Overview
ISO 21885:2019 - Ships and marine technology - Testing specification for stairsteps using electrical resistance trace heating - specifies a standardized test method to evaluate heated stairsteps that use electrical resistance trace heating for exterior anti-icing on ships and marine structures. The standard defines test facility requirements, environmental and wind conditions, specimen construction and installation, test procedures (two options), pass/fail criteria and the required test report content. Its focus is verifying that heated stairsteps prevent ice formation and operate correctly in low-temperature environments.
Key topics and technical requirements
- Test purpose: Verify anti-icing performance and operational function under low-temperature conditions.
- Test facility: Cold chamber capable of maintaining specified ambient temperatures and controlled wind flow; wind generator must not directly disturb specimens.
- Temperature control & stabilization:
- Ambient temperature considered stabilized when it varies by no more than ±2 °C over 30 minutes.
- Specimen temperature stabilized when it varies by no more than ±2 °C over 60 minutes.
- Wind temperature to specimen within ±2 °C (may be widened to ±3 °C down to −25 °C where chamber size limits apply).
- Instrumentation: Minimum of 9 temperature sample points to identify cold spots; sensors must be calibrated and adjusted for material emissivity. Wind sensors located within 10 cm of specimen and wind speed maintained within 10%.
- Specimen geometry: Heated stairsteps consist of two steps; recommended dimensions include tread depth 280 mm, width 1 000 mm, max vertical distance 230 mm, 25 mm overhang, step angle 38°–45°.
- Test procedures: Two options detail sequence for powering heating media, wind generation and temperature sequencing. Wind generator typically started before cooling to avoid startup issues in low temperatures.
- Pass/fail criteria: Stabilized specimen temperature (excluding the single lowest and highest values from 9 sample points) must remain constantly above 0 °C.
- Reporting: Test reports must include laboratory ID, test conditions, instrumentation, results and stabilization data.
Applications
- Certifying and validating anti-icing systems on ship exterior stairs, ladders and gangways.
- Design verification for shipbuilders and marine outfitting manufacturers using electrical resistance trace heating.
- Acceptance testing by owners, purchasers and classification societies for cold-climate operations.
Who should use this standard
- Marine equipment manufacturers and suppliers of heated stairsteps.
- Test laboratories and third‑party certifiers performing environmental and anti-icing tests.
- Shipbuilders, maritime operators and classification societies evaluating safety and compliance for exterior stair installations.
Related standards
- IEC/IEEE 60079-30-1 - Electrical resistance trace heating - General and testing requirements
- IEC/IEEE 60079-30-2 - Application guide for design, installation and maintenance
Keywords: ISO 21885:2019, heated stairsteps, electrical resistance trace heating, anti-icing, ships and marine technology, testing specification, cold chamber, test procedure, pass/fail criteria.