Technology and Operations
This forum is for discussing technological & operational matters pertaining to U-boats.
Re: Air Conditioning on Type XXI's ?
Posted by:
J.T. McDaniel
()
Date: June 23, 2002 05:11PM
They go together. The "conditioning" the manual argues is needed on long submergence is mostly dehumidification. Human exhalations contain two main things that weren't in the inhaled air, carbon dioxide and moisture. A/C doesn't do a thing for the CO2, but it does extract the moisture. Various chemicals are used to absorb the CO2.
Crew comfort is mentioned first, but is that the real priority, or more of a morale issue? It makes sailors feel better if you tell them you're thinking about their comfort and not about the radio. The engineers designing the boat usually give less thought to habitability, beyond the minimum required to keep the crew in good health, than they do to making sure the equipment will work when its needed. Still, no argument about the need to keep it cool, particularly in the engine rooms, which could reach 130 degrees at the beginning of a dive. The engines don't actually get hotter when they're shut off, but since the coolant stops circulating more of the heat is radiated into the engine room through the exterior of the engine instead of into the ocean through the heat exchangers. (In American boats, which used fresh water cooling.)
As for "firsts," it's arguable if any firsts really are. There's been a lot of discussion of snorkels recently, including just when the Dutch invented them. In fact, even the Dutch snorkel was more a development than an innovation. The Turtle had one, way back in 1775, complete with a float valve to close it when the head went under water. And that was no doubt merely an incremental development from a Neanderthal hiding from his enemy breathing through a hollow reed.
J.T. McDaniel
Crew comfort is mentioned first, but is that the real priority, or more of a morale issue? It makes sailors feel better if you tell them you're thinking about their comfort and not about the radio. The engineers designing the boat usually give less thought to habitability, beyond the minimum required to keep the crew in good health, than they do to making sure the equipment will work when its needed. Still, no argument about the need to keep it cool, particularly in the engine rooms, which could reach 130 degrees at the beginning of a dive. The engines don't actually get hotter when they're shut off, but since the coolant stops circulating more of the heat is radiated into the engine room through the exterior of the engine instead of into the ocean through the heat exchangers. (In American boats, which used fresh water cooling.)
As for "firsts," it's arguable if any firsts really are. There's been a lot of discussion of snorkels recently, including just when the Dutch invented them. In fact, even the Dutch snorkel was more a development than an innovation. The Turtle had one, way back in 1775, complete with a float valve to close it when the head went under water. And that was no doubt merely an incremental development from a Neanderthal hiding from his enemy breathing through a hollow reed.
J.T. McDaniel
