I read that book when I was little, and man, was five-year-old me pissed off by the ending. I hadn't thought of it in years but I wandered through the SF Railway Museum a few weeks ago and they had a copy of it for sale, which brought all the childhood "WTF" flooding back.
Spoiler alert: after doing the John Henry thing, in a robot-on-robot kind of way, the fellow and his shovel dig a basement but forget to dig a ramp, so they can't get out. So what do they do? Do they dig a ramp, then fill it back in?
They cut off the anthropomorphic shovel's legs and turn it into a furnace. Human Boss gets to stick around as the building's new janitor. Presumably they lower him a ladder at some point.
I mean really, W the F.
Anyway, as you can see above, the Central Subway crew did not make this mistake. No furnaces will be harmed. I'm not sure if they plan a rescue op for the tunnel boring machines, though, or if they're gonna do a Mars Rover on them.
If I recall correctly, TBMs often end up entombed in a sealed-off tributary tunnel. They're unwieldily large and difficult to get out, and there doesn't seem to be much of a market for second-hand TBMs. Perhaps they have to be custom-made for each job as well.
The teeth of a TBM used to build one of the London Docklands Light Railway tunnels stand in the foyer of Greenwich DLR station, IIRC. The rest of the machine presumably rusts in peace nearby.
The new ones are somewhat more modular so only the largest, worn, external parts get left below.
There's a huge battle going on right now up at the north end of this line over whether and where to exfiltrate the TBM.
"Usul, we have wormsign the likes of which even God has never seen."
I've read Mike Mulligan to my kids about 50 time in the last few years. They have a slightly different take on the ending than you do. I hope some day they'll read a book about the last of the TBMs to their kids.
Hm, no previously for Werner Herzog Reads Mike Mulligan And His Steam Shovel?
I have never seen that before.
I have been completely outclassed.
Slow clap. Slow clap.
Damn you, that xkcd still makes me tear up a little. :p
The alternate version at http://www.unmannedspaceflight.com/index.php?act=attach&type=post&id=20543 might cheer you up.
Well, compared to being callously disposed of in the face of superior technology, finding a small niche where you can still be useful could be a happy ending, in sort of a Puritan work-ethic, Wal*Mart greeter kind of way.
Wait, that was supposed to sound more uplifting...
"finding a small niche where you can still be useful could be a happy ending, in sort of a hacker work-ethic, beer seller kind of way."
I tried to resist, I really did.
They cut off the anthropomorphic shovel's legs and turn it into a furnace. Human Boss gets to stick around as the building's new janitor.
It was turn the shovel into a furnace or sell it for scrap.
And ... janitor isn't such a bad job. Mrs. McGillicuddy bakes him nice hot apple pies, after all.
So basically we can reboot this into some sort of steamshovel zombie movie, right? The demographics will love it.
The current plan is to continue the tunnel to Washington Square Park, and dig a big pit, and pull out the TBMs there. While it costs millions, perhaps tens of millions, to refit a TBM for its next job, that's still cheaper than building a whole new one, so if it will cost less than somewhere around $50 million to retrieve the thing, they'll try.
Incidentally, the TBMs are supposed to arrive in SF this month, but it will take two months to move them into place, assemble them, etc., before they start tunnelling.