Next message: Alexandre Eremenko: "Re: Role of CN at sea, was RE: Averaging sights ..."
Nels,
Well, one large scale incident that comes to mind was the grounding of
the Panamanian passenger ship Royal Majesty in the mid 90's. It ended
up on a shoal east of Nantucket Island, and about 17 nm from where the
watch officers thought the vessel should be.
The incident was investigated by the National Transport Safety Board,
where they concluded that performance of the ship's integrated bridge
system and GPS failed. They also examined the effects of 'automation
on watch officers' performance...'. This, I think, is a good issue, as
obviously they weren't also keeping a good lookout, but relied totally
on their electronics. Just sloppy seamanship, really.
Lisa
Nels Tomlinson wrote:
> Well, what I really meant was: has anyone heard of a boat loosing or
> breaking all of its receivers? At 5 to 10 knots, loosing the signal
> for a quarter hour or so shouldn't be a big deal, but loosing all the
> GPSs to a lightning strike, simple failure or some series of
> accidents could be a big deal, and it seems as if it's bound to happen
> sometime.
>
> Nels
>
>
> On Tue, 12 Oct 2004 19:15:25 -0500, Bill <> wrote:
>
>>>Has anyone ever heard of a vessel loosing all of its GPSs while at
>>>sea? If it hasn't happened yet, I suspect it will.
>>
>>In approx.. 700 hours of land and water operation over the past 3 years, I
>>have experienced five loss-of-satellites-signal situations, usually lasting
>>from 5-15 minutes. Three were on land, one due to a detour through the
>>mountains in Pennsylvania after a 50 car/truck pile up in front of me. With
>>mountains on all horizons and a blinding snowstorm overhead, would hardly
>>blame that on the system or unit.
>>
>>The other two land situations I have no explanation for. Great weather,
>>flatlands, no military bases nearby.
>>
>>Of the two on water (Lake Michigan) all units (my Garmin 76, an older
>>Magellan, and the owners chartplotter) all failed to get adequate signals
>>for 10 minutes or so. Partly cloudy sky. In one case an older Garmin showed
>>our speed-over-ground on a broad reach in a 34' Catalina as 33.8 kn. Not
>>too shabby--lucky the rudder stayed attached ;-)
>>
>>I have seen people sit on their unit left on the cockpit cushion and it lost
>>all of its waypoints. A friend's older Magellan unit failed to find
>>satellites after 3 hours. It is been replaced by a new unit. Have also
>>seen two different Loran C units go haywire, with errors of more than 5' lat
>>and lon.
>>
>>In talking with about a dozen sailors on the 600 dock at Michigan City, each
>>and every one of them has experienced unexplainable signal loss of 5-15
>>minutes while on the water.
>>
>>Perhaps the Great Lakes don't meet the definition of "at sea," and is mostly
>>coastal piloting, but there is ample evidence a single unit can malfunction,
>>and even with multiple units, there are periods where signals cannot be
>>received.
>>
>>Not a big deal on the southern half of Lake Michigan where it is pretty much
>>point-and-shoot, but uncomfortable in the area where Michigan, Huron, and
>>Superior merge.
>>
>>Bill
>>
>
>
>
--
Kind regards
Lisa Fiene
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