I think their point is that when changing engine output is labor-intensive, it made perfect sense to have an officer giving orders and somebody else implementing them. Why the command structure hasn't shifted to accommodate modern technology is an interesting question

It's not labor-intensive, it's attention-intensive. You want the person managing the speed to be focused on that. You want the person managing the heading to be focused on that. And you definitely don't want the officer to be distracted by maintaining course and speed when they need to be keeping track of what's going on around the ship.

You want the person managing the speed to be focused on that if managing speed is still inherently and unavoidably attention-intensive - if modern control technology is able to automagically maintain speed at x knots, adjusting all the various engine control parameters to implement that, then an extra person in the loop only means an extra chance for mistakes or delays.

If the military learned a lesson from exploding a reactor with an automatic control system, you might never know - it's not required to be reported to the public.

If an automatic control system can blow up a reactor so can the manual one. You have a problematic design issue in both cases. You can also still assign someone to keep an eye on the reactor in case things go bad an have that person pull an emergency stop or warn the guy in charge. There is no reason to relay every little speed change through several people.

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?

A basic of driving a steam engine is not to waste steam, since steam represents fuel, which in turn represents money. As you say, not having an accident is more important than wasting a bit of fuel (hence safety valves on steam boilers), but in everyday operation wasting fuel is a cardinal sin and something that is to be avoided. At one point I was involved in steam rail preservation, and the old-timers used to mourn the loss of engine driving/firing skills whenever engines sat at the platform with the safety valves blowing.

The ship command structure was a form of information hiding, whereby the commander only worried about the speed, whilst the engineer worried about how to efficiently deliver the requested speed.

> Are you going to choose to crash into something because it's wasting fuel to vent part of the steam?

Under emergency you will vent, but under normal operations where you just want to slow down you care very much about efficiency.

Not just for monetary reasons either (though that's a factor) but because the lumps of coal you're not burning now could save your ass in bad weather and make you reach safety instead of being stranded in the middle of the ocean.

At sea, efficiency gets you back to land.

I think if the same volume of steam is being produced then it's going to cause problems regardless