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
    Re: Fw: Grounding of cruiser PORT ROYAL
    From: Frank Reed
    Date: 2009 Jul 18, 06:25 -0700

    I've been looking at a couple of the photos of the Port Royal on the shoal 
    south of the airport. In one of them (attached), you can clearly see the 
    skyline of downtown Honolulu not far in the distance. The airport and its 
    main runway were just to port. This was a visually "busy" environment at 
    night with all sorts of airport lights, city lights, and the bright lights 
    from the sewage treatment plant and the vast port facilities dead ahead. It 
    got me wondering just what it would all have looked like from the bridge of 
    the vessel that night. And of course to find out, I needed to know just where 
    they were. This is where it gets fun...
    
    I prowled around on the web for a while yesterday looking for photos of the 
    vessel on the reef from various angles. There are a couple of photos taken 
    from the tugs and salvage vessels nearby, and they offer some hints. There 
    are also a number of photos taken with the airport in the foreground, but 
    these don't seem to help much since that runway doesn't have many 
    identifiable features visible from ten feet above sea level. Then I found a 
    couple of photos taken with telephoto lenses apparently from tall buildings 
    in downtown Honolulu that are quite useful. I patched them together into a 
    couple of composites (also attached). And one of them, no doubt taken for its 
    artistic qualities, includes the setting sun! That gives us an angular scale 
    and a good estimate of azimuth. In the foreground of the daylight portion of 
    the image, you can see a bunch of containers all labeled "Matson". So go to 
    Google Maps and ask for "Matson Honolulu HI". That takes you right to their 
    big lot on Sand Island between the airport and downtown Honolulu. Line things 
    up just right, and we should be able to figure out just where the Port Royal 
    came to rest on the shoals on February 6, 2009. There's some entertaining 
    geometry and navigational calculations here. I won't spoil it by giving my 
    results. Besides I would like to see what some of you get independently. One 
    warning: the facilities at the Water Treatment Plant on Sand Island have been 
    significantly expanded since the last imagery was acquired for Google 
    Maps/Google Earth. That big egg-shaped structure is a "sludge digester" and 
    it's new. See if you can find the wind sock for the helipad (I think it's a 
    wind sock at least).
    
    Some questions to ponder: what is the true bearing from that big circular 
    sewage tank in the mid-ground out to the Port Royal? Can you do a "dip short" 
    or similar to figure the distance to the vessel? Can you make a guess how 
    high the observer was who took the photo (assuming it was taken from the 
    central area of downtown Honolulu)? And finally, with all the available 
    evidence, what were the latitude and longitude of the Port Royal's bow and 
    stern while she was parked on that reef?
    
    -FER
    
    --~--~---------~--~----~------------~-------~--~----~
    NavList message boards: www.fer3.com/arc
    Or post by email to: NavList@fer3.com
    To unsubscribe, email NavList-unsubscribe@fer3.com
    -~----------~----~----~----~------~----~------~--~---
    
    
    

    File:


    File:


    File:


       
    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