Turns out it's pretty tricky to make a padlock secure against bolt cutters. Of course improving the security of the lock would soon lead to thieves cutting off the locking bars on the container instead.

It doesn't have to be the lock that's secured. What about a hinge mechanism which takes a programmable amount of time to open the container door? If it takes 10 minutes for the door to open, the lock doesn't matter as much, since the thieves have a very limited amount of time before the trains start moving again, apparently.

Those are standardized containers standardized which are made in the millions as cheap as possible. That stuff needs to work, think of all the means of transport where it is used (vessels, trains, aircraft), be accessible for inspections (customs) and so on. The costs to secure and upgrade the containers for the whole system is probably a lot higher than accepting a small percentage of stolen parcel.

Way too complicated. Apparently shippers are opting to start just welding the door shut and unwelding it at the destination.

That sounds like it could be quite error prone. If it's electronic, what about power failures? If mechanical, sounds like lots of intricate machined parts which will wear down over time.

Time locks have been around for more than 100 years, I'm pretty confident that if something like this was desired by the powers that be, it would have been implemented. What I'm assuming is stopping it aren't the engineering challenges, but the fact that currently it's cheaper to let the thefts happen than it is to mitigate them.

I wonder what the cost of engineering secure containers would be vs. addressing the societal problems in the USA that lead to situations like this would be.

I guess you could apply some of the same solutions used in refrigerated shipping containers for power redundancy.

Containers are secure in the sense that you can tell when you receive them whether someone has been inside them (and had the opportunity to change their contents). They are not secure in the sense that they prevent people from entering them.

so .. tamper-evident but not tamper-proof?

Correct. I think the main reason is that this "security" is geared more around Customs & Border enforcement than anything else.

It helps with customs, but it's a big deal for private businesses too. Before containers, you effectively had to have one trusted person's eyes on the cargo at all time -- and still people along the way lightened the load as they handled the stuff. It was almost considered part of the compensation for a longshoreman.

With tamper-evident containers, you have a trusted person watch the container being loaded and locked, and then a trusted person watch as its unloaded at its final destination, and you don't have to care what happens at every point in between.

Makes sense. 99% of what I know about container shipping comes from the movie Contraband and Season 2 of The Wire. ;)