In one embodiment, a system includes a first door assembly operable to at least partially cover an opening of a rail car. The system includes at least one Network Routing Element, a Service Broker, a media sever, a plurality of application servers and a plurality of border elements, all of which are coupled to the CCE. Another method embodying the invention can include electronically receiving a lien waiver from a participant in a construction project, electronically transmitting payment to the participant in response to receipt of the lien waiver, and releasing the lien waiver in response to the payment. The supporting seat has a positioning hole facing to the positioning groove.