Structures Functional Group

Technical Committee 28 – Clearances

This committee is responsible for maintaining current knowledge of clearances required by law or regulation in each of the political entities through which the member roads of the Association of American Railroads (AAR) operate and making this knowledge readily available to members of the AAR. They are also responsible for publication of clearance diagrams defining clearances required by various AAR interchange rules and developing procedures to protect the movement of excessive dimension or overweight loads.


Joseph B. Boehle

AVP Marketing

Kasgro Rail Corporation


Vice Chair

Greg McComas, Jr.

Clearance Manager

BNSF Railway


Success Stories

CSXT recently moved a Mitsubishi Power Systems Americas, Inc. Turbine and Generator from the Port of Charleston SC. to Smyrna GA. to a Southern Companies power generation plant. The move was unique account two (2) privately owned schnable / shiftable cars owned by Emmert International and Mammoet Inc. were consisted in the same train. The Turbine weighed 734,000 lbs and measured 16 ft 9 in. wide and the Generator 659,000 lbs and 15 ft 1 in. wide. Altogether there was approximately twenty (20) lateral and vertical shifts required to get this monster shipment home safe . The move required close coordination between the car operators and railroad crew in charge of the train. The Car Operators shown in the last photo are from L to R, Mr. Tom Bell and Ray Wonnek with Mammoet, then Mr. Stig Broman , Chip Kachel and Carl Youman with Emmert.


RICA Website:

Subcommittees and Current Assignments

Subcommittee A: Recommendations for Further Investigation and Research.

Subcommittee B: Revision of Manual.

C-1-62: Compilation of the Railroad Clearance Requirements of the Various States. Ongoing assignment.

C-2-85: Compilation of a comprehensive glossary and bibliography pertaining to the technical literature on railroad high and wide clearances. Ongoing assignment.

C-4-85: Equipment Diagrams and Ratings. Ongoing assignment.

C-6-89: EDI/Web page development and maintenance. Ongoing assignment.

C-8-94: Research and develop any new methods for measuring clearances, particularly means of measuring high/wide loads at interchange points. Ongoing assignment.

D-8-94: Maintaining existing clearances. Ongoing assignment.

D-10-97: Study car behavior and recommend tolerances between various types of equipment and obstructions at different speeds. Identify all factors involving tolerances. Ongoing assignment.

D-11-99: Parameters for handling high combined center-of-gravity loads. Ongoing assignment.

D-10-04: Identify significant clearance critical structures and facilities and the maintenance procedures and events. Ongoing assignment.

D-12-04: Identify clearance critical structures and the activities that could potentially reduce clearance at each structure. Ongoing assignment.

D-01-10: Clearance EDI exchange. Ongoing assignment.

D-01-11: 3rd Rail Clearance.

D-12-12: Buffer Car Study.

D-13-12: Plate L Clearance Study.

D-14-12: 3rd Rail Clearance Study.

D-1-15: National Transformer Emergency Procedures.

D-2-15: Standardization of Clearance Rules.