This is the first of a series of articles that celebrates the ingenuity of English men and women that are linked to Yorkshire in some way. These articles are not in any particular order. Each individual has been selected simply upon merit. In this case, Wilson Benesch has launched Trinity, so we thought that it might be interesting to mention Trinity House.
The safety of shipping, and the well being of seafarers, have been the prime concern of Trinity House since it was granted a Charter by Henry VIII in 1514. Part of this responsibility is of course the lighthouse which John Smeaton will always be remembered for. In addition John Smeaton was a Yorkshireman. As Wilson Benesch is based in South Yorkshire what better place to begin the series.
Navigation off Plymouth would remain hazardous whilst ever Eddystone rock stood without a lighthouse. The two previous wooden designs had failed the test resulting in the death of the designer himself in one case. For 52 years mariners looked forward to the day that a replacement would be found. During this time, Trinity House placed a light vessel to guard the position until a permanent light could be built. It was clear from the demise of the previous designs that the task would not be solved by any ordinary solution however. In 1756 the Royal Society recommended a Yorkshireman, John Smeaton, for the task. The assignment would capture the imagination of the world.
The idea of being inspired by natural forms is often used today but of course it is not a recent phenomenon for designers to draw upon millions of years of evolution. Smeaton’s inspiration came from the Oak tree and he decided to construct a tower based on the same shape for strength, but made of stone rather than wood, as in the case of previous designs. Such a decision is of course, not an easy choice to make. How would the rock be transported, never mind assembled upon to an organic form in the middle of the sea. The level of workmanship would have to be exemplary, but why would any quality craftsman wish to work in such dangerous conditions? Trinity House arranged with the Admiralty at Plymouth to have a medal struck for each labourer to prove that they were working on the lighthouse. This would ensure that they were prevented from conscription into the Navy.
The foundations and facing were constructed from local granite. To bond the granite Smeaton invented a quick drying cement, ‘hydraulic lime’ (a form of concrete that will set under water) it is a formula that is still used today. An ingenious method of securing each block of stone to its neighbour, using carefully cut interlocking joints and marble dowels was employed. Of course the technology for assembling such a structure was of it self, a huge engineering challenge.
To enable the transportation of the large granite blocks from the vessel to the rock a device was designed by Smeaton that is still in use today by ships at sea to enable them to lift to considerable heights. The design that he created has never been improved upon. The combined result of these and other innovations enabled the completion of the tower within three years. Engineering of such a quality in the days of candle power seems all the more extraordinary. 24 candles were used to provide light on 16 October 1759.
While in use, Smeaton’s lighthouse was 59 feet (18 metres) in height, and had a diameter at the base of 26 feet (8 metres) and at the top of 17 feet (5 metres). It remained in use until 1877 when it was discovered that the rocks upon which it stood were becoming eroded each time a large wave hit the lighthouse it would shake from side to side. Smeaton’s lighthouse was largely dismantled and rebuilt on Plymouth Hoe, in the city of Plymouth, as a memorial. The foundations and stub of the old tower remain on the Eddystone Rocks. The foundations proved too strong to be dismantled so the Victorians left them where they stood (the irony of this lighthouse is that although the previous two were destroyed, this one proved to be stronger than the rock upon which it was built and could not even be intentionally taken apart).
The remaining stump still stands on the Eddystone Rock. Testimony to inspired Yorkshire ingenuity.
Note that the A.C.T. tonearm was designed with the same form, essentially a hyperbolic curve. This provides any beam or tower with the highest possible strength to weight ratio. It is naturally correct and when allied to a carbon fibre helix the ultimate is possible. No other form or materials technology can be demonstrated to outperform this solution. It is the stiffest, lightest and of itself, most highly self damped tone arm tube in the world.
