Chapter 3 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.
THE CITY’S RAPID GROWTH and the limited efficiency of the water works machinery then (1819) in use, combined with the high cost of using steam power to pump the city’s water supply, led Councils after a thorough study and examination of the subject to turn to water wheels for power. In 1823 the Fairmount steam engines were displaced by breast wheels, and it was then thought that steam would never be used again for this purpose.
[NOTE: The Water Bureau records give January 14, 1822 as the date of termination of the service of the steam engines at Fairmount Works, but others of the Bureau’s records indicate an error in the entry of the year, that the year must have been 1823 and not 1822. As recited in this chapter the dam itself was completed July 25, 1821, the first water wheel was started operating July 1, 1822, almost a year later, it began regular pumping service October 25, 1822, and the second and third wheels went into service soon after that date. All of this points to January 14, 1823 as the date of termination of the service at this station for there was no other station serving the city at that time. To assume January 14, 1822 to be the correct date of termination of the service of the steam engines would require that the July 1, 1822 and the October 25, 1822 dates of starting and placing in service of the first water wheel be taken as 1821 dates, and thus present two errors for correction in lieu of one. However the fact that the dam was not completed until July 25, 1821 would seem to preclude any such assumption, for it is extremely unlikely that a wheel would be started (July 1, 1821) before the dam was complete.]
The use of waterpower had received some attention as early as 1807 as shown by the Falls of Schuylkill water power rights and reservations to James Kennedy in a charter granted him by the State of Pennsylvania during that year.
In 1815 the state granted the Schuylkill Navigation Company a charter which carried the right to improve the navigation of the Schuylkill River to its mouth. Having completed a great part of its improvement work, the company invited the city to join it in the building of a dam across the Schuylkill, thereby creating a pool or reservoir from Fairmount upstream to the Falls of the Schuylkill. It was thought that this reservoir of water would be of great benefit to both the city and the Navigation Company. The company was not financially able to undertake the project alone. It was finally determined by Councils to proceed with the construction of the dam, and Captain Ariel Cooley, of Chicopee, Massachusetts, was consulted upon its practicability. After a careful examination he reported favorably on the project and presented plans and estimates for the work.
Several other plans and estimates were submitted but that of Mr. Cooley was accepted and on April 8, 1819 a contract was entered into with him for the construction of the dam, locks, head race, etc., for the sum of $150,000. Mr. Cooley carried out his contract with the utmost integrity. Work was commenced April 19, 1819 and water flowed over the dam July 25, 1821.
Soon after this date and a little before the work was entirely finished, Mr. Cooley’s health failed by reason of the close application and exposure attending his labors, and he found it necessary to return to his home where disease soon resulted in his death. The following tribute to his memory is recorded in the report of the Watering Committee of 1823 referring to the Fairmount Water Powered Works:
“This work is a monument to his memory, and he had nearly completed it when he was taken off by disease, supposed to have been contracted by his exposure to the sun and night air, at the closing part of his work. His talents, his integrity, and his general worth, will long be held in grateful remembrance by the citizens of Philadelphia.”
At the point where the Fairmount dam was constructed, the river bed was about 900 feet in width, one-quarter of which, on the eastern side, was supposed to be rock covered with approximately 11 feet of mud, and the remainder shoal rock. The greatest depth at high water was 30 feet and it gradually shoaled to the western shore where the rock was bared at low water. The river, whose average rise and fall at that time was six feet, was subject to sudden and violent freshets.
Mr. Cooley, in forming his foundations on the exposed bed rock, sank cribs 50 feet long by 17 or 18 feet wide formed of logs. These cribs were weighted down with stone and securely fastened to each other above low water. The upstream side was planked from the bottom to the top and the space immediately above was filled with earth, small stones, and other materials, to prevent leakage.
Where mud was found covering the rocky river bed, the dam was made of quarry spalls and earth, and was raised about 15 feet higher than the other part of the dam, which served as the over-fall for the water. The base of this mound was at least 150 feet and its width on the top 12 feet. The whole of the top, also the upstream side from the water’s edge, was paved to a depth of three feet with building stone, in order to properly withstand pressure and erosion by water and damage by ice.
Connecting the mound dam and the over-fall, a stone pier was built in 28 feet of water. This supported the end of the mound and protected it from injury by ice or water. The contraction of the river’s width by the mound dam, gave Mr. Cooley the idea of forming the dam in a diagonal line running up stream, and when nearly across, to run the rest of the distance at a right angle to the western shore, so as to join the head pier of the guard-lock, on the western side, and by this means create a large over-fall and abate the rise above the dam, in cases of freshets. The whole length of the over-fall was 1,204 feet. The mound dam was 270 feet and the head arches leading into the forebay 104 feet, making the whole over all length of the dam, including the western pier, about 1,600 feet. The water was backed up the river for a distance of about six miles.
On the west side of the river a head pier was erected with guard locks from which a canal extended down stream 569 feet to two chamber locks. On the east side of the river the entire bank was solid rock. It was necessary to excavate the rock to a width of 140 feet, in order to form a race and site for the mill houses which ran parallel with the river.
The length of the mill race excavation was 419 feet. At the upper part of the mill race the three head arches were erected and extended from the east end of the mound dam to the rock of the bank thus practically forming a continuation of the dam. The mill houses were erected on the west or river side of the excavation thereby forming the west side of the race, while on the land, or east side, there was solid rock rising perpendicularly to a height of 70 to 80 feet. The south end of wall of the race was also solid rock and the mill houses being built on rock gave the entire works a secure and most substantial setting.
The mill race was about 90 feet in width, the water entered through the head arches, which allowed a passage of water 68 feet in breadth and six feet in depth. The race was suitably excavated below the over-fall of the dam, thereby allowing for a continual passage of 408 square feet of water. The head arches were at the north end of the race, with the mill buildings on the west. The water passed therefore from the race to the wheels, westwardly and was discharged into the river below the dam. At the south end of the mill buildings a waste gate was installed eight feet wide by which, when the upper gates were closed, the water could drawn from the race.
The mill buildings were built with stone in harmony with the surroundings. They were 238 feet long and 56 feet wide. The lower section was divided into 12 compartments, four of which were intended to house eight double-acting pumps. In the other eight compartments the forebays were to be located leading to the water wheels. The pump and forebay chambers were arched with brick.
Concerning these works we find much favorable comment and the records of the Water Department show the following:
“In the erection of the mill buildings, Mr. John Moore was employed as the mason; and the city is much indebted to his care and skill, not. only for the excellence of the work in appearance, but for its substantial properties it being ascertained that in the whole extent of the foundation along the race, and under a six feet head of water, there was not a single leak.
“Mr. Frederick Erdman, the carpenter, also deserves particular notice for his part in the work, which was most faithfully done, and to the committee’s entire satisfaction.
“For the calculation of the water power of the wheels, and a variety of valuable information on other matters connected with the work, the committee was indebted to Mr. Thomas Oaks, a gentleman of science and practical knowledge, who was at that time employed as engineer of the Schuylkill Navigation Company.
“The water wheels being sunk below the usual line of high water, it might be supposed that they would be obliged to stop operations at that time; but this seldom happened except in the spring tides, at the full and change of the moon, which stopped them on an average, about 64 hours in a month, thereby curtailing the effective usefulness of this type of power nearly 10 percent, by this one cause alone.
“It was found that the efficiency of the wheels were very little affected until the back water was about 16 inches on the same, but when the back water depth reached 24 inches above the lower edges of the wheels their use was prevented entirely.”
“The excellence of the work on the wheels and gates, with the whole arrangement of the mill works does the highest credit to Mr. Drury Bromley, whose attention had been most assiduous, and whose skill was of the highest caliber.”
This early installation of breast wheels appears in a drawing of 1851, FIGURE 14, when some of them were still in use. The pumps were built by Rush and Muhlenberg according to the designs of Frederick Graff. As appears in FIGURE 13 they were worked by a crank on the water wheel attached to a pitman connected with the piston at the ends of the slides. They were fed under a natural head of water, from the forebay of the water wheel and were double acting forcing pumps connected to an iron main, 16 inches in diameter, which was carried along the bottom of the race to the rock at the foot of Fairmount, and then up the bank into the reservoir. At the end of the pipe there was a stop valve which was closed whenever necessary.
The wheels as originally constructed were of the type known as the breast pattern. The breast wheel obtains its power by the action of the weight of the water on the paddles and is a modification of the undershot wheel. With the breast wheel the water is admitted to the paddles at a considerable height and retained during the descent by a casing or breast. The efficiency of this type wheel commonly varies from 50 to 80 percent depending upon its size and construction, but it has a higher efficiency than the undershot wheel. Originally three wheels were constructed of wood and they constituted the first water power units installed immediately after completion of the mill buildings.
The first wheel, which started operating July 1, 1822, was 15 feet in diameter, 15 feet wide and operated at 14 revolutions per minute, driving a double acting force pump, 16 inches in diameter with a 54-inch stroke. This pump raised 1,836,168 gallons in 24 hours, without any allowance for shutdowns due to tidal conditions or repairs or adjustments.
The second and third wheels were started in operation soon after the first one and were 16 feet in diameter by 15 feet in width, and operated at 13 revolutions per minute, each driving a double acting force pump, 16 inches in diameter with a 60-inch stroke. Each of these pumps could raise 1,894,464 gallons in 24 hours of continuous operation. These pumps gave very efficient service and were in constant use for 24 years before being replaced by new units in July 1846.
On November 10, 1827 the fourth wheel was put into service. This wheel was constructed of cast iron with wooden buckets and weighed 22 tons. It was 18 feet in diameter, 15 feet wide, operating at 11 revolutions per minute and driving a double acting force pump 16 inches in diameter with a 72-inch stroke. This pump raised 1,922,976 gallons in 24 hours continuous operation.
By April 5, 1832 the fifth wheel similar to the fourth wheel had been installed and began operation, thereby increasing the capacity of the pumping system by an additional 1,922,976 gallons of water per day.
November 5, 1834 the sixth wheel was put into service. It was 16 feet in diameter, 15 feet wide, and operated at 13 revolutions per minute, driving a double acting force pump, 16 inches diameter, with a 60-inch stroke, raising 1,894,464 gallons per day, excluding shutdowns for tidal and other conditions. This wheel was the same size and had the same pumping capacity as the second and third wheels but was built with cast-iron frames and wooden buckets similar to the fourth and fifth wheels.
On August 24, 1843 two more breast wheels, the seventh and eighth, were added to the station. These wheels were 18 feet diameter, 15 feet wide, and operated at 11 revolutions per minute, each driving double acting force pumps 16 inches in diameter with a 72-inch stroke and raising 1,922,976 gallons in 24 hours.
The fourth, fifth, sixth, seventh and eighth wheels all had cast-iron shafts and worked under one foot head and 7½ foot fall when the dam was full and the tide low. The pumps driven by the seventh and eighth wheels were built by the Levi Morris Company of Philadelphia.
By this time the water powered water works had proven very successful from the standpoint of adequate supply and economy, and the fame of its mechanical efficiency spread throughout the land. Thomas Ewbank, in his Descriptive and Historical Account of Hydraulic and other Machines for Raising Water Ancient and Modern, says:
“We took the opportunity while at Philadelphia in October 1840 to visit Fairmount….It is impossible to examine these works without paying homage to the science and skill displayed in their design and execution. In these respects no hydraulic works in the Union can compete nor do we believe they are excelled by any in the world. Not the smallest leak in any of the joints was discovered; and, with the exception of the water rushing in the wheels, the whole operation of forcing up daily millions of gallons into the reservoirs on the mount and thus furnishing in abundance one of the first necessaries of life to an immense population was performed with less noise than is ordinarily made in working a smith’s bellows. The picturesque location, the neatness that reigns in the buildings, the walks around the reservoirs and the grounds at large with the beauty of surrounding scenery render the name of this place singularly appropriate.” The total capacity of the Fairmount works with all of the eight wheels and pumps working was 633,811 gallons per hour. For more than 20 years the Fairmount dam continued in constant service and remained as originally constructed, except for minor repairs and replacements, thereby proving of greater durability than had been anticipated at the time of its construction. In 1842 the Watering Committee of the City of Philadelphia deemed it advisable to have the dam reconstructed and work was started on May 2, 1842, and finished on December 7, 1843, at a cost of $56,216.85.