Ware River Power Inc. Hydroelectric Plant Rehabilitation Project

Introduction and Project Overview

SAM recently helped to rehabilitate a hydroelectric plant on the Ware River in central Massachusetts. Our team was contacted directly by the proprietor of the Ware River Power Inc. hydroelectric plant, a multi-generational family operation. Having taken over operations of the facility from his father, the current operator remains committed to preserving the plant due to a deep sentimental connection. A previous engineering assessment had indicated that the penstock, which channels water to the plant’s turbines, had become structurally unsound, requiring immediate attention. Recognizing the need for ongoing maintenance, he sought to ensure the facility’s structural integrity.

To address these concerns, The HL Turner Group was engaged to assess the penstock and propose a solution. The plan included reinforcing some sections of the tube and filling other sections that were no longer needed with flowable fill concrete. However, before these solutions could be implemented, a detailed survey of the entire penstock was necessary to guide the design and planning process. SAM was chosen for this task due to its expertise in advanced surveying techniques, which were essential for accurately capturing the location of the penstock and ensuring that the proposed solution would be effective.

Key Challenges

The most significant challenge of this project was the difficulty of accessing the penstock tube for surveying. The confined spaces within the tube, compounded by tight access points, made traditional surveying methods completely unfeasible. Additionally, precise measurements were crucial for the engineering team to plan and implement the necessary repairs. The tight openings and complex structure of the penstock tube posed additional challenges for accurate data capture.

Surveying Technology and Equipment

To tackle these challenges, SAM used advanced Leica P40 laser scanning technology to capture high-precision measurements of the penstock tube. The Leica P40 is known for its ability to capture detailed point cloud data and maintain level measurements with its dual-axis compensator, making it ideal for this project. Despite the difficulties accessing the penstock, the team successfully used small openings at both ends of the primary tube and ensured proper scan control was set up for accurate data collection.

The scanner and its container, which together weigh over 50 pounds, were initially going to be lowered through a vertical surge tube into the primary penstock tube using an extension ladder and rope, but we deemed this method unsafe. Instead, a more secure solution was developed, allowing just the scanner to be carefully passed through a small access point while the empty container was lowered down through a vertical surge tube. The scanning process provided the engineering team with a 3D model of the penstock in relation to the surrounding buildings and ground-level features, which was crucial for planning the repairs.

Safety Considerations

Given the confined space and proximity to large volumes of water, safety was a top priority. The team implemented a confined space entry plan and coordinated with the local fire department, which had trained personnel available for confined space rescue. This ensured that safety protocols were followed and that a response team was on standby throughout the scanning process.

Data Collection and Deliverables

Using the Leica P40 scanner, the surveying team collected detailed data on the penstock’s structure, which was then used to create a CAD plan. The final deliverable included both planimetric topographic surveys and elevation views, providing the engineering team with an accurate map of the penstock’s current location and its spatial relationships to surrounding structures. This data was essential for planning the reinforcement and filling of the damaged sections.

Outcomes and Future Plans

The data collected from the survey enabled the engineering team to plan the next steps in rehabilitating the penstock. The proposed solution involves reinforcing sections of the tube and filling the most damaged portion with flowable fill concrete. These repairs will stabilize the penstock and ensure that the plant continues to operate efficiently.

The project not only provided the engineering team with the necessary information for a successful rehabilitation plan but also set a positive precedent for future projects requiring advanced surveying techniques in difficult-to-reach locations.

Conclusion