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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.
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.
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.
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!
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:
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The early 19th century
working platform on the shore at Fife Ness for the
stone beacon
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"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 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."
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)
 The
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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