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Radio Control Boats – Kind of Hulls

Author: Bmus

The next great choice is which style of radio controlled boat hull to decide on. If your are planning a scale project, your selection will apparently be determined by the full-size boat you would like to model. But sport, racing and sailing boat hull types display very unusual personality. In general, there are two hull classifications: monoplane and hydroplane.

MONOPLANES
Monoplane hulls have one uninterrupted surface in contact with the water.  Monoplane hulls can be divided into two subcategories: deep-V’s and shallow-V’s.

• Deep-V’s. Nearly all monoplane hulls are deep-V’s. This traditional layout brings the keel to a sharp point well below the surface of the water. The underside of the boat is sloping upward steeply toward the hull’s sides, resulting in a radio controlled boat that knifes through the water with a relatively large wetted surface area. This type of hull is steady at every speeds and provides sharper steering reaction. The downside is that the extra hull surface that contacts the water causes drag that restricts maximum speed. Still, as well as the right power system and correct tweaking, these radio controlled boats are quite fast-particularly for newbees.

• Shallow-V’s are the faster of the two monoplane types since they function with a lesser amount of surface area in contact with the water. The shallower keel v’s-angle produces a flatter bottom that causes less drag. The downside is that a reduced amount of contact with the water means a reduced amount of stability, so they are more difficult to control and demand more defined trimming. Shallow-v’s are very standard for entry-level racing, the so-called Crackerboxes being the most common.

HYDROPLANES
Hydroplanes maintain more than one surface in contact with the water. They include tunnel hulls, catamarans, outriggers and stepped hydros.

• Tunnelhulls are most often related with full-size racing boats. They get their designation from the raised center section of the hull. 2 outer sections (sponsons) sit in the water with a “tunnel” between them. As the boat gains velocity, air builds up in this tunnel and raises the boat higher out of the water; this reduces the surface area that contacts the water. This means less drag and higher speeds, while the relatively wide spacing of the sponsons maintains stability. This design provides a excellent balance of speed and handling for beginners.

• Catamarans (cats) operate on the same principle as tunnelhulls and differ only in shape . They have more steeply angled sponsons-much like deep-vee monos with a tunnel along the center. A cat’s tunnel tends to be taller and narrower than a tunnelhull’s, so it takes longer to preserve stability. These also, are a good beginner model.

• Outriggers are at the highest of the performance ladder; their sponsons and main hull are separate pieces. This improves the airflow at high speeds, so outriggers are the fastest radio controlled boats; several even run at more than 90 miles per hour! The obstacle is that they’re designed to work best at full throttle. At slow speeds, they sit too low in the water and do not handle well. In addition, they are the least forgiving when it comes to setting the trim.

• Stepped hydroplane hulls have notches perpendicular to the centerline that divide the wetted surface into 2 or more sections. These notches get the radio controlled boat up on step quicker, and that improves performance. At speed, these notches lessen the wetted area, reducing drag. This hull type includes a diverse group, from plain deep-v’s with little steps in the hull, to 3-point hydro racers such as the full-size Miss Budweiser turbine-powered, unlimited hydroplane. At full speed, three-point hydros ride on 2 tiny areas of the forward sponsons and the centrally located propeller at the rear.

Any way you look at it radio controlled boats are a marvelous way to spend a sunny afternoon.    Take the time to enjoy the hobby and spend time with your family and friends.

Tags: radio controlled boats
November 1st, 2009  |  Posted in Types of Hulls  |  2 Comments »