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Thread: Manual Wind Query

  1. #101
    Eddie should receive recognition for providing regular opportunities to enjoy the hand winding experience with TF offerings - past and present: the PRS-53, the Smiths Vintage PRS-35, Smiths Vintage Cushion Case PRS-36, both the Military Smiths PRS-29A and 29B, the PRS-20 series, the PRS-9, the PRS-5, the PRS-6, the PRS-8 Richmond Spencer and I may have missed some.

    My PRS-29B, so easy to wind with that crown.


  2. #102
    Master Saxon007's Avatar
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    A Speedy with a good crystal and seals can be gotton wet, I've done it several times with no ill effects. Even Omega says you can swim with them (just don't use the pushers underwater).

    http://www.omegawatches.com/fileadmi...aterResist.pdf

    I love hand winding watches and currently have four of them, two of which are Speedmasters. They are fantastic. :)


  3. #103
    Quote Originally Posted by bitfield View Post
    So anyway, I thought I remembered reading a good piece about the actual NASA testing process recently. Here it is: Qualifying a watch to fly to the Moon

    Executive summary:

    • Timekeeping test
    • Hot test (200F)
    • Cold test (0F)
    • Vacuum test
    • High-pressure test
    • Humidity test (95%)
    • 100% oxygen atmosphere test
    • G-load tests (40G)
    • Vibration tests (2000Hz)
    • Acoustic test (130dB)


    Only the Speedy survived all the tests. The other watches included a Wittnauer chronograph, a Valjoux 72-based Rolex Cosmograph, and a Breitling Navitimer Cosmonaute (source: Omega Speedmaster NASA Testing Process) and none of them made it. The Breitling failed on timekeeping, the Rolex failed on humidity (the second hand warped), and the Wittnauer's crystal blew out in the pressure tests.

    So that is actually quite impressive. I don't know if anyone has re-run those tests recently, on modern watches - it would be a fun experiment.
    Been thinking about this, wrt the testing being repeated.it would be an interesting experiment,and one I'd like to see repeated with an off the shelf speedy. My thinking here is, are NASA issued speedys standard speedys or are a little more care and attention put into watches going to NASA. I've read that cosc certified watches are a little bit more Er.. shall we say worked on than a none cosc equivalent of the same model. Maybe that's untrue.

    anyway, something to think about. Just have to find someone willing to have their watch smashed up for internet forum science/curiosity.

  4. #104
    Master lysanderxiii's Avatar
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    Quote Originally Posted by rfrazier View Post
    Yes.

    "Good morning watch. What nice shoes! Would you like a bit of a wind?"

    What if it says "no"?

    Best wishes,
    Bob
    That's why you have more than one watch.....

  5. #105
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    Quote Originally Posted by Saxon007 View Post
    A Speedy with a good crystal and seals can be gotton wet, I've done it several times with no ill effects. Even Omega says you can swim with them (just don't use the pushers underwater).

    http://www.omegawatches.com/fileadmi...aterResist.pdf

    I love hand winding watches and currently have four of them, two of which are Speedmasters. They are fantastic. :)

    Superb photo! Been wearing my 29b since this thread started :)

  6. #106
    Quote Originally Posted by Ian_O View Post
    I meant to add that the two Apollo 13 mid-course correction burns timed by Jack Swigert on his Omega and referred to in an earlier post were 15 seconds and 22.4 seconds, rather than the "minutes" suggested. So in those circumstances it was probably far easier to use a chronograph to time them accurately.
    Let's not downplay the fact that, in the history of mankind, this is probably the most important use of a watch ever.

    That said, let's see it in context. Jim Lovell doesn't say in 'Apollo 13' whether or not Swigert used the chrono function of his watch. Here is his description of what happened:

    Lovell looked at his watch. The time for the burn had not nearly arrived.

    "We're counting down, aren't we?" he asked. "Or do you want us just to start anytime?"

    "Your choice," Lousma answered.

    "You guys are getting easy."

    "It's not time critical, Jim."

    "I understand." Lovell turned to his crewmates. "You guys ready to try this?"

    Haise and Swigert nodded.

    "All right," the commander said. "Jack, since we don't have any countdown clock, you time the burn with your watch. We're firing for 14 seconds at 10 percent... Let's say we'll make this burn in two minutes."

    Swigert fixed his gaze on his watch. "Two minutes on my mark," he said. "Mark."

    ...

    "Ignition," the commander said to his crewmates. Swigert looked at the second hand of his watch. "Two seconds, three seconds."

    ...

    "Fourteen seconds." Lovell mashed the button hard, far harder than he needed to. "Houston, burn complete."

    "OK, guys," Lousma said. "Nice work."
    That reads to me as though Swigert was waiting for the second hand (not the chrono second hand) to reach zero before starting his count. There's no mention of him pressing any buttons. He just starts counting at a certain point, and when he reaches fourteen, Lovell hits the switch. Of course, that's the way any of us would time fourteen seconds if our watches didn't happen to have a chrono complication. If the burn had, in fact, been a matter of minutes, as I mistakenly said, it would have been easy to lose count of the minutes timing this way, and a chronograph would have made much more sense. But for fourteen seconds I suspect he simply didn't bother.

    There is also the question of how critical the duration of the burn was. Obviously, broadly speaking, the burn itself was critical. But the way these things actually work is that you compute beforehand how long an engine burn you needed to achieve the required delta-V. You then burn the engine for the specified time, and look at what the guidance system is showing as your change in delta-V. Rocket engines are not entirely predictable things, and they may burn a little faster or slower than nominal, and take a second or two to get going or to shut down. So it's very much a suck-it-and-see process. What you do is you make a 'gross' course correction, which usually gets you pretty close to the ideal course, and then one or more optional fine corrections to even out the slop. (See W. David Woods' wonderful book 'How Apollo Flew To The Moon' for exhaustive details of Apollo's orbital mechanics, rocket flight dynamics, and guidance systems.)

    As you can see from the text, there was no particular critical moment when the burn had to start. If they had been a little bit off with the burn, they could have made another one, or as many more as they needed to end up on the right course. The exact timing was much less important than precisely maintaining the attitude of the spacecraft during the burn–which, as you'll recall, Lovell and Haise managed visually, by keeping the Earth centred in the window.

    I'm not sure how close to fourteen seconds would have been acceptable for the burn. I would guess a second or two either way wouldn't have mattered. Simply counting out loud, "One Mississippi, two Mississippi...." would probably have been fine. Alternatively, Mission Control, who of course still had working digital computers and timers, could have counted it off for them.

    In conclusion, it was a glorious day for watches, but the Apollo 13 astronauts can't really be said to owe their lives to a watch in general, or the Speedmaster Professional in particular. However, it is the watch that was there on the day, and that matters.
    Last edited by bitfield; 9th January 2015 at 15:07.

  7. #107
    Great post!

    For me, I think it's not just that it's the watch that was there on the day, although I see your point, but rather that it was the watch tough enough to pass the tests you posted details on earlier in thread. That's why it was the watch there on the day. And that is what draws me too it. It's just because I come from an engineering background.

    Had nasa not flight qualified a watch, not tested a watch for missions, it's perhaps not inconceivable that there may have been no functioning watch there on the day, in order to time the burn.

    I mean ok, also,let's be realistic an omega mechanical chrono is way sexier than a g shock, models of which are also qualified and have inumerably more, and easier to utilise functions.

  8. #108
    He may or may not have used the chrono function; I don't think the book was written for WIS so detailing the exact method of timing may have ruined the narrative flow. In any event the crew and NASA were happy enough with the watch to give Omega a 'Snoopy' award by way of thanks.

  9. #109
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    I am officially now looking for a manual wind chronograph! Quite possibly a speedmaster but I have a lot of research to do on the model.
    Last edited by omarcomarco; 12th January 2015 at 22:03.

  10. #110
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    Quote Originally Posted by omarcomarco View Post
    I am officially now looking for a manual wind chronograph! Quite possibly a speedmaster but I have a lot of research to do on the model.
    Although not in the same league, have you thought a Seagull 1963 or a Strela, lots to choose from but the Cosmos is gorgeous.

  11. #111
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    I was in a jewellers and got talking about the Seamaster 300. I thought it looked great but then I spotted the Speedmaster.
    They go well together!


  12. #112
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    Quote Originally Posted by barryw View Post
    Although not in the same league, have you thought a Seagull 1963 or a Strela, lots to choose from but the Cosmos is gorgeous.
    thanks for the suggestion, I'll check them out.

  13. #113
    Craftsman chester's Avatar
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    Eh bye gum! When I were a lad most watches were hand crankers and only posh folk had autos - manual wind isn't a negative at all (unless you forget to wind it up).

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