This report summarizes an incident investigated by the Nationwide Transportation Security Board (NTSB) involving a collision between a multi-purpose cargo vessel and a moored bulk provider within the Houston Ship Channel, Texas, on August 25, 2023. The occasion resulted in important vessel harm however no accidents or air pollution.
What Occurred
Whereas departing from a terminal on the Houston Ship Channel, a multi-purpose cargo vessel misplaced main steering management. The vessel was underway underneath pilotage, with regular steering verified earlier than departure. Throughout switch of steering management from the port bridge wing to the principle bridge console, the rudder unexpectedly moved onerous to port as a substitute of responding to helm instructions.
Makes an attempt to regain steering by means of the first system failed, prompting the grasp to activate the emergency override mode. Regardless of regaining restricted rudder management, the vessel couldn’t keep away from putting a moored bulk provider on the close by terminal. The collision triggered hull harm to each vessels, estimated at roughly $1.175 million. There have been no accidents or air pollution.
Why It Occurred
The NTSB decided that the first reason for the collision was a failure within the vessel’s steering management system. A malfunctioning element—particularly the bridge wing non-follow-up (NFU) steering tiller micro change—seemingly triggered an unintended rudder motion and lack of management.
Contributing elements included a delayed crew response in executing emergency steering procedures, which lowered accessible time to stop impression. Submit-casualty inspection recognized inside cracking and moisture ingress within the tiller’s rubber protecting boot, resulting in electrical malfunction. The steering gear producer later confirmed related points in different vessels and issued a Security Bulletin citing micro change failures in NFU tillers delivered between 2002 and 2009.
Actions Taken
Following the incident, the vessel operator changed each bridge wing NFU tillers, “in-command” push buttons, termination playing cards, and the ability provide transformer with unique gear producer components. Similar parts had been additionally changed on two sister vessels with comparable steering programs. Refresher coaching was carried out for bridge and engine groups on transferring steering management and utilizing emergency override programs. The producer’s Security Bulletin was distributed to vessel operators worldwide to boost consciousness of potential failures in related tiller assemblies.
Classes Discovered
Speedy response to steering failure is vital throughout confined or maneuvering operations the place hazards are close by.
Routine inspection of steering management parts, together with tiller micro switches and rubber protecting boots, ought to be emphasised to detect degradation or moisture ingress.
Bridge and engine crew coaching should embrace scenario-based drills simulating lack of main steering to make sure fast transition to emergency modes.
Redundant verification of steering switch earlier than departure may also help detect latent management faults.
Security communication from producers, reminiscent of bulletins, ought to be promptly reviewed and acted upon by vessel operators.
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Supply: NTSB
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