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Comment by ghufran_syed | Hacker News Reader

I have no experience in ship-handling, but my naive question for this who do is: What is the rationale for being able to independently transfer control of different aspects of ‘steering’ (prop1, prop2, rudder) to different stations? . The coordination required between two or more stations inherently makes the task (control of heading and thrust) more difficult than if a single station was coordinating the process inside one brain. Is there some benefit I am not seeing that justifies the increased complexity?

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Battle Damage or Engineering Casualty (Engine Troubles). Arleigh Burke speed is controlled by two factors, the RPM of propellers AND the pitch of propeller blades. https://en.wikipedia.org/wiki/Variable-pitch_propeller_(mari... Obviously this controls steering as well if system isn't functioning properly.

In normal situations, computer mostly handles this and single station (Helm) has control over all 3. If computer fails, the pitch control fails or propeller engine fails, this will need to be controlled manually by the crew and workload is too much for single person. Also, in certain situations, like underway replenishment, all 3 control stations may be manned because if there is sudden failure, you need to be quickly able to respond.

Also, the problem is touch screen period. This is case where putting iPad instead of levers/switches/buttons is NOT an upgrade. See your car climate control as good example everyone can relate to.

I'm not a mariner but from what I've seen on boats and motoryachts the controls are typically transferred with the engines in neutral. This step ensures that the person who takes control positively knows the state of the engines and avoids having to do some kind of synchronisation with the current state. Perhaps this is problem on a destroyer or they imagined the controls being routinely moved around the bridge. On most vessels it's in the same place for the whole passage and for docking or departure you chose which station to use.

Idling the engines for a minute while you have isn't an imposition as anyone prudent would be doing propulsion and steering tests before entering a confined area at that point anyway.

I can only think the imagined the controls being passed about on a regular basis and because they didn't need to synchronise the physical position with the current state they skipped that step.

Why transferring one engine at a time made sense I have no idea.

It seems to me that the checkbox, and even the UI, is the least of the issues. Even with the most intuitive manual controls, this problem still could have easily happened simply because the transfer of control from one station to another is fraught with potential misunderstanding of what state the different parts of the ship are in (rudder, engines, etc.) and who has control of each at any given time. Lack of sleep will exacerbate it tremendously. More training will only help so much; I'm guessing, they probably already train on this a lot.

My armchair assessment is that these ships should be controlled 99% by computer, which decides the best combination of thrust, rudder, etc. to move the ship where the navigator directs it (whether by joystick to indicate direction, or touch-screen to indicate where on the map you want the ship to go, as well as what speed), and the individual controls (engines, rudder, etc.) should only be overridden in the most dire of circumstances.

I'm sure there's much more to it than that, but the general idea remains the same: this is too complicated to be left to humans, whose time is better spent thinking about other parts of the mission.

Having rudder and propeller on different stations can be useful to organize work on the bridge, especially on a warship. The possibility of having the two propellers on different stations is imho insane. The only reason that I can think of is a runaway "safety" requirement ~"if one prop control fails you still must be able to take control of the other prop on a different station". That would fit what the article says about them essentially running in manual backup mode all the time and not in the intended mode of operation.

I like this other article on the topic, here's what it says about splitting rudder from speed:

> Sanchez quickly noticed that his new helmsman seemed flustered by the difficulty of having to control the ship’s steering and speed at the same time. He decided to split the helm, giving Bordeaux control over the ship’s wheel. While Bordeaux remained at his station, Dontrius Mitchell, a second sailor on the bridge, was assigned to take control of the speed of the McCain at a neighboring station known as the lee helm.

> Sanchez’s order was unexpected — he had not discussed the possibility in meetings with the crew before entering the straits. Nor had the crew practiced the maneuver much. Bordeaux could only remember doing it once or twice before.

> https://features.propublica.org/navy-uss-mccain-crash/navy-i...

The traditional method of control splits helm(rudder control) and lee helm(throttle control). Both are under the direct command of the conning officer, who is responsible for all orders to the helm and lee helm and setting and maintaining the course ordered by the officer of the deck.

You need to be able to shift control of steering to aft steering in case of battle damage or steering failure on the bridge, and you need to be able to shift throttle control to the engine room for the same reason.

The concept of splitting throttle control of engine 1 and engine 2 between stations as a part of the normal transfer of control is absurd and I have no idea why that was even a thing. I never heard of it when I worked on this system.

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