(DORVAL, Quebec) — The Transportation Safety Board of Canada (TSB) has released its investigation report into the 2024 grounding of the general cargo vessel Heemskerkgracht in the South Shore Canal of the St. Lawrence Seaway off Kahnawake, Quebec.
On August 22, 2024, Heemskerkgracht ran aground after the main engine shut down due to the activation of a false alarm on the oil mist detector (OMD). The vessel was anchored while awaiting assistance and was later refloated and towed to the Port of Cote-Sainte-Catherine, Quebec. There were no injuries or pollution reported. The vessel sustained minor damage to its hull.
OMDs are used to measure the presence of oil mist in an engine crankcase and, in medium-speed engines like the one in Heemskerkgracht, shut down the engine when oil mist is detected. These detectors cannot differentiate between oil mist, water vapor, or smoke, which can trigger false alarms. To reduce this risk, the vessel’s OMD was fitted with a heater to prevent vapor buildup.
In March 2023, as part of scheduled maintenance, Heemskerkgracht’s OMD measuring head was identified for a replacement, and a purchase order was made. However, the vessel received a different model which required an external source of power for the heater, unlike the previous unit, which had a power source built into the head. As a result, the heater was left unpowered, leaving the measuring head vulnerable to false alarms caused by water vapor.
The investigation found that during the occurrence voyage, water vapor built up in the OMD measuring head and caused a false alarm that then triggered an automatic shutdown of the main engine. As a result, the vessel lost propulsion and ran aground in the canal.
Following the occurrence, the vessel operator replaced the OMD measuring head with a unit matching the original model. The measuring head was confirmed to have been installed per the manufacturer’s instructions and was calibrated and tested.
Click here to read the complete report.
– Transportation Safety Board of Canada
