damage control crew (kancolle)
In Kantai Collection, a Damage Control Crew, or "DameCon" for short, is a type of single-use equipment that prevents a shipgirl from sinking from extreme damage.
In KanColle itself, they appear as a trio of girls wearing construction helmets, work jackets, pleated skirts, and shoes. Each one has a different hair style, but they include grey_hair, brown hair, low twintails, ahoge, swept bangs, hairclip and short hair. They carry planks of wood, tape, and a hammer.
In fanarts, only a single girl may appear, and there's no guaranteed traits, although the helmet and hammer are common traits.