The need for a new power transmission line is assessed, followed by meticulous planning, procurement of materials, and installation. The newly constructed tower is fortified with a protective layer of zinc, commonly referred to as galvanizing, which can have a lifespan of 20 to 50 years, contingent upon its quality, quantity, and service environment. This is financed through Capital Expenditure (Capex) funding, thereby distributing the financial responsibility to ratepayers through their imposed rates.

Over the tower's lifespan, regular maintenance tasks are performed. Bolts are periodically replaced, foundations undergo repairs, and in some instances, structural elements are swapped out. However, it's important to note that these routine maintenance activities do not mitigate the gradual degradation of the galvanizing layer, which ultimately leads to corrosion and, ultimately, the failure of the entire structure over time.

Maintenance activities for the tower are categorized under Operations & Maintenance expenditures. Given that the asset was acquired using CapEx funds from ratepayers, the mentality of operation-to-failure takes hold. The objective then shifts to maximizing the asset's operational lifespan before allocating further CapEx funds for its replacement.

As the galvanizing layer diminishes, corrosion sets in, initiating the deterioration of the asset itself. This progression leads to visible corrosion and a reduction in structural integrity, ultimately necessitating the replacement of the entire structure.

Once the existing tower has reached the end of its serviceable lifespan, the cycle starts over — thorough planning, procurement efforts, and assessment for a rate case to install a new replacement tower that is incredibly expensive and potentially disruptive to critical power transmission. This will be classified as a Capital Expense, thereby falling within the responsibility of the ratepayers again.