Washington professor Charles Harris, owner and builder of the innovative 1920 motor cruiser Scamper, a vessel featured in Wooden Boat number103. Reportedly, Vavachi is still sailing somewhere on the East Coast.
Tony’s older son George came into his own as a designer and illustrator during the early 1930s. George worked with Anchor and his father on the conceptual design of several motor cruisers, the most important of which was the art deco 38’ Meteor. One of the most interesting boats built by the yard, it was a product of George Jensen’s styling, Anchor’s under water design and Tony Jensen’s impressive wood working skills. The streamlined Meteor turned heads in 1938 as she still does under the current owner, glass sculpture guru Dale Chihuly. The “streamlined” Meteor was cutting edge boat design in 1938 for she had hardly a straight line and absolutely no sharp corners. Just as important, she was designed to go fast, hitting 25 knots with her original twin 152 hp Chrysler Crown engines. At some point in the boat’s long life, Anchor added a “wing” or large trim tab to the stern to aid in lifting her up on a plane. Drafted during WWII by the Navy, her brightwork painted grey, Meteor spent the duration zipping about Puget Sound delivering officers to their ships.
During the Prohibition years, the line between Jensen runabouts and race boats thinned. Big money came to the yard (actually to all the Seattle yards) to buy top speeds. Ralph Hugg, a Jensen foreman, designed and built an especially fast “runabout,” the Falcon. Anchor was known to take Falcon up to Canada (100 plus miles) for one day “fishing” trips. The 50 mph Falcon was powered by a Curtiss Wright airplane engine, a foreshadowing of the marriage between wood and aviation engines that was to mark the Jensen yard.
The R-77-2, a handsome Ed Monk designed 38’ twin diesel was delivered to it’s Idaho owner in 1939 by Anchor, who towed it across-state behind his father’s 1929 V-12 Cadillac!
World War II brought a steady stream of military contracts to the Jensens. They built many MT-325s - 36’ tunnel hull tow boats used by all the services. And the war years builtup a desire (and the money) for new pleasure craft. In1945, working around military projects, the Jensens produced the 42’ Miss Boise, with a hull design by Ed Monk and the cabin top and interior by the boatyard crew.
John Graham Sr., a prominent Seattle architect and serious boater, ordered the 62’ Pelagic built by the Jensens in 1946. Graham, who had owned many boats prior to the war, was so pleased with Pelagic that he never again bought another boat. Rather, he single and double handed Pelagic all up and down the West Coast through his retirement years.
The Slo Mo Shun era:
Stanley Sayres loved speed and the racing of fast vehicles above all else. A successful Seattle automobile dealer, he began hot rodding and racing cars during the 1920s, until a disgusted driver sold him a outboard racing motorboat in 1926. From then on, Sayres was an obsessed speedboater. Soon he was having lunch with Harry Jensen, a Seattle man who also loved fast boats. At Jensen's urging Sayres purchased a Hacker runabout to race against Jensen’s MISS LIBERTY, a Bearcat speedboat powered by a Liberty V-12 aircraft engine. Both men kept their speedboats at the Jensen Motorboat Company on Seattle’s Lake Union and it was there that Sayres became friends with Harry’s young nephew, Anchor Jensen.
When his Hacker SLOMOSHUN burned and sank in 1941, Sayres purchased a very fast Ventnor three-point hydroplane, the 225 cc race boat TOPS III and thereby entered the cutting edge of raceboat technology. That boat, renamed the SLOMOSHUN II, had been designed by Adolph Apel, the chief designer for Ventnor, the boat building company that pioneered three-point hydroplanes in the early 1930s. Responding to an order from the Chinese government for fast “suicide” boats to use against the invading Japanese, Ventnor designed a fast boat with a heavy explosive charge built into the bow. The prototype boat proved so nose-heavy it would not climb up on plane. Since Ventnor manufactured waterskis, Apel hit on the idea of placing one big water ski on each side of the bow. The concept worked, and Apel further developed the idea into a permanent double-bow structure that he called “sponsons.” The three-point "hydroplane"—named for its ability to take near flight while contacting the water at each sponson and a small bit of the stern—had been born. Ventnor patented the three point design in 1935 and went on to build a number of successful race boats prior to World War II.
SOMOSHUN II suffered damage during transport to Seattle and when Sayres asked Anchor Jensen to repair it, the busy Jensen suggested that Sayres contact Ted Jones, an established Seattle race boat builder. So began the relationship that was to give birth to the world’s fastest boat.
Throughout the war years, SLOMOSHUN II’s speed and handling fermented in Sayres’s mind. In 1947, looking toward an even faster boat, he and Ted Jones began to plan a hydroplane based on Jones’ previous designs. Jones had been building boats since the late 1920s including fast sponson three point style race boats reflective of the Ventnor designs. Jones agreed to build a competitive new three-point “shovel nose” 225cc-class hydroplane to be named SLOMOSHUN III. Unfortunately, Jones’ job at Boeing Aircraft Company testing aircraft engines held his production to a crawl. Frustrated, Sayres talked a reluctant Anchor Jensen into finishing the boat at the Jensen Motorboat Company. While Jensen finished the construction, he was critical of the overall design. His concerns were confirmed when the boat came out heavy, slow, and in Sayres words, “wild as a March hare.” There were rumors in the Seattle racing boat world that the boat was capable of over 90 mph, but that was never proven. After some disappointing runs, Sayres sold the boat.
Sayres had begun to dream of something big, something like setting the world speed record, or winning the Gold Cup’s Unlimited class. He told Jensen and Jones that he wanted a boat that would “win the Gold Cup, the Harmsworth, and beat Campbell’s mile record, with a budget of 12,000 dollars.” With that charge, and despite Sayres’ disappointment with Jones’ SLOMOSHUN III, the three men began working on concepts for a new Unlimited class hydroplane. They were very interested in “prop riding” boats, an idea going back to the early 1940s when Chauncy Hamlin published an article in Motor Boating magazine speculating on the increased speed and reduced drag of a hull that lifted completely out of the water.
Each man had strong opinions about the optimum design, opinions that often clashed. But they agreed that the new boat should be a three point prop riding craft utilizing a straight forward gearbox-drive train system. While no written contract was signed, they agreed orally that Jones would provide the plans and work closely with Anchor who would build the boat while Sayres would supply the money and make all the final decisions. Word of their intentions somehow reached the Ventnor Company in late 1948 prompting a telephone call to Anchor threatening a lawsuit over the three point design. Only when Sayres’ lawyers convinced Ventnor that they were not developing a production boat did the law suit wither away.
By 1950, their collaboration brought forth the SLO MO SHUN IV, soon be the fastest powerboat of her day. The hull was built on the three-point hydroplane concept but refined it so that the boat’s “flight” would lift the stern completely out of the water, leaving the boat to ride only on the sponsons and its surface-piercing propeller—the source of the famous Unlimited racing boats’ “rooster tail.”
Although much of the new boat’s design was original, much was borrowed from the rich mix of engines and hull shapes that had been bubbling in racing circles during the post World War II years. Variations on the Ventnor three-point hydroplane had proliferated. In 1946, GOLDEN GATE III was the first three-pointer built around the famous Allison aircraft engine. GOLDEN GATE III’s engine had been taken from a surplus P-38 fighter purchased for $1,800 complete with a tank of gas! The boat proved very fast but also very difficult to turn. Another influential boat of the period was the SUCH CRUST. She, too was powered by an Allison and had an overall design that foreshadowed SLO MO SHUN IV.
DeWitt Jensen, Anchor’s son and the Jensen yard’s current owner, says that his father had been especially impressed by one of the first propeller-riding Unlimiteds, the HURRICANE IV. That boat, designed and owned by Morlan Visel of California, was launched in 1948. She raced that year in the Gold Cup in Detroit, where Jensen had a chance to examine her closely. She, too, was powered by an Allison, and her hull shape was reminiscent of today’s tunnel-stern boats. She displaced a very light 4,600 lbs. DeWitt says his father was so fascinated by HURRICANE IV that he later traveled alone to California to inspect it again, undoubtedly bringing back ideas for the design of the SLO MO SHUN IV.
The Seattle group’s technical challenge for the fourth SLO MO SHUN can be seen as fivefold: First, build a hull able to withstand the punishment of high speeds. Racing powerboat experimentation wasn’t always successful, and race boat hulls routinely flew apart at speed, especially when the water was rough. Second, design a three-point, propeller-riding hydroplane competitive around the oval Gold Cup courses. Third, create an aerodynamic topside form that contributed to high-speed stability. Fourth, incorporate a V-shaped step between the sponsons to break the airflow and reduce the bow’s tendency to lift—an application on SLO MO SHUN IV that “Wild Bill” Cantrell, a top driver and builder of the day, considered it’s most important breakthrough. Fifth, make the boat as mechanically sound as possible, keeping in mind that Allison engine drivetrains had proven especially troublesome.
The original verbal agreement called for Jones to supply the plans which turned out to be simple hull sketch with some offsets, so Jensen took on the task of drawing up the construction blueprints. Jensen and Jones collaborated—and clashed—over many design details. In Jensen’s words, they had “. . . nothing to guide us except to look at what was running (other three-point hydros) and their good and bad points.” They had no stress data for speeds over 100 mph. Since the boat was intended to reach speeds as high as 200 mph, they were beyond even the cutting edge in design and construction.
Anchor Jensen, who later stated that the boat’s success stemmed primarily from the surface-riding propeller design, worked through several prototypes to get what he called the “negative angle of attack” needed to keep the propeller in the water and the bow from flying up. He knew that the design concept demanded that the boat be as light as possible. His natural engineering sense, bolstered by engineering course work at the University of Washington in Seattle, together with his mastery of wood construction, produced a “model airplane” basic structure —that is, a delicate, lightweight, but strong wooden cage sheathed with very thin mahogany plywood. Jensen recognized that the Allison engine block could be used to stiffen the boat’s structure, allowing a lightweight hull to be built around it.
The boat lofted out at 28’6” overall with an 11’ 4” beam across the sponson spoon bow, a beam considerably wider than that of the boat’s competitors. Hull weight was approximately 4,600 lbs in racing condition—very light when compared, for example, with MISS PEPSI, a twin-engined boat then racing on the Unlimited circuit that weighed five tons. Jensen also understood that the hull needed flexibility to survive the stress of 150 mph plus speed. He considered building with aluminum, but decided to stick with what he knew best—wood.
In 1951 Anchor wrote, “Every item was carefully weighed for its usefulness and then planned for strength and lightness. The major factors to cope with in keeping a hull together are fatigue, vibration, and localized stresses. A flexible hull using deep, stiff side panels 1/2” thick and 27” high, frames 7/8” x 3” deep, battens 7/8” x 1-1/4”, and solid engine beds 1-1/4” x 14” form the backbone. All members are piled on to each other instead of the split-starting conventional notching for battens, etc. Faying surfaces were glued and bolted and all joints were scarfed and glued. All joints that were deemed necessary to work are soft-glued and those not expected to do so are hard-glued.
“The motor—the largest concentrated load—is distributed forward and aft through the engine beds and athwartships direct to the sponsons with deep dural and plywood formers. Oak, which is our best available wood, was used exclusively where strength, good fastening, and flexibility were needed. (Frames, battens, chines, etc.) Spruce, a lightweight, tough wood, was used for engine beds and deckbeams. Tanguile mahogany, a lightweight long-fiber wood, was laid up in five plies at 45° from center line—alternate—to form the 1/2” plywood for bottom and sides. The decking is 3/16” Tanguile mahogany with 5/8”-square oak fore-and-aft battens on 6” centers.... Decking is glued and nailed with Anchorfast Monel nails. All plywood was glued with resin on the hot press.”
The SLO MO SHUN IV team knew of the Liberty V-12 airplane engines that powered Gar Wood’s 1920s race boats (as many as four per hull), as well as the contemporary hopped-up marine racing engines. But Jensen lobbied hard for using an Allison in the new boat. Allisons had powered the fastest aircraft of World War II and were lightweight wonders, displacing 1,710 cu in. Each of the 12 cylinders had two spark plugs and four valves activated by overhead cams. A powerful supercharger required 450 hp to crank but provided the air pressure needed for high-elevation flight. At sea level, the supercharger produced 2,300 hp. The Jensens were impressed by the 1,400-lb Allisons—impressed enough that they went into partnership with Sayres and Harry Jensen to purchase 500 of the engines at a surplus price of $330 each. With the Allison placed in the hull, the SLO MO SHUN IV, fully outfitted and fueled up, came out with an hp-to-weight ratio of 2.5:1—that is, 2-1/2 hp per pound.
They knew the boat was super powerful, but would she be controllable at high speeds? And would she be competitive around the two to three mile Unlimited courses? The Allisons had no gear system, so one had to be configured that would be lighter and more reliable than those running—and failing—at the time. Working with Western Gear in Seattle, Jensen designed a lightweight step-up gear that turned the propeller three times faster than the engine’s rpm rate. At, say, 3,200 engine rpm, the propeller would turn at more than 11,000 rpm. Jensen worked through prototypes of the gear shapes. He also worked with H.I. Johnson of California on propeller design. After several prototypes, they settled on a 14”-diameter propeller with a 25” pitch for straight-ahead speed runs and a 13”-diameter, 23” pitch model for around-the-oval Unlimited racing. Lacking a clutch, the boat jumped to 40 mph immediately after starting the engine. At speed, SLO MO SHUN IV rode with just 4” of each sponson on the water. The stern lifted 8” above the water with only the lower half of the surface-piercing propeller in the water. This hydroplane truly flew!
Having solved speed issues, the remaining challenge was that of control. The team tested a single rudder amidships, then tried a dual rudder setup, then finally settled on a single rudder offset to starboard. A small, fixed blade to port, called a skid fin, aided the left turns around the Unlimited courses. The team knew that oval racing placed tremendous stress on a rudder. In response, an aircraft-style tail fin—the first of several design shapes—was added behind the cockpit and eventually fitted with a trim tab to utilize air pressure in reducing stress on the rudder. The boat originally did not have such a fin, but the stability advantage of having one soon became apparent. The fin concept harked back once again to the early Ventnor speedboats.
The boat hit the water in October 1949. After a few months of testing and refining, she was ready. With Sayres driving, SLO MO SHUN IV set a world record of 160 mph in June of 1950, eclipsing the 10-year-old world record set by Sir Malcolm Campbell’s BLUEBIRD II (see WB Nos. 154-155) by nearly 20 mph.
Within the small world of hydroplane history, controversy exists over who actually designed the breakthrough SLO MO SHUN IV. Hot words have flown between the Jensen-Sayres camp and that of the Jones family. After splitting with the Sayres team in 1951, Jones went on to design and build a number of successful Unlimited race boats. No doubt he applied all that he learned during the SLO MO SHUN IV development to his subsequent winning designs, most successfully to the MISS THRIFTWAY, a boat that compiled 14 major wins between 1960 and 1963. Before exiting the hydroplane world suddenly in the late 1960s, Jones was “the man” when it came to fast Unlimited design. Unfortunately, his heady success may have caused him to elaborate and embellish his role within the SLO MO SHUN IV group. Oddly enough, despite all of his post SLOMOSHUN winning designs, he often talked the most about the breakthrough aspects of his first Unlimited design.
Jones was quoted by Weldon Johnson in the 1980 Spirit of Detroit Regatta Program as saying, "It became important for a lot of people to take credit for the MO. But I'd like it known that I designed it and that I had many, many firsts with it—things that had never been used in a raceboat before. Almost everything was entirely different from any other boat. And I'd like to have credit for doing those things."
However, Donald Peterson, in the introduction to his self-published book, SLO-MO-SHUN: The Sayres Legacy, presents a different view. “I believe what happened to Ted was, after years of feeling like a nobody, he was suddenly thrust into the spotlight. Over night he was touted as the ‘premier boat designer’ in the U.S. Bear in mind, Jones was not employed in the boating business in any capacity at the time. Jones had some training in blueprints, but this he might have learned on his own. Ted did not possess an engineering degree, nor did he ever attend college. Thus, when he was thrust in with the Jensens, there was much animosity. In addition, Jones had a large ego, which added fuel to the fire. What Sayres saw in Jones was a talented person that had some very innovative ideas. Sayres realized that Jones could not match the Jensens in boat building craftsmanship. In fact, few could. They were perfectionists. When Jones was talking theory, the Jensens were thinking practicability. This caused the clash of ideas continually.”And it might be said, that this very “clashing” of ideas may also have produced a most successful synergy.
Among Jones’s more questionable public claims over the years were the following:
• That he alone designed the SLO MO SHUN IV. This was refuted by Sayres and Jensen, who possessed the lofted plans, the blueprints, and even a patent for the steering system. Jones never made any public showing of any plans for the boat. Rather, he tried to get Anchor to give him blueprints. Jones did make the original “sketch” of the boat and that may well qualify as the design. The reality seems to be that the design was a collaboration with most of the “raceboat” knowledge coming from Jones.
• That he had steered the boat leaning over from the mechanic’s seat during Sayres’s first world-record speed run.
• That he had run the boat to more than 200 mph numerous times.
• That the Jensens had partially plugged the fuel line prior to the first world speed record run and that Harry Jensen had crossed the path of the SLOMOSHUN IV during the speed run in order to create a dangerous wake wave.
• That he had invented the three-point hydroplane hull during the 1930s. He had built boats during the 1930s that incorporated primitive three-point hulls similar to the Ventnor designs. He once stated about those early boats: “After rebuilding these sponsons some twenty times, I had a fairly fast boat that turned pretty well. It was a few miles faster than a conventional hydro of comparative horsepower.”
• That Sayres paid him nothing for his work on the SLO MO SHUN IV.
• That he had unwittingly signed a contract under pressure from Sayres promising never to build a boat for anyone else and never to divulge the lines of the SLO MO SHUN IV and is successor, SLO MO SHUN V, to anyone. In truth, Jones had requested such a contract from Sayres, signing it the day before the 1950 Gold Cup. Before ending the contract, he served as a consultant with several race boat projects, contributing unknown information to their design.
Anchor Jensen, in response, never claimed that he had designed SLO MO SHUN IV or V, always stating that it was a joint development by the three men with critical input from all. Sayres, the man in the middle and once a great supporter of Jones, became most irritated by Jones’s public statements and in several written documents tried to set the record straight.
Sayres reported in a letter that he had placed Jones on the Jensen payroll during the development of the SLO MO SHUN V, with Sayres paying Jones the equivalent of his Boeing salary so that he could devote full time to the new boat. In the end, Sayres reported that he also paid Jones $3,000 for his work on the IV and $5,000 for work on the V.
And starting in 1951, Sayres wrote, Jones “took credit for everything and became very antagonistic to Anchor.” Later, Sayres wrote, “The only reason I continue to refer to Ted as the designer is as a concession to his ego.” And finally, “It is a matter of sincere regret to me that a man of whom I once thought very highly and with whom I dealt most liberally and whose standing and reputation I promoted to the best of my ability—should gradually decide that I am a most reprehensible person.”
Unfortunately, the old adage that if you say something long enough and loud enough, people will believe it, has proven true for Jones’s claims about SLO MO SHUN IV. Much has been written—and much continues to reside on the Internet reflecting Jones’s claims, the breadth and detail of which expanded as he grew older. There is a long diatribe on the website: www.lesliefield.com/personalities where Jones makes a number of remarkable claims. The lingering controversy is regrettable, given the results of what they produced. It’s quite possible that their success came because of the tension, rather than in spite of it. What is important is their breakthrough boat, not the subsequent squabbling, for the SLO MO SHUN IV remains a shining star in the Northwest boat building world.
A month after setting the 160-mph record, SLO MO SHUN IV, now considered the fastest in the world, showed up for the 1950 Gold Cup races in Detroit, with Jones driving. She won, but only after the quick-turning MY SWEETIE, driven by Lou Fageol, broke down in the last heat. Still, SLO MO SHUN IV had set a new Detroit speed record of 78 mph around the three-mile oval course, thereby deflating the race world “buzz” that the Seattle boat was slow in the turns. Later that summer, the boat won the International Harmsworth Cup in Toronto, setting a new lap course record of 102 mph and becoming the first boat to ever run a full race heat averaging 100 mph or more. The boat’s success created a whirlwind of new construction through the Unlimited racing world. SLO MO SHUN IV had so completely eclipsed other designs that everyone scrambled to copy her. That was a heady year for Sayres, Jones, Jensen, and the citizens of Seattle who had no other "pro" sports at that time. Having won the Gold Cup, Sayres arranged to defend it during the new Seattle SeaFair celebration the next summer, 1951.
During that 1951 Seattle Gold Cup race, SLO MO SHUN IV finished third, with Jones at the wheel for the last time. The race’s winner was IV’s newly hatched sister, SLO MO SHUN V. Driven by Lou Fageol, the new boat set a three-mile lap record of 108 mph, a huge jump over the existing 86 mph Gold Cup lap record.
The inspiration for SLO MO SHUN V began not long after SLO MO SHUN IV was launched. The Sayres group began speculating about an even better Gold Cup boat. SLO MO SHUN IV, designed to set a new world speed record, was not especially fast through curves and Jones believed that he could design a boat faster on the straightaways and better in the curves. The new design and construction became yet another source of friction between Jensen and Jones.
“SLO MO SHUN V,” DeWitt Jensen has written, “was designed by Ted Jones and Anchor Jensen. Ted supplied some new sponson sketches on a piece of 8” x 10” paper as his ‘design’ of the boat. The boat was lofted by Anchor. The difference from the IV was that the V had a tunnel/air trap 6” wider and the sponsons were more pointy, not as flat at the ends—a sponson design that Ted insisted on and Anchor strongly disagreed with. This resulted in a hunting-porpoising or hooking effect such that the boat was very unstable over 120 to 125 mph. After the first race, Anchor had to reshape the sponsons somewhat, which improved the ride up to around 145 mph, where it became unstable again. When Lou Fageol refused to drive the boat for the 1953 season (because he thought that it was too dangerous) the sponsons were completely redesigned and rebuilt by Anchor Jensen. The riding characteristics improved such that the boat didn’t become unstable until it reached 165 mph. Note that the SLO MO SHUN IV became more stable, it seemed, the faster it would go.” Jones was hired to lead the secret construction of the SLO MO SHUN V in Jensen’s upstairs loft, but after his progress proved slow, Sayres placed Anchor in charge with only 28 days before race day. Miraculously, Jensen and his crew did the job, and the boat raced on schedule in June 1951.
SLO MO SHUN V went on to win the Gold Cup in 1954 after being repowered with a Rolls Royce Merlin V-12 engine instead of her original Allison. The following year, with Lou Fageol driving, her stability issues contributed to a spectacular flip. “Obviously,” one newspaper reported, “he (Fageol) was determined to beat the 117.91-mph trial record set Wednesday by SLO-MO IV. But Fageol boiled the SLO-MO V toward the turn. In an amazing twinkling, the boat shot into the air. Her 28’ of length veered vertically 10’ or more above the water. She twisted in a ghastly way, did an outside loop and came down on Lake Washington right side up and continued slowly on course for 50 yards before she stopped and started to sink. Somewhere in the gyration, about 20’ up, Fageol slipped from her cockpit.” Fageol never raced boats again. Sayres sold the wrecked boat to a group that rebuilt and raced her, with mediocre results, as the MISS SEATTLE.
SLO MO SHUN IV, meanwhile, was hardly ready for retirement. In May 1952, Sayres took her out to set a world speed record of 178.497 mph with one run of 185 mph. She was on a roll. She won the Gold Cup after all the other competitors, including SLO MO SHUN V, dropped out with mechanical problems. She won again in 1953 when, once again, SLO MO SHUN V withdrew with mechanical issues.
SLO MO SHUN V was not as fast as IV. Even after her Rolls Royce Merlin with an improved supercharger and several other modifications by Jensen were installed, the boat never exceeded SLO MO SHUN IV’s top speeds. However, V came out of turns much faster than IV and got back up to speed faster than any contemporary Unlimited hydroplane. Jones’ changes in widening SLO MO SHUN V’s sponson design had succeeded in making a faster race-course boat.
Having won the Gold Cup race three times and upped the world water speed record twice, SLO MO SHUN IV could have been retired triumphantly. Instead, she continued to race in Unlimited events, although she began to fall behind new boats built to improved versions of her design. In fact, the basic SLO MO SHUN IV and V design dominated Unlimited racing for the next decade, fading only after the introduction of turbine engines necessitated new hull shapes. Finally, in a qualifying round for the 1956 Detroit Gold Cup, SLO MO SHUN IV hit some big wakes, did a nosedive, and sank. She was raised and returned to Seattle, but she never raced again. Sayres, whose health was declining, died in his sleep just 12 days after the demise of his beloved boat.
Yet the dance between Jones and Jensen was not over. While the Jensen yard never again built a complete hydroplane, it did repair and modify several others over a six-year period. In 1957, Edgar Kaiser brought Jensen his HAWAII-KAI, describing it as a “dog.” Designed and built by Jones, the boat had not performed up to expectations, in large part due its heavy displacement. After being almost completely rebuilt under Jensen’s direction, the boat shed 2,000 lbs and went on to win the national championship.
That same year the Jensen yard rebuilt the hydroplane CORAL REEF into a new configuration named MISS ROCKET. By 1959, the yard had completed a rebuild of the MISS BARDAHL as well as restoring the SLO MO SHUN V for display in Seattle’s Museum of History and Industry. The yard’s final race boat project consisted of Anchor Jensen’s sponson designs for a top-secret boat powered by a Boeing turbine. Unknowingly, Jensen was once again on the cutting edge, contributing to naval architect Phil Spaulding’s “pickle fork” design, one that became the prototype for today’s turbine-powered, Unlimited-class hydroplanes.
With that project completed, the yard’s run at the top of the speedboat world came to an end, much to the relief of Tony Jensen. Tony had grown testy with Sayres and all things hydroplane, frustrated by the time and manpower demands and tired of the round-the-clock noise outside his boatyard apartment. Tony had lived in the apartment since establishing the boat yard on Portage Bay in 1926. Anchor would live there until his death in 2000.
Tony may have complained about the hydroplanes, but even he probably mused over what an improbable exciting run the SLO MO SHUNS had provided. Considering that a humble wooden boat yard had produced two of the fastest boats in the world using pencils, paper, wood and ingenuity, produced hydroplanes that were as much figured out as they were engineered, makes the whole adventure even more improbable. Considering the CAD programs used by today’s designers in determining stress, materials, speed and shape, what Anchor, Jones, and Sayres accomplished was truly remarkable. They had successfully placed a hugely powerful engine in a very light wooden hull configured to take racing stresses far greater than any previous boat had ever endured. Today, the 75 year old Jensen yard remains a busy boat repair shop. But fifty years ago, it harbored the cutting edge in wooden boat design and construction.
For more about the SLO MO SHUNS, Ted Jones, and the hydroplane racing world, see <www.slomoshun.com>, a web site maintained by Jensen’s Motor Boat Works, or read Donald Peterson’s book: “SLO-MO SHUN: The Sayres Legacy.” Searching on the web will bring up several sites with information about hydroplane racing, including many quotes from Ted Jones about his involvement with the SLO MO SHUN boats.
