Abstract: A backhoe boom lock for locking the boom to the swing frame during transporting and craning operations. The boom is provided with two upwardly open hooks that project on either side of the swing frame when the boom is retracted into its craning or transport positions. Two bell cranks are located on each side of the swing frame and are provided with transverse catches for engaging the upwardly open hooks. The bell cranks are biased downwardly by springs. A linkage for lifting the bell cranks against the biasing force of the springs extends from the bell cranks into the interior of the operator's cab. The linkage is provided with a control lever, located inside the operator's cab for lifting the bell cranks. After the boom has been retracted into its transport or craning position, the control lever is released and the bell cranks rotated by the biasing springs so that the catches engage the upwardly open hooks on the boom.