Home |
Search |
Today's Posts |
#10
![]() |
|||
|
|||
![]()
Jim Donohue wrote:
Calling it a "system" was a euphemism. It was a GPS attached to an autopilot. They ignored the depth sounder, the radar, and visual cues. Actually, the same thing could have happened to most anyone with an Autohelm and a Garmin, except the the Autohelm (now Raymarine) gives a better indication of faulty input. Neither the page of causals nor the 3 pages of recommendations has a single mention of the term GPS...not one. There were a number of failures but not one that indicates GPS was a problem. Incompetent seamanship is the proximate cause with poorly designed and poorly operated equipment creating the opportunity for the incompetent seaman to ground the boat. You've made this claim several times and its total Bull****! You're claiming, in essence, that because the satellites broadcast a good signal, there is no problem with over-reliance on GPS. This is a textbook case in what can go wrong with such over-reliance. The bizarre thing here is that on one hand you've been arguing that GPS should be learned first because it is nearly perfect, but then here you're claiming that the problem was the "incompetent seaman" who relied too much on GPS. In the "Conclusions" section of the report the NTSB describes what happened and what went wrong. The majority of the 22 conclusions talk about the failure of the GPS (mentioning it specifically) system or the failure to double check by other means, i.e. the over-reliance on one system. Here's some examples: 5. Had the fathometer alarm been set to 3 meters, as was the stated practice, or had the second officer chosen to display the fathometer data on the control console, he would have been alerted that the Royal Majesty was in far shallower water than expected and, thus, was off course. He would have been alerted perhaps as long as 40 minutes before the grounding, and the situation could have been corrected. 6. The watch officers’ monitoring of the status of the vessel’s global positioning system was deficient throughout the voyage from St. George’s. 7. Deliberate cross checking between the global positioning system and the Loran-C to verify the Royal Majesty’s position was not being performed and should have been on the voyage from St. George’s. 8. Even though it is likely that the watch officers were not aware of the limitation inherent in using the position-fix alarm to monitor the accuracy of GPS position data, it was inappropriate for them to rely solely on the alarm to warn them of any problems with the GPS data. 9. The sighting of lights not normally observed in the traffic lanes, the second officer’s inability to confirm the presence of the BB buoy, and the sighting of blue and white water should have taken precedence over the automation display on the central console and compelled the second officer to promptly use all available means to verify his position. 10. The chief officer and the second officer did not observe good watchkeeping practices or act with heightened awareness of the precautions that are needed when a vessel approaches the Boston traffic lanes and landfall. 11. The master’s methods for monitoring the progress of the voyage did not account for the technical capabilities and limitations of the automated equipment. 12. The watch officers on the Royal Majesty may have believed that because the global positioning system had demonstrated sufficient reliability over 3 1/2 years, the traditional practice of using at least two independent sources of position information was not necessary. 13. All the watchstanding officers were overly reliant on the automated position display of the navigation and command system 25 and were, for all intents and purposes, sailing the map display instead of using navigation aids or lookout information. The report continues with other items in the same vein, though focused more on the problems with the integrated system and the training, such as: 16. Had the navigation and command system 25 autopilot been configured to compare position data from multiple independent position receivers and had a corresponding alarm been installed that activated when discrepancies were detected, the grounding of the Royal Majesty may have been avoided. Although the "Probable Cause" section which follows does not mention GPS specifically, it is quite short (two small paragraphs) and mentions simply "overreliance on the automated features of the integrated bridge system," the lack of training, and the failure to take "corrective action after several cues indicated the vessel was off course." In other words, they relied too much on one source of position (the gps) and ignored others. While the "Recommendations" section does not mention GPS specifically, it clearly recommends against over reliance on one system. We've never claimed there was anything "wrong" with GPS, only that other forms of navigation are just as important. The report includes comments like: Review the bridge watchstanding practices on all its vessels, and revise, as necessary, to ensure that all watch officers adhere to sound watchstanding practices and procedures, including using landmarks, soundings, and navigational aids to verify a vessel’s position, relying on more than one source for position information, and reporting to the master any failure to detect important navigational aids. .... As part of the foreign flag passenger ship control verification examination program, verify that the watchstanding procedures of ships’ officers include the use of multiple independent means of position verification. It is true that the bulk of the recommendations have to do with better standards for automated systems, but even then it deals largely with the need to use more than one form of input: comparing position-receiver data for significant discrepancies between position receivers, and subsequent positive annunciation to the crew; Sorry Jim, its clear that you've been disingenuous with us. The NTSB study is quite specific in finding fault with relying completely on GPS. Though they don't fault the GPS system itself (i.e. the signal leaving the satellite) they make it quite clear the overreliance on one electronic navigation system was the cause of the grounding. |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Salt water and Fibreglass Boats | General | |||
Bathtub For Outdrive In Salt Water? | Boat Building | |||
Salt water in my engine | ASA | |||
South Florida Salt Water Crocs (crocodiles) NOT ALLIGATORS | General | |||
Electric Trailer Brakes in Salt Water - Am I Nuts? | General |