The Unanticipated Impact of Unity

The London Millennium Bridge opened to the public on 10th June 2000 when an estimated 80,000 to 100,000 participants in a charity walk on behalf of Save the Children crossed it. As with all bridge structures, the Millennium Bridge is subject to a degree of movement but the designers and engineers had predicted that this would be no more than 4 millimetres. However, when the large groups of people were crossing, greater than expected sideways movements occurred. The bridge began to sway and twist in regular oscillations. The worst of the movement occurred on the central span where the deck was moving by up to 70mm, the frequency of the oscillations increased, leaving people unnerved and unsteady. The engineers insisted the bridge wouldn’t fall down but two days after it opened closed it completely after attempts to limit numbers proved unworkable. It would not reopen for nearly two years.

The bridge’s movements were caused by a ‘positive feedback’ phenomenon, known as synchronous lateral excitation. The natural sway of people walking caused small sideways oscillations in the bridge, which in turn caused people on the bridge to adjust their gait to the same lateral rhythm as the bridge. The adjusted footsteps magnified the motion – just like when four people all stand up in a small boat at the same time. As more pedestrians locked into the same rhythm, this reinforced the effect, leading to the dramatic swaying captured on film.

The bridge reopened on 22nd February 2002 after remedial work costing in the region of £5M, though it is still nicknamed the “Wobbly Bridge” by Londoners and it remains a testimony to the disruptive effects of unity.

People sometimes ask me why there is a need for strong credit unions in this country when interest rates are so low and while there are so many alternative financial options such as crowdfunding and peer-to-peer lending available. The answer is in the common bond. Credit Unions are made up of people who have something in common, doing something in common for the common good. This sense of (comm)unity underpins credit unions from the smallest operating in a village hall to the largest serving thousands of employees of huge organisations.

Just as thousands of people walking in step disrupted the Millennium Footbridge so by choosing to save with and borrow from a credit union we can all challenge the status quo of the financial sector in a way that ultimately leads to a change for the better.

This is the crucial lesson from the tale of London’s Wobbly Bridge; never underestimate the impact of people working in unity.