If time stopped in the tunnel, wouldn't the repairs have been completed remarkably ahead of schedule from the perspective outside the tunnel? After all, the workers would put in a full day of repairs in no (outside) time at all.
So the foreman goes down to check the progress of works and of course finds them complete, because the workers have been working hard for days and days in the tunnel. And upon exiting the tunnel the foreman checks the plans and finds once again that the project is falling further behind schedule. And the workers are beyond tired from continuously ascending and descending into the tunnel all day and night, so of course the tunnel repairs fall further behind schedule.
A more probable explanation might be obtained by searching for a carbon monoxide leak or other poison-induced mind altered state of working in the tunnel. Of course once you return to the surface from investigating the results taken will be invalid as you've only been gone a moment so how could that reading possibly have been accurate.
2) If a worker in the tunnel completed a day's work instantly, the worker would have still completed a days work and would need to go home and rest. You could, in theory, have a rolling start time, so the worker has 15 hours rest and then is required to come into work again. Unfortunately, legislation doesn't really account for time anomalies and so this would likely fall foul of Union and EU standards.
Setting aside the implausibility of such a secret remaining a secret (none of the workers had a boffin brother or cousin to show?), and never mind the implications for physics, with the right incentives, foreman could hire additional workers, finish the job faster, get paid for that job, and move onto the next job while looking like they're exceptionally good at things rather than ending up over-budget and behind schedule, as is expected for publics works projects. And all without coming up against per-worker Union/EU standards.
One is getting the outside-tunnel work done - redoing the lifts, trucking in more tiles, and so on. That's happening at real-world time, so it's going to be a bottleneck.
The other is getting approval for what looks like a blatantly dishonest hiring scheme. Sure, the foreman knows he can get 80 hours of work done in that tunnel every day, but a request to hire that much staff looks like pure make-work from the outside.
So there doesn't seem to have been any personal benefit from the time dilation - the crew still put in 8 hours of work per person per day. Sending a guy across the tunnel to deliver some tool still costs the same amount of his workday, but it'd be instant for the people on the outside, which would save a bit of time. On the other hand dealing with the weirdness and scheduling around it might well eat up any time gained.
Now if they'd convinced the head office about the weirdness, I suppose they could have dispatched another dozen crews and gotten 80 hours of work done each day - at least in the tunnel.
> Biggest problem was making sure that if anyone from head office came down it wouldn’t look like he was sending people home ten minutes after they logged on
It's a fun story, but my overly cynical mind would suspect that there was probably some timesheet gaming going on somewhere here with agency workers. It would explain why the project went on a lot longer than it should have as well.
What got worse was the larger scale structures that were meant to keep your interest over a long period of time. A story made up from fragments that never form a greater whole is usually unsatisfying no matter how good the fragments are. (Exceptions to this rule can be found - an exercise I leave up to the reader)
Personally I find things like 'Star Trek' and 'Dr Who' to be enjoyable, but they almost never makes sense... the science seems to be always bent to suit the plot in absurd or self-contradictory ways.
Perhaps you're either much more informed than average, or have a weaker ability to suspent disbelief for some reason, or both?
Don't ask me about the last three Star Wars movies.