nursing tanks = nursing tank top shirt.
Has nothing to do with war tanks, or other euphemisms that are censored.
If you are looking for full torso zip instead of a quarter zip, look into cycling jerseys. most are half zip, but you can find full torso zipper.
They go up to high XXL men sizes. (not all cyclists look like Lance A.)
and as an added benefit, cycling jerseys have three convenient reachable elastic pockets in the back.
Search REI for keyword: Cycling Jerseys Full Zip.