Welcome to the NavList Message Boards.

NavList:

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

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Ship Speed
    From: Bruce J. Pennino
    Date: 2018 Mar 22, 08:21 -0700

    Good Morning:

    On the topic of ship speed, I worked for a while at a research/engineering place where we calibrated Pitot tubes and similar devices. For those unfamiliar with a Pitot tube, it is an "L" shaped open tube where the short leg is impacted by air or water as the tube extends into the flow. The higher the speed of the flow (or the ship) the greater the water rise in the tube. If the probe is used in the air, there are various means of converting the air pressure  rise (above ambient) or water rise to speed. Of course there have been several terrible air accidents where the Pitot tube has frozen or failed in some manner.  Anyway , a long time ago I was working on a historical exhibit of early methods to measure velocity of flow using various types of propellar meters. I discovered in a closet a  6 ft long very heavy ellipsical  cylinder( 2-3 inches in short dimension) with a Pitot tube sticking out of the bottom of the enclosing cylinder. I aked my boss, an old USN fellow, he told me it was a modern ship log. The device protruded through the hull of the warship. Is this correct?

    Thanks

    Bruce

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    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:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    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