GR translation: bone-deep laborings up impossible grades

[David Payne]

I think it's along the lines of the idioms "work it to the bone" or "work your fingers to the bone", which mean working very hard.

I think that the basic image is of pain cutting deep into a person.

(On the off chance that anyone here is as dumb as me, "la-borings" means "laborings" -- split across a line break in the original text.)

On 7 Mar 2013 01:41:44 -0500, Mike Jing wrote:
> 
> P260.25-40 A week later he’s in Zürich, after a long passage by 
> train. While the metal creatures in their solitude, days of snug and 
> stable fog, pass the hours at mime, at playing molecules, imitating 
> industrial synthesis as they are broken up, put together, coupled and 
> recoupled, 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, long waits in marshaling-yards whose rails run like 
> layers of an onion cut end to end, gray and desolate places, nights of 
> whistles, coupling, crashes, sidings, staring cows on the evening 
> hillsides, army convoys waiting at the crossings as the train puffs by, 
> never a clear sense of nationality anywhere, nor even of belligerent 
> sides, only the War, a single damaged landscape, in which “neutral 
> Switzerland” is a rather stuffy convention, observed but with as much 
> sarcasm as “liberated France” or “totalitarian Germany,” “Fascist 
> Spain,” and others. . . . 
> 
> What is "bone-deep" trying to invoke here? 
>