7.2 Swings

7.2 Swings

Domain 1O for swings is a motion-and-clearance chapter. Name the axis and the seat before you pull a tape, or you will apply a belt-swing use zone to a tire and miss the 24-inch bucket height. The U.S. Consumer Product Safety Commission (CPSC) Public Playground Safety Handbook, Publication 325 (July 2025) §5.3.8 is the narrative. ASTM International F1487-21 and the NRPA Table of Dimensions (Rev 1/2024), including §9 use zones, supply the numbers on the exam sheet.

CPSC splits swings into two mechanical families. A single-axis (to-fro) swing moves in one plane on at least two suspending members, each on its own pivot. A multi-axis (rotating) swing hangs from one pivot — usually a tire on three chains — and can travel in any direction. The seat then decides the rest of the Table: a belt (flexible strap) used without adult help, a full-bucket tot seat, or a tire.

Seats, hangers, and the 60-inch measurement plane

A full-bucket seat must support the child on all sides and between the legs. The child cannot enter or exit without adult assistance. Full buckets are generally for children under 4. CPSC §5.3.8.3.2 adds: the seat material must not be a noose (no rope or chain as part of the seat), openings must pass the §3.3 entrapment tests, hang the buckets in their own bay when you can, and keep the pivot more than 47 inches and no more than 96 inches above the surfacing. The NRPA Table seat-to-surface minimum for a bucket is 24 inches (CPSC Table 7 dimension D3 for the toddler full bucket is the same 24 inches).

A to-fro belt seat is for one child. The Table seat-to-surface minimum is 12 inches — and you measure that after loose-fill has been compressed. Lightweight rubber or plastic seats are the impact-injury control; wood or metal seats should be avoided. Edges are finished or rounded. Nothing on the front, back, or underside may stand more than 1/8 inch (CPSC §5.3.8.5).

A tire is the usual multi-axis seat. Do not hang it in a bay that already has other swings. Do not hang it on a composite. Skip heavy truck tires. If a steel-belted radial is used, inspect for exposed belts and add drainage holes on the underside. Clearance from the seating surface to the uprights, when the tire is closest to the frame, is 30 inches. Seat-to-surfacing is not less than 12 inches. The hanger mechanism sees extra rotational load; treat worn swivels as a Priority finding, not as cosmetic rust.

Clearances on a to-fro bay are taken in one plane: 60 inches above the protective surfacing.

The 13.1-inch seated hip breadth is how you occupy the seat when you check D1 and D2. Measuring chain-to-chain on empty, twisted belts understates the collision distance. A-frame supports should not have horizontal cross-bars (they become a climbing ladder to the beam). Hardware that holds the hanger to the beam or the seat must need tools to remove. Fiber rope is not an acceptable hanger — it degrades. Locate the bay away from run paths; a low fence or hedge around the swing area is allowed if it stays outside the use zone and does not block sight lines.

Use zones, overhead clearance, and what you must not add

CPSC and the NRPA Table describe the same empty air in different letters. Learn both; the exam will hand you the Table.

To-fro (single-axis) belt. CPSC: the front-and-rear use zone is twice the vertical distance from the pivot to the surfacing, and it never overlaps another equipment use zone. Full-bucket front-and-rear is twice the distance from the occupant’s sitting surface to the pivot. Side use zone is 6 feet from the perimeter and may overlap an adjacent swing structure. The NRPA §9 line you will see on the sheet for the support structure is a 72-inch minimum.

Rotating / multi-axis. CPSC: from a point directly beneath the pivot, the use zone runs in every direction 6 feet plus the length of the suspending members, and that circle never overlaps another use zone. The support-structure side zone is again 6 feet and may overlap. NRPA §9 writes the same idea as Y + 72 inches of non-overlapping use zone, where Y is the distance from the pivot to the top of the seat, plus a Y + 30 inch rotating multi-axis figure and a 72-inch side use zone at the support structure. When a stem cites the Table, use Y, not a freehand “twice the beam height.”

NRPA §9 also prints two rocking/swinging side numbers you will meet again in Chapter 8: 72 inches for sitting rocking or swinging, 84 inches for standing rocking. Do not put the 84-inch standing-rocker envelope on a belt-swing bay.

Overhead clearance is not the 84-inch designated-play-surface rule from Domain 1N. For a swing, CPSC §3.8 and the Table want X + 42 inches from the pivot to the obstruction, where X is the distance from the pivot to the protective surfacing. A shade-sail beam 10 feet above grade is still a hit if the pivot is 8 feet up (X + 42 = 11.5 feet). Fall height for swings, CPSC §5.3.8.2, is that same pivot-to-surfacing vertical — not the seat height. Surfacing under a swing is therefore sized to the beam, not to the 12-inch or 24-inch seat gap.

CPSC §5.3.8.1 and Appendix A close the bay:

• No more than two single-axis swings in one bay.
• Do not attach swings to a composite structure.
• Do not add extra ropes, belts, or a third swing to a bay. User-tied ropes are a maintenance take-down, not a capacity upgrade.
• S-hooks must be pinched so the opening is no greater than 0.04 inches (about the thickness of a dime). An open S-hook is a clothing-catch strangulation on a moving seat.
• Swings should be impact-tested as suspended elements under F1487. Flexible seats exist because a moving belt that hits a waiting child is still a missile; a flexible seat just makes that missile less deadly.

Field order: name axis and seat, measure seat-to-surface (12 or 24), occupy the seat to 13.1 inches and tape D1 / D2 / D4 at 60 inches, pinch every S-hook to 0.04 inches, walk the front-rear non-overlap (2X or Y + 72), check the 72-inch support-structure side zone, then look up for X + 42. That is Domain 1O for swings.