NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Cel Nav and missile submarines
From: Lu Abel
Date: 2012 Apr 10, 18:08 -0700
From: Lu Abel
Date: 2012 Apr 10, 18:08 -0700
Just a couple of quick points:
It is my understanding that the periscope on many WW II subs had a "sextant" mode where a navigator could shoot sites while submerged. Pretty useful for getting daytime (moon, sun) shots. I had a friend who was a real nut about US subs in WW II (they mostly operated in the Pacific since Japan depended on ships to supply all of its conquered Pacific islands). In the autobiography of one of the most famous (and, unfortunately, I forget whom -- it was years ago) he described getting a junior officer to take very high-angle sun sights (like 88 or 89 degrees and then draw a circular LOP on their chart by simply plotting the GP of the sun at the moment the shot was
taken.
As to 0.1' accuracy -- with nuclear weapons, as with hand-grenades, "close" is usually effective. In fact, the problem with much of the cold war may have been accurately knowing the lat/long of the target rather than of the missile launch site!
From: Alexandre E Eremenko <eremenko@math.purdue.edu>
To: NavList@fer3.com
Sent: Tuesday, April 10, 2012 5:14 PM
Subject: [NavList] Cel Nav and missile submarines
Thanks to Fred and Gary
who helped to clarify the picture.
And I apologise again for the message which begins with
"Fred,..." while this was really an answer to Gary:-)
Here is a short chronology.
The first submarine ballistic missle was Zemlia R-11FM (SS-1 Scud A).
It had an inertial guiding system.
It was launched from the submarine Zulu B-67, some say in 1956,
and even give exact date: September 16,
others say in 1955, and became operational by 1959.
It had a nuclear warhead, and was liquid-propelled.
There was only one missile on the sub, it was launched from surface
position, and had to be put vertically before the launch.
(I imagine this mess: fuleing the missile standing vertically on
the deck, with liquid fuel. The fuel was nitric acid + liquid oxigen :-)
I would be delighted to see this:-)
As the very first satellite was launched only in 1957, the submarine
clearly relied on Cel Nav. And the whole accuracy of the missle
depended on Cel Nav. Inertial navigation for the submarine itself is a short time
solution; inertial navigation cannot give your position for long time
without checking it with some other means.
Further development on the Soviet side were
R-13, R-21 (1962) and R-27 (1967) missiles,
(SS-N-4, SS-N-5, SS-N-6), all with inertial navigation,
and Yankee class submarines. They already had missiles permanently
in vertical position but the missiles were still liquid fuel propelled.
Now, in the 50-s (don't know exactly when) Soviet dip meter spreads,
and on the US side, Shufeldt makes his research in 1958-61.
Which was first classified, but then quickly unclassified,
and the satellite system Transit 1 comes in use in 1964,
and is made open to everyone in 1967.
This system does not measure any angles (as I wrongly assumed in the beginning) but uses the Doppler effect created by the motion of the
satellites. Few satellites do
not cover all Earth surface.
The accuracy 0'1-0'2 is better than Cel Nav.
Only by 1980-s the Soviets apparently developed their own satellite
system.
Concerning other non-Cel nav systems. Inertial system for submarines
is probably insdispensible when the submarine sails under ice
(or under a helicopter which tries to find it).
When it is near the water surface, a sextant can be used through the
periscope, and I read somewhere about such sextants.
The systems based on shore radio stations, like LORAN, have limited
range.
Now, in te case of a nuclear attack, all satellite systems might
be switched off, and it will remain to rely on Cel Nav for missile launch from a submarine... if there still will be people who know how
to use it:-)
Alex.