On an overhead crane or gantry crane, brakes are typically required anywhere uncontrolled motion could create a safety hazard, damage equipment, or cause positioning errors. The most critical is the hoisting mechanism brake, because it must hold a suspended load safely during stops and power loss. The trolley travel (cross travel) brake is also important for controlled positioning and to prevent unintended rolling on sloped rails or due to inertia. The bridge travel (long travel) brake on an overhead crane—or gantry travel brake on a gantry crane—controls acceleration/deceleration and prevents drift during parking.
In higher-risk environments (outdoor gantry cranes, ports, wind-prone yards), a dedicated storm brake or rail clamp may be required to secure the crane against wind loads, which is a different duty than normal travel braking. The correct brake layout depends on crane class, duty cycle, speed, and safety requirements.