The relatively rare category of vertical boilers with multiple firetubes. Owing to problems with tube erosion around the water level, these boilers were problematic. Most small vertical boilers were actually a single flue with cross-watertubes.
Alternative approaches were to use either horizontal firetubes, or submerged tubes (with an unheated header above, so that the entire tube could be below water level).
Media in category "Vertical multi-tube boilers"
The following 8 files are in this category, out of 8 total.