Showing posts with label mean. Show all posts
Showing posts with label mean. Show all posts
Tuesday, 17 May 2016
NEMA oops I mean NMEA
Language is a wonderful and changeable thing. Acronyms, and our attempts to pronounce them can bring about decidedly weird effects, so today we are discussing the National Marine Electronics Association, or in its acronym form NMEA. This is not to be confused with NEMA, the National Electrical Manufacturers Association, the National Emergency Management Association, or even the New England Multihull Association.
Somehow over linguistic time, the acronym NMEA has ended up being universally pronounced, such as acronyms can ever be pronounced, as Nee ma. This verbal utterance has become so pervasive, that the marine populous, has actually changed the spelling of the acronym NMEA to NEMA to reflect how we actually say the acronym. If you search "NEMA 0183" -NMEA, Google finds over 24,000 references. I did some snipping off the web of examples, and noted that even the Installer himself has screwed this up at times, and boy I'm not alone. I have purposely not changed it as a personal reminder to myself.
The rate of change from NMEA, to NEMA has been increasing rapidly over time. There are a few references in the eighties, even more in the nineties, and in this decade using NEMA in place of NMEA is almost common place.
So there are are three options available, do nothing, and continue to pronounce NMEA as Knee ma, change the name of the National Marine Electronics Association to the National Electronics Marine Association, or change the way we pronounce it to "NA Me Ah. My vote is to be diligent about spelling it correctly, and to continue to pronounce it Knee ma, or Knee maw if you live in the south. Tomato, tomahto, potato, potahto. Nmea, (it is a word, sort of) that is a cool electronics network on your boat bro.
By the way this was all triggered by attending the NMEA conference on Sanibel Island (almost). I am just about done with the piece.
The photo above was taken by Canadian Phil Boisse.
Thursday, 17 September 2015
Yacht certified Whats that mean
When I read about the 34' Silverton with 27 souls on board that capsized, my initial reaction was "Clown car". I mean where could you put all of these people on a boat of this size, and what was the boat's rated capacity? It turns out there is no rated capacity for passengers on this vessel. It falls generically into the category of "Yacht Certified", if it was certified at all.
Power boats up to 20' in length are legally mandated to have a permanent label indicating maximum horse power, and passenger capacity. Larger recreational vessels, 26' and up typically fall into the "Yacht Certified" category, or not certified at all.
The "Yacht Certified" label is bestowed upon a vessel by the NMMA (National Marine Manufacturing Association) because it complies with all applicable ABYC (American Boat and Yacht Council) standards. This is an extensive list, but for vessels over 26' in length, but there are no standards related to capacity or stability, and I asked the NMMA to verify this. The USCG also has a lot regulations regarding passenger capacity, and stability, but recreational vessels over 26' in length are excluded from compliance. It seems to me there is a hole in the system that the 34' Silverton disappeared into.
Lets take a quick look at the numbers. 17 adults at 180 lbs equals 3060 lbs. 10 children at 90 lbs equals 900 lbs. 250 lbs of gasoline (full tanks) equals about 1500 lbs. 40 gallons of water (full tank) equal 340 lbs. The holding tank full weighs 150 lbs. The boat's dry weight is 12,500 lbs. If the tanks are full you have 1990 lbs at or near the waterline, and you have movable loads of 3960 lbs.
This is where it gets complicated. I think that the movable load, if properly distributed wouldn't have been as dangerous if properly placed. I think that a much smaller movable load improperly placed could be very dangerous. The question is what information does the captain have about the vessels actual passenger capacity, and stability? The answer is all too often close to zero. There are no rules that are usable, other than your instincts. If the tanks near the water line were nearly empty, does that mean you can increase the loads, or decrease the loads? If you have four people sitting on the flybridge, does that change the equation? The owners manual for most vessels is mute on the subject.
This is where it gets complicated. I think that the movable load, if properly distributed wouldn't have been as dangerous if properly placed. I think that a much smaller movable load improperly placed could be very dangerous. The question is what information does the captain have about the vessels actual passenger capacity, and stability? The answer is all too often close to zero. There are no rules that are usable, other than your instincts. If the tanks near the water line were nearly empty, does that mean you can increase the loads, or decrease the loads? If you have four people sitting on the flybridge, does that change the equation? The owners manual for most vessels is mute on the subject.
If you own a Cessna 182 aircraft, the manual tells you exactly what loads have to go where, and how much is load is allowed to insure proper balance and center of gravity in flight. Why is there so little information available to the owner of a powerboat? I'm pretty sure had the captain had some capacity/stability information available about this boat, it would have been followed. Some manufacturers do provide some general guidelines, but a lot don't.
In the end, I think manufacturers need to do a far better job of advising boat owners what the weight/load/placement limits are for their vessel. After all they design and build them. I'm not going to be an arm chair captain on what happened in this case. There are way too many variables here that are unknown. Was the boat taking on water? What were the sea conditions at the time? Were the actual loads too great, or in the wrong place? The list is endless, and in the end the experts will figure it out, and we will all learn something from it. But I don't like the fact that for most, there is no information available other than guessing, and this seems to be a shame.
The photo I used is mine, and is not the vessel discussed.
The photo I used is mine, and is not the vessel discussed.
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