Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

True North direction.

  • 22-05-2013 5:38pm
    #1
    hexosan
    Registered Users, Registered Users 2 Posts: 1,740 ✭✭✭


    Can anyone tell me if irish ordnance maps show true north or magnetic north. Don't have one to hand to check it.


Comments

  • #2
    sydthebeat
    Subscribers Posts: 42,171 ✭✭✭✭sydthebeat


    this implies they use true north


  • #3
    topcatcbr
    Registered Users, Registered Users 2 Posts: 1,477 ✭✭✭topcatcbr


    hexosan wrote: »
    Can anyone tell me if irish ordnance maps show true north or magnetic north. Don't have one to hand to check it.

    As magnetic north moves it would have to be true north.


  • #4
    hexosan
    Registered Users, Registered Users 2 Posts: 1,740 ✭✭✭hexosan


    topcatcbr wrote: »
    As magnetic north moves it would have to be true north.

    I would have assumed true north myself due to magnetic north moving, but two people I was talking to in the construction game introduced the element of doubt by both confidently claiming its magnetic north.


  • #5
    topcatcbr
    Registered Users, Registered Users 2 Posts: 1,477 ✭✭✭topcatcbr


    hexosan wrote: »
    I would have assumed true north myself due to magnetic north moving, but two people I was talking to in the construction game introduced the element of doubt by both confidently claiming its magnetic north.
    Don't mind them.

    If it was magnetic north it would say so. It would also give the date and deviance from true north.

    Orienteering maps often give mag north. This is to simplify it for novices


  • #6
    hexosan
    Registered Users, Registered Users 2 Posts: 1,740 ✭✭✭hexosan


    topcatcbr wrote: »
    Don't mind them.

    If it was magnetic north it would say so. It would also give the date and deviance from true north.

    Orienteering maps often give mag north. This is to simplify it for novices

    Makes sense, Suppose we all know you can't trust most in the building game to be up to date and correct with the relevant info.


  • Advertisement
  • #7
    gman2k
    Registered Users, Registered Users 2 Posts: 4,076 ✭✭✭gman2k


    Irish maps point to "Grid North" which is very close to true north. See diag 6 pg 10 on the linked pdf.
    If using a map and compass, one has to use declination to account for the difference between magnetic (compass) north and true (map) north. The declination amount (measured in degrees will vary from year to year depending on where the magnetic north pole lies.

    For all intents, Irish maps point to True North.
    This image shows the shifting position of the magnetic pole.

    Full info here (PDF link)


  • #8
    Poor Uncle Tom
    Registered Users, Registered Users 2 Posts: 14,547 ✭✭✭✭Poor Uncle Tom


    hexosan wrote: »
    Makes sense, Suppose we all know you can't trust most in the building game to be up to date and correct with the relevant info.

    This is an extremely silly generalisation and helps perpetuate the stereotype of the bungling bodging cowboy being portrayed as your average building professional.

    Whether people realise it or not correct building is a science and it takes a lot of experienced professionals carrying out highly specialised jobs to work as a team to complete a job properly. And what most outside of the building industry fail to see is that this is happening on a daily basis, it's because these people do their jobs correctly that we don't hear or see any more about the jobs. The problems happen when someone acting as a professional attempts to do what they see as easy work for easy money and mess up, that's when bad workmanship comes to light, which is an extremely small percentage of the works being carried out every day, however, that's a discussion for another thread.

    Be nice people, don't generalise, /rant.


Advertisement