What are facts about Roman engineering?

Answer 1

The Roman roads are known for their straightness. Most, if not all of them, went from here to there in a straight line. They were well drained with ditches on the side for runoff. They had milestones giving the traveler the distance to Rome. They had inns and rest stops along the way. There is evidence that some of the most heavily traveled roads had a median strip down the center dividing incoming and outgoing traffic. Although the army built the roads, the maintenance of the roads was the responsibility of the province or town/city where they were located.

Answer 2

Whilst the Etruscans invented the simple (barrel) arch (arches have a great load bearing strength and provide stability) the Romans developed the vaulted arch which is more complex and has even greater load bearing capacity. It became crucial to support large roofs and to build basements and essential to build large buildings. They also developed a new and more resistant type of concrete which was as strong as modern concrete, though it was less fluid and had to be layered by hand. The use of the arch and of concrete made helped to build scale projects, such large public buildings, military facilities (forts and fortifications) warehouses, amphitheatres, circuses (racing tracks) temples, baths, bridges, aqueducts and dams, and to build domes.

The arches and concrete also made it possible to build longer bridges which could cross much wider rivers and valleys and much deeper valleys. When bridges had to reach great heights, two or three tiers of arches could be built on top of each other to make the top of the bridge much higher. The greatest example of this technique is the Pont du Gard, a bridge with three tiers of recessed arches with the main piers in line one above the other. The first two tiers have very high and wide arches and a third tier has low and narrow arches. It reaches a height of 48.8 metres (160 feet). The lower tier is 142 metres (466 feet) long and has six aches with a height of 22metres (72 ft.). The second tier is 242 metres (794 ft.) long and has eleven arches 20 metres (66 ft.) high. The upper tier is 275 metre (902 ft.) long. It originally had 47 arches (only 35 have survived) 7 metres (23 ft.) high. The width of the first pier is 6 metres (20th.), that of the second pier is 4 metres (13 ft.) and that of the third pier is 3 metres (23 ft.).

Since Roman concrete set underwater, it was also used to build the docks of ports which were much larger.

The Romans also perfected the construction of domes, and they used concrete to build them. The dome of the temple of the Pantheon in Rome is still the largest unreinforced concrete dome in the world.

The Romans built great aqueducts. Most were underground conduits. When above ground the conduits were on bridges when the aqueducts had to cross a valley or when they were needed to keep a gradient to make the water moving. The Pont du Gard, mentioned above, was a bridge for an aqueduct which supplied Nines, in southern France. When the valleys were too steep, a system of siphons was used. The siphons took the water to tanks lower down which fed other conduits.

The Romans were the first to build stone paved roads. The network of these roads reached 80,500 kilometres (50,313 miles) which was 20% of the network of 400,000 kilometres (250,000 miles) of roads in the Roman Empire.

The Romans adopted the cranes of the Greeks and massively improved on them. The simplest one was the trispastos, which had of a single-beam, a winch, a rope, and a block with three pulleys. It had had a mechanical advantage of 3:1, and single man operating the winch could raise 150 kg. The pentaspastos had five pulleys and the polyspastos had a set of three by five pulleys with two, three or four masts. The latter was worked by four men at both sides of the winch and could lift 3,000 kg. When the winch was replaced by a treadwheel, the load could be doubled to 6,000 kg with only half the crew, because the treadwheel had a larger diameter and thus a much bigger mechanical advantage.

The Romans invented the hypocaust, which was an underfloor heating system for heating houses and the baths using hot air. The floor was raised above the ground by pillars which left a space inside that was filled with hot air from a furnace. The heat from the underfloor heated the air in the room. Passages boxed by ceramic tiles were put inside the walls to move the air to flues on the roof and to heat the walls.