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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

#281

Post by LeifCarrotson »

Animats wrote: post #73

There was a ferry accident involving a similar transfer of control problem in New York harbor.[1] Ferries have a lot of maneuvering modes and directional thrusters, because they do so many dockings, and so they have a more complex control problem. The pilot put the system into a backup dumb mode while in cruise, then changed stations to where he could best see the dock while still in the wrong mode. Rammed the dock a…

Splitting command is still useful when maintaining control takes constant effort. If there needs to be a human in the loop maintaining and adjusting speed or heading, rather than using a 'cruise control' and letting an automated control loop maintain that setting, then it does make some sense to let different people handle it so that the person actually in charge can focus on what they need to do rather than the minutiae of that controller.

This was used on the America's Cup New Zealand hydrofoil [1]. Conventional designs gave a helmsman a wheel to control the rudder with a twist grip on that wheel which controlled the angle of the hydrofoils and therefore the ride height of the boat. On the New Zealand design,

> they've got control of the boat divided between three people, so that Peter Burling is just steering. You can see he's just driving Miss Daisy when he's going down the run. And there's a guy trimming the wing sheet [adjusting power], he's doing a relatively conventional job. But then the third man forward in the boat has got his arms in what look like biathlon bars and he's controlling both the daggerboards all the time. He's in charge of just keeping the boat ride height at the right level, whereas on the other boats it's the helm with his buttons and paddles on the wheel who's actually having to fly the boat up and down and do the steering.

This does leave just one person - the helm - with real control of the boat. The others are just maintaining the ride height and maximum power from the sail. In the naval model, the helm doesn't actually have control of the boat.

But I think that you're correct that a naval ship which would allow electronics to maintain speed and bearing doesn't require that, and the primary reason for retaining it is political desires from the brass.

[1] https://youtu.be/bAXA0mIXGmU

Re: USS McCain collision ultimately caused by UI confusion

#282

Post by [deleted] »

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.

[deleted]

Re: USS McCain collision ultimately caused by UI confusion

#283

Post by dragonwriter »

wruza wrote: post #277

Maybe I’m too late or too simplistic, but why do ships and aircrafts have so complex control systems in normal functioning modes at all? Why can’t layman ship commander like me just tell the system to be “there” in specific time via hand-drawn or standard route? If my engines malfunctioning, or steering lost it is one thing, but if everything is okay, can’t a simple swipe-to-sail iphone app just coordinate all ship c…

> Maybe I’m too late or too simplistic, but why do ships and aircrafts have so complex control systems in normal functioning modes at all?

In the case of warships, specifically, its because normal operations are reduced-complexity training opportunities.

Re: USS McCain collision ultimately caused by UI confusion

#284

Post by LeifCarrotson »

cocoablazing wrote: post #126
ineedasername wrote: post #101

Earlier quoted context omitted.

Yep, but that freeze is limited with more training, and mixed watches when teh newbs have to be rotated in for the real thing so the "hold my beer" guys aren't outnumbered 10 to 1 by the frozen folks.

I can't believe these watchstanders had the LOK they should have had on the steering system, or every one involved in ship control would have been able to immediately identify the problem and realign the steering system, other than bmow. I don't think the senior watch team had their st either, or the orders to prepare to take manual control of the steering and propulsion system aft would have immediately been out. Al…

There's a lot of acronyms in there.

LOK = Level of knowledge?

BMOW = Boatswain's Mate Of the Watch

ST = ? Not "Subject to" or "Such that" as I've seen.

CPA = Collision Prevention Assist in automotive systems, but maybe not here?

Re: USS McCain collision ultimately caused by UI confusion

#285

Post by LeifCarrotson »

nicwolff wrote: post #37
theyregreat wrote: post #20

Earlier quoted context omitted.

That is super dumb and dangerous. They should just flip the inputs on one end. EDIT (since some people obviously don’t understand the problem): ... so that each set of controls is always correct for the respective side on which it is located. No switch is necessary.

No, they just have a big button by each wheel marked "MAKE THIS THE BOW".

When would you ever not press that button?

Re: USS McCain collision ultimately caused by UI confusion

#286

Post by Zeebrommer »

wruza wrote: post #277

Maybe I’m too late or too simplistic, but why do ships and aircrafts have so complex control systems in normal functioning modes at all? Why can’t layman ship commander like me just tell the system to be “there” in specific time via hand-drawn or standard route? If my engines malfunctioning, or steering lost it is one thing, but if everything is okay, can’t a simple swipe-to-sail iphone app just coordinate all ship c…

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.

Re: USS McCain collision ultimately caused by UI confusion

#287

Post by sandworm101 »

Animats wrote: post #73

There was a ferry accident involving a similar transfer of control problem in New York harbor.[1] Ferries have a lot of maneuvering modes and directional thrusters, because they do so many dockings, and so they have a more complex control problem. The pilot put the system into a backup dumb mode while in cruise, then changed stations to where he could best see the dock while still in the wrong mode. Rammed the dock a…

>>> The brass hated it. The person in the pilot's seat was really the one in charge. The officers were just back-seat drivers.

Which is why pilots in modern air forces are officers. It isn't about guarding traditions. It's about the level of training and responsibility needed when navigating a vessel. The Albacore operated in a totally different environment. Its "pilot" wasn't navigating in a busy shipping channel and could turn on a dime. The reason that the watch officer doesn't operate the control is because that frees him/her to concentrate on actual navigation, the forward thinking needed when operating a huge object that cannot turn on a dime. Civilian vessels at sea are going from A to B. For a military vessel (ship or aircraft) the A->B navigation is one of many different missions going on simultaneously. That's why they need more heads making decisions.

" ... did not have the right type of watch on duty for navigation in congested waters ... "and neither attempted to make contact through Bridge to Bridge communications."

The system did not fail. The system wasn't implemented. UI issues were secondary to the fact that this was an undermanned ship with an unconfident crew.

Re: USS McCain collision ultimately caused by UI confusion

#288

Post by freeone3000 »

pbhjpbhj wrote: post #256
hvidgaard wrote: post #192

Earlier quoted context omitted.

Modern automatics are almost always more efficient. The biggest is that the torque converter has a lockup clutch during crusing, and often more gears and a near perfect knowledge of when to shift gear.

Do they break more often too? Like TCO is higher? Automatics in UK certainly cost more, if one doesn't ride the clutch I imagine the manual will have lower maintenance costs?

Manual has lower maintenance costs regardless. A clutch plate is about $500, an automatic transmission is between $1500 and $4000. Manual doesn't require its fluid to be changed.

Re: USS McCain collision ultimately caused by UI confusion

#289

Post by freeone3000 »

Zeebrommer wrote: post #286
wruza wrote: post #277

Maybe I’m too late or too simplistic, but why do ships and aircrafts have so complex control systems in normal functioning modes at all? Why can’t layman ship commander like me just tell the system to be “there” in specific time via hand-drawn or standard route? If my engines malfunctioning, or steering lost it is one thing, but if everything is okay, can’t a simple swipe-to-sail iphone app just coordinate all ship c…

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.

We have those! Or at least, we have close enough to one of those for a secondary autopilot system.

Re: USS McCain collision ultimately caused by UI confusion

#290

Post by krschultz »

Animats wrote: post #73

There was a ferry accident involving a similar transfer of control problem in New York harbor.[1] Ferries have a lot of maneuvering modes and directional thrusters, because they do so many dockings, and so they have a more complex control problem. The pilot put the system into a backup dumb mode while in cruise, then changed stations to where he could best see the dock while still in the wrong mode. Rammed the dock a…

Reading the raw accident report, I draw the opposite conclusion. The sequence of events that led to the accident started with one person controlling both steering & throttle. The reason for splitting responsibility is that the original helmsman was overwhelmed by the number of actions required to control both.

This reminds me of the Air France crash that was largely due to split control. The UX of transferring control of a system is difficult, and I don't know the details of what it looks like in an Arleigh-Burke.

Though the 2nd helmsman getting confused by having the throttles split points to training. That's ship control 101. I do think the loss of practical training is a root cause here. How many hours does the average helmsman have under their belt? It's just not that much.

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