#... yet ORE is not canon to any of them 😔)

[mean-scarlet-deceiver]

IMO "Old Reliable Edward" is a 1000% improvement on "Edward the Really Useful Engine"

but that's still not the same thing as being actually good (TO ME)

[enderneverends]

Science in HTTYD pt. 1: Gronckle Iron

Hello hello, enderneverends here, scientist and HTTYD enthusiast! I'm working through Dreamworks Dragons for the first time and I've been thinking a lot about the science used (or lack thereof. When Lightning Strikes is... in need of some work) and I'd love to start with the DoB episode The Iron Gronckle:

Sidebar: If this is a discussion that's been had on Tumblr before I joined I'm so sorry! I haven't seen those posts if they exist 😔

Sidebar Sidebar: If this is also a topic in SoD that I haven't played yet I'm also sorry! I haven't had much time to play!

Sidebar Sidebar Sidebar: If this is expanded upon later in the series again I apologize! I'm currently on The Night and the Fury!

Firstly, based on the appearance and quality of the Gronckle Iron I'd argue that the material created is steel, given that it's light and incredibly durable. Cast iron and wrought iron both don't look the same and/or don't match in quality. Both wonderful for their purposes, but not what is made.

Ductile iron would also be a great contender, but that requires incredibly pure iron ore which isn't what Meatlug digests. Also, ductile iron is more capable of deforming, which is fantastic for construction and automobiles that require impact resistance, but not so great for hand-to-hand combat. Higher impact resistance would result in softer blows, which isn't the case when Gobber slices Snotlout's sword.

Secondly, I'd argue that Meatlug (and Gronckles in general (and Hotburples in the future? But I'm not there yet)) are a way of biologically recreating the Bessemer process.

This is a basic layout of the furnace used to make steel (which, funnily enough, kinda fits the profile of a Gronckle). The general idea is that air is blown through the tuyeres, which oxidizes with the impurities found in the melted pig iron, turning them into gas which is then released. This leaves you with steel to be molded as you (or Gobber and Hiccup) please.

In the episode itself, Meatlug is able to produce Gronckle Iron after eating an excessive amount of various rocks. Later in the episode, Gobber tries to help Fishlegs find out which rock produced the Iron, but to no avail (and multiple consequences). I believe that is where they went wrong. It wasn't a specific type of rock that produced the Iron, it was

A. the amount of trace iron found in all of the rocks themselves (some of which could actually be iron ore, but that's not confirmed to my knowledge) and

B. the amount of air ingested by Meatlug due to her eating quickly

Now the part that's missing is how the tuyeres would be mimicked. My theory is that much like how humans digest food, the Gronckle would have to move their stomach around a bunch to maximize surface area for the oxidation to occur. Theoretically, even if the gas is in equilibrium with the steel (as it isn't immediately expelled in the episode) the equilibrium should favor the gaseous state due to the high temperature. The steel doesn't enter a gaseous state due to it's incredibly elevated boiling point, leaving the impurities and steel well separated.

And huzzah! The full Bessemer Process (Gronckle Edition) is then:

eat an large amount of rocks really quickly to ingest air and iron

have the stomach slosh around to maximize surface area for oxidation.

expel both the gas and the steel so that the system leaves equilibrium and gives relatively impurity free steel!

By the looks of Gronckle biology in general, they don't seem to produce any slag (if I had to guess they'd probably poop it) so that makes keeping the impurities out that much easier.

And also later in the series, I'd have to watch RTTE to make determinations about the Hotburple and how it prefers iron ore to rocks, but that won't be for some time!

That's my theory on Gronckle Iron! Again, if this is explained in canon or in SoD I'm sorry! I just love science and httyd so much I couldn't help but combine the two! Anyway, if you made it to the end thanks for tuning in to my scientific hyperfixation fueled yap sesh!