8.2 Rocking Equipment, Seesaws & Spring Rockers

8.2 Rocking Equipment, Seesaws & Spring Rockers

Domain 1O continues from spinning platforms to equipment that rocks, teeters, or rolls underfoot. The injury pattern changes. A merry-go-round runs a child over. A fulcrum seesaw crushes a limb at the pivot or slams a seat into the surfacing. A spring rocker shears a finger between coils. A log roll dumps a child who has not yet got the balance to stay on an 18-inch drum. The CPSC Public Playground Safety Handbook, Publication 325 (July 2025) splits the family across §5.3.1 (balance beams), §5.3.3 (log rolls), §5.3.5 (seesaws), and §5.3.7 (spring rockers). ASTM F1487-21 and the NRPA Table of Dimensions (Rev 1/2024) add the seat-height, footrest-width, handgrip-length, and sitting-versus-standing use-zone numbers you will see on the exam sheet.

Balance beams

A balance beam is a designated walking surface used to practice dynamic balance, not a bench and not a guardrail cap. CPSC 2025 §5.3.1 and the NRPA Table use the same height caps:

• Toddlers: not recommended
• Ages 2–5 (preschool): 12 inches maximum
• Ages 5–12 (school-age): 16 inches maximum

Fall height is the distance from the top of the walking surface to the protective surfacing. A 20-inch “challenge beam” on a preschool pad is not a creative 2–5 event; it is over the Table. Beam width is not a published NRPA Table number — do not invent one. What you do inspect is designated-play-surface geometry (at least 2 inches by 2 inches and less than 30 degrees from horizontal), crush/shear if the beam pivots, and the use zone of a stand-alone beam under the general 72-inch stationary rule unless a more specific rocking row applies.

Log rolls

A log roll is a spinning cylinder the child stands on and drives with the feet. CPSC 2025 §5.3.3 is blunt about age: log rolls are not recommended for toddlers or preschool-age children. Those users generally lack the balance, coordination, and strength to stay on the drum. School-age is the intended group.

CPSC performance you measure:

• Handholds are required to assist with balance and must follow §5.2.2 (rigid 0.95–1.55 inches; must not turn).
• The highest point of the rolling log is a maximum of 18 inches above the protective surfacing. The NRPA Table repeats that 18-inch roller-height cap.
• Fall height is the distance from that highest portion of the rolling log to the surfacing.
• When the log roll is not part of a composite, the use zone may overlap a neighbor that itself allows overlap if there is at least 6 feet between equipment when adjacent designated play surfaces are no more than 30 inches high, or at least 9 feet when those surfaces are more than 30 inches high.

A log roll is horizontal-axis motion, but it is not inspected as F1487 “horizontal rotating equipment” for the 8.1 use-zone row. Stay in §5.3.3. The 18-inch cap is a fall-height and ejection control, not a crush-probe diameter.

Fulcrum seesaws and spring-centered seesaws

The typical fulcrum seesaw (teeter-totter) is a board or pole with a seat at each end, supported at the center. Because two children must cooperate and combine their actions, CPSC 2025 §5.3.5.1 does not recommend fulcrum seesaws for toddlers or preschool-age children. Table 1 lists them only in the grade-school (5–12) column. The NRPA Table / F1487 maximum seat height is 60 inches.

CPSC fulcrum rules you fail in the field:

• The fulcrum must not present a crush hazard. Offer the common 0.62-inch crush/shear rod (Domain 1M) at the pin and at any shroud opening that closes during the arc.
• Partial car tires or other shock-absorbing material must be embedded in the ground underneath the seats or secured on the underside of the seats. That dual purpose is published: prevent a limb from being crushed between seat and ground, and cushion the impact. A seesaw over packed dirt with no bumper is a §5.3.5.1 fail even if the fulcrum is boxed in.
• The maximum attainable angle between a line connecting the seats and the horizontal is 25 degrees.
• There should not be any footrests on a fulcrum seesaw. A child who plants a foot on a peg and is launched is using a lever you were told not to install.
• Handholds at each seating position must allow gripping with both hands, must not turn when grasped, and must not protrude beyond the sides of the seat (CPSC §5.3.5.4). The NRPA Table length for a seesaw or spring-rocker grip is 3 inches minimum if the design is one-handed and 6 inches minimum if it is two-handed.

Fall height for a seesaw is the distance between the highest point any part of the seesaw can reach and the protective surfacing — measure at the top of the up seat, not at the fulcrum.

Spring-centered seesaws are a different machine. CPSC §5.3.5.2 says preschool-age children can use them because the centering device prevents an abrupt ground strike if one child dismounts, and because two children do not have to coordinate. Inspect them generally as spring rockers (§5.3.7). If the unit behaves more like a fulcrum seesaw, footrests may not be appropriate — do not bolt preschool footrests onto a long-board teeter just because the catalog says “spring.”

CPSC use zone for fulcrum and spring-centered seesaws: minimum 6 feet from each outside edge; overlap is allowed only when the neighbor allows it and the 6-foot / 9-foot (≤30 in / >30 in) separation is met.

Spring rockers

Spring rockers are the bouncing animals and motorcycle springs that toddlers and preschoolers actually enjoy. CPSC §5.3.7 states that those ages are the primary users and that older children may not find the event challenging enough. That is why a 5–12 playground whose only moving challenge is a cluster of duck rockers is a poor design even when every dimension passes.

CPSC 2025 seat heights:

• Toddlers: 12–16 inches
• Preschoolers: 14–28 inches — this is also the NRPA Table preschool/school-age seat-height band you will be asked

CPSC also requires the seat not to invite more users than intended; opposing toddler seats intended for more than one child need at least 37 inches between seat centers. Each seating position gets handgrips and footrests. The NRPA Table adds two numbers CPSC does not print in §5.3.7: footrests minimum width 3.5 inches, and the 3-inch / 6-inch one-handed / two-handed grip lengths already stated for seesaws. Grip diameter still follows §5.2.2. Springs must minimize crushing of hands or feet between coils or between the spring and the rocker body — that is the Domain 1L coil-shear, tested with the 0.62-inch rod.

CPSC spring-rocker use zone: minimum 6 feet from the “at rest” perimeter. Overlap is allowed only when the neighbor allows it, the 6-foot / 9-foot height split is met, and the rocker is designed to be used from a seated position. A standing spring toy does not get that overlap sentence.

Use zones, surfacing, and the 5–12 site role

The NRPA Table / F1487 §9 split you must carry is not the CPSC 6-foot sentence. It is posture:

Impact-attenuating surfacing belongs under every elevated or moving seat. A fulcrum seesaw without F1292-capable surfacing under the seats is not “saved” by the tire bumper; the bumper is crush control, not a substitute for critical height. Spring rockers belong on preschool pads. Fulcrum seesaws belong on 5–12 pads with other challenge — climbers, overhead events, track rides — not as the only moving piece on the site.

Inspection list for the rocking cluster:

• Beam height 12 in / 16 in; log-roll high point 18 in; seesaw seat 60 in max; spring-rocker seat 14–28 in (toddler 12–16 in).
• Fulcrum boxed against the 0.62-inch rod; tires or equivalent under or on the seats; no fulcrum footrests; 25° max.
• Footrests 3.5 in minimum width on spring rockers; grips 3 in (one hand) or 6 in (two hands); springs closed to fingers.
• Use zone 72 in sitting / 84 in standing; CPSC 6-foot at-rest overlay; seated-only overlap.
• Ask whether a 5–12 playground has been reduced to preschool rockers. Dimensions can pass and the site can still fail the developmental job Domain 3B will score later.

That is rocking equipment: four machines, two postures, and a fulcrum you never leave untested.