Even so, it's still 8 hours of sleep per 24 hours, which is adequate, even when only being able to take 6 at a time makes it somehow seem worse. And I have a sneaking suspicion that it only exists because the Navy found that sailors were useless after the 12th hour of working, so decided to set the workday to 12 hours, and just make the whole duty cycle 18 hours. I'm guessing that people on that schedule stop being very effective after just 9 hours of wakefulness. But I'm no somnologist.
Obviously, someone has to be in command on the bridge at all times, but it does not have to be the captain the whole time. That's what watch commanders are for, right? The guy cleaning toilets does not need two more guys backing him up for the 2nd and 3rd shift. Dirty toilets wait until he rolls out of his bunk, or until the captain eats a volatile burrito, and someone wakes the toilets guy up to deal with that specific problem outside of regular duty hours.
Command staff already needs to have enough redundancy to operate the ship if an unlucky hit takes out the entire regular command, just as a requirement of being a war vessel. In theory, that Junior 2nd Lt. should be able to limp back in to port after everyone else in the chain of command is killed, so the Navy can send it back out with a fresh crew.
Surely, there's a person whose function is to alert person X when situation Y happens, so that person X is not expected to be awake and alert and staring at green lights for N continuous hours, and then exhausted or asleep when one of them turns red?
That isn't how it works.
So there are all kinds of functional roles in the Navy (and I'm going off of submarines since that it was my experience was in), roles having to do with operating the sonar equipment, IT/comms equipment, torpedoes, and the engine room. So these people will be on watch (hourly logs, monitoring system conditions, etc.) and then after they are relieved they'll do whatever maintenance and cleaning they are assigned to. There is not a "clean-the-toilets" job role.
In AEW, specialization rules everything, so the toilets are cleaned only by a specialist toilet cleaner, and specialist toilet cleaners only clean toilets. If you try to shoehorn AEW onto a ship, you only need one toilets guy, because having clean toilets is important, but not so important that it has to be done 24-7.
It is an open question whether it would be more efficient to have 3 radio operators providing 24-7 coverage on the radios during their duty hours and doing other jobs when they are off watch, thus giving them 16-hour workdays divided up into 8-hours of "important" work and 8-hours of "grunt/scut" work, or to have 2 radio operators on watch 12 hours each, and one specialist cleaner taking up that extra 8 hours in that bunk, cleaning toilets 12 hours a day. Is that last 4 hours of work squeezed into the day okay if it requires no dedication or focus?
Most watch stations take months of training to not only get qualified but also for the command to have enough confidence in you to stand the watch. I myself stood a regular 12 hour rotation during times we where on the surface because we had only 2 qualified operators and the rate that actually owned the equipment was undermanned so they could not provide bodies. There are very rarely extra people to do grunt work you do that in your off watch time when you are not studying, qualifying, or doing maintenance. Very frequently commands will care about filling the watch bill over a person not just being qualified but also competent enough to stand a watch, thus accidents happen due to negligence and ineptitude.
- I'm not sure if this is the primary point of the 100hr+ work-weeks. In my case, our submarine was going through an Engineering Refueling Overhaul in Norfolk so we were just incredibly busy.
100-hour work weeks not only save direct worker costs (you get 2.5x the labor at the cost of 1x), but also in managerial and other costs (you get 2.5x the labor for the cost of managing a 1x headcount).
But each individual is super proud of being able to give a 280% effort. It's just that after that long on the job, you are no longer capable of detecting when the math no longer adds up. And they are "high-spec" components--most people drop to 0% efficiency long before that 60th hour worked in a week. But there are no supermen in real life. Nobody on this planet can produce positive value in the 112th hour worked in a week, even if there are people out there willing to try, and also resilient enough to bounce back from it regularly.
It often boils down to the thoroughly debunked yet oft-echoed labor theory of value. In some people's minds, a person that works 60 hours in a week is 50% better than someone working 40. And if everyone in the organization works that hard, then the whole organization is that much better. The harder you bust your asses, the prouder you are of it, and the more you can ignore any objectively measurable outcomes.
In reality, this just gives the military completely unrealistic ideas about how actual productive labor happens, and how much it costs in time and money, and contractor businesses of the military-industrial complex gleefully take advantage of that.
And that is why a lot of my former shipmates got out after their initial enlistment and went into the contracting business.
If the whole system is being redlined when it's peacetime, then it only takes one thing going wrong, a single casualty, some damage to the ship, anything really to make the whole system collapse
There are a few people who do this, for whom "being awake" is basically the same as "working". Generally these few people are not employees, but part of the entrepreneurial world. However, they're outliers, and don't really counter your point.
Driving the ship around is the exact same activity that takes the same amount of work. Keeping all the gear running takes the same effort. If you've not been hit, you have the same people doing the same things; and if you've been hit, you're either dead or swimming towards the shore in a much smaller boat.
US navy is much stronger than any navy in the world. A long war with a minor power, or a limited war with a major power is not going to cause meaningful casualties to US navy and it's not going to result in a Navy that's significantly shorter in personnel.
A significant war capable of significant damage to the navy as a whole (as opposed to a lucky strike on some ship) essentially requires an open, high stakes war with a nuclear power; and due to MAD such a war can't really be long - if the problem is so irreconilable that it escalates to large scale open hostilities with significant casualties, then that also escalates to nukes, and then it'll be over in a single day.
There's also a good chunk of personnel who, even in peacetime, end up injured or disabled on the job (such as my friend the CPO with a sudden heart condition) who are required by doctor's orders to not do some tiny part of their job, and then regs dictate that they just not do that job at all—so they're either honourably discharged (and now receive VA benefits), or they're kept, but desked. In a more "efficient" military, these people (who are mostly still able to do 99% of their jobs) would just have their duties adjusted, with the one part of their workload they can't handle reallocated to their peers, so they can continue converting payroll into duties performed, rather than chairs sat on.
[1] http://www.washingtontimes.com/news/2016/apr/5/ash-carter-sa...