A tensioning mechanism for a conveyor system includes a support structure, a first carriage, a second carriage, and a brake mechanism. The first carriage is positioned proximate a first end of the support structure and is supported for movement relative to the support structure. The first carriage includes first rolls for receiving the belt such that movement of the first carriage modifies a tension in the belt. The second carriage is supported for movement relative to the support structure and includes second rolls and at least one return pulley. The second rolls are configured to support a portion of the belt extending between the first carriage and the second carriage. The brake mechanism is positioned proximate a second end of the support structure and includes a brake pulley and a brake selectively retarding rotation of the brake pulley. The brake pulley supports a portion of the belt extending between the brake mechanism and the return pulley.