Forum: scifi.stackexchange.com
Tags: <game-of-thrones><a-song-of-ice-and-fire>
Title: Can the Wall be melted?
Question: Is it possible for the enemies of the Wall (wildlings etc) to light a fire so big that it will melt the Wall?

Answers:
sents: text: Let's run the numbers: The wall is 700 feet high = 213 meters On its top, 12 knights can ride abreast and it's wider at the base.
text: Let's say that's 25 meters wide at the top and 75 at the base, so 50 on average.
text: It takes 334 kilojoules to melt 1kg of ice (if it's at 0 degrees C to begin with, but the melting energy is large compared to what it takes to heat up).
text: Oak wood yields about 15 megajoules per kg when burned An oak tree weighs about 14 tonnes
text: So: A 100m section of wall would contain about 213*50*100*1000 = about 1 billion kg of ice.
text: Burning
text: 1 kg of wood can melt (at 70% efficiency) about 30 kg of ice.
text: Which means you'd need to burn about 2500 fully grown trees
text: In practice, efficiency would be lower, but you wouldn't need to melt the entire wall section to make it collapse.
text: OTOH, the melting water as well as partial collapses would tend to extinguish the fire.
text: Given a force of many thousands of wildlings, as well as giants and Mammoths, it seems doable.
text: But it would be a massive effort requiring many days, and giving the Night's Watch ample warning (via a gigantic smoke cloud, even if there were no patrols) and time for countermeasures.
text: Simply digging a tunnel would seem to be an easier and quicker alternative.
answer_details: author: scifi.stackexchange.com/users/6079/Michael Borgwardt
score: 96
sents: text: It should be.
text: In the very first sentences of the first book GRRM writes that the wall "was weeping", that is, it was dropping water from the ice.
text: This means that during the Great Summer the ambient temperature is really near to the water melting point (0C).
text: A different question is if the Night Watch would allow it.
text: A third point would be that melting the wall in part will cause water enough to kill the fire!
answer_details: author: scifi.stackexchange.com/users/21161/Envite
score: 12
sents: text: With the release of the latest episode, the answer now appears to be yes.
text: In Season 7, Episode 7, with the help of an undead dragon, the wall has been melted.
text: The discussion on if the dragon was breathing fire is discussed below.
text: Was it Ice or Fire?
text: One plausible counter argument you could make, is that fire didn't destroy the wall, but rather the magic of the Dragon Fire and/or Night King himself.
text: The wall was created by magic (the details are uncertain), and you could argue it takes magic to destroy magic.
answer_details: author: scifi.stackexchange.com/users/70537/Goose
score: 6
sents: text: Yes, no, but.
text: There are good answers on if it, as it stands, would be feasible.
text: One point though is that a ice-construction like the wall would not remain with that shape.
text: Put simply it would become more like a big heap of ice as the weight of the wall forces the construction to widen making it a slope of ice rather then a wall.
text: A big one, but still.
text: From what I know there is no maintenance crew making sure the walls are steep etc.
text: so in other words other forces has to be at work for it even to be standing as it is.
text: As such once have to take into account that the wall itself is under some sort of protection or time-warp-anomaly.
text: By which the melting by fire also might prove futile.
answer_details: author: scifi.stackexchange.com/users/24829/user13500
score: 4
sents: text: Why not?
text: There are tunnels through the wall
text: so we know that the wall isnt indestructable.
text: So, if the wildings could get enough raw material ( Wood, oil etc ) to the wall and they could light a fire and keep it going for a few days they could start making dents in the wall.
text: I dont think that the entire wall could be melted but a hole through a wall could deff be done if done in secrecy.
text: Most of the rangers are dead.
text: Only 3 forts on the wall are operable ( barely ) and the Black Brothers are very few in numbers.
answer_details: author: scifi.stackexchange.com/users/15632/Cherubel
score: 3
sents: text: As far as I know, (no sources at the moment, sorry)
text: the wall is magically protected against melting completely, but partly the ice can melt ("The wall is weeping" from the prolog from the first book)
answer_details: author: scifi.stackexchange.com/users/22905/arc_lupus
score: 0

Summary of the answers:
Given a force of many thousands of wildlings, as well as giants and Mammoths, it seems plausible to be able to at least melt a section of the wall or melt a hole in the wall. Indeed, Season 7, Episode 7 confirms that the wall can be melted.
The wall from Season 7, Episode 7, can be melted with the help on an undead dragon.