Bell epoch

CURIOSITIES: STROLLING ALONG Sir John Rogerson's Quay on the southside of Dublin's docklands, one is apt to be so caught up …

CURIOSITIES:STROLLING ALONG Sir John Rogerson's Quay on the southside of Dublin's docklands, 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 sweet shop in Edinburgh, arrived in Dublin 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 Sir John 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 was used to create the North Wall Extension and the Alexandra Basin. A team of six men would climb the ladder on the 38-foot high funnel, pass through an airlock and then climb down into a 400sq ft chamber.

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. It was unpleasant, claustrophobic work. The chamber was often unbearably hot and the pressure was particularly tortuous for anyone with a cold; ears frequently bled and many men never recovered. Stoney's bell continued to be used until 1958.