When the US Navy and NOAA archaeologists decided to recover the emblematic Monitor gun turret from the ocean floor, the entire engine room was in the way and therefore had to be recovered first. This included the main engine, ventilation engines, auxiliary pumps and the condenser. Now, in order to conserve these complex pieces of machinery, a large part of our job is to disassemble them. This allows for appropriate treatment of the different materials (iron, copper alloys and gaskets have different conservation requirements), while more exposed surfaces provide better extraction of harmful salts and thorough surface cleaning. Disassembly can be quite time consuming but there is no way around it! In 2019, one of the conservation team’s projects was to further disassemble the condenser (yes, parts had already been separated).
But first things first, what’s a condenser condensing and why?!
Condensers were invented in the late 18th century by a Scottish gentleman, James Watt, to make steam engines run more efficiently. Such engines used water properties to activate pistons. When steam (water in a gas form) located in a cylinder is quickly cooled and turned back to water (condensed), it takes up less space than in its gaseous form which creates a vacuum in the chamber. As a result, the piston is first pushed in one direction before being pulled back in the other direction when a vacuum is created by cooling down the steam. Originally, in order to create this vacuum, water was sprayed directly on the steam within the piston chamber. It worked well but overall wasted a great deal of energy by repeatedly cooling and heating the cylinder. James Watt therefore saw the need for an external piece of equipment, a “condenser”, where steam would be condensed away from the piston chamber. The addition of this device rendered steam engines faster, more efficient, more reliable and more economical… And consequently condensers were used in different configurations in all marine condensing engines through the mid-19th century.