[I can't give you the goals for this speech because I screwed up. Libby helped me to design this speech from the Entertaining Speaker book, but at the meeting I told them it was from the Speaking to Inform book; wrong. Anyhow, Libby and I thought that is was the most fun speech so far. Unfortunately for you the sound effects and timing that added drama don't come out in written form. I used Red text to indicate sound effects. Verbally though, those sound interrupted me mid-sentence, adding to the drama.]
A Fatal Lack of KISS
Start the countdown. 5 minutes from
now 10 people will die.
Ladies and gentlemen.
Last August, the destroyer USS John S
McCain was in the Straight of Singapore. That is a congested area
of the ocean with lots of ship traffic going in and out. In those
circumstances, one would think that the captain would order all
stations to be fully manned with the most experienced crew, including
himself, the master helmsman and the systems engineer. That did not
happen this night.
On the bridge are several stations.
The CO or commanding officer, the helm on the left that steers and
controls engine speed, the lee helm on the right, the aft station
behind, and the radar man. [BUZZ 4 MINUTES] The ship was modern, each of those
stations had a screen, keyboard and mouse. Steering wheels and
throttle levers don't exist any more. Normally there are also
lookout stationed outside, but not this night.
At 520 in the morning, the McCain was
moving fast at 20 knots. It was overtaking a tanker to the left
traveling maybe half as fast. My information comes from the official
navy report on the incident. What you see on the screen is the
record of the actual positions of the two ships at one minute
intervals
Suddenly, helm reported trouble
steering and controlling throttles at the same time. The CO barked
his order. LEE HELM YOU TAKE OVER THROTTLE CONTROL WHILE I HELP HELM
WITH STEERING.
Lee helm says, “Aye Aye sir.” Then
he used a pull down menu to select TRANSFER CONTROL.[BUZZ 3 MINUTES]
What nobody on the bridge understood is
that the software did not allow transfer of just throttle control. I
transferred both steering and throttle to lee helm.
Helm believed that he still had
steering control, but it wasn't working. He complained to CO. “Sir
it isn't working at all.” The CO said, “Let me see.”
Radar reported, “Ship close by on the
port side sir.” The CO responded, REDUCE SPEED TO 10 KNOTS. Lee
helm said, “Aye Aye sir.” and he moved the throttle control
slider on his screen to reduce engine power.
But lee helm believed that the slider
controlled both left and right engines together. He didn't
understand that on another pull down menu that option box was not
checked. So what actually
happened was that he reduced power to
the left engine while the right engine continued full speed. That
made the McCain start a gradual turn to the left.[BUZZ 2 MINUTES]
Nobody noticed the left turn except the
radar man. He said, “We are turning toward that ship sir.
Collision alert.” The CO responded, “REDUCE SPEED TO 5
KNOTS”. The lee helm said, “Aye Aye sir.” and he did as
ordered, again mistakenly only on the left engine. The rate of left
turn increased.
The CO and helm were frustrated that
steering control didn't work. CO ordered, “AFT STATION TAKE OVER
STEERING CONTROL” [BUZZ 1 MINUTES]
Aft station, said, “Aye Aye sir”
and he used a pull down menu to select TRANSFER CONTROL..
But Aft helm forgot to preset zero
rudder angle before the transfer. The previous rudder setting on his
screen was 33 degrees left rudder, so after the transfer the computer
moved the rudder to 33 left. Now the gradual turn became a lurching
sharp turn to the left. The whole ship leaned to the right. It
almost knocked the CO off his feet.
The CO screamed, “AFT STATION WHAT
THE HELL ARE YOU DOING”
Lee helm spoke up. “Sir, I just
realized that I set the throttles incorrectly. I'm attempting to
correct that now.” But he didn't understand that he no longer
controlled anything because aft station had the control.
Radar interrupted, “Sound collision
alarm. Sir, should I warn that tanker on the radio and sound 5
blasts on the horn?”
The CO said, “Everybody shut up. I'm
trying to figure out what is happening with the steering.”
[Crash]
On the screen are the names of the dead.
[At this point I stopped speaking and rang a bell 10 times to toll the dead.]
ding
ding
ding
ding
ding
ding
ding
ding
ding
ding
– 530--
So, what really happened? Who should
we blame? The captain of course. The officers, the crew and the
Navy. But, thinking like an engineer, one thing stands out. Kiss.
I don't mean Kiss in the romantic
sense. I mean the KISS Principle in engineering design. Keep It
Simple Stupid. KISS
Steering of any moving vehicle using
screens, keyboards, and mouse.is insane and an egregious violation of
the KISS principle.
Now, lets bring our attention back to
those of us in this room. All of you may have occasion to make
decisions in everyday life that could affect life and safety. There
is one lesson I want you to learn from this speech. Remember only
one word. What word is that? Everyone: KISS.
Thanks for the great explanation of this accident.
ReplyDeleteThanks for the kind words. But you should really read the official Navy report linked in the post. There's only a couple of pages relevant, and they are shorter than my speech.
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