Which portable tool is typically used when the main aerial device cannot reach a portion of a building?

The portable tool commonly used when the main aerial device cannot reach a portion of a building is the pole ladder. This tool is designed to provide extended reach for firefighters in situations where traditional ladders might not be effective due to height or accessibility issues. The pole ladder is particularly advantageous because it allows operators to extend the ladder to significant heights while maintaining stability and support, which is crucial in emergency situations.

In scenarios where aerial devices are limited by overhead obstacles or when approaching certain building configurations, the flexibility and added height capability of the pole ladder become essential. It can reach difficult spots that might otherwise be inaccessible, ensuring that firefighters can perform their rescue or firefighting operations safely and effectively.

Other types of ladders, like fire escape ladders, extension ladders, and platform ladders, have their own specific uses, but they may not offer the same versatility or height advantage in every circumstance where an aerial device is unable to reach.