BREAKVATER EXTENSION.

Taranaki Daily News, Volume XLVII, Issue 81890, 17 November 1906, Page 2

BREAKVATER EXTENSION.

:IE CONSULTING ENGINEER'S REPORT. AfiW the. '!ong discu-sion ;ii the ■tober meeting of the Harbor Board . ..ucerning the stability of the breakwater ixlcnsion « irk, and Mr Maxwell's reiterated as eriions "that the engineer's estimate of the amount ol -tone rubble in the new wall were a■together wiong, Mr Marchant, the consulting engineer, acting on the suggestion of the Chairman, endeavored to obtain soundings at the end iof 'the wall. His report came be fore Friday's meeting, stating thai the rca was too heavy to admit of .he work being safely carried out, and it had to be discontinued. lie had, however, gone fu ly into the question of the quantity uf stone used in the breakwater extension, and had since prepared a diagram showing what Size of rubble mound had to be built in order to absorb and account for the quantity of stone u?«d. The quantity was stated at 22,052 tons in 196 feet of length, equalling a cubic

in each lineal foot of breakwater. These figures were derived from tallies kept by the Foreman, each truck load of stone being counted and its weight of stone estimated. When the extension w-as commenced the stone was weighed on the harbor weigh bridge, but after 50 feet length , of work had been built, the practice - of weighing was discontinued because [ of the loss of time involved and other [ disadvantages existing just then. , Assuming that th® estimated weight J of stone was approximately correct, and Mr Marchant could see no reason to doubt it, the rubble mound , must be 20 feet in depth below the bottom of the concrete capping work, E ' "' lich itself was 14 feet in thickness, r This made the total height of the • breakwater—concrete capping and .1 nibble mound—a total of 34 feet. If 0 the Board saw fit to pursue this mat1. ter further, then he advised that with

r the commencement of a new length j every truckload of stone should be t weighed, and then certain and uni available results must be obtained. s Soundings," he wrote, "are of no value whatever ill cGnnectioJtn with tins mattter, because no one could ' possibly tell to what depth stone • sctt.es down into the sand bv the a scouring power of the waves. "It is only by reckoning up the quantity of stone tipped into a given length of work that sound opinion) could be arrived at. For his -own part he had no doubt whatever abiut the stability of the work even wnen dredging to a depth of 25 feet close up to the rubble slope, because all > that would be necessary would be to ' tip more rubble to prevent disturbance of that already existing. It never was proposed to dredge close up ' to the rubble s ; ope, as could bo seen by inspection of the plans, but if required he should be quite ready to ' ctj so on the system he had outlined. ' I w ant the Board to clearly undere siand, and I desiie to record it, that tiieie is 110 alternative to this system or construction adopted under the peculiar circumstances of place, it is impossible to stop the sand drift - lOuiid the work or to dredge it from uie end of the breakwater, so that blocks might be set 011 the natural sea-bottom. 'I he only other method e ' would be to resort to the us e of stag"ig, the preliminary work in connec1' llou Wlt h which system would have absorbed all the Board s funds witliout adowing for the construction of ' any permanent work at all. The co b y st( r m construction employed is admittedly unusual, and so are the conditions under which the work is | being carried on. Discussing the 'j icpoit, tne Chairman said that when l)s tii® loads were being weighed some ume ago there was being carried on v wharf extension as well as breakwater *w and the weighing caused 1 m «f e at inconvenience and loss of time, '(]_ again resorted to now, the work 3 _' would mean the loss of probably two t0 trips a day. If the Board wished iss 'urthcr testing and information, ! e he woulc '' suggest leaving it till after en the Christmas holidays. It could not 0 f ' )e fairly done now, for stone had been been tipped oyer the end during the • past week. The Foreman had as sured him that he had under-estimat--0"j l 'd, rather than over-estimated tne ds quantities of stone, and personally , re Mr Connett was perfectly satisfied. n . Mr Maxwell said that since last le. mcot ' n K it l}ad occurred to him that -a, 11 .misconstruction might be placed on ; ]y his statement made at last meeting i | l . that lie had definite information 101 the assertion that there was not the IK ] depth on the rubble that there was 11. su PPOSed to be. It might be inferred 'hat he had got his information from re . some irresponsible person, or from [ IC someone engaged on the works. He :s- w; 's going eTitirely on his lown obser!w vations. lie . had taken the trouble as B'o out to the work at low water arid he J cimiJt'ci to the furthest rock "showhe ln S above water. There lie pushed ist ,' us waiting stick down full depth 1( j into the sand. There was no rubble to feit in that depth. He had taken noas lice, too, that t,ie rocks did no sink x t into the sand as stated by the enginLd c «r; the concrete blocks and boulders swept off the end of the wall last n, March were still visible, lying on the „e IO P of the sand, thus supporting hii 5,. aigument that the stone would not sink in such firm sand. He thought 0 it best to mention how he got his ine. formation

Mr Ward was very glad the explanation had been made, and hoped it would receive due publicity, for people in conversation with him had staled Of inferred that Mr Maxwell had got his information from an oifr ciu l high in the Board's employment. It was freely alleged that this gentleman was surreptitiously supplying information to the detrimont of the port.

When Mr Marchant's account was presented, for work since July, kjos, Mr Maxwell complained that the engineer did not visit the works" often enough. His last visit was in April, KJOS, yet lie was prepared to "stake his professional reputation" ton what had been reported from the breakwater extension work.

FOREMAN'S REPORT, riw amount of stono tipped over the end of the breakwater during the month was U519 One ■few. section of 12 feet was completed, majiipg the total length of new work •!0(j feet. Twelve concrete blocks were made, making 97 now on hand. On the recommendation of the Fore nian of works it has been decided to extend the water soryicc to the end of the wnll_, to save the wear and tear "I the Steam crane which now has V run back some distance for water I supplies for the boiler.