TSB cites hydrodynamic forces in Welland cargo ship collision

(QUEBEC CITY) — The Transportation Safety Board of Canada (TSB) on Monday released its investigation report (M20C0188) into the collision involving the general cargo vessels Florence Spirit and Alanis in the Welland Canal, Ontario.

On July 11, 2020, Florence Spirit and Alanis collided near mile 16 in the canal. Both vessels sustained extensive structural damage to their hulls. No pollution or injuries were reported.

The investigation revealed that an exchange of short, informal instant messages between the master of Florence Spirit and the pilot of Alanis influenced the former’s speed and course-alteration decisions. These decisions increased the complexity of the encounter.

The instant messaging communication between the master and pilot contributed to the master’s attention being diverted from coordinating the meeting with his own bridge team and excluded other bridge team members from having safety-critical information. In addition, diffused responsibility between the master and piloting master on Florence Spirit precluded coordination and communication between the bridge team members of Florence Spirit, which affected their ability to monitor the vessel’s progress and detect the effect of hydrodynamic forces acting on the vessel.

Four images taken prior to the collision show Florence Spirit sheering to port over a period of 47 seconds, as seen from the cargo ship Alanis. Rambow Bereederungs GmbH & Co. KG photo

Florence Spirit proceeded into the meeting at the maximum permissible speed of 9.9 knots, which increased the hydrodynamic forces acting on the vessel and reduced the ability to maintain steering control. The hydrodynamic forces generated, combined with the proximity of the bank, produced a yawing moment such that the vessel yawed uncontrollably to port into the path of Alanis and collided with it.

Following the occurrence, several safety measures were taken by the various authorities in connection with the incident. In February 2021, the TSB issued Marine Safety Advisory No. 01/21 to McKeil Marine, Florence Spirit’s authorized representative, regarding the effectiveness of the vessel’s helm angle in relation to the vessel’s speed.

Transport Canada conducted a flag state inspection and identified deficiencies in McKeil Marine’s quality and safety management system. McKeil Marine reviewed the accident and produced an internal investigation report which was shared with all masters. The Great Lakes Pilotage Authority (GLPA) reviewed the accident with a focus on compliance with the Pilotage Act and its regulations.

– Transportation Safety Board of Canada

By Rich Miller