The difference between dimensions AC and AB should not exceed 2.0 inches. A = Axis of Rotation AB = Minimum Radius AC = Maximum Radius A B Base C Figure 15. Minimum and maximum radii of a merry-go-round platform Automobile Tire Figure 16. Typical Fulcrum Seesaw 31 Handbook for Public Playground Safety 5.3. .2 Fall height The fall height for a merry-go-round is the distance between the perimeter of the platform where a child could sit or stand and the protective surfacing beneath it. 5.3.5 Seesaws 5.3.5.1 Fulcrum seesaws The typical seesaw (also known as a “teeter totter”) consists of a board or pole with a seat at each end supported at the center by a fulcrum. See Figure 16. Because of the complex way children are required to cooperate and combine their actions, fulcrum seesaws are not recommended for toddlers or preschool-age children. • The fulcrum should not present a crush hazard. • Partial car tires, or some other shock-absorbing material, should be embedded in the ground underneath the seats, or secured on the underside of the seats. This will help prevent limbs from being crushed between the seat and the ground, as well as cushion the impact. • The maximum attainable angle between a line connecting the seats and the horizontal is 25°. • There should not be any footrests. 5.3.5.2 Spring-centered seesaws Preschool-age children are capable of using spring-centered seesaws because the centering device prevents abrupt contact with the ground if one child dismounts suddenly. Spring-centered seesaws also have the advantage of not requiring two children to coordinate their actions in order to play safely. Spring-centered seesaws should follow the recommendations for spring rockers including the use of footrests (§5.3.7). • The difference between the minimum and maximum radii of a non-circular platform should not exceed 2.0 inches (Figure 15). • The underside of the perimeter of the platform should be no less than 9 inches above the level of the protective surfacing beneath it. • There should not be any accessible shearing or crushing mechanisms in the undercarriage of the equipment. • Children should be provided with a secure means of holding on. Where handgrips are provided, they should conform to the general recommendations for hand gripping components in §5.2.2. • No components of the apparatus, including handgrips, should extend beyond the perimeter of the platform. • The rotating platform of a merry-go-round should not have any sharp edges. • A means should be provided to limit the peripheral speed of rotation to a maximum of 13 ft/sec. • Merry-go-round platforms should not have any up and down (oscillatory) motion. 5.3. .1 Use zone • The use zone should extend a minimum of 6 feet beyond the perimeter of the platform. • The use zone may not overlap other use zones, unless the rotating equipment is less than 20 inches in diameter and the adjacent equipment allows overlap.
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