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Whatever we do on training; if panic strikes, we tend to go the wrong 50%
Despite all the STCW, ISM and more to come, it still remains a pure human reaction on un-expected situations.
All the other extra ‘tits&bits’ may only aggravate things.
Such as complexity of ship’s design, automation, cargo and combination of cargoes stowed, port calls at not-so-modern ports.
Language barriers and tiredness after (regulated) hours on duty.
A (traditional) boat-drill and fire-drill are just as such.
I started seafaring in 1959 and stopped end of 1995.
Even the weather pattern has changed so much, necessitating added vigilance.
Wish all colleagues (at sea and ashore) safe working.
Certificates, of course, don’t stop people panicking (They don’t even mean that they’re competent to do the job!) but regular training and good leadership can certainly reduce the tendency to panic to manageable proportions.
Very nice article, Bob. But I’m a little bit dubious about your saying: “… At those temperatures the water already inside the casing was breaking up into hydrogen, a fuel, and the oxygen that fuel needed to burn, in what is called a hydrogen fire….” I don’t think that was the case.
My guess is the water reacted with the soot inside the economizer. Would you check this detail?
The two phenomenae considered as likely by the Maritime Accident Investigation Branch were an iron fire, which occurs when steam reacts with iron producing an exothermic reaction in which, in effect, iron will burn, and a hydrogen fire, which occurs when water dissociates into its two constituents, oxygen and hydrogen, at high temperatures. The latter case provides two sides of the fire triangle, oxygen and a fuel (hydrogen). which would explained the observed phenomena.
Prehaps you can clarify the reaction you’re suggesting, prehaps with a reference, and we’ll check it out.
I fully agree with the Iron Fire phenomenon at 1100 degrees C as per your description above. I just doubt that the water decomposed into hydrogen and oxygen in this case. Thermal decomposition of water happens at temperature above 2000 degrees C, while the whole EGE structure will melt down before it reached 1600 degrees.
Here is a reference about carbon(soot)-water reaction in which it produces hydrogen (fuel): http://www.webelements.com/webelements/elements/text/C/chem.html
C + H20 –> CO + H2
Combining H2 from the reaction and O2 pushed down into EGE by the water spray, we complete the fire triangle.
To be perfectly honest, I don’t know details (pressure, temperature, etc.) for this reaction to happen. So, this is only a rough guess.
Let’s just cycle back a little.
A soot fire can occur a temperatures from 120 celcius (Under extreme condition) to 300-400 celcius. This will depend on the dryness of the soot.
Hydrogen fires, which involve the dissociation of water (H20) into oxygen and hydrogen occurs at temperatures above 1,000 celcius. It is self sustaining and exothermic, ie., the reaction gives out heat.
The reactions are:
2H20> 2H2 + 02
H20 + C> H2+C
Both hydrogen (H2) and Carbon Monoxide (CO) are flammable.
At above 1,100 celcius two reactions occur, the rapid oxidation of iron and, when present, a reaction between iron ans steam, again this is exothermic, ie., temperature increases. These are usually lumped together as ‘iron fires’.
2Fe+O2>FeO + heat
Fe + H2O>FeO + H2 + heat
Note that hydrogen fires and iron fires can co-exist.
You might like to check out this article: http://www.manbw.com/article_004063.html
The reaction you mention, which involves pushing steam (H2O) through coke (Carbon) goes:
C+H2O>CO + H2
Both resulting gases are flammable. However, the reaction is endothermic, ie, it cools down the coke. Adding water would, therefore, cause the temperature to go down, not up, as observed on the Maersk Doha. One would then have to introduce dry air to reheat the coke before applying more water. The engine room fire dampers were closed so I’m not sure where the dry air would come from, it doesn’t seem to me that the water initially being sprayed in would have introduced air forcefully enough to reheat the soot.
Certainly, neither the MAIB, nor the engine manufacturer or the manufacturers association seem to have considered that reaction.
thoroughly enjoyed reading ur article ,, wish u cud write some marine engineering text books lol atleast studin will be fun
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