Grounding Report: Pilot Lacked Information After Engine Failure

Nenita

By MarEx 2018-02-04 18:58:39

The U.S. National Transportation Safety Board has released its report into the grounding of the bulk carrier Nenita, citing that the pilot did not have enough information relayed to him about an engine failure that impacted maneuverability at a critical time.
 
On November 19, 2016, the fully-laden bulk carrier Nenita, registered in the Marshall Islands, was outbound on the Columbia River when the vessel suffered an engine failure. The vessel subsequently ran aground at Three Tree Point on the Washington State side of the river, damaging its bulbous bow and hull. After the grounding, the Nenita was towed to Longview, Washington, for temporary repairs. Two weeks later, the vessel resumed the voyage to its original destination. There were no injuries or reported pollution as a result of the accident.

The National Transportation Safety Board determined that the probable cause of the grounding of the bulk carrier Nenita was the failure of a main engine cylinder cooling jacket that initiated an automatic reduction in engine speed, resulting in the eventual loss of steerageway. Contributing to the accident was the lack of information relayed from shipboard personnel to the pilot about the status of the main engine, which prevented him from taking effective corrective action following the engine casualty.

Accident Events

About 0230 on November 19, the main engine cooling fresh water low pressure audible alarm sounded and the visual alarm illuminated on the display panel in the engine control room. The chief engineer acknowledged the alarm as the second and third engineering officers left the control room to the identify the source of the alarm condition. 

The third engineer discovered a crack on the main propulsion engine no. 3 cylinder cooling jacket located near the base of the cylinder cover. Cooling water was reportedly leaking from the cracked cooling jacket at approximately five to 10 gallons per minute. The chief engineer told investigators that he immediately notified the bridge of the failure via the ship’s phone. 

A minute later, the no. 3 cylinder cooling water outlet high temperature above 95 degrees C (203 degrees F) alarm activated, which automatically initiated an emergency slowdown of the main engine to below 30 rpm. This function was designed to protect the engine from damage due to the loss of cooling water until the abnormal  condition was corrected. About a minute later, the main engine cooling water expansion tank low level alarm activated followed by the cooling water outlet high temperature alarms on the remaining six cylinders. The second engineer closed the cooling water inlet and outlet valves to the no. 3 cylinder while the third engineer started to refill the expansion tank with water.

Meanwhile on the bridge, at 0231, the pilot ordered port 20 degrees rudder and then instructed the helmsman to steer a course of 270. About 0232, after feeling a reduction in vibration, the pilot asked, “Hey, what happened to our engine?” The VDR showed a drop in speed from about 90 rpm to 48 rpm while the engine order telegraph was still in the Nav Full ahead position. At the time of the rpm reduction, the vessel was making about 11 knots.

Soon after, the VDR captured audio of the master talking on the ship’s phone to the chief engineer and watch engineer inquiring about the loss of rpm on the main propulsion engine. The conversation between the master and the engineering personnel was not conducted in English, and thus the pilot could not understand the discussion. A minute and a half into the phone call with the chief engineer, the master told the pilot about a “leaking pipe on the main engine . . .. They are fixing it.” During the next 10 minutes, the phone conversation between the master and engineering personnel continued in their native language. The pilot asked several times, “What’s going on with the engine?” and stated, “I need some rpms.”

After the pilot questioned the engine performance, he ordered the rudder to midship and instructed the helmsman, who was trying to maintain the ordered course of 270, that he might have to use a lot of rudder due to the loss of rpm. The master then shifted the engine order telegraph down to dead slow ahead one position at a time to match and go below the actual engine rpm, which had now decreased to about 35 rpm. 

At 0235, the Nenita’s engine rpm decreased further to 25. The master asked if the ship should anchor, and the pilot responded that in the vessel’s present location there was not a place to safely anchor without going aground, primarily due to the anticipated change in current from flood to ebb.

A few minutes later, the pilot radioed ashore inquiring about the availability of two tractor tugs to assist the Nenita. From this point until the last moments before the grounding, the pilot asked the master with increasing urgency and exasperation the status of the engine, the availability of more engine rpm, and the ability of the engine to go astern. He made clear to the master that the lack of engine response was putting the vessel at risk of running aground. The master was likely relaying the pilot’s questions and concerns to the engine room while on the phone, but the conversation was only in his native language, and he never responded back to the pilot in English.

The Nenita continued to decrease in speed, now making about 6 knots at about 25 rpm ahead as it passed navigation marker “27” on the north bank of the river. The pilot ordered increasingly large helm orders to port and starboard to maintain the center of the channel; however, steerageway eventually was lost, and the vessel began to drift to starboard. The pilot, having received no verbal acknowledgement from the master about the engine status, ordered both anchors dropped and then ordered the engine to emergency full astern.

At the same time that the anchors were being ordered let go, the engine momentarily increased speed to about 65 rpm ahead. The engine speed then began to decrease and reversed to about 75 rpm astern, likely in response to the pilot’s last command, emergency full astern. At 0246, the Nenita ran aground at Three Tree Point in Washington State. Consequently, the pilot ordered the engine stopped and commenced making initial calls to the appropriate authorities.