A tub is a wide, low vessel, made of wooden staves or metal; it was usually used for washing, either clothes or persons; in essence, it’s the lower half of an upright barrel. Tubs are period charges, found in the allusive arms of von Wasserburg, c.1340 [Zurich 371]; a form of tub with handles is found in the arms of Mastellizi, c.1550 [BSB Cod.Icon 269].
There is also the “bath tub”, specifically for washing people. This too turns out to be a period charge, in arms of von Suls or Sulz, c.1340 [Zurich 89]. For related charges, see bucket.
The Province of Caldarium bears: Or, on a wooden tub between two peacock feathers crossed in base proper, a laurel wreath Or.
Jorunn Eydisardottir bears: Vert, a tub Or and a ford proper.
Mariah Stern bears: Azure mullety Or, in pale a rainbow proper and a bath tub Or.