ISO 8035:1991

Overview

ISO 8035:1991 specifies requirements for front towing attachments fitted to commercial road vehicles and buses with a maximum authorized mass over 3.5 t. The standard defines location, form, strength and test procedures for attachments designed to accept ropes, cables or bars. It explicitly excludes special-purpose vehicles and production vehicles intended for special applications.

Key topics and technical requirements

• Scope and applicability: Applies to commercial vehicles and buses > 3.5 t (as defined by ISO 1176). Not for special-purpose vehicles.
• Location: Towing devices must be mounted at the front of the vehicle and must not protrude beyond the vehicle’s external contour in the horizontal plane except during towing.
• Form and usability:
  • Configuration is at the manufacturer’s choice but must permit attachment of ropes, cables or bars without tools or auxiliary parts.
  • If bars are recommended, the shape should allow use of the bar described in ISO 1102.
  • Removable parts, where provided, must be securely fixed.
  • The attachment end must allow movement (document specifies movement allowances in horizontal and vertical planes for the attached element).
• Strength and loading:
  • Towing devices must resist a prescribed static load related to the vehicle mass code (as defined in ISO 1176) multiplied by gravitational acceleration (g). The standard specifies different mass-based factors for commercial transport and passenger vehicles.
• Testing:
  • Tests are conducted with the vehicle immobilized on a rigid horizontal surface at the specified test mass (maximum authorized or curb mass).
  • Two tests are required: one in tension and one in compression, with load applied progressively. Manufacturers may alternatively verify compliance by calculation.
  • After testing the device must show no deformation preventing normal operation; adjacent mandatory equipment (lighting, steering, braking) must remain functional.

Applications and who uses it

• Vehicle manufacturers and chassis designers - to design compliant front towing attachments.
• Component suppliers - to certify towing hooks, eyes and bars for OEM fitment.
• Test laboratories and type-approval bodies - to carry out required static and functional tests.
• Fleet operators, maintenance workshops and regulators - to verify safe towing points and conformity for roadside recovery and fleet safety policies.

Related standards

• ISO 1176 - vehicle mass codes and definitions (referenced for load calculations)
• ISO 1102 - towing bar dimensions (for compatibility)
• ISO 5422 - towing device terminology and definitions

Keywords: ISO 8035:1991, front towing attachments, commercial road vehicles, buses over 3.5 t, towing device requirements, towing attachment testing, ISO 1176, ISO 1102.