Metallurgy in the Third Age
James Owen — Wolfson College — Oxford, OX2 6OD — England
The sections on Dwarven and Elven technology which appear in the Moria and Lórien MERP supplements, are, to say the least, woefully garbled. So too is the new Alchemy Law for Rolemaster, from which I was interested to learn that swords are made by the three-step process of hammering, tempering (in order to relieve them of their resulting toughness and brittleness), and quenching the red-hot metal in cold water (in order to harden it).
Well, yes, sort of. But if you do this, then off you go to your first battle and your sword snaps in half because you’ve done it all in the wrong order. As it is a hopeless task to sort out these tangles, I will begin from scratch with some real science, and some other musings.
One of the many problems to be faced in incorporating science into any literary fantasy is that while the imaginary world seems to have evolved politically and socially over the timescale of the book’s narrative, its technology has remained the same for centuries (which is historically unlikely). In the case of Middle-earth, the level of military technology has even declined from the First Age to the Third.
At Agincourt, for example, the longbow may have reigned supreme, but primitive cannons were present and, within fifty years, there was a severe shortage of trained bowmen in the English army, despite laws compelling able-bodied men to practice every Sunday. The main reason for the development of firearms was the speed with which (in a few mere weeks) a man could be instructed in their use (by contrast to the lifetime training required to master the bow). The longbow used at Agincourt was in fact a more powerful weapon even than a Napoleonic musket in terms of range and rate of fire.
Perhaps due to authorial prejudice, it may be that the ruling hierarchy and intellectuals of Gondor scorned science, leaving it to Saruman with his mind of metal and machines; even so, one would have thought that the constant state of war in Gondor would have precipitated the same concentration of effort towards the development of a suitable defense technology. Gunpowder is not difficult to invent, and the Dúnedain would certainly have had the steel for firearms.1
Apart from Gondor, we know that the Dwarves and Noldor smiths of Eregion were fine craftsmen, but elsewhere there is little evidence that there was a sufficiently settled culture to enable fundamental research to be carried out. We could assume that the turbulent history of Middle-earth precluded the buildup of a knowledge base, that the Valar preferred to keep the Children of Ilúvatar blissfully ignorant, seeing what a mess they could make of the place as it was.
Ranking Metallurgical Technology in Middle-Earth
Metals have crystalline structures which account for most of their physical and metallurgical properties. Line defects in these crystals, called dislocations, are able to flow within the crystal, rendering it malleable. All pure metals are therefore soft, and some can even be pulled apart by hand.
In order to strengthen a metal, it is necessary to prevent the dislocations from flowing, which is done by filling the crystal with obstacles of one sort or another. However, these obstacles must be cleverly controlled so that they don’t promote crack growth (which will leave the metal brittle). Alloy production then, is a contest between a high strength and a low toughness, unless by luck you get both at the same time.2
The production of good, hard steel from iron ore has been of great technological importance for centuries, but it is only really in our own century that chemistry and metallurgy have found out why the various bits of black magic work.3 How much of this would the peoples of Middle-earth have known? The Gazetteer tells us that amongst the races of Men, only the Dúnedain have mastered the secrets of steel, while others make do with poor iron. Even so, it would seem that only the Elves of Eregion and the Dwarves have progressed beyond steel to more exotic alloys (e.g., mithril).4
Metals may be ordered according to the difficulty of smelting them and the knowledge and technology required to produce useful alloys from them.
Level 1: Brass and Bronze
The easiest metals to smelt are those which occur naturally.5 The earliest alloys were, not surprisingly, alloys of copper: brass (a mixture of copper and zinc) and bronze (a mixture of cop-per and tin). Both could easily have been discovered by smelting zinc or tin and copper-bearing minerals in the same fire. Brasses have a strength up to 700 MN m — 2, with good ductility in the annealed condition, and will readily work-harden up to 200 VHN. Bronzes are generally slightly stronger and harder than brass, but less ductile, widely used for sword blades in Roman times. Bronze will keep an edge longer than brass.
In Middle-earth, bronze is probably used mostly for coinage, as iron will have percolated even to the more primitive cultures, although bronze would continue to be used where corrosion is a problem (e.g., on boats).
Level 2: Wrought Iron
In the days before the blast furnace was invented, iron could not be heated hot enough to melt. Blooms of a mixture of fairly pure iron with graphite particles could be produced by heating solid ore and charcoal in a hearth-type furnace. In order to make a piece of strong metal, these blooms were then hammered flat while red-hot, folded, reheated, and refolded until a laminate of steel and carbon was produced. This was known as wrought iron.6
The strength and the toughness of the steel was related to the number of times the metal was hammered and folded, as the slag particles trapped in the bloom were broken up into small harmless pieces. The lamination process itself would also have increased the toughness. The finished sword would be quenched and tempered (the correct temperature being judged by the color of the hot metal — from straw to dark blue).
The art of making that best steel would lead to the best craftsmen being able to command an extremely high price for their goods. Wrought iron is certainly much stronger and harder than bronze or brass, partly due to the impurities. For casting purposes with low toughness require-ments, cast iron with around 4% C (i.e., which could be melted) would be used.
This would have been the highest level of technology before the arrival in Middle-earth of the Eldar and the Númenóreans. Even in the Third Age, this kind of process would be used for small-scale metalwork, village smiths making horseshoes and knives, or in Orc-holds in the Misty Mountains. Before they allied themselves with Gondor, the Éothéod would also have been at this level of technology, as would Arnor and Cardolan after the end of the North-Kingdom. The Shire would not have wanted blast furnaces belching out smoke all day, and the Hobbits were sophisti-cated enough to get supplies of good steel from the Dwarves of the Blue Mountains.
Level 3: Cold-Work
Other metals such as Nickel will be smeltable, and nickel-copper alloys such as that used for coinage in Britain and the US, would be available. These are hardened by cold-work, so that ductility and toughness are inversely proportional to strength. They may be used as plating, for a cheap alternative to silver to make keys, and in applications for which corrosion resistance is needed, such as boiler tubes and maritime uses. Their strength is similar to a medium-carbon steel, 600‑1000 MN m-2, with a hardness up to 300 VHN, but much more ductility for the strength than the steel.7
This would be the level of metallurgy found in Gondor, Arnor, Isengard, all Dwarf-holds, and most large Elven communities, especially among Noldor. Sauron, having the Cracks of Doom as a ready source of heat, would have gained this knowledge.
Level 4: Carbon Steel
“Pure” iron can be made from blast furnace “pig iron” by melting it in an open furnace and skimming off the impurities as they rise to the top. This technique is called “puddling.” Blocks of pure iron would then be forged and formed while in a hot, soft, solid state, or cast into molds and left to cool. The iron would then be packed into boxes of charcoal in order to absorb carbon into the surface layer (and, hence, to adjust the strength based on its carbon content). Once quenched, this layer would be extremely hard, and the softer core would prevent it becoming too brittle.
This combination of hardness and toughness would be ideal for swords. Strengths up to 1000 MN m-2 can be produced with good toughness and surface hardnesses up to 600 VHN are achievable. Certain simple alloy steels, with manganese or nickel for higher toughness or impact resistance could also be made. These would probably be discovered by using impure ores rather than deliberate research, however. Tool steels, using tungsten, might also be produced with a hardness of 1000 VHN.
With the aid of water power, many forming operations become possible. Rolling, hot and cold-forging (hammering into shaped dies), extrusion (like a tube of toothpaste) to make wire, rod and bar (Alchemy Law, please note! NOT drawing of crystals form a melt!) could all be used, although this would require a very stable culture, as the capital cost of the equipment would be expensive.
I would doubt that anywhere except Moria and Mordor would possess such facilities. Nowhere else would be able to make large beams, as they would be limited by furnace and crucible size.
Level 5: Aluminum and Titanium Alloys
Skills which come into the highest category would be those for mass-producing steels to a defined composition with high cleanliness and low impurity content, and knowing the complex heat treatments needed to produce strengths of 3000 MN m-2 from steel, or to produce nickel alloys which would hold their strength at white-heat. Of similar complexity are the difficulties of smelting aluminum, which will require electrical power form somewhere, or else magic, and titanium which has to be melted in a vacuum furnace to avoid contamination with oxygen.
There is a vast array of aluminum and titanium alloys, mostly used as replacements for steels on weight grounds, despite the cost and lower stiffness. Aluminum alloys are limited to about 600 MN m — 2 but their specific strength is usually about 50% better than a steel, saving a third of the weight. They are also limited to 100<C, due to the pure metal’s low melting point and the strengthening techniques, mostly age-hardening. Titanium alloys can operate up to 1000<C, and have much higher strengths, up to 1400 MN m — 2. The stiffness of titanium is low, however, so this metal would not be so good for sword blades, as they would bend easily.
Mithril, whose metallurgy is a whole article in itself, would seem to me to be an fcc metal like aluminum or nickel or possibly a bcc metal like titanium, certainly able to form strong, stiff, tough alloys with these elements, so as to produce light sword blades and armour. In its pure state, it would be soft and malleable and able to be beaten like copper and polished like gold.8
The knowledge of this metal, let alone its metallurgy, has been lost to us for millennia and was probably extremely rare in Middle-earth. Only the Elves of Lórien and the Dwarves of Moria would have had that knowledge in the Third Age.9 The places and times when the secrets of aluminum, titanium and mithril alloys were to be found have mostly been destroyed: Gondolin, Núménor, Eregion and Celebrimbor’s smiths, the Dwarves of Moria.10
For most gaming purposes, the best alloys will be steel found in Gondor or the Lonely Mountain (Level 4). Characters from outside these areas will only have access to lower-quality weapons, except at very high prices. A sword that was made in Moria or Eregion from the finest and most secret materials and recipes (Level 5), will be extremely rare and valuable. Dwarves and Elves are likely to keep these to themselves rather than trade them. Frodo’s coat was worth more than the Shire, a sword of similar material would have been worth much the same.
Excursus: Metallurgical Terms
The major properties of metals of interest to the role-player are those pertaining to weapons and armour: the strength, stiffness and toughness of a blade, the durability of its edge, the resistance of armour to weapons, and the weight of the item in question. These properties are here formally defined in metallurgical terms, along with the techniques commonly used to produce or alter them.
- the force which must be applied to break the metal in tension. For pure, single-crystal iron, this is 250 MN m — 2, for a typical carbon steel, this is about 800 MN m — 2 and for the newest strongest steels, this is up to 3000 MN m — 2. Some materials have high compressive strength, but low tensile strength. Since steels are all mostly iron (or elements near iron on the Periodic Table) they are roughly the same density — around eight times that of water; however, their critical property is specific strength (that is, the strength/weight ratio). The weight of com-ponents may be brought down considerably by using a higher-strength steel. A modern example is that of drinking cans, where about half and half are made of aluminum and steel, because they work out at about the same cost and weight, despite the fact that aluminum is a much lighter metal.
- otherwise known as the Youngus or Elastic modulus, is the ration of the force applied to the % extension measured. This is similar for most steels, being a property of the majority con-stituent, iron, and is about 211 GN m — 2.
- a more slippery concept, being the opposite of brittleness. By pulling a piece of metal apart under tension, and plotting the force against extension, toughness may be related to the area under the curve, which is the work done to fracture the specimen. A higher work done means that the metal is less likely to fracture catastrophically. Another way of measuring work to fracture is with an impact test. A small specimen is put against an anvil, and a large weighted pendulum swings down and breaks it. The energy taken to break the metal may be measured as the difference in height between the beginning of the swing and the end. This gravitational energy has been absorbed in the metal. The impact test is easy to perform and gives an accurate measure of the impact resistance of the metal. A brittle metal will absorb perhaps 20J, while a tough piece will absorb 250J. Toughness is not a definite property of a metal, but is dependent upon the heat-treatments applied to it, the amount of corrosion and wear of the surface, etc.
- may be measured by scratching one thing with another and establishing a hierarchy or what scratches what. This is the Mohr scale, with diamond at the top at an arbitrary value of 10. A more quantitative measure is the Vickers hardness test, where a diamond is pushed into the surface of the metal by a known force, and the area of indentation is measured. The smaller the area, the harder the metal. Typical values for steels range from 200 in the annealed state to 600 in the severely-quenched state.
- a measure of the amount of work-hardening that a metal can undergo before it becomes brittle land breaks. It is measured as the % extension at failure in a tensile test.
- the more you deform a piece of metal, the harder it gets, until it breaks. Its toughness goes down, while its strength goes up.
- heating your work-hardened sword at 1000<C for an hour or two, to soften back to a state where you can hammer it some more. Several cycles of annealing and working will increase the strength and toughness together.
- take one red-hot piece of metal, drop in bucket of water, with various secret in-gredients added for their mystical power: blood, urine of clergyman, sacrificed lamb, slave or whatever, wait until fizzing stops, and remove. Warning: the piece of metal will be very hard and brittle.
- heating at various temperatures for sufficient time for a quenched piece of metal to decline in strength to the value desired. This raises the toughness, unless you do it too much. Quench and tempering is a process unique to steels because of a quirk of iron’s metallurgy. Mankind is very lucky that such a useful metal should also be relatively easy to smelt.
- This is an equivalent process to tempering in nonferrous alloys, except that the metal starts out soft and weak, rather than hard and brittle. The purpose is to take a supersaturated solid solution and warm it up, so that some of the solute precipitates out as very fine particles in the metal. These increase the strength, while not encouraging brittleness, as large particles would. The aim is still to change the strength and toughness until they are within desired values.
- This may suggest a casus Belli. Perhaps Gondor had obtained high-grade iron ore or coal from the Haracl, and that with the loss of Umbar, it had been forced to rely upon scarcer supplies or lower-grade materials, and hence suffered a technological setback. Innumerable plot devices along the lines of the politics of technology spring to mind. Furthermore, the barren, desolate landscape of Mordor with many holes for Hobbits to hide in and polluted streams sound to me as if there had been extensive open cast mining in the area. This may be another important source of iron ore which had been denied to Gondor.
- Some alloys have other properties, such as corrosion resistance or high-temperature strcngth, and therefore sacrifice raw strength, but I will not go into these here.
- This new knowledge has led to an explosion in the quality and strength of steels in the last fifty years, and led to a whole new range of alloy steels. Instead of empirical methods handed down from blacksmith to blacksmith for generations, scientists today are able to decide almost ahead of time upon the desired properties and to produce a corresponding steel. The same is true of aluminum and titanium alloys.
- While the Gazetteer is not exactly a primary source, I find myself in agreement with its views on this matter, and will therefore use it as a basis for elaboration.
- These include the common “noble” metals, gold, silver and copper, which may all be beaten into bowls or cups or jewelry, but are too soft for weapons.
- The layers of iron would leave a sinuous pattern along the blade, adding to its mystique.
- Mithril, if available, would be smeltable and could be used for decorative purposes as a noble metal, but the more complex alloys would be unknown.
- A cross between a noble metal and a high-tech low-density metal, mithril is something of a conundrum.
- I don’t believe Sauron could make these alloys, unless he wheedled the knowledge out of Celebrimbor. In earlier times, the Fëanorean school would have known the secrets, but would they tell anyone? The makers of the Nauglimir had a supply, but they may only have known how to utilize its nobler properties for decoration.
- Gondor still has the knowledge, but I suspect that they would have it stored away in a dusty library. The skill and the metal to make Frodo’s coat would have been long gone when he wore it. This highest level of metallurgy is unlikely to be found in use at the end of the Third Age, except perhaps in the Lonely Mountain or Lórien. More and more of the knowledge would be being lost as the Elves went across the sea and Dwarves slowly died off without a means of teaching their secrets to apprentices.
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