"London Bridge is Falling Down"

Remember the nursery rhyme, “London Bridge is Falling Down”? That’s a bridge that Roma Agarwal talks about in her wonderful book, Built. It’s a building she never saw because, hey, it was demolished in 1831, after being in existence for a whopping 600 years!

“Despite its impressive longevity, Old London Bridge failed as a structure.”

 

From the start, it was a tough ask. Nobody had built a stone bridge on a tidal river. Getting stones transported was another challenge. It took one year just to create one arch of the bridge. 18 more arches later, 33 years later, the bridge was finally ready in 1209. At its center was a drawbridge to allow tall ships to pass.

Since the bridge was 8 meters wide and no cars/lorries existed:

“Houses began appearing on the bridge.”

Over a hundred of them, including shops. Some buildings were 3 to 4 stories tall. With so many “residents”, stalls mushroomed! Obviously, the bridge had never been designed for buildings. The houses were too close to each other, making it a high risk to fire.

“The bridge really was an accident waiting to happen.”

The fire of 1212 destroyed all the buildings and killed thousands.

 

The bridge itself survived: it was made of stone after all. Revolts and rebellions in 1381 and 1450 laid waste to many parts of the bridge. By the fifteenth century, the number of buildings on the bridge and their height had doubled.

“Between the overloading of the bridge by the houses, the effects of fires, and the wearing away of the supporting piers by the rapids flowing between them, some portion of the structure was always crumbling and collapsing into the water.”

It was finally brought down in 1831, when the New London Bridge was constructed.

 

“London Bridge is falling down”. Now you know the basis for that nursery rhyme:

“It is a rare song about engineering. It teaches the future engineers among us about the perils of bad design before we can even walk.”