BenBurch
Gatekeeper of The Left
I touched upon this in another topic, but I think it deserves a topic of its own, so here it is.
One of the tiresome refrains of the third-string truthers who pass through here like meat through the sausage grinder is that a hydrocarbon fire can never make steel fail.
Now, we give them diagrams and charts and quote temperatures to them, none of which ever make any more impression upon them than a mosquito does upon a windshield, so I here present a real world example.
A technology that has nearly vanished from the world is the steam locomotive.
Since Stephenson's Rocket, boilers of steam locomotives, with few exceptions, have been on the same plan; A firebox surrouned by water with a grate below the fire to admit air and to release ash, with combustion gasses passing through a barrel-shaped boiler via multiple fire tubes to a smoke box where exhaust steam from the operation of the engine is blown up the stack to create a draft that sucks the combustion gasses from the firebox and causes air to come in through the grates to feed the fire.
At the top of the firebox, and subject to the most heating from the fire because heat rises, is the crown sheet. The crown sheet is attached to the top of the boiler shell by long stay bolts that keep the internal pressure of the boiler from deforming the sheet, which otherwise would have to be very thick and not very good at its job of transmitting heat into the water.
When the crown sheet of a boiler becomes dry, it is no longer cooled by the phase change of the boiling water, and very quickly heats to the temperature of the fire. As it does so, it loses much of its strength, softens and in spite of the stay bolts can be deformed by the pressure in the boiler to pull away from the stay bolts to ultimate failure.
When a crown sheet fails you have a boiler explosion. This is nearly invariably fatal to the operators of the engine and anybody nearby and can hurl the boiler off the frames of the locomotive some considerable distance.
And this is true no matter what fuel the locomotive consumes; Wood, Peat, Coal, or Oil.
But if we believed our volunteer sausages here, the last fuel should never have the capacity to damage a boiler under any circumstances. It should just not be possible for a oil fire to reach a heat sufficient to cause that steel to weaken and deform.
So, what are we to believe? That the truthers are correct that such a locomotive is universally safe with oil fuel and a dry crown sheet? Or the tragic history of railroading which includes several such failures?
(See http://books.google.com/books?id=RZ...SWtZcD&sa=X&oi=book_result&resnum=1&ct=result for one such failure.)
If indeed such failures happen, and they do, then the truthers are proven 100% wrong on this topic.
One of the tiresome refrains of the third-string truthers who pass through here like meat through the sausage grinder is that a hydrocarbon fire can never make steel fail.
Now, we give them diagrams and charts and quote temperatures to them, none of which ever make any more impression upon them than a mosquito does upon a windshield, so I here present a real world example.
A technology that has nearly vanished from the world is the steam locomotive.
Since Stephenson's Rocket, boilers of steam locomotives, with few exceptions, have been on the same plan; A firebox surrouned by water with a grate below the fire to admit air and to release ash, with combustion gasses passing through a barrel-shaped boiler via multiple fire tubes to a smoke box where exhaust steam from the operation of the engine is blown up the stack to create a draft that sucks the combustion gasses from the firebox and causes air to come in through the grates to feed the fire.
At the top of the firebox, and subject to the most heating from the fire because heat rises, is the crown sheet. The crown sheet is attached to the top of the boiler shell by long stay bolts that keep the internal pressure of the boiler from deforming the sheet, which otherwise would have to be very thick and not very good at its job of transmitting heat into the water.
When the crown sheet of a boiler becomes dry, it is no longer cooled by the phase change of the boiling water, and very quickly heats to the temperature of the fire. As it does so, it loses much of its strength, softens and in spite of the stay bolts can be deformed by the pressure in the boiler to pull away from the stay bolts to ultimate failure.
When a crown sheet fails you have a boiler explosion. This is nearly invariably fatal to the operators of the engine and anybody nearby and can hurl the boiler off the frames of the locomotive some considerable distance.
And this is true no matter what fuel the locomotive consumes; Wood, Peat, Coal, or Oil.
But if we believed our volunteer sausages here, the last fuel should never have the capacity to damage a boiler under any circumstances. It should just not be possible for a oil fire to reach a heat sufficient to cause that steel to weaken and deform.
So, what are we to believe? That the truthers are correct that such a locomotive is universally safe with oil fuel and a dry crown sheet? Or the tragic history of railroading which includes several such failures?
(See http://books.google.com/books?id=RZ...SWtZcD&sa=X&oi=book_result&resnum=1&ct=result for one such failure.)
If indeed such failures happen, and they do, then the truthers are proven 100% wrong on this topic.
