ISO 10268:1993

Overview - ISO 10268:1993 (retarders, performance tests)

ISO 10268:1993 defines a standardized test procedure to verify a manufacturer’s published continuous retarding capability for retarders fitted to dumpers, tractor‑scrapers and other earth‑moving machinery. The standard describes how to conduct towing, on‑grade and dynamometer tests, specifies required test conditions and data recording, and sets requirements for presenting retarder performance curves.

Key topics and technical requirements

• Scope: Verifies published continuous retarding capability for machines equipped with retarders; applies to dumpers, tractor‑scrapers and similar equipment.
• Definitions: Includes key terms such as retarder, continuous retarding capability, maximum continuous power, and grade.
• Test methods: Accepts any of three verification methods - towing, on‑grade, or dynamometer - provided the method meets the standard’s stability and measurement requirements.
• Facilities and surface: On‑grade/towing tests must use a hard, dry, well‑compacted course of sufficient length, smoothness and uniform gradient to maintain test speed.
• Machine condition: Tests performed with retarder and machine fully serviced and at normal operating temperature; service brakes disengaged when separate from the retarder.
• Ambient temperature: Reference verification temperature range is 27 °C to 32 °C (32 °C used for published performance); if tests are done outside this range the verification temperature must be recorded and noted.
• Data and accuracy: Record speed, machine mass, towing force, grade slope, dynamometer power and ambient temperature. Measurement accuracy shall comply with ISO 9248; grade slope determination within ±0.5°.
• Verification criterion: Average of three consecutive test runs must be at least 95% of the power calculated from the published data. A single point at published maximum continuous power can be sufficient for verification.
• Presentation: Continuous retarding capability is shown as a performance curve (example in Annex A); additional curves for other temperatures may be included.

Applications - who uses ISO 10268 and why

• OEMs and retarder manufacturers - to substantiate and publish retarder performance and continuous retarding capability.
• Test laboratories and validation engineers - to perform repeatable, comparable performance verification using towing, on‑grade or dynamometer setups.
• Fleet owners and specifiers - to compare retarder performance across machine models when selecting equipment for steep‑grade work.
• Regulatory and safety bodies - to evaluate braking/retarder capabilities in safety and compliance assessments.

Related standards

• ISO 3450:1985 - braking system test requirements for wheeled earth‑moving machines
• ISO 9248:1992 - units for dimensions, performance and measurement accuracies
• ISO 7132:1990 and ISO 7133:1985 - terminology and commercial specifications for dumpers and tractor‑scrapers

Keywords: ISO 10268, retarders, earth‑moving machinery, performance tests, continuous retarding capability, dumpers, tractor‑scrapers, retarder performance.