Drive along I-65 in northern Indiana, and they’re hard to miss. Look as far west and east as you can and there appear to be hundreds of windmills or wind turbines speckling the countryside. These 300-foot giants have three blades, each measuring 120+ feet long and weighing seven tons. The windmills have changed the landscape along the quiet stretch of highway between Indianapolis and Chicago, and some estimate that they produce enough energy to power a city of 250,000 people.
The average wind turbine is expected to operate 20 years or more, and considering the costs, owners will do whatever it takes to prolong the life. Replacing a gearbox can cost a company more than $500,000 between equipment, labor and lost revenues. Mechanical breakdown is the most common risk for mechanical damage to the windmill, accounting for nearly 60% of claims. A study by Indian-firm Cholamandalam MS Risk Services found that 15% of total breakdown damage costs are a result of damage to the gear box.