Pontoon Bridges: an engineering construction used throughout history to get armies across rivers.
Prior to the First Battle of Fredericksburg, Union General Burnside delayed his forward advance toward Richmond at the banks of the Rappahannock River. The pontoon bridges he had ordered had not arrived on time. Concerned about the possibility of the river flooding and splitting his army on separate sides, Burnside refused to send troops to the other side via the upstream fords. By the time the long-awaited pontoon bridges arrived and were ready to be placed, Confederates had dug into the high ground outside Fredericksburg town.
Pontoon Bridges are associated with the Battle of Fredericksburg since they provided the advance and retreat route for the Union Army of the Potomac. (You can check out some replicas near Chatham House if you’re visiting Fredericksburg & Spotsylvania Military Park.)
Did you know General Burnside had something in common with Ancient Persian King Xerxes I? Both commanders ordered pontoon bridge construction to advance their armies in campaigns. Xerxes’s spanned the Hellespont in 480 B.C.E. No, pontoon bridges aren’t a modern warfare invention.
King Xerxes I of Persia held a grudge against the Greek city-states. They had defeated his father at the Battle of Marathon, and the new king wanted no whispers of rebellion against Persia anywhere in his world. Afterall, one of his royal titles – “king of kings” – implied submission from all other rulers. Adding the Peloponnesian territory to his empire would accomplish multiple purposes. First, his father’s defeat would be avenged. Second, it would add new territory to the already immense Persian Empire. Third, it would prevent the Greeks from inciting any weak allies of the empire to revolt.
By the spring of 480 B.C.E., Xerxes had gathered a massive army, estimated at 200,000 total men and about 75,000 animals.[i] The Persian Empire fleet – consisting of war triremes sent by conquered and allied nations – also waited to move against the Greeks. To move his army from Anatolia into the European Continent, Xerxes had to cross the Hellespont. Sensibly, the king (or his engineers) chose the narrow mile-wide strip of water at the southwestern edge of the channel. [ii]
The ancient historian Herodotus left great details about the construction of Xerxes’s pontoon bridges. Approximately three hundred warships were lashed together, covered with wooden walkways, bordered with a railing, and finally “planted” with dirt and grass to keep the animals from spooking.
Ready for the drama? The two bridges were almost finished. A huge storm tore through the strait and wrecked both bridges. Furious and seething, Xerxes beheaded the engineers. Then he ordered his soldiers into the Hellespont waters with whips to beat the rebellious water into submission. Three hundred lashes. Next, Xerxes threw chains into the water to symbolize that he would hold the waters captive, and – just in case the waves hadn’t understood – the king had them branded with red hot irons.[iii]
By the time the second set of bridges was completed, the water decided to remain calm. Flattered and retaining his supreme ruler position, Xerxes performed ritual ceremonies and watched his army begin the crossing. The crossing of the Hellespont took seven days and seven nights, and when it finished, Xerxes’s army had entered Europe, prepared to conquer.
Spoiler alerts: The Spartans at Thermopylae and the Greek Navy at Salamis spoiled Xerxes’s grandiose plans to rule the city-states. He returned to Persia, leaving an unskilled general to “finish” the fighting.
Pontoon Bridges. Though sometimes associated with General Burnside’s schemes in the minds of Civil War historians, they weren’t new inventions during the 1860’s. These bridges had been used for centuries. And Burnside wasn’t the first commander to have trouble with his engineers.
Thankfully, General Burnside realized his humanity and didn’t pretend to be a “king of kings” or demi-god on earth. Nor is there any record that he beheaded the tardy bridge makers or transporters. And he certainly didn’t lash the Rappahannock River.
Times and understanding of leaders and warfare have changed through the centuries, but there are some aspects which remain the same. Engineering pontoon bridges is a skill used by militaries to cross rivers. Hellespont or the Rappahannock.
[i] Barry Strauss, The Battle of Salamis: The Naval Encounter That Saved Greece – And Western Civilization (2004), Page 42.
[ii] Ibid., Page 44
[iii] Ibid., Page 44