1845.] 



THE CIVIL ENGINKER AND ARCHITECTS JOURNAL. 



21 



1 1 miles au lionr ; wliile from tlie Moray Fi itii, at tlie north side of the mouth 

 of which Pulteney-Towii is situated, it ebbs only 4.J hours, on account of the 

 harrier formed liy the Orkney Islands; accordingly, vessels hound to the 

 eastward find no clitliculty in gelling through this strait ; while those pro- 

 ceeding westwar<l having so limited a tide, arc often p\it hack from near 

 Cape Wrath in altcnipting to get round it. The north hnrhonr was lirst used 

 by coasting ve.sils, which at that time were of a very small size, from freights 

 being so high as to enable the smallest class of vessels to pay well. After 

 the conclusion of the continental war, however, freights were lowered so 

 that small vessels, for which this harbour was only fitted, could no longer be 

 lucratively employed. This occasioned the use of vessels of a larger draught 

 of water, which rendered the north harbour almost useless. 



The practice of partially loading in the harbour, and liuishing in the hay 

 by means of boats, was not only attended with extra expense, but also, in 

 many cases, with the loss of lives ami properly, owing to the very great ex- 

 posure of Wick Day. This, together with the cost of removing the sand that 

 accumulaleil in the harbour, and the rising prosperity of the town, led to the 

 erection of the south harbour in deeper water. This prosperity was chiefly 

 induced by the success of the herring fishery, for which I'ulteney-Town has 

 always sustaineil a high reputation, and it is now perhaps the largest fishing- 

 port of the kind in (ireat Britain. 



Construction of thf llARnorn. — The survey for the south harbour 

 was made by Mr. .1. Mitchell, ami bis plan for it, after being revised by Mr. 

 Telford, was adopted in 182:{. The contract, which embraced the present 

 quay, and 17.') lineal feet of the south pier from the inner angle, was let to 

 the author, and in 1825 he was directed to extend this pier 100 feet further ; 

 and in I82G he was again called upon to construct an extension of the south 

 pier to its present length, a great part of it being from 4 feel to 8 feet under 

 the line of the lowest spring tides. In the same year, the author entered 

 into a contract for building the north pier; building and embanking the 

 jetty ; making au opening from the south to the north harbour; and closing 

 in the old entrance of it; and for completing tlie harbour as it remains at 

 present. 



In preparing to carry on these works, two powerful barges of 40 tons and 

 60 tons burthen respectively, were built; one of them having one crane, and 

 the other two cranes on a new construction. liy means of a double line of 

 railroad to the quarry, a plentiful supply of slone was procured at all times. 

 I he barges were also, in good weather, enabled to carry stones from a part 

 of the hay about a mile without the harbour, and were worked with safety 

 and expedition, by means of track-lines laid out in the direction of the load- 

 ing place. The importance of having a large supply of materials for a work 

 of such magnitude and hazard, will at once be seen, when it is stated, that 

 only about 24 weeks in the year arc fit for carrying on such works. Aware 

 of this danger, and of the heavy nature of the work of forming the last 100 

 feet of the south pier, the author had a large number of masons, quarriers, 

 lightermen, and other men employe.l night and day in the season of 1827, 

 and had made rapid progress towards its completion. All would have been 

 finished by the 20tbof September of that year, but unfortunately on the 10th 

 of that mouth a violent storm arose, and, notwithstanding the temporary 

 blocking up, which was used as a precautionary measure, about 100 feet of 

 the pier head were swept down in one tide, to the level of low water. From 

 having to bonil the last portion properly with the end of the former, this 

 joining was laid open, and 20 feet within it was also laid in ruins by the nr.xt 

 tide. The stones were carried to a distance of nearly 100 feet from the 

 work, by the force of the sea, and chiefly into deep water. 



To prevent the breach from spreading, and causing the destruction of the 

 whole work, 50 shipwrights, and .300 masons and labourers were employed, 

 in placing neariy 40 tons of chain cables round the open end, and upon the 

 pitching of the roadway, and fastened them securely inwards ; this was ac- 

 complished in two tides, although the storm did not abate. Very large stones 

 were afterwards laid on the open end ; this proceeding, with due attention to 

 the chains, was the means ot avoiding the destruction of the whole work, 

 during the stormy winter that followed ; as it was, the loss sustained in the 

 two tides amounted to 5,000/. The cause of this failure, may justly be as- 

 cribed to the great slope and the low parapet, by which the sea was thrown 

 bodily upon tlie roadway, the pitching of which first gave way ; a portion of 

 the hearting then followed ; afterwards the front wall fell, until at length all 

 support was removed from the pitching stones of the slope, and they also 

 were carried away. 



In order to prevent such an occurrence in future, a wall of large rough 

 stones was built under the parapet, as shown on the cross section of the south 

 pier (Fig. 3) ; the roadway pitching was, in addition, wedged firmly with fir 

 wedges, on which cills of 1 J inch hoards, going along the roadway, were 

 spiked down at intervals of 10 inches apart ; on these cills, boards 1 inch in 

 thickness were fixed and closely joined together, the outer ends laying to the 

 foot of the parapet, while the inner ends reached half way over the coping of 

 the front wall, so tliat the sea in falling from the parapet, was not allowed to 

 touch the pitching. 



Early in the spring of 1828, preparations were .made for rebuilding the 

 work which had been thrown down ; so much difficulty was experienced in 

 the erection of machinery and clearing out the old materials, that it was 

 found easier to quarry most of the stones afresh, than to drag out of deep 

 water the stones which iiacl been carried thither by the sea. 



The machinery used by the author, consisteil of four jib cranes, which v\ere 

 set in strong frames of timber, of suflicient height to build the front wall and 

 the parapet. There were also Jtwo radiating beam cranes, each 110 feet in 



length working upon rails supported by posts built into the slope, moved, 

 round by a small rope tackle on each side, and having a travelling carriage 

 on each for the crane chain. These cranes took in the whole range of slope, 

 without being moved, and were very ellicient. 



The stones used for the construction, were of hard quality and naturally 

 well shaped for the work ; they varied in dimensions from ;5 feet lo 20 feet 

 in length, by '■' feet to 8 feet in breadth, and 8 inches to 15 inches in thick- 

 ness. In tlic slope they were set on edge, and the courses were placed 

 diagonally; in the front wall they were laid Hat, the beds being perpendicular 

 lo the line of face. 



In laying the foundations under water, the two-crane lighter was parlicn. 

 larly useful, one crane being used for clearing away the sand, hy means of a 

 bag and spoon, while the other set the stones in their places. The founda- 

 tion course of the slope, consisted of large blocks of stone, each from 15 tons 

 to 20 tons weight, anil it was fur floating these stones, that the author first 

 used the casks, of which he presented the description to the Institution. 



In the month of September in the same year, the whole length of 120 feet 

 of pier was completed, and since that period not a single stone has been re- 

 moved hy the sea. 



The parapet of the south pier being only C feet in height, with a flat slope 

 on the outside (Fig. o). was but ill adapted for artbrding a shelter on the in- 

 side of the pier in storms ; in fact the sea broke over it at high water as over 

 a half-tide rock. After many representations on the part of the author, it 

 was resolved to raise the iiarapet to the present height of 14 feet (Fig. 3), 

 which was done in the following year. The necessity for this, appears from 

 the fact, that even now, during storms, the spray is carried a distance of lOU 

 feet, after passing over the parapet. If the slope had been less, the force of 

 the receding wave would have been increased, so as to counteract the force 

 of the wave, on meeting it, before touching the slope; at its present inclina- 

 tion of 3 to I, the receding wave only adds to the bulk and violence of the 

 approaching wave. 



During the year 1830, great progress was made with the north pier and 

 the interior works. The harbour was excavated to the level of low water of 

 ordinary spring tides, and the material obtained was used in the hearting of 

 the jetty. A very slight batter was given to the hack wall, because the sea, 

 in running along the face of the pier, at an angle of 45 . exerted but little 

 force against it. 



The south harbour was completed in 1830, and 20,900/., including the 

 opening connecting it with the north harbour, closing the old entrance, and 

 all repairs for three years after its completion ; the quarry was near, and 

 labour was cheap, or nearly double the amount would have been expended. 



The effect of the north pier, in contracting the bay, has led to a large ac- 

 cumulation of sand on the north side of the river, which is a proof, in the 

 author's opinion, that if the sea he carried past the entrance of any harbour, 

 the sand is, necessarily, carried past with it ; in this case, great change was 

 produced by the junction of the two harbours. The north harbour was ren- 

 dered much more convenient and safe, and less liable to be sanded up ; it 

 was soon after deepened, and the pitching of its roadways partially rehiid. 



It is still to be regretted, that in stormy weather, the south harbour does 

 not aflbrd proper shelter, and considering that it is surrounded (excepting a 

 slope of 300 feet in length), hy perpendicular walls, which add to the recoil 

 of the sea within, this is not to be wondered at. Besides this evil, it is liable 

 to become partially sanded up, probably from the etlects of the river running 

 against the projection of the soulli pier, beyond the projection of the north 

 pier; the removal of this sand has been attended with some cost and trouble. 



Casks used por Floating Large Stones. 



" Description of the Caslis iixecl for FInatimj Large Stones, to construct Sea 

 ll'atbs in Deep ll'afer." By James Bremner, M. Inst. C. F. 



The ordinary mode of conveying stones for harbour work, is by means of 

 two large boats, with baulks of timber lashed across them, from which rope 

 tackles are suspended. These tackles are hooked on to " lewises" insetted 

 into the stones, and tightened at low water. When the tide flows the stone 

 floats, and it can be conveyed to the spot where it is intended to be laid. 

 Stones weighing 40 tons each have been thus transported several miles, with- 

 out dirticulty, in good weather; but it has been found, that the boats were 

 soon strained and became leaky, and on an exposed coast, when had weather 

 came on, they were liable to be destroyed; the author therefore devised the 

 plan described iu the paper, as a substitute for the united boats. 



About eight years ago, the author was consulted as to the improvement of 

 the harbour of Banii', and the repairs of the sea slope of the north pier, ilie 

 foundations of which had partially failed. He found, that the previous ai- 

 tempts at preventing the destruction of the pier, by laying down stones of 

 from 2 tons to 4 tons in weight, brought from a quarry in the neighbourhood, 

 had been quite ineflectual, as such materials could not withstand the force of 

 the waves, lie had observed along the shore, at several miles westward of 

 the harbour, iu almost inaccessible situations, ranges of large rough stones of 

 hard quality, weighing from 25 tons to 40 tons each, and be deierndned to 

 use them for the repairs of the work. It would have been almost impossi- 

 ble to get the boats near them, so he resolved to use casks for the purpose, 

 as be had formerly done, under somewhat similar circumstances, at I'ultency- 

 I'uwn harbour. 



There was but little novelty in the construction of the casks (Figs. I and 

 2), which were of tir timber ; the ends had each two cross boards inside 



