The United Kingdom has a lot of famous things. Queen Lizzie, Big Ben, Buckingham Palace, St. Paul’s Cathedral, Top Gear, Mock the Week…famous authors, terrible weather, national cuisine of a questionable quality, colourful slang and one of the most powerful naval forces in the world.

And then there’s this thing:

Tower Bridge, which crosses the River Thames in London, the British capital, is one of the most famous structures in the world. It’s recognised and admired all over the globe as a national, aesthetic and engineering masterpiece of the Victorian age. Despite what we might think, Tower Bridge is nowhere near as old as some of us would like to think. In fact, Tower Bridge opened on the 30th of June, 1894. Little more than a hundred years ago. Today, we could hardly imagine London without it.

Before the Bridge

London has been around for centuries, ever since a town called “Londinium” was founded by the Romans in 47AD. For a considerable time, there were very few crossings of the River Thames and for centuries, London Bridge (originally built by the Romans) was the only bridge crossing the Thames within the boundaries of London.

Fast forward a few centuries, and you’ll find more and more bridges added to London to cross the river it’s built around. By the time the Tower Bridge was dreamt up in the 1890s, the River Thames had…

Regent Bridge (Vauxhall Bridge) (1816)
Westminster Bridge (1862)
Waterloo Bridge (1817)
London Bridge (1831)

Increasing commercial and industrial development in the East End of London during the second half of the 19th century (brought on by the Industrial Revolution) meant that another bridge needed to be built across the Thames to ease the congestion on London Bridge and the nearby Tower Subway tunnel (which, despite the name, was really a pedestrian tunnel and wasn’t actually used by trains).

By the 1870s, congestion on London Bridge was chronic and a committee was set up in 1876 to decide on a new crossing-point on the River Thames, down-river from London Bridge. A competition was held, inviting engineers and designers to send in their ideas for a new bridge to cross the Thames. One of the big challenges in designing the new bridge, however, was the fact that in building this bridge, it would be blocking river-access to the Port of London. Any bridge built down-river from London Bridge would have to be high enough to allow ships and boats to pass safely beneath it, not an easy thing to accomplish when the Thames is a tidal river with tides that rise and fall several feet at a time.

London Bridge, Ca. 1910. Although this painting was completed sixteen years after Tower Bridge was opened, it shows quite clearly how congested London Bridge had become, and the absolute necessity for a new river-crossing

Over fifty designs were sent to the bridge committee for consideration, but a potential winner was not decided upon until, in October of 1884, two men, Horace Jones and John W. Barry, came up with their idea for a bascule-suspension bridge. The Committee were quick to see the advantages of Jones and Barry’s design and approved it for construction.

The suspension-bridge is able to span great distances, such as the River Thames, easily. The double-bascule segment of the bridge in the middle meant that ships could easily pass through the structure to head upriver. The ‘bascules’ were the two leaves of the central drawbridge, which could be raised (to let ships pass through the bridge) and lowered (to allow vehicular and foot-traffic to cross the river) by mechanical means.

Building the Bridge

Construction of Tower Bridge started in 1886. For the number-crunchers reading this, here’s a few statistics:

Number of Contractors: 5.
Number of Construction-Workers: 432.
Construction-time: 8 Years.
Amount of Concrete to make bridge piers: 70,000 tons.
Amount of Steel for the bridge’s framework: 11,000 tons.
Cost of Construction: 1,184,000 pounds sterling (approximately 100,000,000 pounds sterling today).

Tower Bridge under construction

As the bridge was constructed, tons of granite and Portland Stone was brought in to build the bridge’s distinctive towers. At the top of the bridge, linking the two towers, is a pair of walkways. These were included in the bridge’s design so that pedestrians could continue to cross the bridge even when the drawbridges were opened and crossing the bridge via its main span was impossible. The walkways were closed soon after, though, when they became a favourite haunt of prostitutes and thieves.

The bridge was completed in 1894 and was originally painted chocolate brown. It’s current red, white and blue colour-scheme was added in 1977 in commemoration of Queen Elizabeth II’s Silver Jubilee (which marks the 25th year of the Queen’s reign).

Opening the Bridge

The bridge was formally opened on the 30th of June, 1894, by His Royal Highness, the Prince of Wales (King Edward VII later in life).

A painting capturing the atmosphere of the formal opening of Tower Bridge in 1894. Note all the ships dressed with their signal-flags for the occasion

Tower Bridge became popular in a hurry. Not just because it looked really neat, but also because it was toll-free (a surefire hit with any bridge-crosser). The nearby Tower Subway tunnel charged a toll for its use while the bridge did not. Because of this, intelligent Victorians soon abandoned the Tower Subway tunnel and started crossing the bridge regularly instead. The bridge was so popular that by 1898, the Tower Subway tunnel closed due to a lack of revenue!

If you’re wondering why the two structures are called ‘Tower Subway’ and ‘Tower Bridge’, it might do well to examine a map of London. The tunnel and the bridge which put the tunnel out of business were named ‘Tower’ due to their close proximity to the Tower of London, the ancient fortress and prison on the north bank of the River Thames.

Raising and Lowering the Bridge

One of the most famous things about Tower Bridge is not its shape or its size or the fact that it was named after some spooky old castle next door…it’s the fact that it moves! The raising and lowering the drawbridges that make up Tower Bridge’s central span, is the most recognisable feature of this marvel of engineering. So how is it done?

From its opening in 1894 until 1975!…Tower Bridge was opened using steam-powered hydraulic engines. There were two engines, one to raise each side of the bridge. At the press of a button, the two halves of the bridge could be raised up to their full angle of 86 degrees each. This whole process took about one minute. Speed was important on the River Thames, when ships needed quick access to the London Docks further up-river.

During the Second World War, a third steam-engine was made. Its purpose was to act as a standby in case Tower Bridge was hit by a German bomb during the Blitz and one of the operational engines was put out of commission by the damage. Fortunately, this never happened and the third engine (along with the other two original steam engines) is now a museum-piece.

In 1976, the bridge’s original steam-powered engines were removed and replaced with more modern electrical ones. They still raise and lower the bridge using hydraulic power, but don’t require as much maintenance.