Railroad equipment managers, leasing companies, and railroads use the 456 Railroad Equipment Inquiry or Advice transaction to request information about or provide updates regarding railroad equipment such as freight cars, locomotives, and chassis. Typically sent by one railroad or equipment lessor to another railroad, regional carrier, or equipment provider, this transaction can initiate inquiries about equipment location and status or serve as an advisory notification. The EIA (Beginning Segment for Equipment Inquiry or Advice) segment establishes the transaction’s purpose and scope, while the N7 (Equipment Details) segment—nested within the optional LX Loop—provides specific information about the equipment being inquired about or reported on. The ER (Rail Event Reporting) segment, contained in the optional ER Loop, allows senders to communicate significant events or status changes related to the equipment.

Norfolk Southern Railway might send a 456 transaction to CSX Transportation to inquire about the location and service status of twenty refrigerated boxcars that Norfolk Southern owns but are currently in CSX’s possession for interchange. The inquiry would reference specific car numbers and equipment identifiers in the N7 segments, request stop-off information via the S1 Loop if the equipment is expected to move through multiple yards, and ask for event reporting details that CSX would populate in the ER Loop regarding recent handling or maintenance performed on the cars. CSX would respond with a 456 advice transaction confirming equipment location, adding route information via the R2 segment, and documenting any special handling instructions in the H3 segment to inform Norfolk Southern of current conditions and expected movements.