Safety note after the thematic investigation of several incidents in which semi-trailers detached from the tracking vehichle during transport

Based on initial findings in the investigation, the NSIA issued a notification of safety-critical issues (NSIA no 2022/01) to the Norwegian Public Roads Administration (NPRA) on 21 January 2022 (see appendix). Based on this, the NPRA has initiated several relevant safety measures.The further investigation has not generated findings that warrant additional safety recommendations. The NSIA has therefore chosen to communicate safety findings and learning points through this final safety note. 

In connection with this thematic investigation, the NSIA wishes to highlight the following learning points for users, organisations and authorities concerning secure coupling between tractor units and semi-trailers: 

• Fifth wheels of the type Fontaine 3000 may be susceptible to technical damage that occurs in connection with the locking mechanism not being set in fully open position when coupling the vehicle combination.

• The damage may develop over time and eventually affect the locking mechanism and its ability to be securely connected over time.

• The damage can be detected visually through relatively simple procedures – when you know what to look for – before it develops and causes minor or major incidents and accidents.

• The damage is preventable if all users follow the manufacturer’s user manual for maintenance, connection, and safety checks.

• A ‘pull test’ with a tractor unit only demonstrates whether the vehicle combination is connected, but not whether the fifth wheel coupling is securely locked.

• The safety check must always include a physical inspection to ensure that the release handle is securely locked. 

Gratangen. Photo: NPRA

Lørenskog. Photo: The police

Published 05.06.2024