Playground Swing Set Product

Overview

A playground swing set is a frame for pendulums. Its A-Frame Structure holds a horizontal Top Beam about 2.3 m above the ground; from the beam, Swing Unit seats hang on chains via pivoting hangers, and the rider drives the pendulum by shifting body position in phase with the swing. Residential sets add play value around the same frame: here a Wave Slide on one end and a Trapeze Unit in the third bay. The engineering problem is almost entirely dynamic — a swinging child loads the structure cyclically and at angles a static climbing frame never sees, so the design centres on the beam, the pivots, and the Anchor Kit.

Loads and structure

At the bottom of the arc, a swing chain carries the rider's weight plus centripetal force; for a wide swing this peaks near 3 times static weight, so a 50 kg child briefly loads one swing position with about 1.5 kN. The chains pull alternately forward and back of vertical, which is why the structure is an A-frame: the splayed A-Frame Leg pairs, joined to the beam by Apex Bracket castings, triangulate the fore-aft loads, and the Cross Brace ties stop the frame racking along the beam axis. Steel sets use ~60 mm tube; timber sets use 90×90 mm posts with the same geometry. Even braced, an unanchored set "walks" — the cyclic load rocks the feet and migrates the frame — so each Leg Foot Plate bolts through an Anchor Bolt pair to a Ground Anchor set in concrete or screwed into the soil. ASTM F1148 (home playground equipment) and EN 71-8 both test for tip-over under prescribed dynamic loads.

Hangers and bearings

The pivot is the highest-wear point on the whole set: a moderately used swing cycles millions of times over its life. Each chain hangs from a Beam Hanger through-bolted to the beam (never lag-screwed — cyclic load works lag threads loose), and the moving Hanger Clevis yoke oscillates on either a sacrificial Pivot Bushing or a sealed Ball Bearing. Bushed hangers are cheaper and squeak when dry; bearing hangers run quiet and shift the wear from the pin to a replaceable cartridge. Hanger spacing is regulated: hangers for one seat sit wider apart than the seat itself (typically ~50 cm) so the swing tracks straight instead of yawing, and adjacent swings keep ~60 cm clearance.

Seats and chains

The Belt Seat replaced the rigid board seat for a blunt reason: a heavy wooden seat returning at head height was the classic swing injury. The belt is EPDM rubber vulcanised around a steel insert; it wraps the rider, weighs little, and hurts far less on impact. The Swing Chain is 4-6 mm welded-link, zinc-plated, with a breaking strength more than ten times the working load; Connecting Link quick links join it to the seat triangles and clevises so worn parts swap without cutting chain. The upper chain run wears a plastisol Chain Sleeve because small fingers gripping bare chain at the pivot end get pinched as the links articulate. The Trapeze Unit bay hangs a knurled Trapeze Bar with Gym Ring rings on shorter chains for climbing play.

Slide

The attached slide is a rotomoulded HDPE Slide Bed with a double-wave profile — the waves limit rider speed by repeatedly trading slope for flat. Riders climb the Deck Ladder to a guarded Slide Deck at about 1.2 m, supported by Deck Post uprights, and exit over a flared Exit Lip that levels out near ground height to drop exit speed below walking pace. Polyethylene took over from sheet steel in the 1980s because steel slides reached burn temperatures in summer sun and dented into scalpel-edged creases.

Siting and surfacing

The structure is only half the safety case; the ground is the other half. Guidelines call for a use zone extending twice the beam height fore and aft of the swings — roughly a 6 × 8 m clear area for this set — over impact-attenuating surfacing: 23-30 cm of loose fill (engineered wood fibre, mulch, sand) or rubber tiles rated for the fall height. Grass over compacted soil fails head-impact criteria from as little as 60 cm. Assembly uses galvanised hardware from the Fastener Set throughout, with all bolt ends capped or recessed, since protruding threads at child height are a laceration and entanglement hazard the standards explicitly prohibit.