Navigation in submarines

Discussion in 'Submariners' started by Crabman, Oct 17, 2007.

Welcome to the Navy Net aka Rum Ration

The UK's largest and busiest UNofficial RN website.

The heart of the site is the forum area, including:

  1. Something that has puzzled me for sometime is the subject of navigation when a submarine is dived. I can't imagine that a magnetic compass is all that reliable when surrounded by tons of steel, not to mention magnetic fields generated by sonar, coms etc. Astro? er no. Satnav? also no. Radio nav aids? given the piss poor propagaion of EMR underwater that sounds like a non starter.
    Look out on the bridge? could be something for the SBS. That leaves INAS with its attendant problems.

    Or is there something else?
  2. janner

    janner War Hero Book Reviewer

    Its a secret
  3. INAS - King of the west Saxons in the late 7th century? I don't think so!
  4. Yes

  5. It's all to do with pools of error, clever inertial nav platforms, bloody accurate charts, using our chum the echo sounder, high standards, good training, experience and a large dollop of good luck.
  6. Contributor Mode

    Time and Speed give a Distance Run on a Course steered by a expert helmsman plot on chart. Its Rocket Sience.

    Now I will have to eat my PC cos I have given the secret away.


    PS As I heard the Captain say to Vasgo on the Bridge, "Steer East and when you get Ireland on the Seaguard (radar if it has had a name change) tell me"
  7. Except on Revenge - the number of things she ran into !
  8. Thank you Nutty, this high tech method is otherwise known as dead reckoning. It's interesting to see that a method that served Columbus and others of his era or even the Romans is still alive and well. :thanks: So don't eat your PC, although it is low on calories and BSE free.

    I assume from the other replies that the writers are not navs or daren't admit it.

    So if there are any navigators out there, don' t be shy give me a bit more gen please, without compromising national security that is.
  9. How could that happen? After all it's not as if a woman was in command or at the helm. :w00t:

    Sorry Ladies.
  10. Laser inertial reference systems plus a gps fix every so often = very accurate position.OOps the men in the black cars are knocking on the door!
  11. Cool, lasers, where can I get one?

  12. SINS.
    Ships Inertial Navigation System..........Which, if you told it exactly where it was it would tell you roughly where you were.
    On Swiftsure....a mighty fine submarine and Cold War warrior who should NOT be rusting away up in Rosyth by the way......had a sign on the SINS door. It said in plain English, along with the other message of dissembowlment and wotnot if you let slip any of what goes on behind the door along the lines of.
    SINS is a multi million pound piece of electronic equipment that, if you tell it exactly where it is - it will tell you roughly where you are. Keep your mitten grrrrabben hands in pockets.....relax.....sit back and watch the spitzensparken. On no account are you to say ANY multiplication tables out loud.
    The SINS room.....always a quiet space in which to boff up on your Part Three quals....if you could handle the continuous high frequency whine. Eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee. It was like tinnitus in a cup. :slow:
  13. In the 70s, inertial navigation was great, provided you got it right when you input where you started from - if not, all sorts of LOA went in & right out again in the blink of an eye.........good job we never had these all-singing, all-dancing Tomahawks and similar thingies !!
  14. Thank you all for the informative replies. :thanks: It would appear that the RN has as much fun with inertial nav as the RAF. Namely black boxes that lie like a cheap Changi watch, unless you have decent platform, which with procurement Scrooges doing the buying not very likely.
  15. The best I ever saw ,after 12 hours of operation with gps/irs was 8 metres off track!!!
  16. No its not :bball: You need a Haircut.
    and a wash :threaten: :rambo:
  17. I always used to use the little compass stowed in the heel of my steaming boot...FACT. Honest. :nemo:
  18. Contributor Mode

    What compass in the heel of steaming bats. The bastards never told me. No doubt they did not want me to escape and come back and I thought they liked me.

    :crying: :shakefist:

  19. As far as I can make out, not having navigated a boat for over 30 years currently like almost any one else they use inertial systems updated with GPS or other navigational systems as available. IN systems do provide a good record of where yu have been and thus where you are, they are normally stable but drift with time, hence the need to update from GPS or other navigational systems. The rate of drift though should be stable and as navla and boat systems are operating for days, weeks and moths at a time that drif can be monitrored, measured and predicted enabling an IN system to give a very good predicted position at any time.

    Magnetic compasses can be made to operate satisfactorily in a submarine environment and were standard, but as I served on the first boat not to have a magnetic compass I suspect that now they have a multiple gyrocompass system and rely on at least one working at any time.

    Submariners us whatever suitable means of determining ones position are available, and as mentioned above pay particular attention to the scale of uncertainty of their position at any time, eg if you only know your position to an accuracy of 5 miles then it would be fullhardy to try to get through a passage that is only one mile wide, but keeping to a subnote lane 10 miles wide would be OK.

    AS a point of interet I completed my Ocean Navigation Certificate (successful completion of a passage out f sight of land of more than 48 hours) without the use of astro, which in those pre GPS days was the norm, and without access to the IN system.
  20. After 170 hrs under ice using SINS, first fix the platforms were within 500 yards of true posn. Bloody clever if you ask me!

Share This Page