C the narrator traveled with the artillery man
If they are your anchor, they are keeping you from being tossed {think BOAT out in the water} this way and that, and being swept away by [life, circumstances, a fad, bad emotions,,,, ____ ]
in other words, they keep you stable, and in place (so also you do not drift away either, like a boat without an anchor can do)
Going down from the top
simile,metaphor,simile,similie,onomapodia,. imagry, simile, metaphor