Vertical cylindrical boiler for the production of steam. By producing steam under pressure, it generates potential energy allowing to start a machine. This type of boiler was used mainly in workshops, small industries and steam pumps due to its rapid vaporization. Equipped with a small heating surface (5kg/cm2), it was intended for use requiring low engine power.
Placed on a narrow-gauge railway flat wagon, the boiler moved on rails.
The workshop unit where it operated is not known, but it is believed that it could be Mirandela, Viseu or Bragança.