Brandon switched the pump off and it coasted to a halt.
“Well done, men,” Tolbert said. “Once we get the ice cream machine up, you guys get first dibs.”
The other men grinned.
“I’ll take a long hot shower,” Brandon said.
“You got it,” Tolbert said. “Speaking of hot”—he turned to Lieutenant Commander Swenson—“restore Engine Room ventilation and heaters. Let me know once everything has thawed and you’re ready to commence start-up.”
The Engineer acknowledged, and Tolbert left Engine Room Forward, stopping in Maneuvering to check on the battery. Electrician’s Mate Second Class Allen Terrill was the sole person on watch again, seated at the Electric Plant Control Panel with a worried look. Tolbert followed his eyes to the battery meters, and was shocked at the low voltage.
Tolbert’s bubble of excitement over repairing the condensate pump had been burst. Battery capacity had dropped from thirty percent when they opened the battery breaker to only fifteen percent now.
“We’ve lost capacity because the battery cooled down after we open-circuited it,” Terrill said. “Maybe it will recover as it warms back up, giving us a few more hours than it appears.”
Tolbert hoped Terrill was right.
35
Eight hours later, Tolbert returned to the crowded Engine Room, shielding his eyes from the light as his pupils adjusted. They were getting close to commencing reactor start-up, so essential equipment had been energized, along with a portion of the Engine Room lights. Now that the ventilation heaters in the compartment had been restored, every member of North Dakota’s crew congregated in the warm compartment, thawing out after living in a sub-zero climate for the last week. However, even though the Engine Room had been heated to eighty degrees, it was taking longer than expected to melt the ice in the Condensate and Feed systems. As he reached Maneuvering, he almost didn’t want to receive the update on the battery’s status.
Tolbert entered a fully manned Maneuvering this time, with the most experienced personnel on watch. With the battery draining ever faster as voltage lowered, they might have to take a few shortcuts during the Engine Room start-up, so the Engineer Officer had stationed his most senior personnel in Maneuvering and throughout the Engine Room. Lieutenant Vaugh, the most experienced Engineering Officer of the Watch, sat at his console behind the two enlisted watchstanders: Electrician’s Mate Art Thompson as the Electrical Operator, and Electronics Technician Joe Hipp, who was seated at the Propulsion Plant Control Panel.
Lieutenant Commander Swenson joined Tolbert in Maneuvering, his eyes focusing on the battery voltage and discharge rate. Battery capacity was down to five percent.
He turned to Tolbert, “The Feed System is ready to go, but Condensate is still frozen in a few spots.” He glanced at the battery meters. “We can’t wait any longer. I recommend we start up now, and by the time we’re ready to open the steam stops, Condensate should be ready.”
Tolbert concurred. “Commence reactor start-up.”
Swenson passed the order to the Engineering Officer of the Watch, who initiated the procedure.
Once all prerequisites were verified, the Propulsion Plant Operator announced, “Latching Group One rods,” then he twisted the shim switch to the IN position while applying latching current. A moment later, he announced, “Withdrawing Group One rods,” then shifted the shim switch to the OUT position.
Tolbert watched the battery discharge rate rise as the Control Rod Drive Mechanisms atop the reactor pulled the control rods upward. Petty Officer Hipp alternated between control rod groups, withdrawing each set in stages as he monitored reactor start-up rate.
A short while later, he announced, “The reactor is critical,” meaning the fission rate inside the reactor had become self-sustaining, no longer overcome by control rod neutron absorption. Hipp continued withdrawing the control rods, and a few minutes later announced, “The reactor is in the power range.”
Power had been increased to one percent and the reactor was now generating heat. But they still had a long way to go. They needed to heat the plant several hundred degrees to its normal operating temperature, but could heat up only so fast. Submarine reactors were pressurized water reactors, meaning the water inside was kept at extremely high pressure to keep it from boiling, which would interfere with heat transfer from the fuel cells.
Because of the high pressure, submarine reactors were built with one-foot-thick Inconel walls. At extremely low temperatures, the reactor vessel could brittle-fracture if the thermal stress across the metal was too great. They had to warm the reactor vessel slowly. From a temperature this low, it would be several hours before the plant was hot enough to generate steam.
Tolbert’s eyes went to the battery meters. It was going to be close.
It was barely an hour later when Tolbert received the bad news. He was still in Maneuvering with the Engineer when the Electrical Operator reported, “Battery cell reversal has begun.”
North Dakota’s battery was comprised of 126 cells connected in series. There were minor manufacturing differences in the four-foot-tall, two-thousand-pound cells and some would deplete faster than others. When a cell depleted, it would reverse, and begin charging itself at the expense of others. They needed to disconnect reversed cells quickly to minimize the power drained from the remaining good cells.
The Engineer Officer ordered, “Get me a readout of all cells.” A minute later, Vaugh handed the Engineer a printout. Swenson circled a few readings with his pen, then handed it to Tolbert. Cell eighty-nine had reversed, and there were six other cells whose voltage was lower than the rest and wouldn’t be far behind.
“I recommend we jumper out these seven cells.”
Tolbert agreed. However, they had a problem. The battery breaker was usually opened before jumpering a cell, to eliminate current flow while personnel were inside the cramped Battery Well. Unfortunately, the battery was their only source of power, which meant he would have to send someone into the Battery Well with the breaker still shut.
The Engineer reached the same conclusion. “Request permission to jumper out cells without opening the battery breaker.”
In Forward Compartment Lower Level, Chief Moran held the battle lantern in the darkness while Petty Officer Tim Brandon stripped the SEIE suit from his body, then removed all metal accoutrements from his clothing. No belt buckles, metal-framed glasses, military insignia — nothing metal would go into the Battery Well aside from the tools and cables needed to jumper out the bad cells. However, the tools and cables were rubber coated, with bare metal exposed only at the ends, so he could handle them without getting electrocuted.
Brandon folded the paper Moran had given him, listing the cells to be jumpered out, and slid it into his pocket, then inventoried his tools and jumper cables. “I’m ready,” he said.
Moran spoke into his headset. “Maneuvering, Forward Compartment Lower Level. Request permission to enter the Battery Well. The battery breaker is still shut.”
Seconds later, Moran replied, “Enter the Battery Well, aye.”
Moran passed the order to Brandon, who donned a pair of plastic goggles. He was entering the Battery Well with 126 lead-acid cells filled with sulfuric acid, potent enough to eat through flesh. Skin would heal, but eyes were a different matter. Brandon pulled the hatch open, then lowered himself into the cramped compartment, his feet hitting wooden support plates on top of the cells three feet down.