The Stevensons
Introduction
Who Built the Bell Rock Lighthouse?
Stevenson v. North Carr Rocks
Robert Louis Stevenson
RLS, Erraid and
Dubh Artach

Instrument Makers and the Northern Lights
Smith, Thomas
(1752-1815)

Stevenson, Robert
(1772-1850)

Stevenson, Alan
(1807-1865)

Stevenson, David
(1815-1886)

Stevenson, Thomas
(1818-1887)

Stevenson, David A.
(1854-1938)

Stevenson, Charles
(1855-1950)

Stevenson, D. Alan
(1891-1971)

Stevenson, Dorothy
Emily (1882-1973)



Stevenson v. North Carr Rocks

The One That Got Away

Flushed with success after the building of the Bell Rock Lighthouse, Stevenson now turned his attention to another "nasty", which lay not exactly a million miles away from the treacherous Inchcape Reef.

Nautical Map
Map showing the relative positions of Arbroath, Bell Rock, North Carr and the Isle of May.
©The Hydrological Office

The North Carr rocks lie at the end of a tidal reef approximately 1¾ miles off Fife Ness where the headland juts out into the greater Firth of Forth and North Sea . . . at that point the Bell Rock is only 12 miles distant to the north-east!

These Rocks had already taken its fair share of shipping over the years. In his "Account" Robert Stevenson lists a decade of losses (1800-09) - in all some 16 vessels were known to have been either shipwrecked or stranded there.

List of Shipwrecks

In 1809 a floating buoy was moored off the rock, but, due to the strong tides and currents, it broke adrift five times in four years! On Stevenson's advice, therefore, the Northern Lighthouse Board decided to mark the rock with a stone beacon surmounted by a bell.

To tackle the problem, however, he felt rightly that experience gained at the Bell Rock would stand him in good stead. He had, after all, the equipment, manpower and expertise at his fingertips. At that time, too, he was busy building a new lighthouse on the Isle of May, only 8 miles distant from the Carr rocks. All very convenient, for when the state of tides and weather conditions did not permit work there, the men could be still gainfully employed at the May. The Isle of May, which straddles the River Forth at its mouth, was Scotland's earliest coal-fired station, dating from 1636.

The Rock

But Stevenson was also well aware that the North Carr rocks came with their own treacherous problems; firstly, the currents and conditions of the sea in that area (the "turning point", as he called it, between the Rivers Forth and Tay for north-bound shipping hugging the east coast); secondly, the waters, even at low tide, scarcely ever left the rock at all; and thirdly, and ultimately the most difficult problem of all, there was scarcely space available on the rock to get even a "toehold" large enough to built a small beacon, far less a lighthouse!

The Tower
Stevenson's design for the North Carr beacon -
it was never completed

Stevenson's plans for the North Carr was a hollow stone tower some 40 feet high, at the top of which would hang a bell. The mechanism used to ring the bell took the form of a "tide machine".

The complexity of the working parts of this machinery in itself makes a fascinating study. Stevenson, in his own words, explains:

Working platform on the shore at Fife Ness
The early 19th century working platform on the shore at Fife Ness for the stone beacon

"In Fig. 2. the letter a represents an aperture measuring 3 inches in diameter, which was perforated with much labour and care through a block of granite 7 feet in length, previously to its being laid. This canal was intended to admit the tidal-waters into the interior chamber of the building marked b, in which the flood-tide was to act upon an air-tight copper-tank, marked c and its rod of connection formed into a rack with teeth, by which motion was to be given to a train of machinery, represented at d in the void of the building. The machine was to act on the vertical shaft e, connected with a series of hammers f, placed under the great bell g, which was to have measured 5 feet in diameter, and became the cupola or roof of the building. In this manner the bell was to be tolled to forewarn the mariner of his approach to the dangers of the Carr, and the other extensive ledges of sunken rocks in its neighbourhood. By the rise of the flood-tide, and consequent admission of the waters into the canal a the tank c, with its connecting rod, not only lifted the bell-hammers f, and, at the same time, also elevated the weight marked h, which, in its descent during ebb-tide, was to have continued the motion of the machinery; and thus, by the alternate operation of the tides, the continuing tolling of the Bell was to have been preserved."

D. Alan Stevenson ("The World's Lighthouses Before 1820") considered to the world's leading expert in Lighthouses and last of the Stevenson engineers, takes up the story:

"The top of the Carr Rock lay below the low water of spring tides and the maximum diameter of rock available for a foundation was 18 ft. These two features, coupled with strong currents and exceptional exposure, made the proposition extremely difficult. Much unsound rock had first to be removed by a cofferdam, an inconvenient appliance which had to be lifted from the sea-bed whenever work was interrupted. On only two or three tides each fortnight did the sea recede to a level that allowed work to proceed. Its quick susceptibility round Fife Ness to the slightest adverse change of weather prolonged the work far beyond the expectation of Stevenson and his small gang of men who had gained experience of tidal work at the Bell Rock. The expense of this tedious enterprise would not have been justified but for the construction simultaneously of a lighthouse on the May island 8½ miles away, where work was available whenever a rough sea prevented operations on the Carr Rock. On completion of the May lighthouse, expeditions were made to the Carr Rock when other lighthouse work permitted.

"The operations proceeded reasonably well during the first two seasons 1813-14, considering that only one-sixth of the hours work in two years at the Bell Rock 17 miles distant were obtained. The foundation was prepared and 10 dovetailed stones laid. At the end of 1815 the sea carried away the 3rd complete course of 9 blocks before the cement had time to harden. During the summer of 1816 a sudden gale forced the men to leave the work before securing the 7th course, and several of its stones were washed away. At the end of that season 16 courses to a height of 20 ft. were completed and anchored for the winter by a weighty cover of 4 tons of lead. The year 1817 saw the beacon raised to within a few feet of its intended height when a storm removed its top above the 5th course. The design was then changed so that this base would be surmounted by 6 cast-iron columns carrying a ball about 10 feet lower. This superstructure was completed in 1821, £5,000 having being spent during the 9 years of intermittent work.

The Beacon
The beacon as built - it still stands

* "This experience showed that at such an exposed site more weight was required to resist the sea action, that is, a higher tower and a broader base were necessary. In 1887 a manned lightship was established in the vicinity."

Comparisons and Vital Statistics

North Carr Rocks and Bell Rock

At low water during spring tides -
North Carr - Length 75 feet; breadth 23 feet; Bell Rock area for building was 427 feet in length and 230 feet in breadth

Due to the fractured state of the rock - only 18 feet was available for the base of stone tower; as opposed to the Bell with no restrictions - 42 feet.

During the first 2 years (1813-1814) - working hours on rock -
North Carr - 41 and 53 hours; whereas 180 and 265 at the Bell

First 2 years at Carr was taken up with excavation and foundation work, with only 10 stones being laid; whereas three courses were completed at the Bell (382 stones in all)

Beacon as seen todayThe final beacon at Carr was completed in Sept. 1821 -
The lower part consists of a solid circular platform of 4 masonry courses, the first complete course measuring 18 feet in diameter. This formed a base for six pillars of cast-iron, which terminated in a hollow ball (3 feet in diameter) made of the same metal, and elevated about 25 feet above the average level of the sea. See Vital Statistics for the Bell Rock

This beacon of 1821 can still be seen off Fife Ness.

* This comment by D. Alan Stevenson in 1959 echos that of his great-grandfather who said in his "Account" of 1824 about the stability of the Bell Rock Lighthouse: ". . . but it is on the gravity of the materials that the chief dependence is placed for the stability of the fabric. D. Alan, however, takes it one step further. He adds that, apart from more height, a broader base (not possible on the Carr, of course) was also necessary!

Which again harkens back to the controversy about whose design was finally used for the Bell Rock - Rennie's sketch of 1807 or Stevenson's earlier design of 1800. At the end of the day, the completed lighthouse in that instance (base and curve) more resembled Rennie's than Stevenson's!

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