Clear the Bridge! by Richard O'Kane

working area on the depth gauge, which hit the pin at 612; and the unlikelihood of getting any close depth charges. Depth-charging is three-dimensional bombing. If the Japanese even possessed a depth charge with a hydrostatic exploder capable of operating at this depth, the chance of getting one close enough was extremely remote.
    Distant depth-charging continued as I tried to relax over a cup of coffee. Before the first cup was finished, Fraz reported another contact. In the conning tower, Caverly, who was still at his station, flipped on the small speaker that carried the same sounds he had in his earphones. The faint
thump-thump-thump
of heavy screws came through the background noises.
    We checked with the after torpedo room. Hank and his reload crew were just pulling the last torpedo home. A moment later the big bronze bayonet ring had secured the torpedo tube’s inner door, and
Tang
’s bow rose. Swimming up, like a guppy, seemed to take longer than it had during the approach. But then we had known that the enemy was coming our way and all hands were occupied. Now, we could only wonder at what lay topside and listen to Bill’s frequent orders as he flooded the auxiliary tanks from sea. So many operations appear simple when they go smoothly, and it would not be impossible now to overlook crucial details such as the vertical component of
Tang’s
movement. If it became excessive, there might be no stopping her at 60 feet. Without the urgency of a pending attack, we paused at 100 feet to check the trim.
    We reached 60 feet within moments; it was still too dark to spot distant ships, but a quick SJ search showed one good-sized pip and some smaller ones off at 14,000 yards. We surfaced and put all engines on the line or charging batteries, then raced against the coming dawn to get ahead of the enemy and jam a charge into our batteries. It would be close, for on its course of 300 degrees, the convoy was heading nearly away from us at 7 knots.
    Like all diesels, our main engines had mean effective cylinder pressures, called MEPs, that could not be exceeded for long withoutinviting trouble, even piston seizures and wrecking an engine. Battery charging was guided by temperature voltage gravity curves, called TVGs. If the TVGs were exceeded, our batteries would gas and could quickly generate enough hydrogen for a devastating explosion. To prevent the accumulation of gas, a separate ventilation system was provided, fitted with blowers, flow meters, hydrogen meters, and alarms.
    To reach an approach position,
Tang
would have to exceed the MEPs and push the TVGs. As captain, I viewed a possible engine casualty as one of the lesser risks in going after a million-dollar enemy ship. I didn’t blame the engineers for not agreeing with me, for those diesels were their babies, but they fell in line admirably.
    A fortunate characteristic of a storage battery is its ability to store enormous amounts of energy during the first part of the charging cycle and still remain well below maximum TVG curves. The engines on charge carried their share. All of them laid down a trail of smoke, indicative of overload, but
Tang’s
engines were Fairbanks Morse, and if anything could get us there with enough battery capacity for an approach, it would be these rock-crushers. They did; 40 minutes after surfacing we dived well ahead of the enemy.
    The morning twilight was short here, close to the equator, and we had good details on the first periscope look. They were disappointing, however, for the ship had zigged away and was showing a 50-degree starboard angle on the bow. We knew where to go but, fortunately for the enemy ship, she didn’t. During the next six hours she presented angles around through her stern to 150 port. Our best sustained speed closed to 6,000 yards at one time, but then she drew slowly away to the south and disappeared toward an area that should now be occupied by our submarine
Burrfish
. An
Asashio
type destroyer, a
Chidori
torpedo