Steering Micro Switch Failure Led to Houston Collision

A steering control system component failure on a multi-purpose carrier resulted in a collision with a bulk carrier in the Houston Ship Channel, the National Transportation Safety Board said in a newly-released investigation report.

The multi-purpose carrier BBC Africa lost steering as it was departing the channel on Aug. 25, 2023, and struck the moored bulk carrier Common Faith. No injuries or pollution were reported. Damage to the vessels was estimated at $1.1 million.

The crew told investigators they did not find any issues with the steering control systems during the pre-departure tests. When the vessel departed, the vessel steering was functioning from the port bridge wing. When the steering control was transferred to the bridge’s center helm using the in-command (FU) button at the center helm, the rudder swung hard to port, contrary to the pilot’s orders and the helmsman’s actions.

The chief officer made several unsuccessful attempts to regain primary steering control by re-pressing the FU button. After about a minute, the master regained rudder control by using the emergency override function. It was too late at that point to sufficiently turn the vessel before the contact.

Investigators determined the delayed response from the ship’s crew to implement the emergency steering procedure from the bridge contributed to the collision.

Following the contact, technicians from the manufacturer and investigators inspected and tested the mechanical and electrical components of the three control stations and control system panels. Based on the rudder’s movements and the post-collision testing and inspection, the steering control failure was likely due to the bridge wing tiller micro switch failing.

“Steering control system failures can result in damaging consequences,” the report said. “In channels or during maneuvering, where immediate hazards (grounding, traffic, objects) are in proximity and therefore response time is critical to avoiding a casualty, steering system failure contingencies require immediate crew response. Training in steering recovery procedures, including scenario-based drills for bridge and engine teams, is critical to ensure crews can respond in the shortest possible time.”

The operator replaced three components following the contact that could have led to the steering failure: the port bridge wing tiller, the power supply transformer in the control cabinet located behind main bridge, and the push button relays to take “in command” status when requesting control.

Additionally, the steering gear manufacturer released a safety bulletin on switch failures in the bridge wing tillers. The bulletin specifically noted that micro switch failure could lead to unintended rudder movements.