1995. B 28 Bat-Boat, the racing bolide

Welcome to the special section “BAM 35 Years.” We are presenting “cult” articles from the Motor Boats archive, starting in 1990. A journey through time among stories unobtainable today, even in the great sea of the internet! A dive into the world of epic moments in motor boating. We begin with one of the stories we were most passionate about.

Bat-Boat

From Motor Boats 1995, no.1, February, pp. 34-35.

Two wings to fly, an engine to speed, Speed Rails to glide: this is the B-28, Ocke Menerfelt’s racing bolide. Three elements make this creature revolutionary: the “stepped” hull design, aluminum profiles from Volvo Penta placed longitudinally on the hull, and, impossible to ignore, two large Formula 1 wings. It is called Bat-Boat because it looks awfully like the speedboat of Batman, the comic book hero. Also… it does 100 knots!

It looks like something out of a Batman comic book the latest creature from Swedish firm Ocke Mannerfelt, which has been designing high-speed boats since 1989. The result is jaw-dropping. In fact, the B-28 Sport has features that are absolutely out of the ordinary. Starting with the very high-performance hull, which is equipped with Volvo Penta ‘s revolutionary Speed Rails. This is a new type of aluminum profile that is applied longitudinally on the hull and is in addition to the normal support rails cut into the hull molding. The pilot confided to us that, thanks to the Speed Rails, the B-28 increases its speed by two knots. In addition, the hull has an ‘original structure with three steps, created by visible grooves in the profile that further improve performance. But the most original detail comes from the two rear wings, hence the resemblance to Batman‘s boat, which give it a Mephistophelean air and still serve as stabilizers at high speeds. We were lucky enough to try it out at the Genoa Boat Show. Armed with helmets and life jackets, curious but trepidatious, we went out on a frigid northerly day without a ray of sunshine and with swell seas. “Ready? Fasten your seat belts.” The pilot told us in perfect English with a slight Swedish inflection, looking as cold as the day. Fast, very fast: the bolide flew at 60 kilometers per hour. It reached glide speed with impressive agility thanks to the aerodynamic line of the hull increasing lift.

Calculating the speed with the help of a VPP (Velocity Prediction Program ) computer program, the results showed that the B-28 actually proves to be about 24 percent faster than conventional monohull vessels of the same size. The designers also claimed a 35% drop in fuel consumption. We tested the B-28 Sport, the cruising version that even offers two unsuspected berths below deck; behind the driver’s seat is a C-shaped rear settee for the crew, while the cockpit is equipped with racing seats, half-roof and windshield made of Lexan, a special high-strength material. There is also a Racing version on which the beds and the rigid wraparound structure protecting the cockpit disappear: the boat is transformed into a racing monster for offshore classes II, 4 and 6 liters.

The shipyard suggests its purchase only to seasoned pilots. Ocke Mannerfelt worked closely with Volvo Penta to test the new DPX transmission system. Powered by a 390-hp Volvo Penta 7.4 V8, the engine features a DuoProp transmission capable of propelling the B-28 Sport to 70 knots. The Swedish engine manufacturer is also responsible for the design and application of Speed Rails at “key points” of the hull. To date, seven examples of this boat have been built, constructed of sandwich-structure composite materials and designed to reach up to 100 knots in racing conditions. The 22-foot prototype from which the 28-footer was derived received the 1992 Swedish Design award and won the 1993 Swedish offshore championship.

by Alice Bertazzoni

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