4 ms·

The Grounding of the Royal Majesty (2009) [pdf]

17 points by URSpider94 12y ago

tlb 12y ago
TL;DR: On a large cruise ship the GPS antenna broke, and the GPS continued to display plausible coordinates based on dead reckoning with only a tiny icon to indicate the data wasn't based on a satellite fix. The dead reckoning error accumulated to 15 miles, which drove them aground near Nantucket.
- mikepalmer 12y ago
  omg, spoiler alert! :-)
- walshemj 12y ago
  :-) One of my uncles has just retired from the main UK collage for training Merchant Marine officers - he commented that a lot of the younger officers don't have much experience of using the traditional methods of fixing your position.
- gumby 12y ago
  Actually I think the real TL;DR is that the crew failed to "trust but verify" and that the automated cross checks were set up in such a way that they cancelled each other out. It's a cautionary tale for anyone developing self-navigating devices. Plus for me the document is cut off mid-sentence.
  - URSpider94 12y ago
    Plus for me the document is cut off mid-sentence. It's a copy of a book chapter, plus the end notes (notice how the page number jumps near the end). The end notes aren't paginated by chapter, so you're seeing the first paragraph of the end notes for the NEXT chapter at the bottom of the page.
- URSpider94 12y ago
  More than that, the dead reckoning data from the GPS "infected" numerous other automated systems that should have caught the error, because there was (is?) no defined standard for what a GPS receiver should do in the event of losing its fix. In this case, it kept transmitting position data and added a proprietary "invalid" tag that wasn't parsed by other equipment.
grkvlt 12y ago
This is really well written, the author has a very engaging story-telling style, and manages to get the facts across while still being entertaining. And, I love the Proverbs quote at the start. Anyone know what book it comes from, as I'd love to read it if all the content is like this. It appears to be the entirety of Chapter 8 of something, but I couldn't find the actual book title mentioned anywhere...
- grkvlt 12y ago
  I found Chapter 12, 'Incorrect Blood Pressure' http://ti.arc.nasa.gov/m/profile/adegani/Incorrect%20Blood%20Pressure.pdf http://ti.arc.nasa.gov/m/profile/adegani/Incorrect%20Blood%2... Also 'A comparative study of two shovel designs' by A. Degani http://ti.arc.nasa.gov/m/profile/adegani/shovel.pdf http://ti.arc.nasa.gov/m/profile/adegani/shovel.pdf A quick search for PDFs on the same NASA site by the same author (http://1.usa.gov/1c0S7of http://1.usa.gov/1c0S7of) finds Chapters 9, 13, 15 and 17 as well.
- grkvlt 12y ago
  Degani, A. (2004). Taming HAL: Designing interfaces beyond 2001. New York: St. Martin’s Press/Palgrave Macmillan. 320 pages, 105 figures. ISBN: 031229574X The book details a new approach, mostly based on software engineering and formal methods, for the describing, analyzing, and identifying potential design errors in human-automation interfaces.

17 points by URSpider94 12y ago

tlb 12y ago

TL;DR: On a large cruise ship the GPS antenna broke, and the GPS continued to display plausible coordinates based on dead reckoning with only a tiny icon to indicate the data wasn't based on a satellite fix. The dead reckoning error accumulated to 15 miles, which drove them aground near Nantucket.

mikepalmer 12y ago
omg, spoiler alert! :-)
walshemj 12y ago
:-) One of my uncles has just retired from the main UK collage for training Merchant Marine officers - he commented that a lot of the younger officers don't have much experience of using the traditional methods of fixing your position.
gumby 12y ago
Actually I think the real TL;DR is that the crew failed to "trust but verify" and that the automated cross checks were set up in such a way that they cancelled each other out. It's a cautionary tale for anyone developing self-navigating devices. Plus for me the document is cut off mid-sentence.
- URSpider94 12y ago
  Plus for me the document is cut off mid-sentence. It's a copy of a book chapter, plus the end notes (notice how the page number jumps near the end). The end notes aren't paginated by chapter, so you're seeing the first paragraph of the end notes for the NEXT chapter at the bottom of the page.
URSpider94 12y ago
More than that, the dead reckoning data from the GPS "infected" numerous other automated systems that should have caught the error, because there was (is?) no defined standard for what a GPS receiver should do in the event of losing its fix. In this case, it kept transmitting position data and added a proprietary "invalid" tag that wasn't parsed by other equipment.

grkvlt 12y ago

This is really well written, the author has a very engaging story-telling style, and manages to get the facts across while still being entertaining. And, I love the Proverbs quote at the start. Anyone know what book it comes from, as I'd love to read it if all the content is like this. It appears to be the entirety of Chapter 8 of something, but I couldn't find the actual book title mentioned anywhere...

grkvlt 12y ago
I found Chapter 12, 'Incorrect Blood Pressure' http://ti.arc.nasa.gov/m/profile/adegani/Incorrect%20Blood%20Pressure.pdf http://ti.arc.nasa.gov/m/profile/adegani/Incorrect%20Blood%2... Also 'A comparative study of two shovel designs' by A. Degani http://ti.arc.nasa.gov/m/profile/adegani/shovel.pdf http://ti.arc.nasa.gov/m/profile/adegani/shovel.pdf A quick search for PDFs on the same NASA site by the same author (http://1.usa.gov/1c0S7of http://1.usa.gov/1c0S7of) finds Chapters 9, 13, 15 and 17 as well.
grkvlt 12y ago
Degani, A. (2004). Taming HAL: Designing interfaces beyond 2001. New York: St. Martin’s Press/Palgrave Macmillan. 320 pages, 105 figures. ISBN: 031229574X The book details a new approach, mostly based on software engineering and formal methods, for the describing, analyzing, and identifying potential design errors in human-automation interfaces.