• Question: Can jet fuel melt steel beams?

    Asked by FrameSomeone to Philippa, Pete, Paula, Neil, Matthew on 10 Mar 2015. This question was also asked by THE GINGER BANTER.
    • Photo: Neil Taylor

      Neil Taylor answered on 10 Mar 2015:

      Hi!

      Without knowing more about the specifics, I can’t really think why the beam should melt (comparing the melting point of steel vs jet fuel burning temperature)- so I think the answer is no (and your username is correct!)

      However, the heat would likely have a significant effect on the strength of the beam and reduce its ability to hold weight. Depending on the dimensions of the beam and whether the ends of the beam were free to expand or not, it may also experience “buckling”, where the middle of the beam suddenly moves sideways – you can check out a similar effect by pushing in the ends of a plastic ruler.

      Hope this helps!

    • Photo: Philippa Jefferis

      Philippa Jefferis answered on 10 Mar 2015:

      Do I get the feeling this question has come from a conspiracy theory?

      There are lots of different types of steel. Traditional steel is iron with carbon added to it. Different amounts of carbon have an impact on how the steel behaves. Perhaps you remember from chemistry the properties of a metal? Well these properties are affected by putting in carbon such as the hardness, ductility, and tensile strength.

      Steel often melts at around 1370 degrees C, but it starts to lose its strength at much lower temperatures. As such burning jet fuel would not be hot enough to melt steel, but it would be enough to severley weaken the structure.

      There are strict regulations on protecting steel framed buildings from fire. They are often designed so that the steel will withstand heat for long enough in order to allow the building to be evacuated. The cleverest way I know how this happens is by using a special paint that has a chemical in it that generates an expanding foam when it reaches a certain temperature. This insulates the steel from the fire and slows the rate at which it fails, giving more time for people to evacuate.

    • Photo: Pete Symons

      Pete Symons answered on 10 Mar 2015:

      I hope not, otherwise my new jet with fuel tanks made of steel is going to end badly!

      I think Philippa is spot on with the conspiracy theory origins of this and I agree with both especially as Jet Fuel has very similar characteristics as diesel and petrol used every day in cars! The only real difference is that there is is a more refined form of petrol with more additives for anti-icing etc, some forms of av gas have slightly higher flashpoints than normal diesel but there similar enough that if Jet fuel could melt steel beams then petrol and diesel probably could as well, but they can’t, so there.

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