ISO 13216-2:2004

Overview - ISO 13216-2:2004 (Top tether anchorages)

ISO 13216-2:2004 specifies top tether anchorages and attachments for child restraint systems (CRS) in road vehicles. It establishes positioning zones, dimensional rules and static-strength requirements for top tether anchorages used together with seat bight anchorages (ISO 13216-1) or other lower attachment systems. The standard applies to CRS intended for children with a mass up to 22 kg and defines how vehicle anchorages must accept and transfer tether loads to the vehicle structure.

Key topics and technical requirements

• Positioning zones

  • Defines the wider ISOFIX zone (for CRS with rigid ISOFIX bight attachments) and conventional zones (compatible with US/Canadian regulations).
  • Specifies geometric limits including angles and clearances (examples from the standard: maximum 45° above horizontal in side view; origin of tether on the CRS located 550 mm above the CRF horizontal face; strap path wraparound lengths of 250 mm and 200 mm).
  • Anchorage must be located between 200 mm and 2 000 mm measured along the strap from the tether origin on the child restraint fixture (CRF).
  • Notes on routing devices if anchorages are placed outside nominal zones (minimum setbacks and strength requirements).

• Anchor dimensions and usability

  • Anchorage hardware must permit hook-type connectors and provide adequate clearance for latching and unlatching (see figure references in the standard).

• Strength and testing

  • Static-strength testing using a Static Force Application Device (S-FAD) engaged with ISOFIX seat bight anchorages per ISO 13216-1.
  • Webbing properties referenced (low-elongation polyester webbing, ~7–9% elongation at 11 kN) and loads applied during tests.
  • Permanent deformation is acceptable in tests provided the anchorage does not break or separate from the vehicle.

Applications - who uses ISO 13216-2

• Vehicle manufacturers - design and integrate compliant top tether anchorages into seats and vehicle structures.
• CRS (child restraint) designers and manufacturers - ensure CRS tether connectors, straps and intended operating envelope match vehicle anchorages and ISOFIX conventions.
• Testing laboratories and certification bodies - perform strength and positioning verification using S-FAD procedures.
• Regulators and safety engineers - assess compatibility with national regulations and specify installation guidance for end users.

Related standards

• ISO 13216-1: Seat bight anchorages and attachments
• ISO 6549: H- and R-point determination for vehicle seating reference
• SAE J1100: Motor vehicle dimensions
• (ISO 13216 Part 3 - classification of CRS dimensions - is under preparation)

Keywords: ISO 13216-2:2004, top tether anchorages, child restraint systems, CRS, ISOFIX zones, tether strap, S-FAD, vehicle anchorages, static-strength testing.