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Osterkraut
Osterkraut Dork
7/13/10 12:34 p.m.
wlkelley3 wrote:
slantvaliant wrote:
Appleseed wrote: I still want to find an old engineer to teach me how to use a slide rule.
Slide rules aren't that hard. Some private pilots still use the round E6B aviation version for navigation. I still have my dad's.
Still have my dad's also. These are still in use today although some of the younger crowd like the electronic versions.

I was forced to use the military version of the E-6B, the MB-4 through flight school. Manual flight and fuel planning on it was...tedious... to say the least.

chuckles
chuckles New Reader
7/13/10 1:25 p.m.

Those interested in this thread, and almost everybody else, would enjoy "Longitude" by Dava Sobel.

TJ
TJ Dork
7/13/10 4:44 p.m.

This is the version you get to play with on a submarine. We call it a bearing rate computer, but it is essentially a circular slide rule. Longitude is an interesting book.

triumph5
triumph5 Reader
7/13/10 5:04 p.m.

In reply to Dr. Hess: R.Hess. One half a mile. That's impressive! Most of my sites have been taken on 40ft and smaller sailboats. Isn't Bowditch available on CD now at considerable savings? For home use. Aboard, give me paper! Sad fact is that, here on Long Isand Sound, I've heard way, way too many calls on the radio by people who were lost because their GPS died. On a clear, sunny day.Plot a course, what's that? Automotive collary: "The car just stopped. It's broke." And it's simply out of gas.

aeronca65t
aeronca65t Dork
7/13/10 5:06 p.m.
Capt Slow wrote: What little navigation skills I learned was riding around with my dad in his 172 as a kid. Dad used to joke that we were flying IFR. As in "I Follow Roads"

I often navigate my ~Airknocker~ by following railroad tracks.

We call the tracks, the Iron Compass.

Keith
Keith GRM+ Memberand SuperDork
7/13/10 5:10 p.m.

I taught myself how to use a slide rule in high school in the 80's. Even brought it along to a final exam for physics in university - I thought the prof was going to pass out from excitement when he saw it. They're a really cool thing to know how to use, but I haven't pulled mine out of the case in years.

Dr. Hess
Dr. Hess SuperDork
7/13/10 5:43 p.m.

I met a guy once that would hire out as a crewman on yachts, you know, for rich people. I asked him where he went and he said around the Caribbean and halfway to Europe once. I said: Halfway? He replied that they got in a storm half way there and the satnav (GPS) went out. I asked if they had a sextant and he said yeah, but nobody knew how to use it. They turned around and looked for jets and followed their paths.

triumph5
triumph5 Reader
7/13/10 5:57 p.m.

In reply to Dr. Hess: I've sailed with a couple like that, delivering their 48ft ketch from Annapolis to Newport. When I told them we'd be sailing directly out of the Chesapeake, then around Montauk to Newport. They both freaked. "Out of sight of land??!?!?!?!" And they had plans to winter over in the Islands and Keys. When we got to Newport, via the East river, LI Sound route, I asked them what they would do about Hurricanes, "what do you mean?" was their answer. Never heard from them again.

wbjones
wbjones Dork
7/13/10 6:07 p.m.

probably won't need one for the canoe......

neon4891
neon4891 SuperDork
7/13/10 6:59 p.m.
wbjones wrote: probably won't need one for the canoe......

I keep a compass pinned to my life jaket for the kayak. Can't say I've ever got lost. Stuck in mud and reed once...

TJ
TJ Dork
7/13/10 7:17 p.m.

I've got a hard and soft copy of Bowditch. Good book. Haven't looked at it in a few years as I've become landlocked.

Appleseed
Appleseed SuperDork
7/13/10 10:57 p.m.

Duh... I forgot the E6B qualifies as a slide rule. Still got mine.

914Driver
914Driver SuperDork
7/14/10 6:02 a.m.
TJ wrote: This is the version you get to play with on a submarine. We call it a bearing rate computer, but it is essentially a circular slide rule. Longitude is an interesting book.

Is that an is-was?

grpb
grpb New Reader
7/14/10 6:26 a.m.
chuckles wrote: Those interested in this thread, and almost everybody else, would enjoy "Longitude" by Dava Sobel.

Waay off topic, this thread is about finding latitude!!!!

TJ
TJ Dork
7/14/10 7:03 a.m.

Speaking of taking the thread off-topic:

In reply to 914Driver:

Dan, we always called them whiz-wheels...I've not heard the term is-was before.

pilotbraden
pilotbraden Reader
7/14/10 7:42 a.m.

In reply to aeronca65t:

Nice airplane, my dad had one of those long before me.

Dr. Hess
Dr. Hess SuperDork
7/14/10 8:36 a.m.

With a sextant and NOTHING ELSE, in the Northern Hemisphere you could find your latitude off the North Star and then by just sailing on whatever latitude your destination is, eventually get to where you want to go. Sailors only did this for a couple thousand years before an accurate chronograph (not a clock) was invented. Columbus was aiming for China that way. You'd think these amateurs could figure that out.

mad_machine
mad_machine GRM+ Memberand SuperDork
7/14/10 9:06 a.m.

I have used one once. It was definatly an "aha!" moment when I got it right.

Dr. Hess
Dr. Hess SuperDork
7/14/10 9:16 a.m.

Combining these two sub-threads into one: How about shooting a sun line by taking the altitude with a sextant and then using a slide rule to do the math for the sight reduction? Then all you need is a sextant, slide rule, time piece, and a nautical almanac (or perpetual almanac).

Keith
Keith GRM+ Memberand SuperDork
7/14/10 10:00 a.m.
Dr. Hess wrote: With a sextant and NOTHING ELSE, in the Northern Hemisphere you could find your latitude off the North Star and then by just sailing on whatever latitude your destination is, eventually get to where you want to go. Sailors only did this for a couple thousand years before an accurate chronograph (not a clock) was invented. Columbus was aiming for China that way. You'd think these amateurs could figure that out.

Seems to me Columbus discovered a major problem with that particular technique

Dr. Hess
Dr. Hess SuperDork
7/14/10 10:14 a.m.

The technique was valid. The problem he had was that his chart was wrong, and he didn't actually discover that his chart was wrong, as he died thinking he had found a route to the Far East and not a new continent.

The downside of that technique is that you are not going on the shortest route (great circle), but you will eventually find what you are looking for and it's a whole lot better than looking for con trails.

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