What is a pylon?
In architecture and engineering, a pylon has two meanings: the monumental gateway of an Egyptian temple, and a tall, usually tapering tower that carries cables, as on a cable-stayed or suspension bridge. The word comes from the Greek pylōn, gateway, from pylē, gate.
1. The pylon of the Egyptian temple
In ancient Egypt the pylon was the gateway between two massive towers that narrow towards the top. The towers have a trapezoidal front and are covered with reliefs, often showing the pharaoh smiting his enemies. Tall flagpoles stood in recesses in the facade.
- A temple could have several pylons in succession; the temple complex at Karnak has a whole series.
- The Temple of Horus at Edfu has one of the best-preserved pylons.
- The form later inspired Egyptian Revival architecture, such as gatehouses and cemetery entrances.
2. The pylon as a modern structure
In modern construction a pylon is a tall mast or tower that carries cables:
| Use | Function |
|---|---|
| Cable-stayed bridge | The stay cables run directly from the deck to the pylon |
| Suspension bridge | The main cables pass over the pylons (towers) and carry the deck through hangers |
| Electricity pylon | Lattice tower carrying overhead power lines |
A well-known Dutch example is the Erasmus Bridge in Rotterdam, with its angled pylon 139 metres high.
How a bridge pylon works
- The cables pull on the pylon. Because the cable forces on either side largely balance, the pylon is mainly in compression.
- Where the forces don’t balance, for example on an asymmetric bridge, backstays or a heavy foundation take up the difference.
- The foundation under a pylon carries very large vertical loads and is often piled.
Related terms
- Obelisk
- Mastaba
- Anta temple
- Suspension bridge
- Chain bridge
Want to learn more about construction terms? Visit our knowledge base at fredsdiyplans.com.