Chapter 11 of The Water Works of the City of Philadelphia: The Story of their Development and Engineering Specifications
Compiled in 1931 by Walter A. Graf (Staff Engineer, The Budd Company, Philadelphia), with the assistance of Sidney H. Vought and Clarence E. Robson. This online version was created from an original volume at the Historical Society of Pennsylvania, Catalog No. WZ 23591 (4th Fl. Folio).
Walter Graf History Home Page
(With Notes on the Text, Preface, and Acknowledgements)
Reading the Preface will give a quick overview of the beginnings and expansion of the Philadelphia water system.
IN ORDER TO GIVE a better supply of water to Germantown and to serve Roxborough and Manayunk, the city built the Roxborough water works on the east bank of the Schuylkill River, approximately 500 feet below the Shawmont station of the Philadelphia and Reading Railroad, and about a quarter mile above the Flat Rock Dam. Construction work was started on the engine in 1865, and on the engine and boiler houses in 1866, but neither the houses nor the equipment were completed until 1869.
The engine was a Cornish overhead beam engine designed by H. P. M. Birkinbine and built by the Bush Hill Iron Works. When it was installed it was capable of pumping 2.25 million gallons per day against a lift of 346 feet. This engine was started in operation April 5, 1869, but when it had pumped almost 9 million gallons into the reservoir it was stopped because the reservoir had started leaking very badly. The reservoir when full contained nearly 12 million gallons. It took until December to repair the reservoir. The engine was then started again. However when the water reached a level but three feet higher than on the first attempt, other leaks were found and the engine once more shut down.[1] This time the reservoir was placed in as near first-class condition as was possible.
In the short runs made before the reservoir’s failure, the engine showed up well, but it was clearly indicated that the lift of more than 330 feet to the reservoir was a gigantic task with serious contingencies if the station was compelled to depend on one engine. Therefore the immediate construction of a second engine and boiler house was recommended. In line with these recommendations, engine No. 2, an H. R. Worthington duplex compound engine of 5 million gallons capacity, was ready for service in 1872. Its rated water lift was 346 feet. This engine was built with four cylinders, two high pressure and two low pressure; the high pressure cylinders having a bore of 36 inches and a stroke of 48 inches, and the low pressure cylinders a bore of 58 inches and a stroke of 48 inches. Connected with the engine were two double acting plunger pumps of 21 inch bore and 48 inch stroke. These pumps were so arranged that they could be used to raise 8 million gallons a day into a lower reservoir than that then in use, if future developments required it.
The operation of the Roxborough water works in its early years was unsatisfactory and expensive and, in order to relieve or lessen the load on the pumping plant, the building of an auxiliary pumping station was soon advocated. This auxiliary station was built on the east side of the reservoir and pumped water from the reservoir to storage tanks built on a trestle on a lot back of the Manatawna church. These tanks had an aggregate capacity of 100,000 gallons. The surface of the water in the tanks was 440 feet above city datum. The tanks supplied the high ground on the Roxborough ridge, one of the highest sections in the city.
As completed in 1870 the auxiliary station was equipped with the two Knowles pumps that were originally bought for emergency purposes at Fairmount during the drought of 1869. The water was pumped from the reservoir into a standpipe, built of 30-inch diameter water mains up-ended, and thence to the tanks at Manatawna. These two engines proved of greater capacity than required by the auxiliary station. so one of them was removed in 1876 and installed in the Chestnut Hill station, and a feed water pump that was formerly used at the Schuylkill water works was substituted.
In 1883, the Roxborough station was supplying the districts of Manayunk, the Falls of Schuylkill, Germantown and Mount Airy. Engine No. 1, the Cornish engine, then 14 years old, continued to operate in a generally fair condition, although it was a ponderous and extravagant machine in comparison with No. 2 Worthington, which had less weight and bulk and was more efficient.
On July 28, 1890, the building of a new 148 million gallon reservoir was started. Situated on higher ground north of the old Roxborough reservoir, this new reservoir became known as the Upper Roxborough reservoir. During 1890, a complete electric lighting system was installed and superseded illumination by coal oil lamps.
On January 19, 1892, the Southwark Foundry and Machine Company contracted to build a 10 million gallon per day pumping engine of the vertical compound flywheel type at a cost of $72,000. This engine and the necessary boilers to serve it were completed on March 30, 1893 and started in service April 24, 1893. On its test 12,765,840 gallons were pumped in 24 hours, phenomenally exceeding the contracted capacity by 25 percent. The old Cornish engine, No. 1, was discarded and the new engine thereupon became No. 1.
The upper Roxborough reservoir was also completed during this year and the first water was pumped into it on September 21, 1893. This reservoir was composed of two basins, the north basin with a capacity of 71,594,000 gallons and the south basin with a capacity of 75,438,000 gallons, with the water surface of both basins at 414 feet above city datum.
In order to supply the highest part of the 21st and 22nd Wards, a second auxiliary steam pumping station including a standpipe was constructed on the east side of Ann Street, opposite the northeast corner of the old Roxborough reservoir. It was known as the Roxborough high service station. Work on the station was started on October 5, 1893, and it was completed and put in operation on May 17, 1895. It supplied the Chestnut Hill district and adjacent territory, and the first auxiliary station, built near the southeast corner of the reservoir, was shortly thereafter abandoned. The standpipe for this new station was 11 feet in diameter and 150 feet high, with a capacity of 106,000 gallons. The water surface was 490 feet above city datum.
A 5 million gallon a day Worthington engine originally erected at the old Delaware water works pumping station, (which was abandoned in 1890) was erected and used at the Schuylkill works for nearly three years, and it was the first engine used at the Roxborough high service station. The demand on this station proved so great that the engine was used day and night continuously without stopping for a single hour. This condition called for a second engine at once and this was recommended. In 1896 after the old engine had run one full year without repairs of any kind, a yet more urgent request was made for a supplemental pumping outfit.
It was not until 1898 that another pumping engine was installed in the Roxborough high service station, and then the pumping installation was experimental. A party named D’Auria had been given permission to make the installation for experimental purposes. The unit was of about 2.5 million gallons capacity. It was started in service on May 12, 1898, but was run at uncertain intervals only.
The recommendation which followed called for the acquisition of a new 5 million gallon unit, and on September 19, 1899, the new unit was ordered from the H. R. Worthington Company. It was completed and started in service in 1900. This pumping engine was the well known horizontal compound high duty duplex type with tandem high and low pressure cylinders respectively of 13 inch diameter and 36 inch diameter, and pump barrels of 17 inch diameter, all of 36 inch stroke. The engine speed was 26 revolutions a minute with a piston speed of 156 feet a minute.
In 1896, a new 10 million gallon a day triple expansion pumping engine installation complete with the necessary boilers, engine and boiler house, stack and intake was requested for the Roxborough pumping station at Shawmont. The arguments for it were the following. In addition to a steady increase in the demand for water, the extra pressure required to force water into the recently completed upper Roxborough reservoir was beginning to tell on the engines and pumps in this station. They had been designed to work under the head of the old Roxborough reservoir, or 346 feet city datum, whereas the new or upper Roxborough reservoir, which they were required to fill, was at 414 feet above city datum. In the Water Bureau report of 1898, it was mentioned that although the new or upper Roxborough reservoir had been completed for more than five years it had never been filled, owing to the insufficiency of the pumping capacity at Shawmont. It was also pointed out that the largest pump at this station (the 12 million gallon Southwark which was installed in 1893) was constantly breaking down and required the greatest care to keep it in operation. After only five years of service it was considered practically useless and its removal and replacement by more serviceable machinery was urgently recommended.
Recommendations and requests for additional pumping facilities continued through 1897 and 1898. On May 8, 1899, and on September 19, 1899, four 5 million gallon a day capacity Worthington pumping engines were contracted for, two on each of the above mentioned dates. Their complement of boilers, engine and boiler house extensions, and intakes were also contracted for September 19, 1899.
In 1899 the defective Southwark engine, (the 12 million gallon vertical compound unit installed in 1893 as No. 1) had begun to show signs of complete failure. Its condition finally became such that it was unsafe to run it at full capacity, so on August 23, 1899, one side of the pump was disconnected and thrown out of service, leaving it with but one side. In order to keep the districts depending on this station supplied, it was necessary to purchase and install another pump immediately. Mr. Frank L. Hand, then general superintendent of the works, was sent to the Worthington Company in Brooklyn to inspect a 4 million gallon a day capacity pump, then in the mentioned company’s works, and if it was found satisfactory he was given authority to purchase it. This pump was purchased, set up, and it started operating September 20, 1899. It was given No. 4.
On February 10, 1899, the 2.5 million gallon D’Auria pump, which had been installed in the Roxborough high service station, was moved to Shawmont station (as the main station was then generally called) and on March 16 began service as engine No. 5.
The new engine room, boiler house and intake for the four new 5 million gallon Worthington pumping engines, ordered in 1899, were completed in 1900 and the completed engines installed. Also completed were an electric lighting plant, and an additional pumping main to the reservoirs. The first of the four new engines, No. 6 was started on September 12, and the second and third, which had been assigned Nos. 4 and 7, on September 20 and November 27 respectively. This new No. 4 engine apparently displaced the 4 million gallon Worthington bought to meet the emergency of August and September 1899 when No. 1 was crippled. The fourth engine, designated No. 5, (formerly the number of the D’Auria engine) was set up but not placed in service on account of the attention required to get the other three into service. The high and low pressure cylinders of these engines were arranged tandem, the high pressure being 18 inches in diameter and the low 50 inches in diameter, with a stroke of 36 inches and a speed of 26 revolutions per minute at a piston speed of 156 feet per minute.
The four new pumping engines proved very efficient. Steam consumption was lowered and considerably reduced in comparison with the engines formerly used. A reduction of 34 percent was claimed, and this at then current prices represented a saving of $29,481.30 a year.
When these new pumps were started, old Nos. 1 and 2 were shut down. It was recommended that the Southwark engine be moved to the Frankford station. Accordingly a contract was made to repair and place this engine and pump in first class condition and set it up in the Frankford station by July 1, 1901. The D’Auria pump, old No. 5, was removed to the Frankford high service or Wentz farm pumping station in 1900.
The Roxborough water works system has the distinction of being the first water works plant in Philadelphia to be equipped with a filtration system.
On April 9, 1901, work was started on the construction of the lower Roxborough filters, and later in the same year, work on the construction of the upper Roxborough filter. According to the records of the Water Bureau, the first filtered water delivered to the mains flowed from the lower Roxborough filter plant August 12, 1902, though Mayor Ashbridge’s report of 1902 claims a date of August 2. The Manayunk district above Green Lane, between Silverwood and Main Streets, was the first district to be served. The service was extended to additional sections from time to time, until on August 27, the filtration system was in full operation. By December 1, 1902 the system was supplying from 7 to 9 million gallons of filtered water.
The lower Roxborough filter plant is located near Ridge and Shawmont Avenues and is adjacent to and westward of the lower Roxborough reservoir. The plant is still in existence (1931). The water supplying the plant was taken from the Schuylkill River at Shawmont. The lower reservoir with a capacity of nearly 12 million gallons at an elevation of 366 feet city datum was utilized as a sedimentation basin to feed the filters immediately adjoining. After being filtered and purified the water was passed to a filtered water basin and from the basin into two 30-inch distributing mains which supplied Manayunk and a low level district in Germantown. In case of very turbid conditions of the river, when the sedimentation effected through the lower reservoir was insufficient, sedimentated water was drawn also from the upper Roxborough reservoir.
As built, the filtration plant consisted first of five covered filters with a court for the washing and storage of filter sand, and a covered filtered water basin. Because of the topography of the ground it was necessary to arrange the filters in a series of steps. The difference in level between successive filters was made 2 feet 9 inches, and the filtered water basin was located at a still lower level. Each filter measured 109 feet by 219 feet 10 inches on the neat lines, and afforded a net filtering area at the normal sand line of about 23,400 square feet, or .537 acre. The theoretical yield of each filter was originally about 1.6 million gallons per day, so that with four filters in service, the gross capacity of the plant was about 6.4 million gallons per day.
In general design these filters are similar to those that were in use in Berlin, Warsaw, old St. Petersburg (now Leningrad) and other large cities of continental Europe, and also similar to the filtration plant built at Albany, New York, several years prior to 1901. The floors of the filters are built of concrete to form inverted groined arches six inches thick at the center and 14 inches thick under the piers, and on a puddle lining. Puddle lining consists of a mixture of clay and broken stone carried up around the outside walls to a level above the water line of the filters. The piers are built of concrete, each pier built as a monolith. This is the first instance of the use in America of such construction in filters. The dividing walls are also built of concrete and constructed in sections of such length that each section is a monolith. The exposed faces of the piers and of the outside and dividing walls, below the sand line are coated with a thin plaster of Portland cement, mixed three parts to one and dashed with sand before the plaster had set, in order to afford a rough surface for the sand to press against and tend to prevent a rapid downward flow of water along these surfaces. The vaulting is also of concrete and in the form of semi-elliptical groined arches having a span of 14 feet, a rise of 36 inches, a thickness of six inches at the crown, and a thickness of 21 inches over the piers. Ventilator shafts provide for the admission of light and air during cleaning. On top of the vaulting there is a layer of broken stone four inches thick for the purpose of conveying rainwater to the drains leading down through the piers and dividing walls to points just above the sand level.
Twenty-four-inch concrete main collecting drains extend the entire length of each filter, and are covered with movable concrete slabs for convenience of inspection during operation. Six inch lateral collectors in each bay enter this drain at the sides, through special terra-cotta fittings. The lateral collectors consist of six-inch diameter vitrified pipe perforated all around from end to end and plugged at the end remote from the main collector. Surrounding the collectors to a height of six inches from the floor is first a layer of gravel of a size ranging from three inches to 1¾ inches in diameter. Above this there are four other layers of gravel, each of successively smaller size. The second is a four-inch layer of a size from 1¾ inches to 5/8 inches diameter; the third a three-inch layer ranging in size from 5/8 inches to ¼ inch; the fourth a two-inch layer ranging in size from ¼ inch to material which would be retained on a sieve having 14 meshes to the linear inch; the fifth and final layer one inch thick of coarse sand that would pass a No. 14 sieve and be retained on a No. 20. The whole depth of the underdrain gravel is 16 inches. Above the gravel underdrain, to a depth averaging approximately 36 inches, is filter sand having an effective size from 0.28 to 0.36 millimeters, with a uniformity co-efficient of about 2.5. Some of this sand is dredged from the Delaware River and some is procured from sandbanks in the southern part of New Jersey.
Each filter is provided with a regulating house in which are located all valves pertaining to its operation together with automatic effluent regulators that maintain a uniform rate of filtration regardless of the loss of head or the constantly changing friction through the sand. Each filter is also provided with a large entrance at the court level to afford access to care for the filters.
The filtered water basin is similar in construction to the filters except that it is deeper and its piers are 22 inches square for their entire height. The capacity of the basin at the water line is 3 million gallons. On top of the vaulting is placed a layer of puddle, filling up the depressions over the piers, with its top surface graded from a high point at the center of the basin to the four sides. On this puddle is placed a layer of broken stone, and in this layer four inch drains with open joints are laid. These collect the rain water and lead it to an eight-inch pipe extending around the basin and connecting with the overflow.
The pipe supplying raw water to the filters is connected with the sedimentation reservoir at a point diametrically opposite the point where the water is admitted to the reservoir. A main effluent pipe whose branches lead from the effluent chambers conducts the filtered water to the filtered water basin. To draw off the four feet depth of water above the sand prior to cleaning, because the filters are at different levels, arrangement was made to drain this water in succession from the higher filters, to the lower ones. The lowest filter drains into the sewers. The effluent chamber drain removes from the effluent chamber the last water filtered just before cleaning. After the raw water has been drained off, the water level in the filter is allowed to drop a few inches below the top of the sand. This effluent chamber drain connects not only with the filtered water basin, but also with the sewer, in order to waste this last filtered water if it is deemed advisable.
In 1902, a contract was placed with the Maignen Filtration Company of Philadelphia for the construction of preliminary filters at the lower Roxborough filter plant, and work was started the same year. These filters were experimental in character, and the contract included a proviso that payment was to be withheld until one year’s operation was completed, and it was determined whether the water furnished came up to specifications.
Philadelphia was the first city in America and the second in the entire world to use preliminary filters. Through their use it was possible to practically double the production of filtered water from a filtration plant.
The preliminary filters at this station consisted of eleven concrete tanks, 16 feet wide, 64 feet long and 5 feet 6 inches deep inside measurements. In the bottom of each tank was laid five inches of coarse gravel, ranging in size from 2½ to 1½ inches in diameter; next above a layer of crushed furnace slag 10 inches thick, ranging in dimensions from 1½to ¾ inches; then a layer of crushed furnace slag 24 inches thick, ranging in dimensions from ¾ to ¼ inch; and above this slag a layer of compressed sponge, nine inches thick weighing about five pounds per square foot of surface. The sponge was compressed on the layer of slag through a set of narrow planks laid transversely over it with half-inch spaces between, and superimposed timber beams running lengthwise of the filter tank and in turn engaged by screw jacks reacting upward transversely arranged overhead I-beams set in on eight-foot centers. The water was introduced into the bottom of the tanks through five-inch perforated tile pipes, percolated upwards through the gravel, crushed slag and sponge, and was drawn off at the top of the filters over brass wire plates with rectangular notches 22½ inches long and nine inches deep. The water entered these filters at the rear end and was drawn off at the front end into galvanized iron boxes, from which it flowed into the collecting pipe and was then conducted to the plain sand filters.
These preliminary filters each had a filtering area of 1,024 square feet and when all 11 were in service, they had a theoretical capacity of 12 million gallons per day, which was at the rate of 46.4 million gallons per acre per day.
On an average of once a month the preliminary filters were cleaned by reversing the current at a rapid rate and wasting the water into the sewers through a 20-inch pipe drain at the bottom. When the sponges became heavily clogged, which occurred approximately twice a year, they were removed from the tank by mechanical appliances and washed in laundry washers driven by electric motors.
Two sand washers of the ejector type served for cleaning the five slow sand filters. They were located in the outside court. Each washer consisted of a series of hoppers, each hopper 36 inches in diameter, into which series was discharged the dirty sand from the filters. In this type of washer sand finds its way to the bottom of the one hopper and is thereupon ejected to the next hopper. The dirty water that overflows from the hoppers passes to the sewer.
The operation of this filter plant was as follows:
The water was pumped from the river into the east end of the sedimentation reservoir basin, and was drawn off at the west end through a screen chamber near the surface. The sedimentation basin operated upon the continuous subsidence system, and at a rate which gave the water 24 hours subsidence before it passed to the preliminary filters. Passing through the preliminary filters the water entered the plain sand filters, and having passed through them, collected in the clear water basin. The water flow, all the way from sedimentation basin to clear water basin, was by gravity flow. There was necessary no supplementary pumping excepting that done while cleaning the sand. Water for washing purposes was obtained from the Roxborough high service station standpipe.
Today (1931) this entire lower Roxborough filtration plant with the exception of the reservoir is out of commission, service having been discontinued in June 1926. The preliminary filters have been partially demolished. However the slow sand filters are still in good condition and could be made ready for action on short notice.
Construction of the upper Roxborough filters commenced May 15, 1901, and they went into service July 3, 1903. They supplied filtered water to sections of Germantown and Manayunk not supplied by the lower Roxborough stations, and also Chestnut Hill, Mount Airy, Roxborough, Rising Sun, and the upper part of Nicetown. This filter plant is still running (1931). It is situated immediately north of the intersection of Port Royal Avenue and Hagy Street in the 21st Ward and adjacent to and northward of the upper Roxborough reservoir. The water supplying this plant is first pumped into the upper Roxborough reservoir by the pumping station located at Shawmont. This reservoir, finished in 1893, is, like the lower reservoir, used as a sedimentation basin. It comprises two compartments, each 25 feet deep and together having a capacity of over 147 million gallons at an elevation at the water line of 414 feet city datum. Sedimentated water is drawn from this reservoir and supplied to the filters by centrifugal pumps now (1931) located in what is known as the upper Roxborough Booster station. The plant, the interior of which is shown by the photograph of FIGURE 38, consists of eight covered sand filters, a covered filtered water basin, and courts which were formerly used for washing and storing filter sand. These filters are of the same type of construction as those of the lower Roxborough filter plant. The topography of the ground is such that the filters were arranged all on one level instead of in steps with the filtered water basin situated at a lower level. Each filter measures 140 feet 8 inches by 219 feet on the neat lines, and has a net filtering area at the normal sand line of about 30,380 square feet, or .698 acre. The theoretical yield of each filter was at first about 2.1 million gallons a day. With an average of seven filters in service, the initial overall capacity of the plant was about 14.7 million gallons every 24 hours.
Each filter has its own regulating or valve chamber. However, this is not located at the centre of one side of the filter, as is the case at the lower Roxborough filters, but instead the valves for the filters of successive pairs are located at the end of the dividing wall between the filters. The arrangement possesses the advantage of controlling of two filters within one house, thus reducing the number of points for operating the plant.
The filtered water basin of the upper Roxborough plant is similar in construction to that of the lower Roxborough plant. It is 237 feet 8 inches by 318 feet 10 inches on the neat lines, and 15 feet deep, with a capacity of 8 million gallons at the water line. Preliminary filters were not made a part of this station owing to the long period of sedimentation obtained in the great-sized upper Roxborough basins. Their over 147 million gallon capacity was about nine days supply for the filters, as operated during 1900.
The year 1901 introduced the newest and most modern of prime movers, the internal combustion engine, into the service of Philadelphia Water Works systems. Bids for two gasoline engine pumps were received December 18, 1901, but the contract was not immediately awarded, pending an examination of the merits of the several designs submitted. These two engines and pumps, were designed to take water from the filtered water basin and discharge it under a head of 184 feet to the sand ejectors used in the early days of filter service to convey the scraped sand from the filter beds to the sand washers, then located in the court adjoining the filter beds. These pumps also supplied the necessary wash water to these sand washers. The units purchased were of 67.4 horsepower each, and of the vertical, triplex piston type. They were placed in service about July 1, 1903 in what was known as the upper Roxborough pumping station and administration building, which was built in 1902. This building is used today (1931) only for administration purposes. These gasoline engines and pumps were removed after the installation of the electrically-operated upper Roxborough booster station in 1926.
While the upper Roxborough filters were in process of construction, the necessary equipment to pump the water from the reservoir to the filters was contracted for. This pumping was necessary because the upper reservoir did not have sufficient elevation to supply the filters by gravity. After the water passed through both basins of the reservoir, it was pumped to the filters by centrifugal pumps located in an extension of the Roxborough Auxiliary or high service pumping station. This station was situated near the lower Roxborough reservoir, about a half mile from the upper Roxborough filters. The pumps were first placed there because boiler equipment and part of the necessary piping system were already in place and could be utilized in connection with the operation of the upper Roxborough filters. The building extension was located on the north side of the station and south of the standpipe. In every respect it preserved the architectural features of the existing station.
The pumping equipment consisted of three vertical compound condensing crank and flywheel engines built by the Worthington Company of Brooklyn, New York. They were each designed to reach an easy maximum capacity of 10 million gallons a day against a static head of 25 feet with a steam pressure of 100 pounds. The centrifugal pumps were of the horizontal type. When placed in service they pumped the water from the upper Roxborough reservoir at the 414 foot elevation to the upper Roxborough filters, at the 419 foot elevation.
In 1902, recommendations were made to install two additional 5 million gallon a day pumping engines to meet the steadily increasing demand on the Shawmont pumping station.
On February 23, 1902, the Flat Rock dam burst, but the prompt and efficient efforts of the Water Bureau personnel averted what might have been a serious situation. They quickly erected centrifugal pumps on the river front to temporarily draw the water directly from the river channel to the intakes of the main pumps, thereby preventing disruption of the water supply from this station.
So great was the demand for water at this station in 1903. that it was necessary to again place in service old pumping engine No. 4, the 4 million gallon Worthington duplex which had been discarded shortly after the four new 5 million gallon Worthingtons (new No. 4 and Nos. 5, 6 and 7) were placed in service in 1900. Old No. 4 was now designated No. 1. Two 15 million gallon pumping engines, together with eight boilers, a boiler house and a stack were recommended in 1903. The three low duty engines, which were in service in this station, i.e. Nos. 1, 2, and 3, were reputed to be great coal consumers. In addition their efficiency was much lower than their rated 16.5 million gallons per day. Their best performance, ascertained by a Venturi meter, was only 10.725 million gallons. Accordingly their removal and replacement by new pumps of more modern construction was advocated.
Early in 1904, the Flat Rock dam was again partly swept away and again centrifugal pumps and engines were setup on the river’s bank to supply the engine wells with water, as had been done in 1902. Following this break and in the same year, a new dam was built directly below the old one.
When filtration at both the upper and lower Roxborough filtration plants was in full swing, the pumps at the Shawmont station could not supply the quantity of water needed to supply both the districts and to meet the requirements of the filtration plants for cleanings, sand conveying, etc. The acquisition of four 5 million gallon pumping engines and the boiler equipment requested in 1903 was urgently recommended This additional equipment was again requested in 1905. In 1906 the recommendations were modified, this time to call for but two 5 million gallon engines and 10 boilers. None of these recommendations were adopted, but in 1906, the City made a move to increase the pumping capacity of Shawmont by placing a contract to equip with new pumps the 20 million gallon Gaskill compound pumping engine located at the Schuylkill station, and expected to be abandoned, to place the unit in first class operating condition, and then to erect it in the Shawmont station. This was achieved in 1908. Because of the increased head, pump cylinders of smaller diameter were necessitated, so this engine was re-rated at 10 million gallons a day. The 4 million gallon Worthington was discarded for the second time, and the Gaskill then became No. 1.
The Snow Steam Pump Works of Buffalo, New York, were given a contract in 1908 to install two 5 million gallon horizontal cross compound pumping engines. They commenced service in 1909. With these additions the station capacity proved adequate for a number of years. FIGURE 39 is a photostat of the manufacturer’s drawing of these pumps. In the station interior photograph of FIGURE 40 they appear in the right background as they were installed.
In 1909, a DeLaval turbine driven centrifugal pump was installed in the Roxborough high service pumping station for the lower Roxborough filter plant to furnish wash water at 100 pounds per square inch pressure for use in the sand removal and washing operations. The water which was previously furnished from the standpipe for this purpose did not have sufficient pressure, and the washing operations were therefore uneconomical.
Following a number of years of repeated recommendations an extension was made to the boiler room of the Roxborough high service pumping station in 1911, and two boilers removed from the abandoned Schuylkill pumping station were installed.
In 1914, the four 5 million gallon high duty Worthington pumping engines, Nos. 4, 5, 6 and 7 which were acquired in 1900, were reported as unfit for the service conditions under which the station was compelled to operate them, and their removal and replacement with more modern and efficient equipment was suggested. In 1916 a first step was made toward electrification of pumping equipment at the Shawmont and Roxborough pumping stations. In this year contracts were let and work was started on the installation of an electric generating plant at the Shawmont pumping station to supply power for electrical equipment proposed and in process of installation at the Roxborough high service station and the upper Roxborough booster station.
The years 1917 and 1918 at the Shawmont pumping station marked the passing of the old style reciprocating steam engine with its wide variety of designs. In 1917 a 10 million gallon steam turbine driven centrifugal pump, built by the Southwark Foundry and Machine Company of Philadelphia, was installed. This turbine and pump operated against a 400 foot head at 150 pounds steam pressure. This first installation was quickly followed by the installation of two more units of identically the same size and manufacture. All three units appear in the Shawmont station photograph of FIGURE 40, one in the center background, and two in the foreground.
In 1918, the old 5 million gallon Worthington horizontal compound duplex pumping engine was removed from the second Roxborough high service pumping station. As originally installed in 1895 it was a third hand engine. In its place were installed two 6.5 million gallon and two 3.5 million gallon electrically driven 12-inch single-stage centrifugal pumps to operate against an 85 foot head. FIGURE 41 is an excellent photograph of the installation. These pumps were built by the Platt Iron Company. The two larger were driven by 150 H.P. 1800 R.P.M. and the two smaller by 75 H.P. 1800 R.P.M. General Electric motors.
The Worthington 5 million gallon horizontal compound high duty duplex pump installed in 1900, remained in the station, but was not used after the installation of the motor-driven pumping units.
In 1921, work was begun in changes in the filtering system to enable the upper Roxborough reservoir to be used as a sedimentation basin for both the upper and lower filter plants, and so do away with the inefficient sponge and coke preliminary filters at lower Roxborough. July 30, 1922 the changes were complete and these preliminary filters were abandoned.
The high service portion of the Roxborough second steam driven high service station was abandoned in 1922 when a new all-electric high service pumping station was built at the northwest corner of the lower Roxborough filter plant court. The two 6.5 million gallon and the two 3.5 million gallon motor-driven pumps built by the Platt Iron Company and first installed in the steam-driven high service station (see FIGURE 41) were removed to the new station and there set up in series.
In addition, there are in this station two 6 million gallon Frederick Iron and Steel Company 12 inch single-stage centrifugal pumps, driven by 250 H.P. 1800 R.P.M. General Electric motors, and a 1 million gallon 12-inch single-stage Frederick Iron and Steel Company pump driven by a 50 H.P. 1800 R.P.M. General Electric motor. This latter unit was formerly used to supply the water for filter washing purposes at the lower Roxborough filter plant. All these pumps were designed to work against a head of 170 feet. At present, the Roxborough high service station pumps filtered water that flows to it by gravity from the upper Roxborough filtered water basin and boosts the pressure to supply the upper or high portions of Roxborough and Chestnut Hill. The lower sections of Germantown, Roxborough, Manayunk and Wissahickon are supplied by gravity flow from the upper Roxborough filtered water basin. One section of the Chestnut Hill district is so high that an additional booster station is used to supply it.
In 1922, the old Gaskill 10 million gallon compound engine and pump was removed from the Shawmont works and in its place a 20 million gallon turbo-centrifugal unit was installed. This unit consisted of two single-stage 18 inch, 900 R.P.M. Worthington centrifugal pumps arranged in series and driven by a General Electric 1750 H.P. 3578 R.P.M., nineteen stage turbine. This large turbo-centrifugal, together with the three Southwark turbo-centrifugals (each of 10 million gallon capacity) and the two 5 million gallon Snow cross compound engines, were in service at this station until 1926.
Through a series of unfortunately bad breaks, which occurred about this time, this station failed completely and for a while the districts supplied experienced the most severe water famine in their history. This speeded greatly the trend to do away entirely with steam driven pumping equipment, not only that at the Shawmont station, but also that at all other stations.
As rapidly as possible, two 25 million gallon electric motor-driven pumps were installed in the Shawmont station. Current was supplied by the Philadelphia Electric Company. These large electric units were erected in 1926 by the Dravo-Doyle Company of Pittsburgh, Pennsylvania. Each consisted of two DeLaval double-suction single-stage centrifugal pumps in series, driven by a direct connected 2300 volt, 2157 H.P., 900 R.P.M., General Electric synchronous motor, and operating under a head of 410 feet. In the photograph of FIGURE 42, these two units can be readily identified. They were those in the pits surrounded by railings. Ever since these pumps were installed one pump alone has delivered enough water to supply the demand of the reservoirs, while the other is held in reserve for emergency use.
As clearly shown by FIGURE 42, this station strikingly presents the great advances made in pumping equipment. Occupying an entire side of the latest addition to the buildings are two ponderous steam pumping engines and pumps, the combined capacity of which is but 10 million gallons. In the center of the floor occupying less than half the space occupied by the steam engines, are the two 25 million gallon electrically driven centrifugal pumping units of a combined capacity of 50 million gallons, five times that of the two steam pumps. Over and above this, the huge boiler room, boilers, their various cumbersome accessories, the coal bunkers, and the ash handling facilities, like the engines they served, stand today as silent reminders of the era of steam pumping. The powerful and reliable electrified regular and reserve equipment daily adds to the dimness of one’s memories of the old time difficulties. In 1926, an all-electrically-equipped station known as the upper Roxborough booster station was built at the west of the upper Roxborough reservoir, for the purpose of pumping the water from the upper Roxborough reservoir to the upper Roxborough filters, a duty formerly performed by the steam-engine-driven pumps which were located in the Roxborough high service station. This new booster station, together with the new electrically-operated lower Roxborough high service station, permitted the abandonment and ultimate demolition of the steam-powered Roxborough high service station. The brick building of the station is relatively small but substantial. It houses two DeLaval, 24-inch single-stage centrifugal pumps of 20 million gallons capacity driven by two General Electric 150 H.P., 585 R.P.M. induction motors. Included also in this station are one DeLaval 20-inch single-stage centrifugal pump of 17 million gallons capacity driven by a General Electric 100 H.P., 450 R.P.M., induction motor; one Platt Iron Works 24-inch single-stage centrifugal pump of 15 million gallons capacity driven by a General Electric 40 H.P., 1800 R.P.M. motor, and two four-inch single-stage-in-series DeLaval centrifugal pumps of 1 million gallons capacity driven by a General Electric 75 H.P., 1800 R.P.M. motor. The last mentioned unit replaced the gasoline-engine-driven triplex pumps which formerly furnished wash water to the filters. The two 20 million gallon pumps are now (1931) alternately used for furnishing the filters with raw water, and the 15 and 17 million gallon pumps are held in reserve. The 1 million gallon wash water pump is practically idle since the introduction of a Bayard Filter Washing Machine, for this machine does not need pumping equipment.
[1] Annual Report of the Chief Engineer of the Water Department of the City of Philadelphia, presented to Councils February 10, 1870. Philadelphia: E. C. Markley & Son, 1870, p. 10