Elvish Engineering: Airships

Airships were invented by the Elves of Tan'Rar in the year 1590. They provided a decisive advantage during the Second Dragon War, allowing the Elves to drive the Dragons from Loraida and claim the entire continent for themselves. Airships built by the Elves and Drakoni have featured prominently in every major conflict since.

Levistone

Levistone is a marble-like mineral that is blue in colour with veins of black running through it. It has the unusual property that it is lighter than air. If let free it floats at an altitude of 7,000 feet. Levistone is not native to the Prime plane. It was formed on a Shard that was exposed to large amounts of Elemental Air energy and later crashed into Prime during the round of shard collisions from the year 10 to 317. On Prime it's often found mixed with native stone and can be quarried in open pits without risking it floating away. Levistone was first purified by the Elves around 1530. Airships were developed over the next 60 years.

Levistone is extremely rare. It is only found in a handful of places in the world. For this reason only the armies of powerful nations are able to build and maintain airships. Some civilians come into possession of decommissioned or damaged airships and re-purpose them as transports or freighters.

Airships

All airships (regardless of what civilization created them) have the same basic form: a outer hull carved of levistone blocks with a knife-like profile, a set of wood-and-canvas fins for steering, and a lightweight wooden or metal-reinforced interior structure. Propulsion is provided by one or more Air Elementals bound in large powerstones within the hull. These are often just called "engine cores" to overlook the moral implications of keeping bound somewhat-intelligent creatures as a means of propulsion.

A light transport. Art by Pieter Talens.

Keeping an airship aloft requires carefully balancing the lifting force of the levistone hull with the weight of the superstructure, engine core, cargo, passengers, armaments, etc. Only pure levistone floats 7,000 feet up. Most airships fly in the 5,000 foot range. Landing an airship requires adjusting the ballast to make it fly lower and then roping it to the ground. Some mountainside settlements just have pier-like docks.

Weapons & Defenses

Airships intended for battle often have steel-reinforced superstructures, plated hulls, and/or knife-like rams on their bows. Most airships have at least one powerstone-launching gun mounted in a two-axis turret for offense. The largest warships mount dozens of guns, and carry hundreds of air-dropped powerstone bombs. Drakoni also have a class of carrier ships that they use as airborne platforms to fly off of.

The "Searing Fury" - A triple-hulled Heavy Assault Cruiser.
Art by Mac Hillier.

Safety

Airships are rather durable. The greatest danger to an airship is accidental detonation of the ammunition magazine or breach of the engine core. Both ammo and engine core are powerstones. Powerstones are quite fragile and a large enough shock will cause them to chip or crack, releasing the spell energy stored within. This is often catastrophic for the airship and anyone aboard.

More modern airships have "wreck nets", netting built through the superstructure connecting directly to the hull. In the event of the ship breaking up, the levistone hull will continue to naturally float, pulling apart and unfolding the wreck net. Theoretically this would allow surviving crew to float safely away from the wreck. In practice an airship wreck in battle has less than a 10% survival rate regardless of whether wreck nets deploy properly or not.

Next Time

Next week will be a factions article on The Wind People, a group of Human nomads who live on airships.

Elvish Engineering: Powerstones

Another new article series? Madness! I was all prepared to alternate Cities and Factions articles for a couple months when I realized there are some key pieces of tech that are essential to the purposes of certain cities or factions. So I'm going to sprinkle these tech articles into the mix as needed to make later articles make sense. Spoiler: next week's article will involve powerstones, so I'm explaining them now.

Announcements done. Where was I?

Powerstones

Description

A powerstone is a lump of crystal imbued with magical energy. This can be raw, undifferentiated power but more often is a specific spell. Sometimes crystals that don't contain any magic are still called powerstones because they are intended for that purpose. The amount of magic that can be contained is proportional to the quality of the crystal and its size. For example, a very large milky quartz has about the same capacity as a small flawless diamond. Cut doesn't really matter beyond physical size so powerstones are often shaped for a specific purpose.

The most common powerstones are made of rough-cut quartz and are about the size of a fist. Amethyst is another common material. Corundums such as ruby and sapphire are less common. Diamond powerstones are extremely rare. Size naturally decreases with rarity.

Usage

Cracking or shattering a powerstone immediately triggers the spell or releases the raw energy stored within. Raw energy released in this way escapes in a big explosion.

There are three common uses for powerstones:

• The smallest powerstones are used to store spells within jewelery and clothing (this is not the same as Spell Storing items and weapon enhancements). The setting will have a mechanism to crack the crystal and release the spell.
• Medium powerstones are commonly used as weapons by imbuing them with raw energy and intentionally breaking them on enemies. 
• The largest powerstones are used to bind elementals in the cores of airships for propulsion (Airships will get a full article on March 6th).

Powerstones can be used as artillery shells. A smoothly-ground spherical or columnar powerstone be clad in a metal casing and fired from a cannon with some accuracy. The casing cracks the stone on impact with the target. Powerstones used in this way usually have raw magical energy imbued into them but sometimes specific spells are used (such as to create a smoke screen or release poison gas).

Creation

Any crystal or gemstone can be used to create a powerstone. Gems worth 50gp or less can store a 2nd-level spell. The required gp value doubles for each additional spell level; a gem that is large and valuable enough to hold a 9th-level spell would be worth 65,000gp. No such gems are known to exist.

Unlike scrolls, a spell released from a powerstone retains the caster level of its creator. No skill is needed to activate a powerstone. In fact, they must be handled with care to prevent accidental (explosive) breakage.

Next Week

Next week's article will be a Cities article about the dwarven city Kor's Geode, Ashdar. Kor's Geode is a prominent source of raw crystals used in powerstone production.