Overview:
This technical paper from 1910 describes the construction of a large concrete water tower in Victoria, British Columbia. The tower was designed to address the city’s rapidly growing water needs, featuring a 20,000,000-gallon reservoir, a unique design incorporating a steel tank within a plain concrete cylinder, and special attention to aesthetics. The paper details the unique design choices, construction methods, and costs associated with building the tower. The author emphasizes the importance of the tower’s architectural appearance and the need to meet the aesthetic standards of the community.
The paper also includes a discussion section where various engineers express their opinions on the design choices and construction methods. Some engineers criticize the lack of reinforcement in the tower structure and the use of a smooth steel shell to contain the water within the tank, arguing that these decisions could lead to future problems. Others highlight the tower’s unique aesthetics and the difficulties in securing a contract for such a complex project.
Key Findings:
- The paper offers a detailed insight into the construction of a unique and challenging concrete water tower in the early 20th century.
- It highlights the tension between functionality and aesthetics in engineering projects, particularly in urban environments.
- The paper also explores the limitations of plain concrete construction and the potential benefits of using reinforced concrete.
Learning:
- Concrete Construction: The paper provides a detailed description of the forms and scaffolding used to construct a large concrete structure. This can be valuable for understanding the principles of concrete formwork and the complexities of constructing large, detailed structures.
- Key Concepts: Tapered lagging, collapsible forms, centering methods, placement of concrete, and finishing techniques.
- Water Tower Design: The paper showcases an innovative approach to water tower design, highlighting the advantages and disadvantages of using plain concrete and steel tanks. This provides insights into the considerations for water tank design and the challenges of achieving watertightness in concrete structures.
- Key Concepts: The importance of architectural design in water towers, the use of steel tanks within concrete structures, the need for watertightness in concrete structures, and the application of plaster coatings to prevent leakage.
- Construction Costs: The paper provides a detailed breakdown of the costs associated with building the water tower, allowing readers to compare the costs of different construction methods and materials.
- Key Concepts: The high cost of labor and materials in the early 20th century, the impact of weather conditions and delays on construction costs, and the challenges of securing contracts for unique engineering projects.
Historical Context:
The paper was written in 1910, a period of rapid urbanization and industrialization in North America. The city of Victoria, British Columbia, was experiencing significant population growth, leading to a need for expanded infrastructure, including waterworks. The paper provides a glimpse into the engineering challenges and solutions of this era, particularly the use of concrete as a major construction material.
Facts:
- The City of Victoria, BC, is the capital of British Columbia. Victoria is located on Vancouver Island, a large island on the west coast of Canada.
- The population of Victoria, BC, was approximately 35,000 in 1910. The city experienced rapid growth during this period.
- The Victoria waterworks were owned and operated by the city. This was a common practice in many cities during this time.
- Water for the Victoria waterworks was drawn from Elk Lake, located approximately five miles north of the city. The water flowed by gravity to a pumping station and was then pumped to consumers.
- The water tower was constructed on the top of the highest hill in the city. This was done to ensure adequate water pressure for all residents.
- The tower was 109 feet high and had an inside diameter of 22 feet. This was a large structure for its time, capable of storing significant amounts of water.
- The walls of the tower were 10 inches thick for the first 70 feet and 6 inches thick for the remaining 39 feet. This design helped to ensure the tower’s structural integrity.
- The tower was built on solid rock. This provided a stable foundation for the structure.
- The tower was built using plain concrete. Reinforced concrete was not as widely used during this period.
- A steel tank was embedded in the upper 40 feet of the concrete cylinder. This tank was designed to contain the water.
- A concrete dome was used to form the bottom of the steel tank. The thrust of the dome was supported by two steel rings embedded in the concrete walls.
- The tank was covered with a reinforced concrete roof. This roof was designed to protect the water from the elements.
- The tower was built by day labor. This was a common practice for complex projects where specialized skills and close supervision were required.
- The construction of the tower was interrupted by bad weather and delays in the delivery of steel. These factors contributed to the high cost of the project.
- The tower was given two coats of neat cement wash to cover the efflorescence and irregularities in the concrete. This was a common practice in the early 20th century for finishing concrete structures.
Statistics:
- The water tower had a capacity of approximately 100,000 gallons. This was a significant amount of water for the time.
- The tower was built at a cost of $16,578.29. This was a substantial investment for the city.
- The cost of the steel tank was $1,740.69. The high cost of steel was a major factor in the overall cost of the project.
- The cost of the cement wash for the tower was $1.32 per 100 square feet. This was a relatively inexpensive finishing treatment.
- The tower was built in approximately 8 months. This was a relatively short construction time, considering the complexity of the project.
- The dome was poured in one continuous pour. This was a challenging undertaking, requiring precise planning and execution.
- The roof was poured in one continuous pour. This was another challenging undertaking, requiring precise planning and execution.
- The unit cost of the concrete was $25.126 per cubic yard. This was high compared to projects with more favorable conditions.
- The concrete for the sub-base and taper base was a 1:3:6 mix. This was a standard mix for concrete foundations.
- The concrete for the barrel of the tower and tank casing was a 1:3:5 mix. This mix provided a strong and durable concrete.
- The concrete for the dome and roof was a 1:2:4 mix. This mix was slightly stronger than the mix used for the tower and tank casing.
- The plaster coat on the inside of the tank was composed of 1 part cement to 1-3/4 parts of fine sand. This provided a smooth and watertight surface.
- The total cost of labor for the project was $10,398.88. This represented a significant portion of the total cost.
- The total cost of materials for the project was $6,179.41. This represented a significant portion of the total cost.
- The tower was built with a total of 412 cubic yards of concrete. This was a significant amount of concrete, making the project a major undertaking.
Terms:
- Efflorescence: A white powdery deposit that can appear on concrete surfaces as a result of moisture and salts.
- Pilaster: A shallow, flat rectangular column attached to a wall, often used for decorative purposes.
- Cornice: A decorative molding that projects horizontally from the top of a wall or building.
- Parapet: A low wall built on the edge of a roof or balcony.
- Dome: A curved roof or ceiling in the form of a hemisphere.
- Scaffolding: A temporary structure used to support workers and materials during construction.
- Hoist: A lifting mechanism used to raise heavy objects.
- Formwork: Temporary structures used to hold concrete in place while it sets.
- Lagging: The wooden planks used to create the surfaces of concrete forms.
- Sub-base: The base of a structure, usually made of concrete, that rests on the ground.
Examples:
- Tapered lagging: The paper describes how tapered lagging was used to form the curved sections of the tower. This involved cutting 2 by 6-inch pieces to a diagonal shape, creating two staves that were wider at one end than the other.
- Collapsible forms: The paper discusses the use of collapsible forms for the tower’s interior. This allowed the forms to be removed in sections, providing access to the concrete for inspection and allowing the forms to be reused.
- Scaffolding: The paper details the construction of the scaffolding used for this project. This scaffolding included wooden planks, ropes, and pulleys, and it was designed to be strong enough to support the weight of the workers and materials.
- Plastering: The paper describes how a plaster coat was applied to the inside of the tank to prevent leakage. This coat was made of 1 part cement to 1-3/4 parts of fine sand. The paper notes that four coats of plaster were eventually needed to achieve a watertight tank.
- Cement wash: The paper describes how the exterior of the tower was treated with two coats of cement wash to improve its appearance. This helped to cover the irregularities in the concrete and to give the tower a more uniform color.
- Steel tank: The paper details the use of a steel tank within the concrete cylinder. This tank was designed to contain the water and to reduce the amount of concrete needed. It was also designed to be light enough to be lifted into place by a crane.
- Concrete dome: The paper describes how the concrete dome was poured in one continuous pour. This was a challenging undertaking, requiring precise planning and execution.
- Concrete roof: The paper describes how the concrete roof was poured in one continuous pour. This was another challenging undertaking, requiring precise planning and execution.
Conclusion:
This 1910 paper offers a unique insight into the challenges and innovative design choices involved in building a large concrete water tower in the early 20th century. The author emphasizes the importance of considering the aesthetic preferences of the community when designing engineering projects, particularly in densely populated areas. The paper also highlights the limitations of plain concrete construction and the increasing popularity of reinforced concrete. By providing a detailed account of the design, construction, and costs associated with the tower, the paper offers valuable lessons for engineers working on similar projects in the future.