September 19, 2007

Getting Watch Qualified

I did my first shift of watch today which gets me one step closer to getting watch qualified and able to focus on flying. Basically the duties of the watchman are to "babysit" the blimp. The primary concern in addition to security is to monitor the helium pressure in the hull (balloon part) of the ship. There is no internal structure to the envelope (fabric that contains the helium) so it must be kept at the proper pressure to ensure it maintains its structural integrity. Hence one of the duties of the watchman is to take hourly readings of various parameters to check and see what the helium pressure in the balloon is doing. It is noted in the log and used as reference for the mechanic to identify any unusual trends that may indicate a problem with the airship (ex. hole in envelope, bad pressure relieve valve, etc). I'll further explain how the pressure is maintained in the envelope in a future post as I'll have to find a couple of diagrams to illustrate it better.
I should be signed off to do watch after 3 or 4 more training shifts. After that, I won't have to do watch again unless there is a really unusual circumstance and they need me to help out. Its not really that hard so I don't mind if I ever have to do it.
As I mentioned earlier, the watch is in charge of babysitting the airship. From the time it is inflated in the hanger until it is deflated, there is always someone watching the airship to ensure the helium pressure is maintained within its normal range. It is that critical to the life of the airship that there is someone monitoring it day and night.