I’m glad this thread “went conversational.” I’ve gleaned a lot, and thank you @Robot_Arm for that thread. It’s way belated, but I’m sorry for your loss of a teammate–I can directly empathize.
I admit, that sailing has always fascinated me. My only experience being actually on the water, was on my high school friend’s J-35 sailboat appropriately named “Air Force”. We did a few afternoons in Long Island Sound which gave me some seasickness, but also an appreciation for just how much work went into moving a vessel by wind.
Having joined an aforementioned branch of service, my nautical knowledge expired, but was sort of rekindled last year when I read Master and Commander by Patrick O’Brian. Tons of terms were Greek to me, but I kind of got the jist of things. It wasn’t until I saw the thread in my OP that it rekindled some adventurous spirit.
I think my first step back into sailing is going to buy a sextant to learn how to use it. I think I’ll need an almanac too.
Tripler
I think I’ll need to get a canoe, too. . . for “authenticity’s sake.”
I should think a better first step into sailing is to join a yacht club and sail the little dinghys around the harbor rather than go out where a sextant and almanac might come in handy…
I’m geographically limited to the availability of water for yacht clubs. Although if Nebraska can have a Navy, then maybe I’ll see what’s available in Santa Fe.
In that case, it might be tough to practice with a sextant, too. You’re trying to measure the angle of things above the horizon. For that to work, you need a flat horizon.
If you want to be really accurate, you estimate the height of your eye above the water, because the line from your eye to the horizon is going down at a very small angle.
You could still practice using a sextant, I suppose; sighting the sun and some landmark on the horizon and measuring the angle between them. I’m not sure if you’d have any way to find out if you were accurate or not.
Even if the horizon is not specifically correct, one could still get the benefit of practice and see how much error there is from that. But that aside, for a truly dedicated practitioner, you can get an artificial horizon for a sextant.
I can see how that might be a big problem, but, on the other hand, plenty of famous sailors got started on lakes. Perhaps there is a body of water somewhere nearby sufficiently large to support a small sailing club or school (you need access to the equipment plus somebody to instruct you).
BTW celestial navigation is great fun, and they make inexpensive plastic sextants for educational/emergency use. An artificial horizon is essentially a pan of water or oil shielded from the wind. Airmen used bubble sextants or octants.
Oh that’s a fantastic idea! It reminds me of a story that I heard, in that B-47/B-52s ‘back in the day’ had a bubble window for aeronautical sextant readings for navigation–this, of course was before INS and GPS.
Tripler
Hell, if a pilot can learn navigation by sextant, then so can I!
One difference is that in an aircraft the vessel is moving much faster, so there was a navigator observing through that dome pretty much constantly, and with as much as possible pre-computed and pre-plotted, because you do not have the luxury of taking 15 minutes to do your sums. Whereas at sea, especially in the golden age, they kept a log, used it for dead reckoning, observed the altitude of the sun at noon, and when possible observed some stars in the morning and/or evening twilight, or some similar routine. This was one day’s work, and the officers did not have to stand on the bridge with a sextant all day and night. It can all be done even by a single person.
Airplanes as late as the 707 (and I assume DC-8) had a sextant port. Which was essentially a 1-1/4"-ish threaded pipe in the top of the cockpit that led to the outside world with a quarter-turn ball valve in it. You screwed a sealed periscope-type sextant into the port and then opened the valve. They you’d extend the periscope up through the open valve until the upper prism stuck out a couple inches into the breeze. Then you could rotate the periscope in azimuth and elevation to locate your star and the horizon to get your readings.
And pilots didn’t use those things; navigators did. There were Air Almanacs that corresponded to the Nautical Almanacs the ship nav’s used, but with some tweaks for use at a larger than nautical eye-height, and the need for ease/speed of use.
I can’t say whether the B-52 had a port or a bubble big enough for the nav’s head. I’d bet on a port. The B-47 had a bubble canopy already, but may have had a port installed in the canopy crown of the nav’s cockpit because taking readings through a curved canopy would create uncontrolled errors in your readings due to refraction. I’d bet the B-36 was the last airplane with a bubble big enough to stick your head into.
The 707 sextant port was also a source of hazing for newbie flight engineers. Part of the cockpit preflight was to make sure the valve was closed. The ports remained installed for decades after the last navigator and sextant went to the Old Star-shooters Home. At the gate a pilot would open the port before the F/E showed up. During takeoff the noise would go from “easy to overlook” to “screaming banshee”. Shoulda been more careful there, Switches!
In cruise the sextant port was also useful for smokers. You could stand just below it, open the valve, and a pretty good airflow (and noise) would carry the smoke out of the cockpit. Unless all 3 pilots were smokers, polite pilots used it. Impolite Captains of that bygone era (i.e. most of them) would never think to.
I didn’t know about that, nor did I realize that stargazing for navigation was a thing as late as the jet era. I thought that the DC-3 was about the last of them. Many DC-3s were equipped with domes specifically for sextant navigation, as in this pic …
Navigation over even thinly populated land had been based on map reading vs. ground features and ground-based light or radio beacons from the 1930s. But finding your way across oceans or substantially uninhabited terrain like northern Canada, Africa, the Amazon basin, etc., required celestial nav until the first inertial nav systems came into commercial use in the late 1960s.
An interim alternative used in commercial aviation from the late 1950s as navigators were being phased out to the late 1960s when INS came in was the
Back in the day, Doppler or early INS could get you within a hundred miles or so of where you wanted to be by the time you crossed an ocean.
The other techincal alternative in the same era was LORAN. I don’t know how much that was used by airlines of the time though.
I had wondered how they corrected for that. Thanks!
I have the FAA textbook for air navigators. Here is the 71MB PDF for those interested.
I always thought it’d be a fun license to get. Useless, but a conversation piece at least among pilots at the bar.
Jan de Hartog once wrote that standard equipment on lifeboats was a buckram envelope containing the world’s quickest text on practical seamanship, and that it would make a great gift for any young boy - available at any ship’s chandler. (He also recommended buying one because - wait for it - the envelope also contained a useful pencil that could be sharpened by pulling a string!) Now he wrote this MANY years ago. I often wonder if anyone else has ever seen this envelope.
