Marine steam boilersBy Lars Josefsson
Marine steam boilers are not what they
once were; Scotch fire tube
boilers. The steam boilers design remained much the same
and its qualities of ruggedness, reliability, ease of maintenance, and ability
to stand abuse made it a very popular steam boiler in the
marine field. However there was a realization that advanced
steam boiler designs with greater generating capacity, higher pressure, and
increased efficiency were needed to meet the changing requirements brought
about by the development of turbine propulsion machinery. The marine engineers
then began to adapt various types of water tube steam boilers to fit into
the restricted space available for installations on board steamships. It was
also realized that marine boilers would have to be designed to
burn efficiently whatever fuel oils would be available.
Although the steam boilers are basically the same, water boiling cauldrons, modern steam boilers are different in details, especially concerning the control systems. Marine steam boilers today are provided with automatic surveillance and they operate without supervision 24 hour per day.
Just as the need for increased steaming capacities within fixed space and weight limitations spurred the development of the earlier water-tube steam boiler, so did the same need precipitate the advance to boiler designs of the bent-tube type.
The term bent-tube boiler covers a wide range of boiler designs characterized by the ability to raise steam pressure within a short period of time. This means smaller tube diameters, fewer headers, increased furnace ratings and wider application of water-cooled furnaces. The boilers of this category also became known as multi-drum boiler type, express boiler type, or by various other names corresponding to the designers of particular arrangements. With advanced designs available for naval steamships, it was quite logical to utilize adoptions of those designs for high powered passenger steamships.
These pages are not meant to be a steam boiler instruction book whatsoever; it's just a few words about some things that most technicians already know lots about.