I combined two types of concept plan in this list that are very different but share the fact that they show an alternate universe where airports weren't giant fields on the edge of cities.On the one had there are the airports that literally float on water, and although these have become a reality with projects such as Kansai or military aircraft carriers, some of the original designs are for runways floating on rivers right in the middle of cities. Here the concept overlaps with the other type of floating airports: those that metaphorically float above the city on stilts - or over rather than on a river, via a structure like an overhead railroad.These concepts are not as unpractical as they appear, by using short-takeoff, quiet planes, London city airport is very close to the financial center of London and its a shame that aircraft haven't been developed to allow some of these magnificent, early ambitions to have become a reality.

Futuristic megastructures are ironically a thing of the past. An architectural style dubbed supermodernism that flourished in the late 60s and early 70s. Despite the seemingly tongue in cheek nature of projects by Superstudio which threatened to engulf Manhattan in a giant concrete snake or Archigram who proposed plugin and walking cities, these projects have had an enormous impact on architecture. They are the inspiration for both fictional and real projects, from Blade Runners Off-world, to the Pompidou center and continue to influence master-planning projects today.

The same giant multi-axle machines that are used in shipyards to transport impossibly large bits of half built ships are also used to wheel into place pieces of bridges, radio telescopes and, of course space vehicles. Here are 15 different varieties.

Aside from their spectacular size, what makes floating cranes unusual and interesting objects is that they are essentially boats. As such, they dont exactly conjure up the idea of stability, which is the primary requirement for lifting things. They also look weird since boats usually consist of large hulls with smaller superstructure, here the arrangement is reversed making them seem very ungainly.Some of these cranes can lift tens of thousands of tons, at sea, and are engineering wonders.

Jet engines undergo a variety of tests shown here, from chucking water, sand and flocks of dead birds into their gaping intakes. They are also tested to see what happens when a fan blade is destroyed while the turbine is spinning, with an explosive charge, not something to try at home. But the best tests of all are those involving jet engine afterburners and the best of the best has to be those with vector nozzles.These are real oobjects, objects that make you go ooh. Vote for your faves.

Russian oligarch, Roman Abramovich donated money for a giant tunneling machine to build a tunnel between Russia and Sarah Palin's house, when he was governor of the adjacent region to Alaska. The Wikipedia entry for Tunneling Machines and the entry for Civil Engineers in the UK Yellow Pages have something in common, they both read: 'see boring'. Doubly ironic, since boring is one of the most interesting projects for civil engineers, and the machines used to do the job are spectacular. The set here includes a variety of shield tunnel boring machines, TBMs, including those for celebrated projects such as Yucca mountain or the Channel Tunnel. Perhaps the most ironic of all is the Air Force TBM, a machine for digging deep underground, owned by the people who defend the skies.

If there is one kind of hammer that you don't want to get your thumb stuck under, its a steam hammer, a giant hellish machine that defined the industrial age.There are several claims to its invention in the mid 19th century, to hammer steel into shape and smash out impurities. One of these is Creusot, who exhibited a version at the Paris Universal Exposition of 1878.Looking at the Creusot Hammer, I would argue that it was the inspiration for the Eiffel tower, ten years later.Here are a variety of hammers including the mechanical or hydraulic versions that replaced steam, but still have the same titanic look.

There is something fantastically hellish about fiery steel manufacture, nothing seems more gigantic or obviously dangerous looking. The instruments used to transfer molten iron, steel and slag are massive solid items made of the same thing they contain in liquid form and are objects of wonder.Particularly interesting are the torpedo ladle railroad cars, which transfer hot metal from blast to oxygen furnaces. They are dramatic and interesting enough that despite their obscurity they are available in several forms for model railroads. Vote for your faves.

A perfect environmental nightmare, these hellish looking open faced mining machines have been largely decommissioned. Luckily some are being preserved as they are staggeringly impressive. The Ferropolis in Germany has many of these machines on display and forms an industrial park which host the famous MELT music festival. There have been several images of these floating around blogs, including the infamous pictures of the bucket wheel excavator that swallowed a full sized bulldozer, however we have tried to find as large a variety as possible.

Continuous mining machines and Roadheaders are giant automated modern day mining machines that slice through rock at high speed and look like something from hell. Here are some of our favorite examples of these magnificent machines. Vote for your faves.

This is the real business end of $100 oil. An object that allowed Howard Hughes to become the richest man in the world by inheriting the patent. They are the world's most highly engineered pieces of metal. Steel, tungsten carbide or increasingly Polycrystalline Diamond Compact (PDC) toothed drill bits that, in their tri-cone, rotating head form, look like the monster spice eating Sandworms from Dune. Vote for your faves.