Engineering the City of London #2

The 19th Century – dramatic changes for the City

The 19th Century saw the population of the City of London reduce from 128,000 in 1801 to 27,000 in 1901, whilst London overall was growing fast. The electric telegraph increased employment in the City for finance and share trading. Conversely, the exodus of residents led to many parish churches closing, and 16 livery companies were wound up. Others however were thriving in the strongest economy in the world, with 200,000 commuters journeying into the City each day.

A huge influencer on this exodus was the new infrastructure phenomenon – the railway. Over a dozen major projects over a 30-year period saw a massive transformation of the City as the railways carved their way in relentlessly, including two new bridges over the Thames to Blackfriars (1864) and Cannon Street (1866), fuelling the flight to the suburbs.

1866 Cannon Street Rail Bridge designed by John Hawkshaw

Cannon Street Rail bridge, shown here as it originally looked, was widened and strengthened twice – and spoiled (according to Pevsner) by the 1981 refurbishment.

Engineering solves the Public Health Crisis

And in the latter half of the 19th century another transformational project was driven by health concerns. The ‘Great Stink’ of 1858 brought the scandal of the filth in the Thames to crisis point, and the loss of life from cholera and typhus was beginning to be linked to the contamination of drinking water from sewage.

“The silent highwayman” – Punch cartoon 1858

Civil engineer Joseph Bazalgette’s 82 miles of interceptor sewer and 1300 miles of main road sewers were the solution. Under the city and hidden from sight but critical in maintaining the city as a viable entity. London was the biggest city in the world. If it had not solved the problem of public health, the premise of all cities as viable places to live and work would have been under threat.

Another existential threat

Building continued in the early 20th century but slowed in the Depression. A far bigger threat to London came from the 1940s Blitz. Whilst engineering technology did a great deal to reduce the risk of attack in WWII (eg Home Chain Radar, the Spitfire and the Hurricane), London could not be fully protected from aerial bombing.

City War Damage in the Blitz (City of London: Buildings of England, Bradley & Pevsner 1997)

This triggered another exodus of bombed out publishing and clothing firms from the City to the West End. But the Bank of England and other financial institutions were established and stubborn. Finance and commerce stayed behind. Guildhall lost its roof again in December 1940 but rebuilt and carried on.

After the war, grand plans for reconstruction were again prepared and few succeeded – including City Engineer Francis Forty’s plan for a ring road with roundabouts. But Upper and Lower Thames Street did become a wider thoroughfare post-war.

Building bridges – physical and spiritual

Everyone loves bridges. I designed a few in my career. Bridging is also a metaphor for rebuilding broken relationships and communities.  They bring trade, communication, and bind people together. London without its bridges would be two cities, not one. These notes are ordered by date of the first crossing at each site.

1209: The first stone bridge over the Thames and the only one crossing into the City between 1209 and 1760 (further upstream, Westminster Bridge opened in 1750), was Peter of Colechurch’s multiple arch London Bridge, begun in 1176 and completed by the Frenchman Isembert in 1209. It survived over 600 years, by far the longest lasting of London’s Thames bridges so far.

1209-1831 London Bridge designed by Peter of Colechurch

But even without its houses, cleared in 1758, it was narrow and expensive to maintain. John Rennie’s design of a replacement bridge was chosen in 1824 and was completed after his death by his son. Rennie was educated at the University of Edinburgh, came to London to work for Boulton & Watt at Albion Mills, then set up in consultancy. He had a hugely productive career, designing three of London’s bridges and many projects nationwide, rivalling Telford in his lifetime as the greatest civil engineer.

1831-1968 London Bridge designed by John Rennie

The facing stones of that London Bridge were famously sold in 1968 to Robert McCulloch for his resort city in Arizona and a new concrete bridge, clad in Rennie’s original granite, now crosses a canal off Lake Havasu. This made way for the present London Bridge designed by Mott Hay and Anderson.

1972 London Bridge designed by Mott, Hay & Anderson

1760:  Robert Mylne’s rather attractive 1760 bridge was replaced in 1869 by Cubitt’s wrought iron bridge with much longer and wider spans, necessary as the City both attracted and generated trade and traffic.

1869 Blackfriars Bridge designed by Joseph Cubitt

1819: Southwark Bridge,  the first of Rennie’s Thames bridges in 1819, was known to all Londoners as the Iron Bridge.

1819-1921  Southwark Bridge designed by John Rennie

Its successor, opened in 1921, was designed by Basil Mott.

1921 Southwark Bridge designed by Basil Mott

1864: The piers of Cubitt’s 1864 Blackfriars railway bridge remain as empty pedestals at Blackfriars, the wider bridge of John Wolfe-Barry in 1880 being needed as the ever more popular railway elbowed its way into the City.

1864 piers of Cubitt’s bridge with 1880 bridge designed by John Wolfe-Barry, with recent solar energy canopies

1866: Cannon Street Railway Bridge (see above)

1894: Tower Bridge is on our Coat of Arms to signify links with the City (though it actually crosses from Southwark to Tower Hamlets). But the City of London maintains it through the Bridge House Estates. Behind the façade it’s a steel bridge built by another Scot, William Arrol, at the same time as he was building the Forth and second Tay Bridges. Truly, a man of steel.

1894 Tower Bridge designed by John Wolfe-Barry, steelwork by William Arrol

2001, reopened 2002: Completing the City’s Thames bridges is the Millennium Footbridge, initially not one of engineering’s greatest triumphs, but clever retrofitted strengthening succeeded in stabilising the initial wobbles.

2001 Millennium Footbridge designed by Arup and Foster & Partners

Keeping the City of London as a viable, resilient, sustainable centre of commerce and business is a huge challenge. It is, to a large extent, engineers who have kept it moving, kept it working, kept it healthy, and kept it safe.  And they will do so again once this latest health challenge from Covid-19 is overcome. There remains the formidable challenge of climate change and achieving a zero-carbon City.

The unsung heroes who are our infrastructure engineers will be there to take on the challenges and continue to provide bridges to the City of London’s prosperity.

[Adapted by the Master, Gordon Masterton, from his Engineering Soiree talk to the Company by ‘Zoom’ on 28th April 2020.]

Image credits:

The Silent Highwayman: Punch cartoon 10 July 1858 – public domain

London 1: The City of London. Buildings of England. Bradley and Pevsner. 1997

View of London Bridge: Claude de Jongh (c.1600–1663): Yale Center for British Art. Public domain.

Rennie’s London Bridge and Southwark Bridge, Cannon Street Rail Bridge and Tower Bridge: Institution of Civil Engineers

https://commons.wikimedia.org/wiki/File:London_Bridge_from_Cannon_Street_Railway_Bridge.jpg

https://commons.wikimedia.org/wiki/File:Blackfriars_Bridge,_River_Thames,_London,_with_St_Pauls_Cathedral.jpg

https://commons.wikimedia.org/wiki/File:Millenium_bridge_2015.jpg