WATER WORKS OF ST. LOUIS

WATER WORKS OF ST. LOUIS

[Concluded.]

THERE are six settling basins built in pairs. Each basin is 670 feet long and 400 feet wide, and has a capacity of 22,000,000 gallons. The sides and ends are heavy masonry walls backed with clay puddle and earth embankments. The bottoms of basins are lined with sixteen inches of puddle and covered with six inches of concrete in seven-foot squares, the spaces between the squares being filled with asphaltum to take up the expansion The basins slope to a cleaning ditch running east and west through the centre, which drains to a two-foot by three-foot mud gate in the east wall of the basin and leads to the sewer. There are six filling and drawing chambers, with hydraulic lifts for the gates. When all the basins are in operation, four are settling, one filling, and one drawing. Settling is continued in the basins until sufficient mud has been accumulated to justify cleaning them ; then the mud gate is opened and the slush is allowed to run through a twenty four-inch sewer to the river. A stream of water is then turned into the basin by means of a syphon from an adjoining basin, and men shovel the mud down into the cleaning ditch-the mud being carried to the sewer by means of the water. T he water from the settling basins is as clear as can be obtained by twenty-four to thirty hours’ settling. The drawing conduit carries the water along the east side of the basins through an open chamber (where screens catch any floating matter which falls into the basins) into the conduit, which from this point to Baden is eleven feet wide and nine feet high. The conduit is built of brick backed with concrete. When carrying 100,000,000 gallons, the velocity of flow is about one and one-half miles per hour, or two feet per second. T he fall is six inches to the mile, or one in 10.000. T he conduit passes over three bridges in its entire route. The bridge foundations are all carried down to bed rock. The bridges are provided with overflow wires and waste gates. 1 here is a gate chamber at Baden, where the conduit section changes from eleven feet by nine feet to nine feet by eight and one-half feet, and a branch leads off to 11. S. station No. 3. T wo gates cover the openings of both conduits.

WATER WORKS CONDUIT, ST. LOUIS MO.

At Baden station the arrangement of the buildings is much the same as at the Chain of Rocks. T he engine house is fifty-seven feet by 184 feet; the coal house, eighty-eight feet by ninety-eight feet; the boiler house (containing eight 300horse power John O’Brien boilers) is 167 feet by sixty-one feet. A twenty-ton, three-inch motor electric crane traverses the engine house, which is divided into three separate pits, in each of which, when the station is completed, will be two engines-six in all. The pits are twenty-eight feet, six inches deep, and are reinforced with heavy abutments. The water is conducted from the gate chi mber partly through a brick conduit and partly through a seventy-two inch pipe to the wet well, w’hich is 135 feet long. Six iron pipes lead from the wet well through the engine house wall into the pits. Six engines have been contracted for, of which two are completed. These are triple expansion, condensing engines; diameter of cylinders, thirty-one inches, fifty-six inches, and eighty inches; plungers, single acting, twenty-five and one-half inches diameter and sixty-four-inch stroke. T he specifications require a capacity of 10,000,000 gallons per twenty-four hours and a duty of 125.000000 gallons. Two 15,000,000 engines have also been contracted for for this station-to be ready about March 1.

Bissell’s Point terminal chamber is distant four and onehalf miles from the Borden water station. The main conduit extends beyond this point and connects with the old settling basins, in which the water supply of St. Louis was formerly handled. They now act as reservoirs for the water coming from the Chain of Rocks. These basins are four in number, each 600 feet by 277 feet and sixteen feet deep. The capacity of each is 15,000,000 gallons. Connecting with these basins is a conduit leading to the clear well ; another conduit connects this well directly with the terminal chamber. Thus part of the supply may be led into the basins and held in reserve, or the water may be conducted directly to the clear well.

At Bissell’s Point station two separate conduits conduct the water from the clear well to the wet wells of H. S. stations Nos. 1 and 2 (illustrated herewith). II. S. station No. 1 contains two beam and fly wheel engines with bucket and plunger pump, each capable of pumping 16,500,000 gallons per twenty-four hours. T he third engine is a doub’e compound beam and fly wheel engine with bucket and plunger pumps. The cylinders are compounded after the Wolf type.and this engine pumps 20,000,000 per twenty-four hours. Eight Geary water tube boilers, of a nominal capacity of 300 horse power each supply the steam. The engines in station No. 2 are the counterparts of those in station No. 1 and are supplied with steam by eighteen return flue boilers. Each engine is provided with a separate thirty-six-inch main to one of the two standpipes-both of which connect with the general distribution system It is the intention of the water commissioner to begin immediately to pull up the three engines in H. S. .Station No. 1, and replace them with modern machines.

1 he standpipes (illustrated herewith) are two highly artistic structures and serve as ornaments to the city. Each is six feet in diameter, and about 150 feet high. Three thirty-sixinch mains connect them with Compton Hill reservoir-four miles from Bissell’s Point. This reservoir is in two divisions, each 450 feet by 422 feet, and twenty-six feet deep; total capacity about 60,00c,000 gallons.

The water works of St. Louis cost in 1889, $13,345,000; bonded debt in 1890, $5,200,000; operating expenses, last year, $423,259; revenue. $1,264,254. The cost of extensions has been met by revenue. The cost of pumping per million U. S. gallons, including coal, salaries,and supplies was: High service, $7,635. low service, Bissell’s Point (old system), $4,416; low service. Chain of Rocks (new system), $1,388.

Mr. M. H. Holman is water commissioner and superintendent.

WATER WORKS OF ST. LOUIS.

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WATER WORKS OF ST. LOUIS.

S. T. LOUIS. MO, has to supply an average daily consumption of 55,000,000 gallons of water— maximum, last year, 72,000,000 gallons in one day; minimum, 37,000,000 gallons. As its source of supply is the Mississippi (chiefly the Missouri) river, it needs no saying that the water stands in need of any amount of sedimentation, as is proved from the fact that in one year no less a quantity than 208.000 cubic yards of Mississippi mud was removed from 16,257,000,000 gallons of water passed through the settling basins at Bissell’s Point, at a cost of $2.668.20, or about 1.3 cents per cubic yard.

The water works, which were built by the city and two piivate individuals in 1831—becoming the property of the city in 1835, had then as now as the source of supply the Mississippi. At that time the water was taken from the river at Bissell’s Point through an inlet tower of cast iron and pumped into the settling basins by two Cornish bull engines and the Worthen double plunger beam and fly wheel engine—all of which did duty for twenty years, when they were displaced by the present pumping equipment at the Chain of Rocks. There are two sets of these engines in service—those for the low service, which pump the water into the settling basins, and those for the high service, delivering the water after sedimentation into the distribution system. T hat consists of 462 miles of mains, six-inch to thirty-six-inch—the cost of extensions being met from revenue; 53,354 taps (services lead); 3,971) meters, owned by city and consumer, controled and repaired by city, which can compel their use, while any owner can have one; 4 690 hydrants—pressure five to seventy-five pounds.

INLET POWER, WATER WORKS STATION, ST. LOUIS MO.

The pumping stations are five in number, connected with each other by a conduit of brick of semi-elliptic section, eleven feet in diameter from the Chain of Rocks to Baden, an illustration of which will be given hereafter. Three of these stations are at BisseH’s Point; one is four miles higher up at Baden; another, four miles above that, at the Chain of Rocks—illustrated herewith.

The inlet tower, of which an illustration is given, is built on the rock bottom of the river, five miles from the mouth of the Missouri, and 1,600 feet from the shore of that river at the Chain of Rocks. The tower is of granite-faced limestone; its height up to the gatehouse is about fifty feet. In this tower are seven large gates, four feet and six feet, all controled by hydraulic pressure. They are set at different levels so as to meet the varying stages of the river, and are provided with roiled steel screens to keep out small brush and sticks from the tunnel. Internally there are two compartments—the gate chamber into which the water passes after leaving the river, and the shaft chamber which receives the water from the former through a gate four feet by six feet. The water then passes from the shaft char.ber down through a seven-foot circular chamber into a brick-lined tunnel cut out of the solid rock and seven feet inside diameter into the screen chamber. With the engine pumping 100,000,000 gallons, the velocity of the flow is about four feet a second. At the opening ot the ‘unnel into the screen chamber are copper screens of about oneeighth-inch copper wire, one-half-inch mesh. Thus, when the water enters the west well, it is clear of everything but the sediment.

This wet well is connected with the engine pits by six circular brick-lined tunnals, on the inside of which are suction valves and on the inside of the wet well gate valves controling the flow of water. The engine pits, each of which is fifty feet square and fifty-seven and one-half feet deep, stand three in a row in a house sixty feet by 170 feet, whose height from the engine floor to the spring of the roof is 100 feet—total height 100 feet from the ceiling to the bottom of the pits. 1’he roof of this house is finished in yellow pine and supported by bow trusses. A standard gauge track is laid over one of the division walls,by means of which the material is run in on the cars and distributed over the house without any difficulty. A fifteen-ton electric traveling crane of the three-motor type, with two winding drums and a total hoist of about eighty-five feet, is supported by the side walls, which are built very heavy so as to support it. This crane commands the whole house, and all the motions of the hoist, trolley, and bridge are controled by the three rheostats. T he cage hangs by eyebars from a continuation of the trolley wheel axles—by this means the operator is enabled to be directly over the load at all times. Wires provided with suitable take-ups at the points of intersection are placed along the bridge and west wall. The current is supplied to the motor at a pressure of 1 to volts by a fortyhorse power “Ideal” engine and twenty-five K. W. General Electric Company dynamo stationed in the machine shop.

In the centre pit are two Worthington compound duplex, condensing engines, with the Worthington high duty attachment, which have been specially designed with a view to the work they will have to perform. These engines were first operated in October, 1895 and tested in March and April of the following year. They were built for a duty of 85,000.000 foot pounds per t,000 pounds of steam. After a thirty-days’ test the average duty was found to be qS 000,000 foot pounds —about sixteen per cent, over the guaranteed performance.

These tests were continuous—the engines never stopping for thirty days, although the river level rose and fell considerably during that period and the water carried more than the average amount of sediment. The duty was calculated on the measurement of the volume discharge, which was accurately measured every day in the reservoir. Each engine has two twenty-one inch high pressure cylinders, two forty-two-inch low pressure cylinders, four thirty six-inch single acting plungers—the stroke of all pistons and plungers being eighty inches. The steam cylinders are arranged in pairs—one high pressure and one low pressure being connected to the opposite ends of two rocking beams. The pumps are placed directly below the steam cylinder—one single acting plunger being connected to each steam piston through cross-heads. Both the high pressure and the low pressure steam cylinders are fitted with cut-off valves and are jacketed throughout. Reheaters are located between the high pressure and low pressure cylinders and contain tubes filled with live steam. The steam exhausts into surface condensers located in the discharge main and vertical inverted air pumps are worked from the main engine. There is also an independent jet condenser and pump placed in the pit and connected to the engines, to be used in case of emergency, as it was feared that foreign matter in the water might have some bad effect on the condenser tubes This, however, has not been realized and the independent air pump has never been brought into use. The Worthington high duty attachment is applied to these by placing a compensating cylinder at the end of each beam carried on case iron frames. With two plungers working against each beam in opposite directions, the force is all perfectly balanced. The compensating cylinders themselves are connected to a common airtank, in which a pressure of air is carried at about 260 pounds per square inch. On account of the low head against which the pumps opierate the usual form of ac umulator is not used. These engines often pump 25,000,000 gallons each (instead of the 20,000,000 they were designed to pump), and are practically noiseless in their operation.

In the north pit are two compound, condensing, crank and fly wheel engines; cylinders twenty-seven inches by fifty-two inches in diameter; stroke 108 inches; single, direct-acting plungers, forty-eight inches diameter; two four-inch piston rods to each cylinder; four pump rods, each three and one-half inches in diameter from cross-head to pump plungers—the crank and connecting rod moving between the four pump rods, two on each side. These engines are entirely self-contained; the air pump, boiler feed, and air compressor are attached to the main engine. The delivery main supplies the circulating water, which is regulated by a valve from the e gine platform —any deficiency i n feed water being supplied from the engineer’s platform. On the official trial these engines pumped 930,000,000 gallons in thirty days and performed a duty of 118.001,000 gallons—duty required by specifications ioo,000,000 per 1,000 pounds of steam. In the south pit are being erected two 30 M. engines—practically duplicates of the above and completing tae plant.

The steam-generating plant is in a separate building—sixtytwo feet by 124 feet—in which are six National water tube boilers of 300 rated horse power each, placed in batteries of t vo, each of which connects separately by a pipe with one of the pits. There are also by-pass valves by means of which the steam may be changed over to any of the engine pits. The nominal capacity of the boilers is 300 horse power; but they can be forced to 500 horse power. The filter plant is placed in the boiler room; throu h it the feed water passes returning from the engines. These filters are three in number, and are fitted with suitable by-passes for changing from one to the other in eae of emergency. The two-story machine shop, thirty-seven feet by sixty feet, is built north of the boiler house. The shop is run by a twenty-five-horse power Westinghouse dynamo engine and the Ide engine and dynamo used for running the crane already mentioned are placed on one side of the shop. The coal is thrown from the cars into bunkers in the coal house and conveyed thence into the boiler room by the Hunt system of charging cars and tracks.

LOW SERVICE STATION, ST. LOUIS, MO.

The water has a free spill from an elevation of 132 feet (making the head on the pumps from fifty to sixty feet), and passes through forty-two-inch discharge pipes into the delivery well— a distance of 160 feet. This well is of cut stone, forty-seven feet long, fifteen feet wide, and fifteen feet deep. The water stands in it at an elevationof 129 feet. A semi-elliptic masonry conduit, nine feet wide and eight and one-half feet high, leads the water south and along the west side of the settling basins to the six filling chambers, one of which opens into the centre of each basin by means of a four-foot by five-foot gate moved by hydraulic pressure.

(To be continued)