Why Were the Romans so Good at Military Engineering?

In the early days, service in the Roman legions and the imperial Roman navy was always voluntary. The ancient leaders recognised that men who take up service were more likely to turn out as reliable.

It was only during terms of what we can call emergencies that conscription was used.

These Roman men at arms had to be skilled in the use of weapons firstly, but they also served as craftsmen. They had to make sure that everything that the legion required remained ready and mobile.

Levy of the army, detail of the carved relief on the Altar of Domitius Ahenobarbus, 122-115 BC.

From stonemasons to sacrificial animal keepers

As well as being able to fight, most soldiers also served as skilled craftsmen. These ancient artisans covered a vast range of skills: from stone masons, carpenters and plumbers to road builders, artillery makers and bridge builders to mention just a few.

Of course they also had to look after their arms and armour, maintaining not only their hand weapons, but also a range of artillery devices.

Across the Roman Empire, legionary camps became home to groups of highly skilled architects and engineers. Ideally, these men hoped that their skills would lead them into a prosperous career in civilian life, after they had completed their service in the legion.

Large volumes of paperwork with all the daily orders that had to be issued, and not least details of pay for each serving craftsman, were retained. This administration would decide which legionaries received extra payments, due to their valuable skills.

Maintaining the weapons

Ancient Roman soldier-craftsmen had to have considerable knowledge when it came to looking after and repairing the many weapons that needed attention. Blacksmiths were of prime importance, along with other metal trade crafts.

Skilled carpenters, and those who crafted ropes, were also highly-sought after. All of these skills were required to prepare iconic Roman weapons such as the Carraballista: a mobile, mounted artillery weapon that the soldiers could place upon a wooden cart and frame (two trained soldiers manned this weapon). This weapon became one of the standard artillery pieces distributed among the legions.

All roads lead to…

Road construction shown on Trajan’s Column in Rome. Image Credit: CristianChirita / Commons.

Perhaps the most enduring legacy of Roman engineers was their building of roads. It was the Romans who constructed and developed the major roads which in turn paved (literally) the way to urban development.

Militarily, roads and the highways played a very important role for the movement of the army; commercially too, they became popular highways for the transporting of goods and trade.

The Roman engineers were charged with maintaining these highways: ensuring that they remained in a good state of repair. They had to pay great attention to the materials used and also to make sure that the gradients allowed for water to drain efficiently from the surfaces.

By keeping the roads well maintained the Roman soldier could cover 25 miles in day. Indeed, when Rome was at its peak, there was a total of 29 great military roads radiating out from the Eternal City.

Dan has his regular catch-up with Simon Elliott on all things Roman. Why were the legionaries so successful, and how did they maintain that success for several centuries?

Listen Now

Bridges

Another great invention maintained by the Roman engineers was the pontoon bridge.

When Julius Caesar looked to cross the Rhine with his legions, he decided to construct a wooden bridge. This military manoeuvre caught the German tribe’s unready and, after showing the German tribes what his engineers could do, he withdrew and had this pontoon bridge dismantled.

Caesar’s Rhine Bridge, by John Soane (1814).

It is also known that the Romans built bridges by having wooden sailing craft lashed tightly together. They would then place wooden planks over the decks, so that the troops could cross over water.

We can look back across time and admire those ancient Roman engineers – highly trained not only in the immediate drills and manoeuvre for the battlefield but also in their incredible engineering skills and innovations. They played such a crucial role in pushing forward new discoveries, both in technology and in material sciences.

Veteran of the British Army John Richardson is the founder of the Roman Living History Society, “The Antonine Guard”. The Romans and The Antonine Wall of Scotland is his first book and was published on 26 September 2019, by Lulu Self-Publishing .