Flooding in the Engine Room (By the Dock)
Like all Navy ships, our submarine, when not steaming and generating its own electrical power, would take on electrical power from the pier or tender. This is called shore power and is carried onboard in shore power cables. The three shore power cables were like big extension cords. Each cord was rated to carry 400 Amps of current at 480 Volts. The shore power cables had special cast bronze hooded connectors with rubber gaskets, that plugged into special sockets in the engine room escape trunk. You would insert the plug into the socket, then screw the locking ring down firmly on the socket threads which would lock the plug into the socket and make a safe and water tight connection.
All during the shipyard period, the shore power cables were routed into the engine room escape trunk through the escape hatch on the starboard side of the trunk. The engine room access hatch on the top of the trunk was filled with welding leads, air hoses and other shipyard stuff, so engine room access through the trunk was effectively blocked.
As the yard work progressed, it became necessary to move the boat. Our first move was out of the drydock to be moored pierside. This required us, the electrical division NUBs, to disconnect the shore power cables for the move, and then reconnect them when the boat was moored again. Each time the boat was moved, for steam plant testing or to go on sea trials and so forth, we disconnect the shore power cables before the move and then reconnected them after the move. Each time we route the cables into the engine room escape trunk through the escape hatch, like we had always done.
This worked quite well for us. We could use the upper hatch for our convenience while connecting or disconnecting the shore power cables, then close the upper hatch and block traffic through the trunk while the cables were energized supplying power to the boat. Since we had never seen the cables routed any other way, and the “qualified” old salts never corrected us, we always routed the cables this way, through the escape hatch into the escape trunk.
At the end of the Blue Crew shakedown cruise, we returned home to the Sub Base and moored. After the Maneuvering Watch had been secured, the electrical NUBs connected shore power, the reactor plant was shutdown, and the in-port Nukeland shutdown watches settled in. Those not in the duty section bagged it.
Lt. “Chicken Lips”, the A Gang division officer was the EDO. So, since he had to be onboard, he thought that he might as well lead the A Gang duty section in performing some necessary PMs on the MBT venting system. This required opening the MBT vent valves one at a time and inspecting the seating surfaces or whatever. He started with a STARBOARD side vent. It opened and the boat listed slightly to starboard. No problem.
Problem. Shortly after the boat listed, a small waterfall developed from the engine room escape trunk lower hatch. It seemed that the boat had listed enough to allow the open escape trunk to rotate below the waterline of the river. As the water merrily pitter-pattered out of the lower engine room trunk hatch into ERUL, the SMAW sounded the collision alarm and announced “Flooding in the Engine room” on the IMC. The Engine Room Shutdown Roving Watch quickly assessed the situation, and immediately shut and dogged the lower hatch. Flooding secured.
But wait! The engine room escape trunk was now filling with water, drowning the shore power cable connectors. As SEO, Shutdown Electrical Operator (a glorified name for the juniorest electrician on watch) I was parked in front of the Electrical Plant Control Panel. I switched the Ship’s Service Ground Detector to the TG-TG Bus Tie and monitored electrical ground of the shore power connection. If the bus tie ground went below a certain reading, the shore power connectors would effectively be shorted together, which would cause an electrical explosion in the escape trunk. Although the trunk was closed and any explosion in the trunk would be contained, it would cause serious damage to the ship’s electrical system and further delay our turn over to the Gold Crew. This would not please Captain Overhaul and was therefore not desirable.
In the Control Room, Lt. “Chicken Lips” and the Below Decks Watch closed the MBT vents and blew HP air into the ballast tanks. AJ righted herself immediately. Once the ship was back on an even keel, water stopped filling the engine room escape trunk. To recover from this flooding event, it was decided to open the drain valve on the escape trunk and evacuate the water. As the seconds and minutes ticked by, I continuously monitored the Bus Tie electrical ground, ready to trip the TG-TG Bus Tie circuit breakers and divorce shore power from the ship to prevent an electrical explosion.
The ground reading remained high above the minimum value. So after the trunk was drained, the lower hatch was opened, and the shore power connectors were inspected. It seems that Louie, one of the newest electrical NUBs, had been upset about something or other that day and had vented his frustration by torquing the connector lock rings down as tight as he possibly could. You might say that his anger management technique had inadvertently saved the day.
After that, we always brought the shore power cables into the engine room escape trunk through the upper hatch, and left the escape hatch shut and rigged for dive. We never had that problem again.
Charlie Winterfeldt