[R-390] R-390 Digest, Vol 125, Issue 9
bernie nicholson
vk2abn at bigpond.net.au
Tue Sep 9 22:44:49 EDT 2014
Re Mag compass/ Navigation Ect , I spent 7 years at sea in the 1970s as
a Merchant Navy officer, and before the days of GPS navigation , Knowing
where one was was quite problematic , if one couldn't get sun or star
sights , On a passage from London to the far east Via the Cape of Good Hope
, I remember Rounding the Ushant light ,entering the Bay of Biscay , thence
we had bad weather for the next ten days , by that time we were somewhere
off the coast of West Africa BUT the sand haze blown from the Sahara
Precluded any sightings , 9 days later we sighted an Island Dead ahead , it
turned out to be St. Helena , We were 270 Nautical miles off course after 19
days from our last Known position , Our Dead reckoning Navigation was
>From the Smiths Log Hanging off the Stern , and Propeller Revolutions minus
Known slip percentage , And Gyro which controlled the Auto-pilot, We also
had magnetic compass , With compensation a Magnetic compass does work in a
steel hull , Little Bar magnets are Oriented around the compass which cancel
the Ships magnetic field allowing the compass to respond to the earths
magnetic field , and its regularly checked by running the ship in a circle
Known as swinging the compass and taking bearings on known shore positions ,
The Gyro s worked well , BUT if you had a power failure Power had to be
restored within 20 minutes or the Gyro would start to tumble and loose
direction , One can understand how in times past ships ran into reefs ect
, Wind and Ocean currents can cause you to be a long way from where you
think you are if you weren't able to get a fix ! Sorry for the Off topic
post , Regards to all Bernie VK2ABN
----- Original Message -----
From: <r-390-request at mailman.qth.net>
To: <r-390 at mailman.qth.net>
Sent: Wednesday, September 10, 2014 5:46 AM
Subject: R-390 Digest, Vol 125, Issue 9
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> Today's Topics:
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> 1. Re: Magnetic compass and true north (Roger Gibboni)
> 2. Re: OT: Submarine navigation (Norman Ryan via R-390)
> 3. Re: Magnetic compass and true north (barry williams)
> 4. Re: OT: Submarine navigation (GRANT YOUNGMAN)
> 5. OFF Topic -- great radio & Tv magazine and book site
> (comcast mail)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 9 Sep 2014 10:15:45 -0400
> From: Roger Gibboni <rgibboni at lmdulye.com>
> To: Sheldon Daitch <SDAITCH at bbg.gov>
> Cc: "R-390 at mailman.qth.net" <R-390 at mailman.qth.net>
> Subject: Re: [R-390] Magnetic compass and true north
> Message-ID:
> <CADM9CLJUDNU7vA3zGOS0mjaw1qPePRUj0vbKFca3YHXkUf9xMg at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> yes sir but pilots navigate to magnetic north always. boats---for some
> reason---are different. they use true north. Don't know why. Maybe avoids
> a
> conversion from celestial sightings when they used that--R
>
> Roger Gibboni
> Chief Operating Officer
> Dulye & Co
> Spectator Free Workplace
> (Office) 845-987-7744
> (cell) 845-325-8760
>
>
> On Tue, Sep 9, 2014 at 9:33 AM, Sheldon Daitch <SDAITCH at bbg.gov> wrote:
>
>> Roger,
>>
>> The wet compass points magnetic north/south, not true north. But you'd
>> know true north from the magnetic declination charted information.
>>
>> 73
>> Sheldon
>>
>>
>>
>> -----Original Message-----
>> From: R-390 [mailto:r-390-bounces at mailman.qth.net] On Behalf Of Roger
>> Gibboni
>> Sent: Tuesday, September 09, 2014 4:01 PM
>> To: Blair Batty
>> Cc: R-390 at mailman.qth.net
>> Subject: Re: [R-390] OT: Submarine navigation
>>
>> Directional gyro that was reset with star sightings when they could
>> surface. The longer between star or sun shots the more th DG drifted.
>> Same as in an airplane. Enen today the only true north pointing
>> instrument
>> in an airplane is the wet compass.
>>
>> Roger Gibboni
>> 845-987-7744
>>
>> > On Sep 9, 2014, at 8:40, Blair Batty <blairbatty at gmail.com> wrote:
>> >
>> > Sorry for the off topic, but I know there are lots of ex-military
>> > types here; I don't know where else to ask.
>> >
>> > How did a submarine navigate during WW2? Did a compass work underwater
>> > inside an iron tube? Did they just look thru the periscope to see
>> > where they were going? Dead reckoning? Or were they mostly a surface
>> vessel.
>> >
>> > I suppose today they have all sorts of magic, electronic gps devices,
>> > so they can travel for months without every surfacing. But what was
>> > available, say in the 60's-70's?
>> >
>> > Sincerely
>> > /b
>> >
>> > Questions inspired by a cold war submarine movie last night...
>> > ______________________________________________________________
>> > R-390 mailing list
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>
> ------------------------------
>
> Message: 2
> Date: Tue, 9 Sep 2014 06:31:25 -0700
> From: Norman Ryan via R-390 <r-390 at mailman.qth.net>
> To: Roger Gibboni <rgibboni at lmdulye.com>, Blair Batty
> <blairbatty at gmail.com>
> Cc: "R-390 at mailman.qth.net" <R-390 at mailman.qth.net>
> Subject: Re: [R-390] OT: Submarine navigation
> Message-ID:
> <1410269485.26549.YahooMailNeo at web140701.mail.bf1.yahoo.com>
> Content-Type: text/plain; charset=us-ascii
>
> Good question. A quick Google yielded this:
>
>
> Until after World War II, submerged submarines were navigated
> with a simple magnetic compass, supplemented by periscopic sextant shots
> and observation of the shoreline. Most periscopes could not be used at
> depths
> greater than 9 m (30 ft). Improvements in gyroscopic navigational aids
> ultimately
> led to the development of modern inertial navigation systems capable of
> providing accurate guidance without the need for frequent external
> "fixes."
>
>
> On Tuesday, September 9, 2014 9:01 AM, Roger Gibboni
> <rgibboni at lmdulye.com> wrote:
>
>
>>
>>
>>Directional gyro that was reset with star sightings when they could
>>surface. The longer between star or sun shots the more th DG drifted.
>>Same as in an airplane. Enen today the only true north pointing
>>instrument in an airplane is the wet compass.
>>
>>Roger Gibboni
>>845-987-7744
>>
>>> On Sep 9, 2014, at 8:40, Blair Batty <blairbatty at gmail.com> wrote:
>>>
>>> Sorry for the off topic, but I know there are lots of ex-military types
>>> here; I don't know where else to ask.
>>>
>>> How did a submarine navigate during WW2? Did a compass work underwater
>>> inside an iron tube? Did they just look thru the periscope to see where
>>> they were going? Dead reckoning? Or were they mostly a surface vessel.
>>>
>>> I suppose today they have all sorts of magic, electronic gps devices, so
>>> they can travel for months without every surfacing. But what was
>>> available,
>>> say in the 60's-70's?
>>>
>>> Sincerely
>>> /b
>>>
>>> Questions inspired by a cold war submarine movie last night...
>>> ______________________________________________________________
>>> R-390 mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/r-390
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:R-390 at mailman.qth.net
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>______________________________________________________________
>>R-390 mailing list
>>Home: http://mailman.qth.net/mailman/listinfo/r-390
>>Help: http://mailman.qth.net/mmfaq.htm
>>Post: mailto:R-390 at mailman.qth.net
>>
>>This list hosted by: http://www.qsl.net
>>Please help support this email list: http://www.qsl.net/donate.html
>>
>>
>>
>
> ------------------------------
>
> Message: 3
> Date: Tue, 09 Sep 2014 09:44:33 -0500
> From: barry williams <ba.williams at charter.net>
> To: r-390 at mailman.qth.net
> Subject: Re: [R-390] Magnetic compass and true north
> Message-ID: <540F1251.9040601 at charter.net>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> The military also uses grid north. In the low tech aircraft we navigated
> by military topographical 1:50,000 maps mostly set up on a grid north
> basis. There are 3 norths. Grid north. Magnetic north. True north. We
> also used distance scales of miles, kilometers (the metric system) , and
> statute miles. Three airspeeds- indicated airspeed (IAS), true air
> speed, and ground speed. Two barometer scales for altimeters- millibars
> and inches of mercury. In Europe around the Brits we used 2 altimeter
> settings, QNH and QNE. We used two terms for switching ATC services-
> everybody used handoffs when being handed off to another ATC service,
> but you had to say hand over around Brits because handoff means a dirty
> act to them. 8^)
>
>
> the other Barry
>
>
>> yes sir but pilots navigate to magnetic north always. boats---for some
>> reason---are different. they use true north. Don't know why. Maybe avoids
>> a
>> conversion from celestial sightings when they used that--R
>>
>> Roger Gibboni
>> Chief Operating Officer
>> Dulye& Co
>> Spectator Free Workplace
>> (Office) 845-987-7744
>> (cell) 845-325-8760
>>
>>
>> On Tue, Sep 9, 2014 at 9:33 AM, Sheldon Daitch<SDAITCH at bbg.gov> wrote:
>>
>>> Roger,
>>>
>>> The wet compass points magnetic north/south, not true north. But you'd
>>> know true north from the magnetic declination charted information.
>>>
>>> 73
>>> Sheldon
>>>
>>>
>>>
>>> -----Original Message-----
>>> From: R-390 [mailto:r-390-bounces at mailman.qth.net] On Behalf Of Roger
>>> Gibboni
>>> Sent: Tuesday, September 09, 2014 4:01 PM
>>> To: Blair Batty
>>> Cc: R-390 at mailman.qth.net
>>> Subject: Re: [R-390] OT: Submarine navigation
>>>
>>> Directional gyro that was reset with star sightings when they could
>>> surface. The longer between star or sun shots the more th DG drifted.
>>> Same as in an airplane. Enen today the only true north pointing
>>> instrument
>>> in an airplane is the wet compass.
>>>
>>> Roger Gibboni
>>> 845-987-7744
>>>
>>>> On Sep 9, 2014, at 8:40, Blair Batty<blairbatty at gmail.com> wrote:
>>>>
>>>> Sorry for the off topic, but I know there are lots of ex-military
>>>> types here; I don't know where else to ask.
>>>>
>>>> How did a submarine navigate during WW2? Did a compass work underwater
>>>> inside an iron tube? Did they just look thru the periscope to see
>>>> where they were going? Dead reckoning? Or were they mostly a surface
>>> vessel.
>>>> I suppose today they have all sorts of magic, electronic gps devices,
>>>> so they can travel for months without every surfacing. But what was
>>>> available, say in the 60's-70's?
>>>>
>>>> Sincerely
>>>> /b
>>>>
>>>> Questions inspired by a cold war submarine movie last night...
>>>>
>
>
>
> ------------------------------
>
> Message: 4
> Date: Tue, 9 Sep 2014 10:12:42 -0500
> From: GRANT YOUNGMAN <nq5t at tx.rr.com>
> To: "R-390 at mailman.qth.net" <R-390 at mailman.qth.net>
> Subject: Re: [R-390] OT: Submarine navigation
> Message-ID: <CE3336A6-FBEB-440F-8C5C-A4988F4DC0CB at tx.rr.com>
> Content-Type: text/plain; charset=windows-1252
>
> WW2 boats were essentially surface craft that could submerge. Celestial
> navigation was the primary method of position determination. With the
> advent of nuclear power (and even some of the diesel electric subs) in the
> late 50?s, and the teardrop hull design, boats became true submersibles ?
> built to run submerged.
>
> The SINS ? Ship?s Inertial Navigation System was pretty sophisticated for
> it?s time. It worked well, although I do recall at least one time that it
> put us (this was the early 70?s) in the middle of mainland China. And
> the gyros were problematic, very expensive, and failed frequently enough
> that they were a critical supply item. It?s also possible to take a star
> sight with a periscope. We carried LORAN (as I recall it was LORAN-C) as
> well, but I don?t recall it ever being used.
>
> On a trip to the Arctic in 1970 we had one of the first satellite
> navigation systems on board. (No GPS in those days, and the SINS did not
> work well at extremely high latitudes, at least for position). We had to
> come to periscope depth at about the right time, stick a mast out of the
> water, and then it would take about 20 minutes to get a satellite pass and
> fix. Running under the ice, you had SINS and dead reckoning. Never got
> lost :)
>
> Even in the 60?s and 70?s ? (not really the dark ages) ? subs did not have
> to surface. In a typical 8-12 week patrol you'd surface once ? in the
> middle of a moonless night, for as little time as possible ? to clean the
> periscope head windows. A modern (includes 60?s 70?s) boat is completely
> self sufficient (makes water, makes oxygen, cleans the internal
> atmosphere) and can remain at sea and submerged indefinitely ? except for
> the limit of about 120+ days driven by food supply.
>
> Grant NQ5T
>
>
> On Sep 9, 2014, at 8:35 AM, Ben <brloper at gmail.com> wrote:
>
>> If you're talking 60-70's time frame then a pretty advanced INS . WW2
>> they only stayed under water for a few hours and then in an attack.
>>
>> Sent from my iPhone
>>
>>> On Sep 9, 2014, at 7:40 AM, Blair Batty <blairbatty at gmail.com> wrote:
>>>
> ...
>>> I suppose today they have all sorts of magic, electronic gps devices, so
>>> they can travel for months without every surfacing. But what was
>>> available,
>>> say in the 60's-70's?
>>>
>
>
>
> ------------------------------
>
> Message: 5
> Date: Tue, 9 Sep 2014 19:43:50 +0000
> From: "comcast mail"<pmills7 at comcast.net>
> To: R-390 at mailman.qth.net
> Subject: [R-390] OFF Topic -- great radio & Tv magazine and book site
> Message-ID: <20140909194350.468079566.pmills7 at comcast.net>
> Content-Type: text/plain
>
> I came across the reference for this website in
> the latest ER magazine that I received today. It has
> a lot of publications of 1940's and up radio and
> electronic magaines in readable and often searchable
> format. I encourage everyone to have a look at it.
>
> http://www.americanradiohistory.com/
>
> thanks, 73, Phil W5BVB
>
>
>
>
>
> ------------------------------
>
> Subject: Digest Footer
>
> _______________________________________________
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>
> ------------------------------
>
> End of R-390 Digest, Vol 125, Issue 9
> *************************************
>
>
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