Change Length of Rail or Duct To change length of rail or duct, do one of the following: SOLIDWORKS Electrical 3D menu: Change Length of Rail or Duct . In the menu, click Tools > SOLIDWORKS Electrical > Change Length of Rail or Duct . Right-click a rail or duct and select Update length . Define Length Select Component. Select the component to update the length. Length. Specifies the length. The 3D assembly automatically updates with the new length. Parent topicInsert Equipment Under SOLIDWORKS Electrical 3D