In Philip Reeve's Hungry City Chronicles, Traction Cities are vast metropolises built on tiers that are capable of moving on gigantic caterpillar tracks. These cities hunt smaller cities (in order to tear them apart for resources) which in turn hunt towns which in turn also hunt villages and static settlements. This practice is known as Municipal Darwinism.
Traction Cities were first formed by an engineer from London (which subsequently became the first of its kind), Nicholas Quirke after the Sixty Minute War. After the devastating war, the world collapsed into a post apocalyptic state, and immense geological upheaval (such as earthquakes, tidal waves and glaciers) threatened the world's surviving cities. In order to survive, urban areas were mobilised into vast vehicles that move on caterpillar tracks. Naturally this required vast amounts of fuel, and as the earth became stripped of its natural resources, cities resorted to the practice of Municipal Darwinism and began to consume each other for energy. The traction cities were opposed by the Anti-Traction League which sought to return the Earth to its former state and viewed the inhabitants of the cities as barbarians and savages. In turn, the Traction cities also view the Anti-Tractionists as barbarians. Later, a fanatical splinter group of the League called the Green Storm wages war on the cities with its vast military forces including Stalkers. This has led the various cities to form unions to defend themselves including the Traktionstadtsgesellchaft and the Mobile Free States.
Traction Cities range in size from enormous metropolises (or Urbivores) with populations of millions, to tiny hamlets propelled by sails.
There are also aquatic equivalents called "raft-cities" which travel across the oceans hunting smaller raft suburbs and island settlements. Notable Raft Cities include Puerto Angeles, Grimsby, Brighton and Marseille, most of which are coastal ports in the real world.
As well as standard traction cities and "raft-cities" there are combinations of raft and traction cities which are called "amphibious cities" such as Tunbridge Wheels, that work as standard traction cities on land until they reach water at which point a series of quick processes to activate underside floatation tanks or hovercraft systems and propulsion devices.
There are also cities called "ice-cities" which utilise massive iron skates for travel over the frozen seas of the north. Notable Ice Cities include Anchorage, Arkangel and Wolverinehampton. There are also oil drilling cities on Antarctica. There are also conurbations which are formed by the coupling together of multiple suburbs, most notable Panzerstadt-Bayreuth and Panzerstadt-Linz.
There is also a Traction city that travels the skies, by use of light alloys and a nimbus of hydrogen balloons (hydrogen is referred to as lift-gas), called Airhaven. Airhaven is the only Traction City in the books that does not follow Municipal Darwinism - it survives by trading and providing fuel and supplies to passing airships, and since it is airborne it is well out of reach of other cities. Brighton also has a circular airborne park connected to it called Cloud 9. It is the residence of the city's Mayor.
Traction cities in the books are often named after cities in the real world, such as London, Anchorage, Paris or Prague, and sometimes their names have been slightly modified for comedic effect; for example, Tunbridge Wells has been named 'Tunbridge Wheels'.
The most common method of travel and trade between cities is by airship. Railway is impossible due to the mobile nature of Traction Cities, and seaborne ships would be easy prey for any raft-cities.
At the beginning of the series, the most common area for Traction Cities to be found is Europe and Northern Asia, which is now a great wasteland called the 'Great Hunting Ground'. They are also prevalent in South America (known as Nuevo Maya) and Antarctica (where they drill for oil); North America has supposedly been reduced to a nuclear wasteland by the Sixty-Minute War (With the exception of several offshore islands, most notably the one where Anchorage-in-Vineland settled after its journey across the Atlantic), Australia's condition is not specified and South-Eastern Asia and much of Africa is the stronghold of the Anti-Traction League and later the Green Storm.
Notable Traction cities
Traction cities
- Benghazi
- Chidanagaram
- Cittamotore
- Edinburgh
- Glasgow
- Gorky
- Gutak
- Jagdstadt Magdeburg
- Juggernautpur
- Kom Ombo
- London (destroyed)
- Manchester
- Montpelier
- Motoropolis (destroyed)
- Murnau
- Nizhny Novgorod
- Panzerstadt-Bayreuth (Destroyed by London in the first test of the MEDUSA.)
- Pandzerstadt-Linz
- Panzerstadt-Winethur
- Panzerstadt-Weimar
- Paris
- Prague
- Traktiongrad(destroyed)
- Xanne-Sandansky
- Zimbra
Traction towns
- Salthook (Consumed by London prior to its destruction.)
- Speedwell
Raft cities
Ice cities
- Anchorage (Becomes Static between Predators Gold and Infernal Devices)
- Arkangel (Destroyed.)
- Breidhavik
- Kivitoo
- Wolverinehampton (Consumed by Arkangel prior to its destruction.)
- Reykjavík
Amphibious suburbs
- Tunbridge Wheels (Destroyed.)
Air cities
- Airhaven
- Cloud 9 (not actually a city, it is Pennyroyal's floting pallace suspended over Brighton)
- New London (featured in A Darkling Plain and floats via means of huge electro-magnetic plates on its underbelly which ride on the earths magnetic field. General Naga doesn't destoy it because he says it isn't a traction city it's just a large, low flying airship)
Harvester Suburbs
- Harrowbarrow