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USS McCain collision ultimately caused by UI confusion

arstechnica.co.uk

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Re: USS McCain collision ultimately caused by UI confusion

#301

Post by zentiggr »

jabl wrote: post #207
diggernet wrote: post #164

Earlier quoted context omitted.

Absolutely. Maintaining a ship's heading is a full time job. If you get distracted, you get off course pretty quickly. Speed isn't even really handled on the bridge. The engine order (ahead full, back half, emergency stop, etc) goes to the engine room where multiple people do the work. Note: This is in the context of oil and nuclear steam-powered ships. Gas turbine ships may well have an actual throttle on the bridge…

As an outsider (well, I have plenty of experience with pleasure boats/yachts, but none with large ships) it seems really extraordinary that just maintaining a heading would be a full time job. Somehow in airplanes a single pilot manages to control not only the rudder, but throttles, ailerons, elevators, flaps and whatnot while also yakking on the radio. And airplanes zip along at 500 knots rather than 20 like a ship.

Navy sub vet and almost licensed as a pilot: The small aircraft case - one mind, one set of hands, to reduce the feedback loop to fractions of a second overall. Things other than throttle/ailerons/elevators get timeshared in when all else is stable momentarily.

Larger ship - water is never still, and any vessel's helm left untended results in drift, both in heading and real speed vs ordered. Depending on traffic and the reaction time of the hull, corrections need to be made immediately or even well ahead of time. So helmsman watching constant compass shifts and adjusting steering is a full attention task. As is monitoring speed made vs speed ordered. Still need more eyeballs to keep a full 360 visual watch, radar watch, and a quartermaster to plot position against nav hazards and boundaries and warn against the 'invisible' navigation issues.

If a destroyer could respond to control input like a plane, there would need to be a single person at the helm/throttle.

Re: USS McCain collision ultimately caused by UI confusion

#302

Post by pbhjpbhj »

mostlyskeptical wrote: post #43
csours wrote: post #24

Earlier quoted context omitted.

The path to a disaster has been compared to a tunnel [0]. You can escape from the tunnel at many points, but you may not realize it. Trying to find the 'real cause' is a fool's errand, because there are many places and ways to avoid the outcome. I do take your meaning, reducing speed and following well established rules would have almost certainly have saved them. 0. PDF: http://www.leonardo-in-flight.nl/PDF/FieldGui…

As we say when teaching new riders to ride a motorcycle, a crash is often an intersection of factors. If you remove even one of those issues it likely would have prevented it.

I've noticed a lot of learners (eg in YouTube videos) crash because they grab at the handlebars, grabbing the throttle and inadvertently accelerating.

Is there a reason the throttle can't be reversed so that grabbing would reduce throttle and slow the bike?

(FWIW, I'm a fully licensed motorcyclist, don't currently ride.)

Re: USS McCain collision ultimately caused by UI confusion

#303

Post by killjoywashere »

chrisseaton wrote: post #107
a_t48 wrote: post #104

Earlier quoted context omitted.

This would mean wasting fuel, no?

What's that got to do with anything? The comment was about the ability to vary power at all, not doing it efficiently. Are you going to choose to crash into something because it's wasting fuel to vent part of the steam?

At sea, efficiency gets you back to land.

Re: USS McCain collision ultimately caused by UI confusion

#304

Post by mikeash »

foldr wrote: post #223
mikeash wrote: post #74

Earlier quoted context omitted.

There's a big difference between unknowingly fighting over the controls and knowingly fighting over the controls. If Robert had realized that Bonin was making the completely wrong control input then maybe he would have put a stop to it somehow. "Stop that, you'll get us all killed" is likely to be effective. He could have told the captain about it as soon as the captain arrived, rather than just before impact. Note t…

There's no indication that they were fighting unknowingly. I'm not sure what you're concluding that on the basis of. >Note that when the incorrect input was finally identified by someone other than Bonin, it was corrected immediately, it was just far too late. So the popular mechanics article says, but it's not so clear in the report that this ever really happened.

Whether or not they knew they were fighting is not quite the relevant bit. What's relevant is knowing what the other guy's inputs are. Given that the other two pilots were quite surprised once Bonin finally said that he had been holding the stick back the entire time, they clearly were not aware of this.

You say it's not so clear that this ever really happened, but it's pretty clear to me from the official transcript:

Robert: remonte remonte remonte remonte

Bonin: mais je suis à fond à cabrer depuis tout à l’heure

Captain: non non non ne remonte plus là

Robert: alors descends

Robert: alors donne moi les commandes à moi les commandes

My quick and dirty translation:

Robert: climb, climb, climb, climb

Bonin: but I've had the stick back all the way this whole time

Captain: no, no, no, don't climb anymore

Robert: then descend

Robert: then give me the controls, I have the controls

Re: USS McCain collision ultimately caused by UI confusion

#305

Post by 0xffff2 »

tga wrote: post #202
diggernet wrote: post #164

Earlier quoted context omitted.

Absolutely. Maintaining a ship's heading is a full time job. If you get distracted, you get off course pretty quickly. Speed isn't even really handled on the bridge. The engine order (ahead full, back half, emergency stop, etc) goes to the engine room where multiple people do the work. Note: This is in the context of oil and nuclear steam-powered ships. Gas turbine ships may well have an actual throttle on the bridge…

Especially if it's so easy to get off course, and since the responsibility lies with another officer anyway, steering sounds like a job better suited for a computer, rather than a person. As far as I know, airline pilots already dial in most navigational course changes to the autopilot, I would have imagined ships to work similarly.

That seems obvious today, but the McCain was laid down in 1991. Computers were much less sophisticated back then.

I wonder if there is enough information publicly available to compare the workflows on the McCain to the same workflows on the Zumwalt.

Re: USS McCain collision ultimately caused by UI confusion

#306

Post by saulrh »

zentiggr wrote: post #301
jabl wrote: post #207

Earlier quoted context omitted.

As an outsider (well, I have plenty of experience with pleasure boats/yachts, but none with large ships) it seems really extraordinary that just maintaining a heading would be a full time job. Somehow in airplanes a single pilot manages to control not only the rudder, but throttles, ailerons, elevators, flaps and whatnot while also yakking on the radio. And airplanes zip along at 500 knots rather than 20 like a ship.

Navy sub vet and almost licensed as a pilot: The small aircraft case - one mind, one set of hands, to reduce the feedback loop to fractions of a second overall. Things other than throttle/ailerons/elevators get timeshared in when all else is stable momentarily. Larger ship - water is never still, and any vessel's helm left untended results in drift, both in heading and real speed vs ordered. Depending on traffic and…

I understand that keeping on a desired course is not a simple task and requires prediction and understanding of the surrounding waters... But you can say the same thing about crosswinds and thermal layers and pockets of turbulence in the air over a runway, and autopilots land 747s every day. In a far more computationally intensive and less recoverable domain, with more complex system dynamics and controls even discounting the extra dimension, plus sensing that's both more limited and harder to interpret. If modern controls theory can land an aircraft, I'd expect it to be able to run a ship along a trajectory like it's nailed to a rail in space-time.

Re: USS McCain collision ultimately caused by UI confusion

#307

Post by wmeredith »

lisper wrote: post #106

It's not just boats that have safety-critical UI design problems. The avionics in airplanes are becoming so complicated that managing the avionics is almost more difficult than flying the plane. I'm a private pilot who has been flying a Cirrus SR22 for twelve years. In that time it has gone through two major glass cockpit avionics revisions. In the first revision, called the Avidyne, the autopilot was either on or of…

"managing the avionics is almost more difficult than flying the plane" The same goes for modern cars. The electronics is a nightmare. HVAC controls locked away behind touch screens menus. It's awful.

Re: USS McCain collision ultimately caused by UI confusion

#308

Post by wmeredith »

thunderplot wrote: post #103

Militaries are good at making horrible UI. :-) I used to work at early warning radar, that should notify our tops about incoming ICBMs. When there's a target, classified as "suspicious" or "something that's going to fall onto {our, neighbour} territory", the following happens: - very loud sine 1200Hz tone starts sounding - the only output device, "fast-printing device", starts dumping hexdumps of internal structures…

"Militaries are good at making horrible UI."

This is extremely applicable: https://hackernoon.com/why-the-dmv-website-sucks-2f27a367baa...

Disclaimer: it's an article I wrote about why government software contractors suck at their jobs.

Re: USS McCain collision ultimately caused by UI confusion

#309

Post by 0xffff2 »

wruza wrote: post #300
Zeebrommer wrote: post #286

Earlier quoted context omitted.

Although I think ship control can definitely be made more user-friendly, what you are asking for is of similar complexity as a self-driving car.

I thought most of self-driving car complexity comes from guessing the route and stop timings, not from following them?

I'm honestly confused by this comment. If I'm reading it correctly, you have those two backwards. Computers have been able to figure out routes since the mid-90s (see MapQuest, Google Maps, Waze, etc). It's exactly the "following" that is the responsibility of self-driving cars.

Re: USS McCain collision ultimately caused by UI confusion

#310

Post by wnkrshm »

eternalban wrote: post #216
jordanb wrote: post #134

Earlier quoted context omitted.

http://s3.amazonaws.com/CHINFO/USS+Fitzgerald+and+USS+John+S... The McCain entered the TSS at 20 knots and varied between 20 and 18 knots until the steering problem began. The OOD ordered the vessel slowed to 5 knots but due to confusion on the bridge the orders weren't carried out properly and the vessel was still making 11.8 knots and turning to port at the moment of impact. The Fitzgerald was also traveling throug…

Sure, don't believe your lying eyes. Point out a single scratch that indicates anything other thana 90 degree impact with a stationary vessel.

If you read the report that is linked above, you can see the relative speeds, headings and impact geometry.

The McCain crossed in front of the cargo vessel and was hit in the aft section by the cargo vessel that had a constant speed and heading.

You don't stop or turn a cargo vessel as quickly as the McCain can maneuver. You also need to take into account that you don't shove a ship sideways through the water easily - it can't slide as easily as a car can. The majority of the cargo vessel's kinetic energy will go into plastic deformation. It's not a sudden impact, more a crushing and deforming.

Edit: I have to revise what I said about the impact, according to the report, sailors close to the impact likened it to an explosion.

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