Drill (071011)

Learning without thought is labor lost. -- Confucius.

When Jim Hoskins and I relieved the bridge watch well before
midnight, we were looking at what could be a dull four-hour
stretch. Returning from a Mediterranean deployment, our
destroyer was sailing alone in mid-Atlantic, far from
normal shipping lanes. No ships, no aircraft, and no land
were visible, even on radar, and the night orders were
simple: maintain current course and speed and call the
captain only if a ship or plane came within two nautical
miles.

After the enlisted personnel of the relieving bridge watch
had settled in at their stations and I had taken the conn,
the actual control of the ship, Jim and I went out on the
starboard bridge wing to plan. One way to enliven an
uneventful watch is to run drills and the midwatch has a
nightly opportunity because of the steering system.

Steering a vessel souped up to 70,000 horsepower, carrying
300 souls, and having no brakes is something you don't want
to fail, even if the ship is severely damaged. What
actually forces a turn is the rudder, a massive fin under
the stern that is rotated by the steering engine. This
engine is a giant piece of hydraulic machinery powered by
electric motors that are controlled by small electrical
signals. The steering engine is inside the ship in the
aftersteering compartment on the very bottom deck and the
signals must come from the bridge, on the very highest deck
and 300 feet forward.

The steering signals are generated by the helm, a vertical
steering wheel whose outward appearance hasn't changed that
much in 400 years. If you've seen any pirate movie, you
know what a helm looks like. The signals first go to the
steering alarm box on the forward bulkhead (or wall) of the
bridge. The steering alarm can tell if there's a complete
circuit from the helm back to the steering engine so that
the signals can get to it. If not, the alarm sounds, a loud
ringing like an old-fashioned school bell.

From the alarm box, the signals go to a brass rotary switch
on the after bridge bulkhead. This switch can choose
between two independent electrical cables on each side of
the ship that run back to aftersteering. In aftersteering
the two cables come into an identical rotary switch that
selects which cable to connect to the steering engine. Both
rotary switches have a neutral setting which isn't connected
to either cable.

So, for signals to pass from the helm to the steering
engine, both rotary switches must select the same cable.
Alternately, the steering engine can be connected to a wheel
in the aftersteering compartment and be controlled from
there instead of from the bridge.

If only half the ship is destroyed, you can steer from the
bridge using the surviving cable. If both cables or the
bridge have been destroyed, you can steer with the helm in
aftersteering. If that helm is destroyed or you're without
electrical power, you can actually move the rudder by
mechanical means, using the hydraulics if they've survived
or rigging blocks and tackles if the hydraulics are gone.

If a ship is still afloat, you want to be able to steer it.
And you want to be sure you can steer it by testing as much
of the steering system as you can every day. On the
midwatch the system changes from one steering cable to the
other. Even if both rotary switches are changed at the same
time, there will be a momentary loss of the signal path
while passing through the neutral position and this is the
basis of the drill:

(Scene: the bridge at midnight. The watch officer without
the conn approaches the steering cable rotary switch and
stealthily turns it, disconnecting the helm from the cable.)

Steering alarm (from the forward bulkhead): BRINGGGGGGG!

Helmsman: Bridge has lost steering control, sir.

Conning Officer: Very well. Tell aftersteering to take
control and steer course 255.

Bridge talker: Aye, aye, sir. (over sound-powered telephone
circuit) Aftersteering, bridge. Take control and steer
course 255.

(A pause while aftersteering disconnects from the steering
cable, mans its wheel, and steadies on course.)

Talker (hearing from aftersteering): Aftersteering
has control, sir. Steering course 255.

Conn: Very well.

(After a decent interval, long enough to give aftersteering
a good workout, the conning officer turns the rotary switch
to the other cable.)

Conn: Tell aftersteering to relinquish steering control and
switch to the port cable.

Talker: Aye, aye, sir. Aftersteering, bridge. Relinquish
steering control and switch to the port cable.

Helmsman (after discovering that the ship responds to the
wheel): Bridge has steering control, sir.

Conn: Very well. Steady on course 255.

Helm: Aye, aye, sir. Steering 255.

Conn: (ending the nightly loss-of-steering-control drill)
Very well.

This tests the steering alarm, both cables, both helms, and
insures that the watch knows how to handle loss of steering
control.

Now Jim had become concerned that through constant unvaried
repetition this drill had degenerated to an automatic
routine -- almost to a ritual -- performed by the watch
members without conscious thought. While lounging around
the bridge in port, he had discovered that by jamming his
toe into the underside of the steering alarm box, he could
make the alarm go off even though steering control had not
been lost and he hoped to revitalize the drill with this
device. We decided on the details of a little trap and
returned to the bridge.

"Mr. Hoskins has the conn," I said.

"Aye, aye, sir."

"Steering 255, sir."

"Very well."

"Both engines are ahead full, indicating turns for 24
knots, sir."

"Very well."

Jim walked to the forward bridge window, near the steering
alarm box, and stared out into the darkness. I baited the
trap by nonchalantly going to the chart table on the after
bulkhead, right next to the rotary switch. I killed some
time making an entry in the ship's log.

BRINGGGGGGGGGGGG!

"Bridgehasloststeeringcontrolsir."

BRINGGGGGGGGGGGGGGGGGGG (no answer) NNNGGGGGGGGG!

"Sir: bridge has lost steering control, sir!"

The alarm stopped as Jim wheeled away from the bridge
window and stalked back to the helmsman.

"Test your helm," he said.

"Aye, aye, sir. Bridge has regained steering control, sir."

"No it hasn't. You never lost it. That bell doesn't steer
the ship; you do. Check your wheel and your compass.
They'll tell you whether you have steering control or not."

"Aye, aye, sir. Sorry, sir."

"Don't be. Mr. Despain and I will see to it that you get
plenty of practice in the next two hours."

We did: we interspersed false and real alarms; we arranged
to have after steering disconnect while we both stood
innocently clear of the bridge rotary switch; sometimes we
had after steering take control and sometimes we kept
control on the bridge, coming up directly on the alternate
cable; we traded the conn back and forth, once having loss
of steering control occur at the same time. After two
hours, we'd covered every combination of circumstances
involving loss of steering control that we could think of.

Toward the end of the watch, Jim took the conn while I wrote
up the watch log entry. I checked the rotary switch and
discovered that we had ended our intensive drills on the
wrong cable for the day. I joined Jim on the wing and we
arranged one last drill. Jim came back and took his
position at the front of the bridge, once again near the
steering alarm box. I turned the rotary to the neutral
position.

Nothing happened.

The one thing we couldn't rig had occurred: perhaps because
of Jim's frequent prodding, the alarm had hung up, giving no
warning that the bridge had, in fact, again lost steering
control.

I glanced at the helmsman, wondering how long it would be
before he sang out, starting the drill. He was watching his
compass and noticed that the ship was drifting off course.
He put the helm further over, without effect. Suddenly he
shifted the helm, turning it as far to the left as he had had
it to the right.

Good, I thought. He's figured it out. As I waited
expectantly, he turned the wheel back to the right. I
decided he needed a little jog, so I left the cart table and
went to the radar repeater alongside the helm.

"Anything wrong?" I said, thinking he would now realize
that he'd lost control and sing out.

"Gee, Mr. Despain, I don't know, but I think this
son-of-a-bitch is broke."

So much for two hours of drill. We had learned that the
alarm did not necessarily mean loss of steering control.
But we had somehow missed the essential principle: steering
control is when the ship responds to the helm. Just that.
And the alarm is just a fallible hint.