Madeira vs Kansai, Hong Kong & Gibraltar: When There's No Room for a Runway

How do space-starved airports solve the runway problem?

There are really only a handful of moves when a site is too small, and each famous “engineered” airport picks one. You can reclaim land from the sea, build an entirely artificial island, carve a runway into the only flat strip you have, or share that strip with existing infrastructure like a road or railway. Madeira chose a fifth option almost no one else has: suspend the runway in the air on columns, like a motorway viaduct that happens to carry aircraft.

The comparison below lines them up against the same question — where do you put the runway?

Airport	The space problem	The solution	Type
Madeira (FNC), Portugal	Clifftop runway hemmed by mountains and the Atlantic; deep, sensitive bay below	Runway extended over the sea and a ravine on an elevated concrete deck on ~180 columns	Viaduct over water
Kansai (KIX), Japan	No coastal land near Osaka	Entirely man-made island built by reclamation in Osaka Bay	Artificial island
Hong Kong (HKG), Chek Lap Kok	Mountainous, crowded territory	Island formed by levelling terrain and reclaiming land from the sea	Artificial island
Wellington (WLG), New Zealand	Hilly coast, no flat plain	Runway laid across a low isthmus, cut down and filled between two bays	Cut-and-filled isthmus
Gibraltar (GIB)	A peninsula dominated by the Rock	Single runway crosses the territory’s main road; traffic stops for each movement	Runway across a road
Gisborne (GIS), New Zealand	Limited flat land near the city	Runway intersects an active railway line, coordinated so the two never conflict	Runway across a railway

Why is Madeira’s answer different from Kansai and Hong Kong?

The instinctive solution near deep water is to fill it in. That is exactly what Kansai and Hong Kong’s Chek Lap Kok did, building purpose-built islands out into the sea and putting the whole airport on reclaimed ground. Madeira couldn’t: the bay below the runway is deep and ecologically sensitive, and a coastal ravine cuts across the line of the extension, so conventional landfill was impractical.

Instead, engineers built roughly the final 1,000 metres of runway on an elevated, post-tensioned concrete platform carried on 180 tall columns — effectively a giant road-style viaduct for aircraft. The deck sits about 57 m above sea level, runs around 1,000–1,020 m long and ~180 m wide, and is rated for aircraft up to Boeing 747 size, according to engineering write-ups on designboom and Structurae. Rather than filling the sea, Madeira simply flew the runway over it.

Gibraltar and Gisborne: sharing the strip

Where Kansai and Madeira created new ground, Gibraltar and Gisborne did the opposite — they kept a single, scarce strip and made it do two jobs. Gibraltar’s runway crosses Winston Churchill Avenue, the main road into the territory, so barriers halt cars and pedestrians whenever an aircraft uses it. Gisborne’s runway, in New Zealand, crosses an active railway line, with rail and air movements coordinated so the two never meet on the crossing. They are the low-tech end of the same spectrum: when you can’t build more space, you time-share the space you have.

Wellington: cut, don’t build

Wellington sits between the two philosophies. Rather than reclaiming an island or suspending a deck, its runway was laid across a low isthmus that was cut down and filled to make a usable strip between two bays — earthworks rather than a structure. It is constrained and famously gusty, but it solved its problem by reshaping the land, not by building over the water on columns. That is precisely the line that makes Madeira unique.

So what makes Madeira genuinely one of a kind?

Plenty of airports are built on reclaimed land, and a few share their runway with a road or rail line. Madeira is the only one that takes an existing clifftop runway and extends it out over open water and a ravine on a forest of columns — a viaduct carrying a runway. That distinction earned the structure the IABSE Outstanding Structure Award in 2004 (informally, the “Oscars of structural engineering”) and a Guinness World Record for the longest bridge-supported runway extension, at 1,020 m. Kansai made an island; Gibraltar borrowed a road; Madeira built a bridge — and then landed jets on it.