le Genie

[Yperite]

Although I`m still working on a different comicbook story, I`m once again requesting your help for the next;

This time it`s about French engineers "le Genie". What exactly was their task during the attack? Starting from summer 1917, engineers were split into 2 Mining Companies, 1 Park Company and Signals Section, what was the purpose and task of these units?

Does anyone have a photo/illustration of engineer`s uniform (horizon-blue, preferably 1917/18 ).

There`s something I know myself;
"The engineers consisted of 11 regiments, of which one, the 5e, was a railway regiment, and another (the 8e) a signals regiment. They were split up into company-sized or smaller detachments, attached to infantry divisions or army corps."
(The French Army 1914-18 by Ian Sumner)

Now, engineers wore a scarlet-colored number of their parent regiment in their black collar patches. Now, what I wish to find out which regiment`s units operated in 127th Division in October/November 1918?