Big Ben: Powering an icon of the London skyline

One of London’s most iconic landmarks is arguably Big Ben. A staple of the city’s skyline, residents and tourists are used to hearing the iconic hourly chimes — but no more.

As part of four-year conservation work, Big Ben rang out for the last time on 21st August 2017. The work will be carried out to the clock’s mechanism, which will see it dismantled as part of a laborious process that will see each cog examined and restored, the hands removed and refurbished and repair work carried out on the glass.

The clock will continue to keep time during the work, through the installation of a temporary electric motor. Here, electric motor rewind specialist Houghton International discusses the other instances through history when the landmark has relied on an electric motor:

Metal fatigue in the connecting shaft between the clock’s chiming train and fly fan almost lead to complete destruction of the clock in 1976. At 3.45am, the shaft broke, dramatically increasing the speed of the mechanism’s rotation as a result of the shaft’s 1.25 ton weight and the lack of braking from the fly.

As a result, the chiming mechanism was completed destroyed. The speeds reached were so high that many components were thrown with such force they crashed through the ceiling of the mechanism room. 

The chiming train had to be reconstructed from scratch following the large-scale damage caused. Given the scale of the repair work that was required, the permanent installation of an electric motor was considered however, the eventual decision was made to repair the clock’s original mechanism, work that took a year to complete.

Big Ben has encountered other issues throughout its lifetime. In 2005, the clock reportedly became victim to the unseasonable temperatures London was experiencing at the time. As temperatures reached 31.8 °C in May, the clock stopped for in excess of 90 minutes in total.

Six-week maintenance work was carried out in 2007 that saw the striker and chime train replaced. Again, during this time, an electric motor was used to restore the clock’s functionality.

The incidents have led to some considering whether Big Ben would be better suited to having an electric motor permanently installed, as restoration costs continue to rise. Expected to cost £29 million, the figure for the current works grew to £61 million, as the work required was said to be more complex than originally thought.

While reliability may increase and maintenance reduce, the move could sacrifice some of Big Ben’s rich history. The internal mechanism is as fundamental to the tower as its iconic chimes. For now and in the future, let electric motors remain the understudy, there only when Big Ben needs it most.