GR translation: bone-deep laborings up impossible grades

[Michael Bailey]

 he dozes in and
> out of a hallucination of Alps, fogs, abysses, tunnels, bone-deep la-borings
> up impossible grades, cowbells in the darkness, in the morning green banks,
> smells of wet pasture, always out the windows an unshaven work crew on the
> way to repair some stretch of track,

it's the train, of course, laboring up the grade, connoting that the
train is working hard to go further (like the kids' story, The Little
Engine that Could, right, this little choo choo train is going up the
hill, carrying all the kids' toys for Christmas and it almost doesn't
make it, but it keeps saying, "i think i can, i think i can" and then
it gets over the top and it goes "i thought i could, i thought i
could" and then on the down-slope it keeps saying "i knew i could, i
knew i could" - anyway, a personified, anthropo-self-talking train who
considers its activities to be work) -- and for Slothrop, just riding
in the train is work, and his human bones as much as the metallic
bones of the train are affected by the grade - but the phrase also
resonates with the "unshaven work crew" later in the line: to make a
train go takes work!