Standard Road Plans - RF Series Drainage English RF-2 Construction of Type "C" Concrete Adaptors for Pipe Culvert Connections RF-3 Concrete Aprons RF-5 Metal Pipe Aprons and Beveled Ends RF-7 Corrugated Metal Type "A" Diaphragm RF-8 Precast Stock Pass RF-13 Pipe Bends and Half Pipe RF-14 Connected Pipe Joints RF-19A Subdrains for Fill or Foundation Drainage (Standard) RF-19B Subdrains Standard (Farm Tile Replacement) RF-19C Subdrains (Longitudinal) RF-19E Outlets for Longitudinal, Transverse and Backslope Subdrains RF-19F Subdrain Outlets (Standard Subdrain, Pressure Release and Special) RF-21 Culvert Pipe Tee Sections RF-26 Pipe Apron Guard RF-27 Beveled Pipe and Guard RF-29 Safety Grates for Box Culverts RF-30A Culvert (Bedding and Backfill) RF-30B Pipe Culvert (Cover and Camber) RF-30C Pipe Culvert (Installation Details) RF-31 Depth of Cover Tables for Concrete Pipe RF-32 Depth of Cover Tables for Corrugated Pipe RF-38 Intake for Bridge End Drain RF-39 Scour Protection for Bridge End Drain RF-40 Rock Flume for Bridge End Drain RF-42 Low Clearance Concrete Pipe Aprons RF-43 Metal Arch Aprons (for Corrugated Metal Pipe) RF-44 Metal Safety Slope Apron (6:1 Slope) RF-45 Slotted Drain for Median Crossovers