Ah yes, I'm on it now. Mollusque's citation is on the ball. I've read fracteur with the figurative meaning of explosive in one of Hal Porter's short stories. I also seem to remember hearing it during a mine tour ... Walhalla maybe? Sovereign Hill?
*stuff's chained_bear's greedy snout with fracteur and lights the fuse*
...there are men called storemen working underground at the Lake George Mine. These employees issue all fracteur (explosive), and tools to miners working on the various levels; they transport all of this material from the plat to the stores by trolley and have to account for the quantity sent to them, and the quantity issued. --The Industrial Arbitration Reports, New South Wales, vol. 42, 1943, p. 459
Oho, yes. One compound ending in fracteur (looked lithofracteur up; the root is Latin fractor, 'breaker,' shared with fracture). It still makes no sense as a noun here: protecting breakage from damp? Protecting crack from damp? Splinter? The euphonic substitution of a diphthong for a simple vowel, owing to the influence of a following consonant? *dizzied*
"Fracteur" is nowhere in the online OED — could it be related to fractable, "A term used, in the middle ages, for the crest table or coping running up and down the gables of a building?" It's the only thing that suggests shelter; everything else, predictably, relates only to fracture.