Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Re: Battenberg manuals
    From: David Pike
    Date: 2020 Oct 8, 15:54 -0700

    I said: They’re described quite well in a NACA Report.

    [NACA technical report 131 attached]

    Start reading halfway down page 21, and you’ll still need a good imagination. It’s hard to understand unless you’ve one to play with, because it solves the course, wind/current, track over the ground vector without the advantage of a speed slide like the Dalton. As with the Dalton, there’s more than one way of using it, one way is to imagine you’re sitting in the centre of the disc, on the tip of the track required vector. In my middle photo below, align the grid with the track required (360°). Apply the wind/current arm (315°) to the centre. Slide the pink slider to indicate wind/current speed (40kts). Swing the green Course arm until the dot on the air/water speed slider (90kts) is in line along track with the dot on the green slider. You need to alter course port onto 346° to allow for 14°drift, and your speed over the ground is your air/water speed less the wind/current component along track. Your speed over the ground is 90-22=78kts. Like the Dalton, there must be many other ways of using it if you’re using it for convoy station keeping, but the above will give you an idea. The logarithmic sliding circular outer scales do the same job as the sliding scales on the back of the Dalton. DaveP

    “why,” said the Dodo, “the best way to explain it is to do it”– Alice in Wonderland.


    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.

    Email Settings

    Posting Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site