Let me give you an example. We were asked to install drilled shaft foundations for a large power transmission tower in the Midwest. Drilled shafts are great foundations for these towers. They're relatively straightforward to design, and we've installed hundreds of them. But in this instance, the project engineer tried to optimize the design, mistakenly thinking that he could save some concrete and money by applying a little innovation. Instead of calling for straight vertical shafts, the design called for battered (inclined) ones with bell-shaped (flared) ends anchored in bedrock.
MINING NIGHTMARE. We warned the clients before we bid that the job would be tricky, but they asked us to give it a try anyway. Instead of a standard drilling job, the project turned into a mining nightmare. Drilling at an incline through rock required extremely heavy tools--so heavy that they tended to turn downward. Instead of a battered shaft, we got a hook-shaped foundation. It was also difficult to keep the belling tool upright. We ultimately creating a lopsided bell at the end of the hook. Consequently, the "better mousetrap" design was scrapped after the first shaft and completely redesigned. But still, the failed attempt at battered bells ultimately added 30% to the cost of the foundations.