Strolling along Sir John Rogerson’s Quay, one is apt to be so caught up in the shimmering developments of this new horizon as to miss a huge salmon pink wrought iron yoke shaped not unlike a sink plunger.

And indeed, plunging is to the fore for the origins of this peculiarity. Mankind has been fantasising about living underwater ever since Noah got the tip-off about the Flood.

By 1690, Edmund Halley, he of the Comet, had devised a diving bell capable of remaining submerged for long periods of time. The principle was much the same as when you plunge a glass, mouth down, into a bucket of water and it fills with air.

In Halley’s bell, there was sufficient air for a man to be safely contained within and sent underwater. The only problem was that, with increasing pressure, air compresses and so, as the bell sank deeper, its occupants invariably went ga-ga or died.

In 1783, Charles Spalding, a Scotsman who ran a sweetshop in Edinburgh, arrived in Dublin Harbour with a bell of his own creation. It boasted a very long leather tube designed to reach the surface and, by dint of an air pump, ensure a supply of fresh air.

Unfortunately, Spalding died showing off his invention when his signal ropes became entangled, but the stage was set for the new age in diving bells.

The diving bell on Rogerson’s Quay was designed by Bindon Blood Stoney, the improbably named Chief Engineer for the Port and Docks during much of the Victorian Age. It was built in Drogheda by Thomas Grendon & Co and completed in 1866.

The bell, pictured in August 1999 before its restoration, was used to create the North Wall Extension and the Alexandra Basin. A team of six men would climb the ladder on the 38ft high funnel, pass through an airlock and then climb down into a 400 square-foot chamber, which was just about high enough for a man to stand.

From here, the men were able to level the riverbed in preparation for the laying of the 350-ton prefabricated super-blocks that form the North Wall Extension. It was unpleasant, claustrophobic work. The chamber was often unbearably hot and the pressure was particularly unpleasant for anyone with a cold; ears frequently bled and many men never recovered. Stoney’s bell continued to be used for repair work in the Docklands until 1958.

The St Andrew’s Resource Centre later secured it for the Southside and gifted it to the Docklands Authority who, working with FÁS, the Irish Nautical Trust and Dublin Port, ensured its restoration as a 2000 AD Millennium project.

The above is an extract from Turtle Bunbury’s book ‘Dublin Docklands– An Urban Voyage’ (Montague Publications 2009). Available in March.