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mud and meridian lines

When we bought Snark's bare hull in Essex we had the four sections transported by land over the Thames to Turks Shipyard, which occupies the submarine shed at the Historic Dockyards at Chatham, N. Kent. Here the hull was modified and re-welded, painted and the engines installed. We also made the masts and foils and rigged her. She can be seen here on the slip side before she was moved around to be launched. (More on this on the web site. )

Her maiden voyage was not a great success and we ended up sitting on the mud next to the outfall from the Gillingham sewage works with major propeller shaft problems. All that is now fixed and we can look back with wry amusement at our first night on-board spent 'up shit creek' without an engine.


We weren't the first to end up on the Medway mud. In 1667 the Dutch successfully attacked Sheerness, Gillingham and Chatham in what the English call the Raid on the Medway and the Dutch call the Battle of the Medway. They won conclusively, inflicting the worst damage the British navy has ever experienced. To be fair Britain was still reeling from the Great Plague and the Fire of London and the Dutch did spring a surprise attack while both sides were still at the negotiating table.


Most of the ships sunk were scuttled by the British (see the flags sticking out of the water) to block access up the river to the shipyards, a strategy which proved successful. Though they were not completely submerged as the Dutch painting suggests and what projected above the water was burned by the Dutch.


The Dutch also made it as far as Gravesend but sensing a trap turned back before getting as far as Greenwich. The great Naval Hospital and the Greenwich Observatory were not yet built and the old Greenwich Palace was in a very poor state and the beautiful Queen's House was already effectively abandoned.


It was not until much later that the whole issue of where the prime meridian should be came to the fore. Naval charts need a N/S zero line from which to measure east/west distance, for many centuries this varied depending on the national origin of the chart and ship they were carried on. On most ships however the star sights used to determine a ships position in the world tended to be based on the tables prepared by the Astronomer Royal Nevil Maskelyne in the later 18th c. which used Greenwich as the zero line of longitude or prime meridian. In Britain the line was definitively defined by the observations of Sir George Airy in 1851and adopted internationally, despite strong French resistance, in 1884. The world moves however and in 1984 it was moved 100m east to compensate for tectonic plate shift and changes in the magnetic field.



Even with modern sat nav and chart platters we still use the same meridian line to define east/west locations requiring an annoying shit from positive to negative as you pass Peacehaven on the south coast and back as you pass Withernsea in Yorkshire.





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