Account of the Skerryvore lighthouse

by Alan Stevenson

The latter part of the season, although not so stormy as the first, was far from being favourable for the building operations which, on one occasion, even during the month of July, were suspended for five days by a violent gale, which made it unsafe to attempt standing on the Tower. Happily the wind was from the N.E., a quarter from which it has comparatively little power in raising heavy seas, otherwise we should infallibly have lost a large part of the dressed materials which lay piled on the Rock, and, in all probability, should have had our work thus prematurely cut short in the middle of summer.

After building a few courses above the level of the solid part of the Tower, the jib-crane could no longer be conveniently used, and recourse was had to a balance-crane, which, during the previous winter, I had caused to be constructed at Edinburgh, in the workshop of Mr James Dove. That apparatus, which, except as to its greater size and strength, in order to suit the greater dimensions of the Tower, was almost identical with that which was used at the Bell Rock, is shewn in [Plate IX.]; and it is only necessary, in this place, to notice its general construction and mode of working, which is also shewn in Plate XVII. of my Father’s Account of the Bell Rock Lighthouse. In the hollow of the Tower, a cast-iron pipe or pillar was erected, susceptible of being lengthened as the Tower rose, by means of additional pieces of pillar let in by spigot and faucet joints; and on the pillar a frame of iron was placed capable of revolving freely round it, and carrying two trussed arms and a double train of barrels and gearing. On the one arm hung a cylindric weight of cast-iron, which could be moved along it by means of the gearing, so as to increase or diminish by leverage its effect as a counterpoise; and on the other was a roller. The roller was so connected with the weight on the opposite arm, as to move along with it, receding from, or approaching to, the centre pillar of iron in the same manner as the weight did. From the roller hung a sheave, over which a chain moved, with a hook at the end for raising the stones. When a stone was to be raised, the weight and the sheave were drawn out to the end of the arms of the crane, which projected over the outside of the walls of the Tower, and they were held in their places by simply locking the gearing which moved them. The second train of gearing was then brought into play to work the chain which hung over the sheave, and so to raise the stone to a height sufficient to clear the top of the wall. When in that position, the first train of gearing was slowly unlocked and the slight declivity inwards from the end of the arms formed an inclined plane, along which the roller carrying the sheave was allowed slowly to move (one man using a break on the gearing to prevent a rapid run), while the first train of gearing was slowly wound by the others, so as to take up the chain which passed over the sheave, and thus to keep the stone from descending too low in proportion as it approached the centre of the Tower. When the stone so raised had reached such a position as to hang right over the wall, the crane was made to turn round the centre column in any direction that was necessary, in order to bring it exactly above the place where it was to be set; and by working either train of gearing, it could be moved horizontally or vertically in any way that was required. The men who wrought the crane, stood on two small stages of planks attached to either side of the framework, and moving round the shaft along with it.

The balance-crane was safely landed on the Rock on the 20th July and on the 25th it was erected in working order on the top of the masonry. On the afternoon of that day, I had the satisfaction of seeing it put to a severe trial in raising a stone of nearly two tons weight and drawing it from the shear-poles already noticed to the top of the building. As that trial was made at an earlier stage of the works than was originally intended, the Tower was of larger diameter than was quite suited to the arrangements of the crane, which was consequently subjected to the weight of the stone at the very point of the jib. I felt no small anxiety as to the result, and had taken the precaution to relieve the centre pillar or shaft, on which the crane swung, from part of its burden, by means of a guy attached to a lewis-bat on the top of the building; yet even with that aid, the point of the jib was depressed 6 or 8 inches on a length of 14 feet. That test, however, having been successfully passed and not the slightest trace of any injury having been discoverable in any part of the crane, we continued to work it with perfect confidence and in the most satisfactory manner throughout the whole season until the close of the Rock operations for the year on the 17th of August.

The mass of masonry built during the season was 30,300 cubic feet, a quantity considerably more than double that contained in the Eddystone and somewhat more than the mass of the Bell Rock. The whole was very carefully set and when gauged at the upper bed of each course was found to preserve the diameter due to the height, according to the calculated dimensions, within a fraction rarely exceeding ¹⁄₁₆th of an inch. The height of the mass also, when measured, exceeded the specified height only by half an inch. The mortar employed was composed of equal parts of lime from the Halkin Mountain in North Wales and Pozzolano; and I consider it if possible superior to that produced from the lime of Aberdda. When we left the Rock this season, two apartments were covered in and the third was nearly completed, as will appear from the section ([Plate III.]) (on which the progress of the several seasons is marked), and only about one-third of the whole Tower remained to be built.

Our last work on the Rock before leaving it for the season on the 17th August, was to cover the balance-crane with a strong tarpaulin in order to protect it as much as possible from the weather and also to make a temporary lightning-conductor from the top of the building to the sea.

The extent of work done during the season of 1841 at the Rock, must in a great measure be attributed to the advantage of steam attendance, without which numerous favourable opportunities of landing materials must necessarily have been lost, from the uncertainty which pervades all the movements of sailing craft. The number of lighters towed out and discharged at the Rock was 120; and it is remarkable that no accident of importance occurred, although many risks were run, from the breaking of warps while the craft lay moored to the landing quay during heavy seas. I cannot omit in this place to record my sense of the services rendered to the works by the late Mr James Heddle, who commanded the steamer and who died from some consumptive disease soon after the close of the season’s operations. Mr Heddle’s health had been somewhat enfeebled towards the latter part of the autumn; and his excessive exertions and continued exposure during his arduous service, in some measure, I fear, hastened the crisis of his disease, which at length terminated suddenly by the rupture of an abscess in the lungs. Of his anxiety to forward the work, and his unwearied exertion in the discharge of his harassing duty at Skerryvore, which frequently allowed him less than twenty hours sleep in a week, I cannot speak too highly, as I consider his intrepidity and zeal to have been one of the most efficient causes of our success ever since the commencement of the works on the Rock in 1839. Mr Heddle possessed attainments superior to those generally found among persons in his walk of life and was in every respect a most estimable man.

CHAPTER VIII.
OPERATIONS OF 1842.

On the 17th of April 1842, I made my first landing on the Skerryvore, for the season, State of the Rock in Spring of 1842. and found traces of very heavy seas having passed over the Rock during the preceding winter. Its surface was washed quite clean from all the scattered materials which were left lying on it at the end of the last season; and the building, to the height of 6 or 8 feet from the foundation, was covered with a thick coating of green sea-weed. The railway had suffered considerably from large stones having been thrown upon it; and several blocks of about half a ton in weight were found wedged into the deep fissures of the Rock, and lying among the main timbers of the Barrack. Heavy sprays had been playing over the Tower, in the upper uncovered apartment of which a great number of water-worn pebbles or boulders were found. Those stones had been raised by the heavy surf and deposited on the floor of the apartment and on the top of the wall at a height of no less than 60 feet above high watermark; but the balance-crane, which had stood all winter on the top of the Tower, had sustained no damage, although the canvass cover was torn to shreds by the action of the weather. In the Barrack every thing was in good order except the smoke-funnel, which, from the effects of the sea-water, was riddled full of holes and required to be completely renewed.

As I had resolved to keep, during the summer of 1842, a complement of about eighteen or twenty seamen on the Rock, in addition to the usual detachment of masons, in order to work the crabs for raising the materials to the top of the Tower by successive stages; Commencement of Rock operations. my first step was to set about preparing additional accommodation in the Barrack, by converting the open gallery (called store for coals, &c., in [Plate V.]), immediately below the cook-house, into a covered apartment for lodgings for the additional hands. I accordingly landed on the 20th of April, with a stock of provisions, water and fuel and a party of joiners and a smith, to prepare that apartment by simply flooring over the joists of the gallery and closing the triangular, or rather trapezoïdal, spaces between the uprights of the Barrack, with double planking, protected on the seams with painted canvass, so as to render them impervious to the heavy sprays which, even in summer, dashed forcibly on the lower parts of the Barrack. Windows were formed on the sides least exposed to the intrusion of the sea; but, with all our precautions, we could not succeed in keeping dry even the cots or hammocks, which were suspended there; and it must be admitted that the addition to the Barrack proved, in bad weather, but a comfortless retreat, the inconveniences of which few but seamen would have patiently endured. Those discomforts, however, were to a certain extent, counterbalanced by some advantages which that singular abode possessed in hot weather; for, at such times, its inhabitants enjoyed more room, freer air, and more tolerable temperature, than any of their neighbours in the highest storey could obtain, owing to the greater number of persons in that part of the Barrack and its exposure to the heat of the cook’s stove.