What must occur when the control rope is pulled in the direction of travel on an endless belt type manlift?

When the control rope on an endless belt type manlift is pulled in the direction of travel, the brake is engaged to ensure the safety of the operation. This mechanism is important because it prevents the manlift from moving uncontrollably and provides a safe way to stop the device when needed. Engaging the brake provides control over the movement, ensuring that the manlift operates smoothly and safely in accordance with safety protocols.

The other options do not align with how an endless belt manlift functions. For example, increasing the motor speed would suggest that the manlift is accelerating, which is not the intended reaction when the control rope is pulled for control purposes. Activating emergency stops or exceeding load limits would also not commonly occur simply by pulling the control rope; these actions are reserved for specific safety situations or operational anomalies. Therefore, engaging the brake is the appropriate and safe response to pulling the control rope in this context.