Robert Stevenson
continued
Bell Rock Lighthouse
Robert Stevenson's most memorable achievement is his work on Bell Rock Lighthouse. The treacherous reef on which it stands is in the North Sea, between the Firths of Forth and Tay, some 19km south of Arbroath and 23km south east of St Andrews. The red sandstone outcrop is 435m long and the lighthouse is founded on the main section, 130m long and 70m wide, and only 1.2m above the surface at low water spring tide.
The reef was known originally as Inchcape Rock or Cape Rock. According to tradition, in the 14th century the Abbot of Aberbrothok (Arbroath) placed a floating bell on it to warn mariners, hence its present name. Sometime later a Dutch pirate removed the bell but he was later shipwrecked and perished on the same reef. The rocks were dangerous to ships sailing along the east coast of Scotland and by the end of the 18th century the need for a lighthouse was clear.
A severe storm in December 1799, in which about 70 vessels were wrecked, prompted Stevenson to propose a beacon-style lighthouse on six cast iron pillars. It was comparable with the Smalls Lighthouse (1775-76) built west of Milford Haven by Henry Whiteside (1748-1824). Stevenson submitted a scale model of his idea to the Northern Lighthouse Board in summer 1800 — accurate physical modelling was to become something he often employed subsequently on important projects.
In October 1800, Stevenson and his friend the architect James Haldane visited Bell Rock for the first time. The visit showed that his cast iron structure would not be sturdy enough to resist the sea — a stone lighthouse would be needed. Stevenson was aware of the work that John Smeaton (1724-92) had undertaken in the course of erecting Eddystone Lighthouse south of Plymouth, and this design influenced his own, for which he built another scale model.
A Parliamentary Bill was raised for the work in 1803 but it didn't make it through the House of Lords. In January 1804, the 64-gun ship HMS York (launched 1796) foundered on the Bell Rock and was lost with all hands. The Northern Lighthouse Board grew concerned about the hazards of constructing a lighthouse on the rock and the considerable public expenditure it would require. In 1805, they obtained the support of eminent engineer John Rennie (1761-1821), who visited the rock on 16th August. The Cape Rock Lighthouse (Scotland) Act was passed on 21st July 1806.
The Northern Lighthouse Board appointed Rennie as "chief engineer for conducting the work" on 3rd December 1806. On 26th December, Rennie proposed "that Mr Stevenson should be appointed assistant engineer to execute the work under his superintendence", to which the board agreed. The post meant that Stevenson acted in effect as resident engineer.
Stevenson estimated the cost of his stone lighthouse at £42,685. Rennie overhauled the design, though also drawing heavily on Smeaton's Eddystone innovations. Rennie’s design — implemented by Stevenson — was for a taller and more slender tower above a tapering base shaped to cycloidal curves, constructed using dovetailed stone courses jointed with mortar and faced with Roman cement. He costed the whole at £41,843.
Work began in 1807, the same year that Stevenson's son Alan (1807-65) was born. Alan would grow up to follow his father's lead and became a lighthouse engineer and engineer to the Northern Lighthouse Board.
Despite the controversy that sprang up between the families in later years over claims of who designed and built the lighthouse, records show that Rennie and Stevenson had a good working relationship at the time. In 1807, Rennie wrote encouragingly to the younger man hoping that the spirit of Smeaton would "now and then take a peep of us, and inspire you with fortitude and courage to brave all difficulties and all dangers, to accomplish a work which will, if successful, immortalise you in the annals of fame". And so it proved. Stevenson's classic Account of the Bell Rock Light-House was published in an edition of 300 copies in 1824.
A yard was leased for seven years at Arbroath, where stone blocks for the courses were shaped and trial fitted, and accommodation was provided for men and materials. The first task was to erect a floating light near the reef, equipped with stores for men at work on the rock. An 81 tonne vessel with three masts, captured from the Prussians and renamed Pharos, was moored 2.4km north west of Bell Rock on 14th July 1807. A light was exhibited on each mast from 15th September.
A new 41 tonne sloop — named Smeaton at Stevenson's suggestion — was built at Leith and came into service in August. Rennie visited the site to inspect progress on 6th October 1807, just before work halted for the winter. A temporary beacon of 12 timber beams had been erected, though little had been achieved in preparing the rock surface for the lighthouse foundations. From 1808, the beacon supported a working platform and barracks, designed by foreman millwright Francis Watt, which remained in place until September 1812.
The year 1808 was a busy one for Stevenson. On 10th July he laid the lighthouse’s foundation stone, which was almost at the level of low water spring tide, and two days later he was formally appointed as the Northern Lighthouse Board's engineer. The board also provided a new tender, the 81 tonne Sir Joseph Banks, to be used as living quarters for those working on the reef.
By the end of September, four courses of the lighthouse tower were complete, two of which were sunk into the bedrock, and work at sea stopped for the year. Rennie made his annual inspection on 25th November 1808.
Stevenson also celebrated the birth of another son, his namesake Robert (1808-51), who was destined for a career in medicine rather than engineering.
The next work season, April to September 1809, brought the lighthouse to a height of 9.6m. Up to 9.1m the tower was solid masonry, apart from a 250mm diameter hole designed for the reflector-moving machinery. Rennie visited on 24th September and saw the iron balance cranes (forerunners of modern tower cranes) atop the tower, moveable jib cranes for unloading stone from the boats and the cast iron railway for transporting materials around the reef. These innovations were devised under Stevenson's direction and designed and constructed by Watt from 1808 onwards with Rennie's approval.
The lighthouse structure was completed the following year. Stevenson laid the last stone at the top of the 96-step staircase on 2nd September 1810. The timber bridge that had connected the lighthouse to the barrack since April was dismantled the same day and replaced by a rope ladder. The light room was completed on 24th October and the interior of the lighthouse by 5th November.
Bell Rock Lighthouse exhibited its light for the first time on 1st February 1811. It was manned by a team of four keepers, three in residence at a time, each paid about £50 per year. The keepers' families were accommodated in Arbroath, where the shore-based communications comprised a 15m high signal tower (completed 1813) and a 41 tonne supply vessel. The total cost of the project, at both Bell Rock and Arbroath was £61,331.
The light room is 3.7m in diameter and 4.6m high. Apart from the 6mm thick glass, the walls and balcony were made from cast iron and it had a domed copper roof. The original array of seven rotating oil lamps were fitted with Argand burners — invented by Ami Argand (1750-1803) circa 1781 — placed in front of parabolic silver-plated copper reflectors. It was the first lighthouse to display both white and red flashes of light, owing to Stevenson’s use of red glass in front of some of the reflectors.
While it is now clear that Rennie had a greater role in the design of the lighthouse than has been acknowledged hitherto, Stevenson deserves full credit for overcoming the physical difficulties of translating the design into reality. He could not have achieved it without the efforts of his dedicated workmen, many of whom &,dash; and their relatives — continued to work for him on other projects.
Bell Rock Lighthouse is the oldest surviving rock lighthouse in the UK. It is still in service, now with a nominal range of 33km, but is unmanned — as are all UK lighthouses: Fair Isle South Lighthouse in Shetland was Scotland’s last manned lighthouse, automation being completed on 31st March 1998. The keepers left Bell Rock on 26th October 1988, and from the end of 1999 the light has been powered by solar panels with back-up generators.
All items by Robert Stevenson  •  Everything built ... 1772 - 1850
main reference  BDCE1
portrait of Robert Stevenson  courtesy Roland Paxton

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engineer
Biography
Robert Stevenson
This biography was funded by
the ICE R&D Panel
Institution of Civil Engineers
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Bell Rock Lighthouse
Bell Rock Lighthouse showed its light for the first time on 1st February 1811. It was manned by a team of four keepers whose families were accommodated in Arbroath. Three keepers were in residence at the lighthouse at any one time.
The tower is 35m tall to the top of the light room, 12.8m diameter at the base — where the wall is 2.1m thick — tapering to 4.6m diameter at the top. It contains some 795 cubic metres of stone and weighs about 2,130 tonnes.
Five cantilevered, bonded stone floors divide into five chambers the 17.4m of tower between its solid base and the light room. The design of the floors improved on the flat arches used at Eddystone Lighthouse and was adopted in many subsequent stone lighthouses. The three lower rooms each have two windows and the upper two chambers have four.
Photo: © Derek Robertson and licensed for reuse under this Creative Commons Licence
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Bell Rock Lighthouse, copyright The Trustees of the National Museum of Scotland
Model of the construction of Bell Rock Lighthouse.
Photo: © The Trustees of the National Museum of Scotland
Bell Rock Lighthouse, copyright The Trustees of the National Museum of Scotland
Model of the construction of Bell Rock Lighthouse.
Photo: © The Trustees of the National Museum of Scotland
Trip to Bell Rock Lighthouse
Video: by pariawatcher on YouTube