Figure 3. Soil nailing in progress with two steep slopes connected by a valley at the base, creating a river crossing for the pipeline installation.
with the different types of slopes and terrain, and how this affects the operation of the equipment. Constructing pipelines through steep slopes requires a special skillset of the entire crew. Operating heavy equipment with winching processes requires the confidence and experience of the operator and spotter. Pipe stringing and welding activities change based on load size and the equipment’s maximum slope capability, and labour tasks need to be completed with special attention to the effects high altitude may have on the person. Completing competency checks to confirm everyone understands – and is capable of performing – their assigned tasks is critical for safety. “We all have our limits as to what conditions we are comfortable working in and construction through mountainous terrain is not for everyone,” says Mike Lillie, Vice President of Health, Safety and Environment with PPL. “If someone feels uncomfortable with their task and decides to leave the project, I respect that. Knowing yourself and your own capabilities is a priority.”
Equipment and winching
Figure 4. Working on a steep slope requires winching, which is a process of using cables to move equipment up and down the hillside. Sometimes it is necessary to create a daisy chain, meaning multiple pieces of equipment winched together down the steep slope.
Figure 5. Seeding and mulching is more challenging through mountainous terrain and must be completed using less conventional means, such as by helicopter. Skilled pilots maneouvre these nimble aircrafts along the right-of-way to effectively spread ground cover crops from a spreading bucket.
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World Pipelines / EXTREME 2022
Installing infrastructure through mountainous locations uses traditional pipeline construction equipment that has been adapted to the unique challenges of the terrain. Hoisting and rigging configurations are decided and specialised tracks are chosen, typically single grouser pad cleats for enhanced traction. Heavy equipment has additional features added with a focus on winching activities, such as welding specific anchor points and connection systems to each piece to form secure attachment points for the winch cable and a redundancy in safety supports. Once configured for the specialised task of winching, operators can safely move equipment up and down steep slopes. Communication is critical during this process. Winching involves attaching equipment to a secured tractor, secured winch or fixed pole at the top of the hill so the working equipment can be safely lowered down as well as pulled back to the top. This is done by connecting a steel cable between a winch and a piece of equipment using the reinforced anchor points and support systems, sometimes creating a daisy chain of heavy machinery where multiple pieces of equipment are connected to each other. This high-stakes type of construction requires dependable equipment built for the task. Materials used to winch, such as steel cable and shackles, as well as the way they are attached to equipment, is all taken into consideration. The production standards, quality, specifications and composition of materials is evaluated and the best performer chosen to be used across the entire project. “Our largest project through steep slopes required us to assess every process and procedure. We researched new materials available in the market as well as implemented the new technologies available,” says Fenton. “We created approved material lists and didn’t allow any substitutions. With 100% support from our
