Problems discovered during these trials can be corrected before combat.
Shinano had been rushed through this process.
The pressure to move her away from Yokosuka meant the carrier went to sea before normal preparation was complete.
One U.S. Naval Institute account based on postwar examination of the sinking states that the ship's watertight security had never been properly tested.
This was not a paperwork issue.
A ship as large as Shinano contains an enormous internal maze.
Damage-control personnel need to know that maze almost instinctively.
They need to know which valves isolate which lines.
They need to know how compartments connect.
They need to know where portable pumps can be moved.
They need to know which doors must remain shut.
They need to know which spaces can be sacrificed.
Training creates that knowledge.
Shinano's crew had barely had time to become a crew.
A newly assembled crew cannot become a damage-control organization overnight
The Japanese carrier had only been commissioned on November 19.
Ten days later she was on the bottom.
This fact alone shows how little time the sailors had possessed to develop coordination.
Damage control aboard a large warship is not a job performed only by specialized technicians.
It is an organization involving the entire ship.
People must report flooding accurately.
Compartments must be isolated.
Doors must be closed.
Pumps must be started.
Electrical circuits may need to be rerouted.
Counter-flooding decisions require information about list and stability.
Firefighting and flooding control may occur simultaneously.
Officers need reliable reports from below.
Damage-control central needs to understand what is happening throughout the hull.
This coordination becomes much harder in darkness after multiple torpedo impacts.
It becomes harder still when the ship is unfinished.
Shinano also carried civilian workers and technicians because completion work remained underway.
A U.S. Naval Institute postwar account described confusion between crew members and civilians and emphasized the almost completely untrained state of the ship's company.
A carrier can contain thousands of people and still lack an effective damage-control team if those people have not practiced together.
Numbers are not organization.
Shinano had mass.
She had manpower.
She lacked readiness.
Pumping capacity existed more on paper than in reality
Pumps are among the most obvious tools for controlling flooding.
Their effectiveness is often misunderstood.
A pump cannot save a compartment if water enters much faster than the pump can remove it.
Pumps are most useful when the inflow has been reduced, isolated, or confined.
They can remove leakage.
They can keep partially flooded spaces usable.
They can transfer water during stability control.
They can prevent progressive accumulation.
Shinano needed exactly this capability after the torpedo attack.
Much of it was unavailable.
Postwar accounts state that major parts of the drainage and pumping system were not operational because equipment had not yet been delivered or installed. Portable pumps existed, but crews lacked training with some of them, and the available capacity could not match the spreading flooding.
This created another dangerous feedback loop.
Water spread into additional compartments because watertight boundaries were incomplete.
As more compartments flooded, the amount of water requiring removal increased.
The limited pumps became less useful.
The growing list made movement and equipment operation harder.
Damage-control teams became overwhelmed.
Eventually, the problem grew beyond anything portable equipment could correct.
The ship was not simply leaking.
She was losing her internal geometry.
Captain Abe initially trusted the size and protection of his ship
Captain Abe had reasons to believe Shinano could survive.
The ship had been built from a Yamato-class hull.
Her underwater protection was substantial.
Her displacement was enormous.
Japanese officers knew that Yamato-class construction was intended to endure damage that would destroy smaller ships.
The immediate post-attack evidence could reinforce that confidence.
Shinano was still moving.
Engines were still functioning.
The ship remained structurally intact.
She had not exploded.
The initial list appeared potentially manageable.
According to postwar U.S. Naval Institute analysis, Abe ordered the carrier to maintain high speed for a period after the torpedo hits, apparently believing continued movement toward safety was possible.
This decision has often been criticized, because forward motion increased pressure on damaged portions of the hull and encouraged more water to enter.
Yet it should be understood in context.
Stopping in waters where an enemy submarine had just attacked also carried danger.
A stationary carrier would be easier to attack again.
The escorts had not necessarily destroyed Archerfish.
Kure remained the destination.
Abe initially believed Shinano's protection could contain the damage.
If that assumption had been correct, maintaining movement could have been rational.
The assumption was wrong because the ship's internal condition did not match the protection imagined by her design.