We’ve looked at lighthouses and bridges as part of our continuing commemorations for the 200th anniversary of the founding of the Institution of Civil Engineers. Now it’s the turn of breakwaters. This print was purchased for our collections in 1911. It shows Mount Edgcumbe, Plymouth Sound and Plymouth Breakwater from Staddon.

Mount Edgcumbe and Plymouth from Staddon print © Plymouth Museums Galleries Archives

Three men in uniform, plus another man and a woman can be seen in the foreground by the cannons. The harbour is teeming with boats and I think I can spot Maker Church in the distance. In the left hand section of the work the breakwater can be clearly seen with its white lighthouse at one end.

Lying at the mouth of Plymouth Sound between Bovisand and Cawsand/Kingsand, the breakwater can lay claim to helping shape the history and fortunes of South West England.

The story behind this striking man-made feature is one of engineering ambition played out in the toughest of environments.

In 1811 Civil Engineer John Rennie (1761-1821) was instructed by the Admiralty to draw up plans for a breakwater that would transform Plymouth Sound into a safe anchorage. Although the Sound is a large natural harbour it could be a dangerous place when exposed to south westerly gales. Pressure also grew during the Napoleonic Wars (1803-15) with the need to provide a safe base for the Channel Fleet.

Work began on the pioneering structure in 1811-12. Nothing on its scale had been built before. Referred to as ‘The Great National Undertaking’, it took many years to complete.

3.5 million tonnes of Plymouth limestone were quarried locally to help construct it. The first block was dropped onto the seabed from a sailing barge on August 12, 1812.

Rennie and fellow engineer Joseph Whidbey (1757-1833) considered creating a land attached breakwater but ultimately chose an unattached one instead. This eliminated hazardous shoals and rocks and helped retain the historic shipping routes into Plymouth. The angled arms reduced the agitation of water in the tidal channels and provided further shelter.

The breakwater was considered largely complete when its lighthouse was lit in 1844, although work on it continued into the 1860s. Reinforcements began in 1871 and over one thousand 100-tonne concrete wave-breakers have been taken out to it since 1928. Up to 12 of these wave breakers are still added every year.

Although we may take it for granted when we stand on the Hoe and look out to sea it is still one of the largest free-standing breakwaters in the world – and we should be very grateful for it. Modern civil engineering and research mean new ways to protect our ports and shorelines are constantly being developed, but the power of the sea never changes.

Jo Clarke, Marketing and Communications Officer
This article was originally published on 6 March 2018