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Old 01-30-2015, 10:14 AM   #22
sbu22
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City: New Orleans
Country: US
Vessel Name: Panache
Vessel Model: Viking 43 Double Cabin '76
Join Date: Mar 2011
Posts: 859
Ksanders – You’re missing the point.
1. Diesel engine exhaust contains consistent and measurable concentrations of CO. Seems to run in the 1,000-2,000 ppm range. These units were, of course, ugly construction and oil field equipment. They do not emit the same pink, rose scented exhaust that our boats do, but still….

2. The “motor powered cabin vessel” (or something to that effect that the USCG uses as a descriptor to characterize the boats on this forum) have, in my experience and by any objective standard, generally poor interior ventilation (air exchanges per unit time).

3. CO exposure is responsible for about 15,000 ER visits and 500 deaths per year in the US. Been pretty consistent throughout 1999-2010. These numbers exclude structural fires, suicides, etc., etc. See the CDC’s Morbidity and Mortality Weekly Report if you want to drill down the data. I don’t believe you’ll find a data level that distinguishes between gasoline, propane, and diesel.
4. CO is not an asphyxiant – it does not do damage by displacing O2 in the atmosphere. It is a true toxic agent, inhibiting the blood's ability to carry O2 to vital organs.

5. The insult (damage) produced by CO exposure is a function of CO concentration and the duration of exposure to that concentration. For example, an acute exposure to CO at the 12-13,000 ppm level will fatal in 1-3 minutes; an exposure to just 400 ppm for 4 hours is expected to be fatal.

6. The UL CO detector set point standard reflects this “dose” relationship.
a. > 400 ppm CO, device must alarm between 4 and 15 minutes
b. > 150 ppm of CO, device must alarm between 10 and 50 minutes.
c. > 70 ppm of CO, device must alarm between 60 and 240 minutes.

I did not intend to tread on the closely held belief by many recreational diesel boaters that the diesel propulsion and fuel systems are as benign as a kiddy pool in the backyard.

I have DC plugs lanyarded to every through-hull. Because I expect an imminent through-hull failure? Getting ready for a transPac? Nope. Just a firm and long held belief that Murphy was an optimist and I’m going to do everything I can to insure the safety and longevity of the boat, my passengers, and myself.

When presented with a toxic source with no (zero) warning properties, semi-confined spaces below, and a relatively inexpensive means of managing that risk (even though it’s low probability), I’ll go with the “good” vice the “proper”. To each his own.
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