The Seventeenth Highland Light Infantry were at Roode Poorte Farm, using a novel device, something to do with Listening Posts. A Post was distracted by water from a hose while being attacked by 'bombs'. Could they have something to do with that? the wheels may be used to manoeuvre the devices like a wheel barrow?
I think you're right. Looking at the photo above and then again at the first, this seems very likely. And around Diksmuide, they had to build their strongpoints and defences above ground because of the flooding. Sounds like you've solved it, Holmes!
That shield-on-wheels with the German bloke firing through it is an old favourite. It turns out to be a captured Russian contraption. Close-up reveals Cyrillic lettering on steel plates.
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