THE DRAINAGE PUMPINGSTATION.

Globe, Volume XXIV, Issue 2448, 9 February 1882, Page 3

THE DRAINAGE PUMPINGSTATION.

All things have an end, and no doubt Mr Parsons, the contractor for the pumping station in connection with the Ghristchurch Heathcotb Ebgatza. An adjourned Distriot Drainage works, felt on Wednesday elated at finding the long and weary work h» has had in connection therewith concluded* satisfactorily, so far as the Board and Si) publio are concerned j but, unforSunately,n3t, pecuniarily speaking, eo for him. Mr Parsons in the course of his *>rork, has rsst with difficulties sufficient to have applied any oontractor, but, despiia this, he has surmounted them, and the v?ork was yesterday handed over to the Board in a thoroughly oomplete and effieioat state, ana- the machinery in testing worked beautifully smooth, throughout. Before giving an aeooui:t of the proceedings of yesterday, at which, by the way, there was a oomrmndable absence of formality and verbosity, a brief sketah of tbe work now completed may not be cj-unterect-ing. Tho sewage is received into a tank of brickwork 30ft in diameter, the bottom being 23ft below tha surface :i the ground. This BLiwngo lank was constructed under great difficulties in a boiling quicluand charged with rast quantities of wateT. Tho bottom of tha tank is concrste, from sft to eft thick, lined with 9in of hard brick. The walls arc* of brickwork, 3ft thick, and the whole is enclosed ia a wooden barrel 36ft is diameter* heavily hooped with angle iron, tha staves of the- barrel bein;? of 4ln planks 20fii long. This barrel was sunk by mesns of wsights, consisting of sand bags and pig irca. The sand was then drsdged out *antil tha top edge of {Ms barrel disappeared under water, and then the concrete bottom, was put down through 20ft of water, and illowed to set before m n! tempt was made to pump out the barrel. Tho main eewer ecters the tank at a height of 10ft abovo the bottom, und in tho tank are two lar/re iron suction pipes leading to the pump. These heavy pip" re 't on large stones built into tho bottom of the sewage tank, and they rest on indiarnbber rings to prevent any jarring from the action of the pumps being felt by tho brickwork of the bottom of the tank. There sre four double aotion plunger pumps, being two to each set of engines, and these are placed in a deep pit in the engino-houoe. The foundations cf this pit are of great thickness and strength, as they wore built on a very treacherous quicksand, one which gavo very grea,t-

trouble and anxiety to the contractor. These foundation! have to bear the weight of the machinery and pumpa, together with the .heavy wall-of the engini house; and in addition to this, they are required to withstand the vibrations of the machinery, not to mention an oooasional earthquake. They are also made watertight to keep out the great pressure of water in the quioksand below them. The engines which drive these pumpa aro in duplicate, each set having high and low pressure cylinders, the former being fifteen and the latter twenty-six inches diameter, and thirty inches stroke. Eaoh engine has a surface condenser, with the requisite air and circulating pumpa, driven by a rooking shaft off the connecting rod. There ia also an air pump lor forcing air through a small pipe which passes through the sewage tank and termi nates in a ring round eaoh euotion pipe. This ring ia perforated with numeroua holes, and the engine blows air continually through these holes, thus keeping the auction openings clear of filth. The engines are set on masses of brickwork about eight feet above the floor of ths boiler house, and the bed platea of the engine rest on large blocks of Port Chalmers atone. All the machinery ia bolted down through these maaseo of brickwork which have passages and chambers to give ncceas to the bolt-heads, as well as to the main pump-pit and the pita in which the circulating pumps are placed. The pasaeges through the masses of brickwork are ■panned by brick arches, intendod to Bteady -the whole against the walls of the building, and against each other, and to carry the floor. ing of the engine-house, which is almost Bft above the surface of the ground. Eaoh pair of engines drivea a heavy fly-wheel, 12ft 6in in diameter, plaoed beside a oog-wheel 3ft 6in in diameter, and this latter drives a large wheel 10ft 6in in diameter, with wooden cogs. On each end of the shaft of this wheel are metal diaes 4ft in diameter, in which are studs to whioh the pump rods are fixed, and as these revolve, the plungers of the pumps work up and down, sucking the sewage cut of the tank and foroing it through the discharge pipe to the Sandhills. The large oog-wheels alio of the main pumps rest on eleven heavy oast iron girdets, built into the pump-pit, and ■panning it from side to side. The engines zeeeive the water for condensing them from an artesian well whioh flows into a cooling pond 60ft long, 30ft wide, and 4ft 6in deep. This pond is lined with concrete 9in thick, and with buttresses to support the aides. The engines pump the cold water from this pond and force it among the tubea of the condenser. From there it is expelled in a warm state through cast iron pipes into a little ooncrete well, out of which it risea and flows along a ■hallow conorete channel round two sides of the cooling pond, and at the end of ita oourae the warm water fu.Ha back into the pond and mixes with the cold water again. Thia cooling pond cost more than a number of wells would have done, but was adopted to prevent any waste of artesian water. The boiler-house ia at a lower level than the engines and the soil, the foundations of which aro kept dry by a layer of shingle, in whioh are drain pipes leading into the main tank. There are three Lancashire boilers, each 20ft long and 6ft diameter, and furnished with Galloway tubes. The flues from the boilers lead into a chimney 70ft high, of octagonal form, with quoins, plinth and oap of Port Chalmers stone ; the draught from the chimney ia so strong that the damperß have to be kept half-clcsod when the boilers are fired. Into- the base of the chimney a 12in pipe is built for the purpose of ventilating the sewage tank, by whioh means a draught will be created out of the ■ewers into the chimney. The pumps dis charge the sewage through an iron pipe of 2ft diameter; this is provided with a air vessel, whioh stands close to the enginehouse, and the pipea rejt on a heavy concrete wall -at the north end of the house. From this point the pipes are laid under ground as far as the point where they cross the old city outfall drain. At this spot the drain dips under the pipes in a syphon of ooncrete, and the pipes have a Y shaped branch, eaoh branch being provided with a sluice valve, the sluices being built into a concrete chamber. One branoh will disoharge when necessary into the old drain, and the other ia continued on to the Sandhills Reserve, where, at a distance of 1$ miles from the pumps, the pipes terminate in a short tower, intended to raise the sewage to a height sufficient to oon. voy it by a wooden flame and ditches to the different parts of the Sandhills. The laying of these pipea waa let to the contractor of the sewage works, and was carried out sue--cessfully under groat difficulties from quickHand and water, whioh, on part of the line, was found nearly at the surface of the ground. 'ln the line of pipea are three 12in junotions, now closed by cast iron -covers, but to whioh sluice valves may be fixed, to enable the sewage to be conveyed to other sand hills out»ida the Bsard's reserves. The machinery and pumps were built by Messrs Hawkes, Crawshay, and Co., of Gateshead-on-Tyne, from the designa of the late Mr W. Clark. The pump are capable of discharging 500 cubio feet per minute to a height of 34ft, but all the parta are made strong enough to pump against a head of 60ft. All the sewera and pipea in the district bring their contents through a main sewer 3000 ft long, sft high and 4ft wide, to the sewer tank, whioh it enters through a large screening chamber, in whioh is plaoed throe iron screens, intended to arrest the heterogeneous collection of articles which often find their way down the drains in spite of every contrivance whioh has been invented to exclude them. It may be mentioned, in conclusion, that for a water ■upply of 25 gallons per head per day the machinery would be sufficient t > disoharge the sewage of from 60,000 to 70,000 people, but if worked under a 60ft head of water it could do far more than that.

On Wednesday last, at the invitation of the contractor, Mr Parsons, the ohairman and members of the Drainage Board, His Worship the Mayor of Christcfourch, several members of the old Board, and some other gentlemen proceeded to the pumping station. Mr Bell, the engineer of the Drainage Board, was also preaent, to watch the test of the machinery. Shortly after two o'clock, one of the engines was set in motion, the massive machinery working with great smoothness, and the .pumpo discharging the water from the tank out at the commencement of the Vshaped branch already described with considerable force. Every part worked as well and wi'hout heating in the least as though the machinery had been months in work, instead of starting on what may be called the trial trip, and very great oredit is due to the engineer in charge who has erected the maohinery for the way in which it has been put together. The second engine was then cet in motion, and though both were worked ..at a good rate of speed there was little or no vibration felt. The visitors then proceeded to the sluice to inspect the discharge of the water into the outfall drain, ■which was found to work very satisfactorily. On the return of the party to the engine house Mr (Parsons invited the members of the Board and the other gentlemen present to drink suooets to the work that day completed. Mr Leonard Harper, the ohairman of the Drainage Board, was called upon to preside, and said that he had been requested to take the chair, which was somewhat of a mitnomer, as there was no chair to take. However, he would ask them to join with him in drinking the health of Mr Persons, the contractor, and also to offer to him their congratulations upon having that day satisfactorily completed a work which had been a source of great trouble and anxiety to him. Mr Parsons had carried out a very large and important work, one of a character .rarely to be met with in tho colonies, under circumstances of exceptional difficulty owing to the nature of the soil he he had had to deal with. That work he wao glad to be able to say, from information supplied to him by Mr Bell, had been most satisfactorily performed,, notwithstanding the difficulties to which he had referred. _ He need not refer to the working of the engines. Those present had seen for themselves, and nothing could be smoother than the way in which the maohinery us a whole had worked during the trial. He would now ask them to drink ths health of Mr Parsons, and to «ongratnlate him on having concluded the work so satisfactorily to the Board. [Cheeri.j {The toast was drunk heartily.

Kr Parsons briefly responded, thanking Mr Harper and those present for the honor they had done him on the occasion in drinking his health. He oould assure them that ho was very E-uoh pleased to find that his efforts—despite .the difficulties he had mot with— to carry oni the contract in a way whioh should be satisfactory a ' il£ ° to the Board and the public had been .appreciated. Though he had not been so successful in a pecuniary point of view in tho contract as he oould have wished, •wing to the nature of the ground he had met with; stiJLhe felt more than repaid for the trouble it had caused him at finding that lie had been enabled to oomplete the work in a manner deserving the approval of the angineer and the Board. [Hear, hear], Mr Harper said tb,QS9 was just one other

toait he would ask them to drink before separating, and that he had requeued Mr Hobbi, aa an old member of the Board, to propose. He (Mr Harper) was a new member on the Board, and therefore was unable to speak with that degroe of appreciation of the high merits possessed by the gentleman whose health ho wished them to drink that Mr Hobba could do. The toast he desired them to do honor to was the health of " The Rosident Engineer, Mr Napier Bell." [Hear, hear.] Mr Hobbs had been connected with the scheme of drainage from the first, and hid therefore during a long period been able to notioe the exoellent work done by Mr Bell in his capaoity as engineer to the Board. [Hear]. , , Mr Hobba Baid it waa with the greatest pleasure that he proposed the toast spoken of bj Mr Harper. Mr Bell had Bhown, both in the large and important works oarried out by him in connection with the Drainage Board and the no lose important ones connected with the Harbor Board, that he was a gentleman entitled to hold the very highest rank in hia profession. With respeot to the worka that day completed he desired to say a word or two, and that was to express regret at hearing from Mr Parsons that the contract had not been a remunerative one to him. There was this to be said about the matter, that the Board were to be congratulated on not haying accepted the lowest ten J* e *> became, had they done to, viewed by the light of the experience of Mr Paraona, the work could not have been oarried out. Aa a member of the old Board, he desired to bear his testimony to the zeal and effioienoy in the disoharge of his very onerous dutiea displayed by Mr Bell, and throughout thi whole period of their connection the late Board had always been in thorough harmony with their engineer. He therefore BBked them to drink the health of Mr Napier Ball, the engineer of the Drainage Board. The toast" waa drunk heartily. Mr Bell, in responding, said it gave him the greatest pleasure to hear the remarks made by the chairman and Mr Hobbs, and he thanked them both for the way in which the toast had been proposed and responded to. The completion of the worka was, he_ oould assure them, a source of congratulation to himself, as they had been a cause of a great deal of anxiety and work to him. It was, therefore, most pleaaing to be able to say that, despite the difficulties met with and overoome and they had been numerous—the work had been moat satisfactorily carried out by : be contractor. [Hear, hoar.] He felt that both the Board and the publio had reason to be well satisfied at the result of the contraot. With regard to Mr Paraona, the contractor, he had alwaya found him most zealoua and willing in carrying out the work. He (Mr Bell) also desired to pay a well-deserved tribute of praise to the offioera of the Drainage Board who had acted aa his asaiatanta. From them on every occasion he had receivod the utmost assistance, and in the disoharge of their various duties thoy were most assiduous and painstaking. He begged once more to thank them for the kind manner in which his health had been proposed and druok. The proceedinga then terminated.