24 May 2011

Flood Warning Statement as of 8:22 am PDT on May 24, 2011

The National Weather Service in Portland has issued a

*Flood Warning for the Columbia River at Vancouver.
*From this afternoon until further notice.
*At 8 AM Tuesday the stage was 15.9 feet.
*Flood Stage is 16.0 feet.
*Minor flooding is forecast.
*Forecast.... the Columbia River is forexast to rise above flood stage around 12 PM Tuesday. The Columbai will remain near or above flood stage through Wednesday... then slowly start rising by Thursday.
*Impact... above 16 feet... expect minor flooding of some lowland access roads near the river on Sauvie Island... and on the walkway near downtown Vancouver. There will be significant flooding along the banks of the Columbia River that are commonly used for camping such as on Government Island.
*Rivers currents are particularly strong and the water temperatures are very cold. It is dangerous to try to swim in these water.

13 May 2011

Fire Extinguishers

There are several different types of extinguishers based on the type of fire they are intended to extinguish.

For our purpose the three most common extinguishers are the A,B,C or multipurpose type.

These extinguishe
rs extinguish fire by removing one of the facets of the fire triangle i.e. oxygen, heat, fuel or by interrupting the chemical chain reaction that keep the fire burning.

A fires are the common combustibles like paper, wood, fabric, etc. Water is the most common, and if properly applied, most effective extinguishing agent for this class of fire. The water cools the fuel and coast the surface cutting off it's air supply. A pressurized water "can" or "pump can" is a handy extinguisher for class A fires.

Class B fires are the flammable liquids, diesel, gasoline, oils, etc. These require a dry chemical application which will suffocate the fire by cutting off the oxygen supply to the fuel.

Class C fires are electric in nature. The CO2 (carbon dioxide) extinguisher works well by cooling and displacing the oxygen from the device. CO2 is also a nonconductor so it will not conduct an electrical charge back to the extinguisher/operator. Be careful though because the nozzle will quickly become extremely cold.

For use around our homes, vessels, vehicles etc, the common multipurpose ABC extinguishers are what we are most familiar with. They are nonconducting and reasonably simple to use. While they are most specifically suited for class B fires they will do a good job on A and C fires as well.
However, they will cause a major mess and ultimately damage electrical equipment.

The extinguishers are rated by size. For instance you may see a 1A, 10B (no rating for C) extinguisher. What that means is that the extinguisher is equal to a gallon of water for class A fires and should extinguish approx 10 square feet. of burning liquid surface. Of course how you use the extinguisher will effect how much fire you can successfully extinguish.

Extinguishers will have a gauge by the handle. The needle should be in the green zone to be sure there is sufficient pressure for it to work. The extinguisher should be shaken thoroughly periodically to be sure the powder inside does not compact into a useless solid mass in the bottom of the container. You can also tap them with a rubber mallet to break the powder up. However, if you hear clumps thumping around inside your extinguisher, it is likely no good and should be replace. Most the smaller extinguishers are not rechargeable. Once they are used they are done there is no way to refill and recharge them. Larger extinguishers may be rechargeable. These typically have tags attached indicating when they should be tested. Usually most types of common extinguishers should be hydrostatically tested about every 5 years.

Now we must make a decision about whether or not we should fight the fire. FIRST, has everyone been alerted and evacuating the premises? Has 911 or the Coast Guard been called? Is the environment safe enough to stay in close proximity to the job? It does not take an awful lot of heat and smoke to rapidly make a room untenable, especially a small room like a kitchen or pilot's house. Is the fire small enough to be handled by the size extinguisher you have at hand? Is the fire still confined to it's original container or has it already begun to spread to surroundings such as curtains, cabinets, etc? Can you actually see the source of the fire? Meaning is it in the open where you can get to it and not behind something like a bulkhead. You should be sure conditions are such that you can stay to do the job. Starting and then quitting before the job is done puts yourself at considerable risk for little benefit.

Your extinguishers should always be near an exit. You should never walk past the fire further into the room etc to get your extinguisher. When you grab your extinguisher you wont to be able to quickly walk away if you have changed your mind about fighting the fire. Do not keep your extinguisher on a kitchen counter near the stove, or in the engine compartment ( as the only location). If you get a grease/oil fire on the stove top you don't want to have to reach past it to get to your extinguisher.

Assuming we have chosen to fight the fire remember not to get too close. Usually you should be about 6'-8' away for a small extinguisher to 10'-12' for the larger extinguishers. Getting too close puts yourself at risk of injury and can very well actually spread the fire as the burst of dry chemical blows into the container or surface.

Now remember P.A.S.S.

ull the safety pin,
im the nozzle, don't forget to actually hold the rubber nozzle (if so equipped) and aim it at the fire.
Squeeze the handle and
Sweep the fire.
You want to aim at the base of the flames. Your target is the burning fuel not the flames themselves. Aim for the nearest fuel edge to you and work your way to the farther edge. Be aware that the fire can reignite. Class B fires are especially likely to reignite. Depending on the size of your extinguisher you will only have from about 6-18 seconds of use.

Once the extinguisher has been used it is done unless it's a larger rechargeable type. Even the rechargeable's will need to be serviced. You cannot activate an extinguisher and save some for a future use.

NEVER, NEVER, NEVER throw water onto burning liquids! You will create an explosion of fire as the water instantly boils and splatters the burning liquid , oil, etc into a ball of fire.

I hope this helps explain the uses and cautions of using a fire extinguisher. Thanks to Bob Southwick for this great article. If you have any question for Bob relating to fire extinguisher, please email me and I will get it to Bob.