If we’re talking practical, you’d always need people on board to deal with mechanical breakdown or emergencies. And you’d need all the support systems and supplies need for them. After factoring that in, how large is the bridge crew on a container ship?
Also, pirates would become a problem because taking over a ship without a crew would easier and way less risk.
The argument for easier piracy assumes that a self-driving ship would have a standard "people accessible" format. There's no reason for packaging of the vessel to remain the same.
Consider patrol drones. They look nothing like something an individual can get into.
This was already addressed. Most of it would still have to be human accessible for maintenance/emergency purposes. If you're going to have to potentially service the thing underway, there is no point redoing the packaging.
Besides which, an automated ship is about a trio of tugs, a computer replacement, and a buncha fuel away from anywhere.
In terms of maintenance you can put the access below the cargo which significantly increases what it takes to hijack a ship. However for hijacking’s the simplest approach is to simply scuttle the ship remotely. If they get nothing then it’s rather hard to get people to hijack the next ship.
You mean deliberately sink a $10 million ship, causing a massive environmental disaster. Not to mention being a hazard to other shipping if the water is shallow enough or the ship breaks apart.
Do you blow up a grocery store because someone attempts to steal a jar of pickles?
Ships sink all the time, unless it’s an oil tanker they really aren’t an environmental disaster. As to cost, if someone’s hijacking a ship you already lost the ship now it’s just an insurance question.
The question for an insurance company isn’t just about this ship, but the cost of paying out future hijackings. On top of this there is the rather more interesting option of refloating the ship.
You need to improve reliability and have a mobile crew you can dispatch on an emergency. Most mechanical engines do not need a maintenance crew on-site all the time, including the much larger and more complex electricity generators and the disaster-prone airplanes.
About pirates, no, they work will become much harder if you don't have anybody they can point a gun to and tell to stop the ship.
It depends. For last-mile delivery and public transport with small vessels, that may not be the case.
The city of Ghent was eyeing autonomous small crafts as "water taxis", and a big shipping provider wanted to do last-mile(s) delivery for shops, restaurants, and small parcel pickup points along a river. For the latter case, the vessel would still be manned, but instead of having to navigate, that person could sort and prepare parcels for delivery.
I don't think it is the costs necessarily but the availability of people with the right skills. Even with the money, you can't just magic up qualified mariners.
Also, a significant amount of money is spent providing 24 hour cover of navigation in the bridge so I guess you could save something by automating a lot of it.
You are probably right that in the extreme, it would be better to have some humans to make sure your containers make it to their destination!
Economics of scale are the whole point of large vessels so yeah, there's much less money to be saved eliminating crew on ships vs semi truck drivers (or even shipyard equipment operators).
Also, pirates would become a problem because taking over a ship without a crew would easier and way less risk.