The most common firetube boilers are of the Scotch Marine Variety. These are "package' boilers and are most often offered for the lower horsepower outputs (less than 300 bhp).
Watertube boilers are the largest in scale and typically are found in the highest horsepower outputs and highest pressures.
By nature of their size, watertubes require a team to operate and a team to service. Scotch Marine boiler plants can have one operator per shift that can effectively manage the operation of 4 or 5 boilers at a time. Watertube plants will have 5 or 6 people per shift to operate one or two boilers.
We service countless Scotch Marine firetubes and the annual cleaning and inspection takes about 2 days for a licensed technician and the Plant's Lead Boiler Operator to perform. The handful of watertubes that we provide some service for are all multiple story boilers found at paper mills, power plants, etc...We only provide combustion side technical service. The overhaul work is done by union boilermakers.