Roman road-building technique

After a straight course was laid out, the ground was dug until solid bedrock was reached and a solid foundation of rocks and clay was laid. Over this a surface of flat polygonal rocks was laid as the paving. The paving was of durable rock such as basalt, granite or porphyry. The rocks were laid out like a jigsaw puzzle for an overall smooth surface. For less important roads, gravel was sometimes used as the finishing surface. This system of a multilayered construction of road surfaces was adopted continually through history, and today's tar MacAdam (tarmac for short) roads are similarly built with a solid foundation and successive layers of different grades of gravel, though asphalt is now used to bind the material together.

Roman roads also had adequate drainage (continuous ditches dug along the roads) and well-placed milestones (one Roman mile is 87 metres shorter than the modern mile; i.e. around 1.522 km.). The Via Appia, which stretched over 580 km from Rome to Brundusium, was about 3.05 metres wide and paved throughout. The machines of transport included the two-wheeled cart and the four-wheeled wagon. The animals used to draw the carts were mainly oxen, which were strong but slow. For faster movement, horses and mules were used. Lack of proper lubrication - the only available materials were olive extract and animal fat – were costly and not too effective.

Sea

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Considering the slow speed and limited capacity of land transport, sea transport was the preferred mode whenever navigable water bodies were present. Ships of the Mediterranean were of two kinds – the galley and the sailboat. While the sailboat was greatly at the mercy of the winds, the galley used banks of rowers, often at multiple levels, for propulsion. Almost all Greek and Roman warships were galleys. Oared merchant craft relied mainly on the wind but could fall back on manpower during unfavourable conditions.  

Ship-building

Greeks and Romans used similar techniques of ship-building. Unlike earlier civilisations which first built a frame and formed a skin of planks over it, the Mediterranean civilisations worked the opposite. First, the hull was made by joining planks end-to-end with mortise-and-tenon joints which were reinforced with dowels. Then a frame was built into this shell for rigidity. The resulting structure was surprisingly strong and waterproof with minimal caulking. Roman shipbuilders added a sheath of lead on the underwater surfaces to protect the wood from a pest called the borer; a practice which was revived only in the 18^th century.

  By the 4^th century BCE, Greek ships had a capacity of 100 tons, a number which rose to 400 tons by the 1^st century BCE. Roman ships reached an astounding capacity of 1200 tons (these ships were used, among other things, to transport the great Egyptian obelisks to Europe, such as the one standing in front of St. Peter’s Basilica in Rome.)

 

A major invention of the Greeks which was to influence seafaring a great deal was the lighthouse. In 270 BCE, the world’s first known lighthouse, the Pharos at Alexandria, was built by architect Sostratus to guide ships to the port. The 350 foot high structure had a fire kept near its top which could be seen up to thirty miles (48 km) out to sea.² Later, the Romans began to build a network of lighthouses, around thirty in number, many with metal mirrors to further reflect the light from their fire. Lighthouses have evolved today to be a major safety requirement for shipping, thus the impact of the Greeks and Romans on navigation is deep even when the ships themselves are not considered. ^1,2.  Peter James and Nick Thorpe, “Ancient Inventions”, (Ballantine Books, 1994), p. 99.;p. 52.