Our client:

Alphen a/d Rijn crane accident

Orca Offshore in cooperation with Saetech, has performed the technical investigation of the crane accident on request of the Dutch Safety Board (De onderzoeksraad voor veiligheid). The objective of the investigation was to evaluate the feasibility of the plan and to identify the root cause of this accident.
The accident involved a twin crane lift from two barges performed on inland water. The root cause of the accident has been identified and appeared to be a lack of stability of both barges.
It also appeared that a large part of the instability was related to an unaccounted effect related to the flexibility of the cranes. This effect resulted in a critical reduction of the stability which contributed to the incident. The next graph shows the shift of the load work point due to the flexing of the crane boom due to a barge heel which results in a stability reduction of the system.

Crane stiffness effect explained
Shift of load work point explained

Orca Offshore performed the stability analysis of the twin crane lift using a 3-D simulation model. Also a time domain analysis has been performed to simulate the effect of wind and crane actions. For the simulations MOSES from Bentley systems has been used. Below a video of the accident and the simulation of the accident can be found.

Downloads can be found at the bottom of this page.
For a good summary in English of the Safety Board conclusions please visit: www.heavyliftnews.com

Frames from time domain analysis

Available video's

Moses Simuation
Saftey board video
Video of incident

Available downloads

Download white Paper

Technical investigation of an inshore accident with a twin crane lift arrangement from two barges


Technical Note

Crane barge stability using land based crane. Notification to Crane barge operators, owners and designers


Dutch Safety Board

Visit the Dutch safety board website to download the official reports

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