Engineering Feats


The 1893 old pump house and dam located just south of the present Peterborough Water Treatment Plant were the second pump house and dam to serve Peterborough. The pump house and dam constructed in 1893 served until 1910 when they were replaced by the present Water Street pump house and dam. Historically, Peterborough first thought of a community water system around 1870 but it was not until 1882 that a private water company, appropriately named the Peterborough Water Company, constructed the first of three dams and pump houses and Peterborough’s water system was born.

The original pump house, built in 1882 but long since removed, was located approximately 1.25 kilometers downstream from the present pump house, just below the Auburn Dam then known as Blythe Mills.

With the steady growth of the town, the consumption of water rapidly increased, so in 1893 the company secured a new site 1.5 kilometers further up the river, and erected a dam, consisting of a wood crib and piers with rock, and a pump house. Two large and powerful triple action plunger pumps were installed, each of 2,500,000 gallons per day capacity. These pumps were built by William Hamilton Manufacturing Company of Peterborough.

Thus the original pump house and dam were replaced, eleven years after their construction in 1893, by this second pump house and wooden dam structure

The 1893 pump house, with its hipped gable roof, decorative coloured brickwork and 1arge Romanesque windows, was built as Peterborough’s second water pumping station.

In style, it closely resembles the buildings erected in Chicago for the 1893 World Fair, not surprising since the pump house was built in the same year. The contractor for the 1893 dam and pump house was William Kennedy Jr., of Montreal. The William Hamilton company of Peterborough received the contract for the new pumping machinery, with the understanding that it would be ready for operation on January 1, 1894. The machinery designed by Samuel Forster was described as a “triplex, single action, outside packed plunger pump”.

The capacity of the pumps was 2.25 million gallons per day at a pressure of 134 pounds per square inch in the air chamber.

There were three cylinders, each eight inches in diameter with a 30-inch stroke. The pumping capacity of the new pump house doubled that of the old one, which was to be used as an auxiliary for a period of time.

The 1893 pump house and dam were the sole source of water for the then Town of Peterborough, which purchased the entire water system, including the pump house, from the privately-owned Peterborough Water Company for the sum of $230,000.

Two of the four water wheels, as well as two existing triplex direct acting pumps, were relocated from the 1893 old pump house to the current Water Street pump house in 1909. The water wheels are still used today to drive high-lift pumps that deliver water to 75% of Peterborough.

Currently, the 1893 pump house, which has been maintained and restored over the years and described as an architectural gem, is used to house some of the Riverview Park and Zoo animal collection.

In 1983, the 1893 pump house was designated a structure of historical or architectural value or interest in accordance with the Ontario Heritage Act 1974.



The Quebec and Ontario Railway Company constructed the railway line into Peterborough in 1883. The local section of the Trent Canal was built in 1897-98 and this bridge was built as a swingbridge over the canal, just downstream of the Peterborough Liftlock.

The bridge is of riveted construction as a “through-truss”. It consists of two equal arm sections, connected by an “A” frame tower over the turntable. The truss columns are both solid sections and built up lattice struts. The lower girder is of built-up steel plate construction. The bridge is almost 58 metres (189′ 9″) in length. Originally built as a manually operated bridge, it was later converted by Canadian Pacific Railway to be electrically operated. It is one of the remaining through-truss bridges and is the eldest. After almost a century it is still in excellent condition.



The Peterborough Hydraulic Liftlock was constructed between 1896 and 1904 as a part of the Trent Canal. The world’s highest hydraulic boat lift can haul 1,900 tons in 90 seconds and uses no electricity – just water and gravity! This canal was completed to provide another route for the shipment of grain to Britain.

The advantage of a liftlock is that a boat can be raised much higher in a specific time than in a conventional lock, as well as allowing travel in both vertical directions at the same time. A liftlock is, however, more expensive to construct than an equivalent number of conventional locks and is only practical in cases of large elevation differences in short distances.

The Peterborough hydraulic liftlock consists of two large caissons supported by rams that are connected by a closed hydraulic system. The upper caisson is stopped one foot below the level of the upper canal. This gives the upper caisson an extra foot of water or an extra 144 tons in weight, over the lower caisson. When a valve is opened, the heavier upper caisson descends, forcing the lighter lower caisson upward in an equal and opposite movement.

On the 245 mile Trent-Severn Waterway, the Peterborough liftlock is one of two liftlocks in the system. In 1896, the Federal Government sent Mr. R.B. Rogers, Superintendeng Engineer, to Europe to study the operation of this type of lock. Few details of these earlier locks could be incorporated into the Peterborough Lock, so the design and layout was executed by local engineers.

This was the first North American liftlock to be constructed. Its 65 foot hydraulic lift is still the highest in the world and its two cylinders are still the largest ever made. To overcome the torsional movement of the two tubs, and, not use re-bar, R. B. Rogers went to compressed Portland cement. This was accomplished by filling the form with Portland cement, and, then using steam driven tampers. Then more Portland cement, more compression, more Portland cement, more compression until the form was filled. Finally the form was jacked-up once the first layer seemed “tacky” enough to processed to the next one.

During the winter of 1964-65, Dominion Bridge Company carried out a major overhaul for about 1.5 million dollars. The general appearance of the lock has been left as much as possible in its original state. The original construction cost was half a million dollars. The labour rate during construction was 10 cents per hour on a ten hour day with no coffee breaks. The equipment used was horse-drawn scrapers, one horse dump carts and a steam derrick. When one considers the amount of concrete construction knowledge at that time, it was a marvelous job, many years before its time.

Keith Patching, P .Eng. Updated on September 22, 2012 based on information received from Doug Young, Editor, Lakefield Heritage Research.



The Asburnham (Hunter Street) Bridge is the fifth bridge at the Hunter Street location joining the east and west sides of the Otonabee River. The first bridge was a simple wooden structure with three spans, but did not last long due to spring floods. The second bridge was a “Howe truss” built in 1847-1848. It lasted until it burned down. The next bridge was a cast iron bridge, which collapsed January 12, 1875, 1ess than three years after completion, when one of the seams cracked in the frost. The next bridge, a wrought iron bridge, stood for almost 45 years, until demolition began in January 1920.

At that time, Peterborough City Council enlisted the services of Frank Barber, a consultant from Toronto, as the Chief Design Engineer, to prepare the specifications for the new bridge. Barber enlisted the services of Claude Bragdon, an architect from New York, who contributed to the architectural design of the bridge and, noticeably, to the railings, lamp standards, and rough granite finish.

The bridge had several special engineering features. The joints at the skewbacks and crown were “gunited”, that is, filled in with dense sand-cement mortar shot by a cement gun when the temperature of the bridge reached 45 degrees Fahrenheit (which is the average yearly temperature in Peterborough). The arch was completed and the whole dead load was in place before the joints were gunited closed. The result was minimum temperature stresses and the practical elimination of rib shortening stresses.

The key feature of the bridge is the main river arch, which spans 234 feet. The principal stresses in this arch are compressive stresses due to the dead load and are never neutralized or reversed by live loads or temperature stresses. Consequently , the entire rib is always in compression and there is no reinforcing whatsoever in the ring of the river arch.

Although the original cost of the bridge was high and created much controversy at the time, the bridge, known as the Peterborough Arch to some, stands today as one of the most distinguished concrete arches in the country.

Jeff Vissers, P .Eng.



In the late 1930s, the primary activity in the switchgear operations of the then named Canadian General Electric Company, was the extension of ratings and refining the designs of existing oil circuit breakers. These are large switches used to switch high voltage transmission lines on and off. Such breakers are filled with oil that quenches any arcing that occurs during the switching operation. Early designs were basically derived from the General Electric, Philadelphia, “FK” line of breakers. There were some large high voltage, single-tank breakers that were derived from a technical exchange with the British Thomson- Houston Company of England. The design of these large, single-tank breakers was being extended to become a major Canadian design accomplishment.

At this time the manager of switchgear engineering was an engineer named Dr. G.R. Langley (GR), who later became the chief engineer for the Peterborough plant. GR and his staff, including D.R. Dryan, developed a small circuit breaker for use at 7500 volts and 15,000 volts with a rating of 150MVA. This breaker was strictly a Peterborough design. When establishing a designation for the breaker, it was decided to call it the “PL” breaker, signifying Peterborough-Langley.

The PL breaker was a simple and cost effective design and was produced in Peterborough into the 1970s. With only a 150MVA interrupting capability, it became too small for the burgeoning power systems. There are probably some small utility substations still depending on the Pi breaker as the primary switchgear device.

R.H. Rehder, P.Eng.



Power line carrier water heater control has been used in Peterborough since 1948 to reduce the City’s demand for electrical power. Water heaters can be used as energy storage devices, allowing them to be shut off for periods of time without inconveniencing the users of hot water. A 720-cycle, low-voltage signal is generated by motor generator sets in power distribution substations and transmitted over the power distribution line to receivers controlling the power supplies to hot water tanks. Time is used to code the signals so that the receivers can differentiate between off and on signals. An on signal from the transmitters is approximately eight seconds long, while an off signal is approximately 28 seconds long. The original receivers used bimetallic strips to differentiate between off and on signals. The power from the 720-cycle low-voltage off signal heated the bimetallic strip, causing it to bend until a relay attached to the strip interrupts the power supply to the tank. A mechanical latch prevents the bimetallic strip from returning to its original position. The on signal bends the bimetallic strip further, releasing the mechanical latch, allowing the strip to return to its original position and so restoring the power supply to the tank. Today, electronic receivers are used.



The heart of any underground mining operation is the mine hoist. This machine provides access to the mine workings and hauls men, material and mined ore.

The Friction or Koepe Hoist is an arrangement that relies on friction between the hoisting ropes and the hoist wheel surface to cause the hoisting conveyances to be moved up and down the mine shaft.

The Canadian-designed General Electric Friction Hoist was developed in Peterborough in the late 1960s by a team headed by Peter Eastcott. The system was wholly developed by Canadian talent and not simply an extension of something developed elsewhere-something unique and recognized as exceptional. Rather than attempting to balance deflections under all varying hoist-load conditions, the aim of the Peterborough design was to reduce the deflections to an insignificant level, thereby creating a new standard in winding performance, safety, and hoisting plant component life. Under Peter Eastcott’s direction, the Peterborough Mine Hoist Program included the development of many safety systems, as well as a unique brake engine system that was designed and manufactured “in house” at the GE Peterborough plant. It is indeed significant that a number of patents were issued in the name of Mr. Eastcott and other members of the design team.

The success of this product development led to the installation of Peterborough-manufactured hoists, motors and drive systems at a number of mine sites in both Canada and the United States. Among these installations was a facility in Colorado for which a quantity of five hoists was produced. Two of these hoists were powered by 9500-horsepower, direct-current motors, the largest machines of that type designed and produced at the Peterborough plant to date.