RULES OF THE LOAD
What is the OTLRM?
I model the American outline so my loading rules are governed by the rules of the AAR.These load regulations are published by the Association of American Railroads in the form of the “Open Top Load Restraint Manual” (the AAR OTLRM). This manual, which is 1500 pages thick, governs the “North American rail industry requirements for securing commodities that are loaded on open top railcars, trailers, and containers for safe and reliable rail transport” (Section 1, page iii). The Manual was first adopted in 1896 and has been updated on a regular basis since then. The latest edition (March 2003) contains all the changes, revisions and updates for 2003. The 7 OTLRM sections can be ordered from the AAR for about $100-00 a section!
Most railroads advise shippers to consult the OTLRM when shipping their commodities in order to ensure that their loads aren’t going to move about during transportation. Shippers are responsible for re-fastening a load if it happens to come loose during transportation. Several companies employ specialist loadmasters who do reloading for a fee.
Below is a brief summary of what the OTLRM sections comprises:
Section No. 1. General Rules for Loading All Commodities
These are the general rules and guidelines for all commodities shipped on open top railcars in interchange service. These include procedures for testing, legal responsibilities, minimum requirements, guidance on setting up multicar and dimensional load shipments. There is also a list of various approved tie-down and fastening materiels at the end of the book. This section must be used in conjunction with the relevant Section Nos. 2 through 6, depending on the load to be shipped. Section 7, dealing with containers and other TOFC shipments, is not included in this association- see below for the reason.
Section No. 2. Rules for Loading Metal Products, Including Pipe
These are the commodity specific loading figures for various finished and partially finished metal products including wire, rod, structural, fabricated shapes (except machinery), scrap, raw metals, and steel and iron pipe.
Section No. 3. Rules for Loading Construction and Farm Machinery
These are the commodity specific loading figures for various pieces of farm equipment, vehicles, tractors, combines; and heavy equipment and other implements used in road grading/making and excavating.
Section No. 4. Rules for Loading Heavy Components and Miscellaneous Commodities
These are the commodity specific loading figures for various items such as machinery, cranes, cylinders, tanks, transformers, boilers, locomotives, car bodies, extra-heavy car loading, airplanes, boats, and non-metallic pipe.
Section No. 5. Rules for Loading Forest Products and Miscellaneous Building Materials
These are the commodity specific loading figures for various items such as lumber, logs, poles, pulpwood, certain panel products, and engineered wood products such as laminated beams and veneer lumber. Included are miscellaneous building materials and sheet products such as gypsum, hardboard, particle board, cellulose board, and styrene sheets.
Section No. 6. Rules for Loading Military Equipment and Materiel
These are the commodity specific loading figures for various items such as armored tanks and similar combat vehicles, trucks, trailers, artillery, pontoons, cranes, and road building and materiel handling equipment such as forklifts.
Section No. 7. Rules for Loading All Commodities on Open Top Trailers and Containers for Rail Transport
This is a stand-alone section of the manual which contains the general rules applicable to all commodities shipped on open top cars and containers that are to be transported on railcars in interchange service.
The AAR publishes the diagram index on its website, so that if you need to purchase sections of the manual, you know which ones you’re after.
Why do we have loading rules?
The aim of the OTLRM is to provide safe movement of loads from origin to destination by using common, economical methods of fastening. These rules are mandatory and set the basic requirements a shipper must meet for the load to be within the legal scope of shipping.
It’s interesting to note that the AAR also covers intermodal trailers and containers, flatbed trailers and flat-rack containers that are not enclosed in the OTLRM as they expose the commodities to the environment. Their definition of “Open Top” is even broader than the one I subscribe to.
Another importance in the manual is the specs on the materials which are to be used for what type of load. There is a common view that ropes and wire cable are not as effective as chains due to the fact that ropes have an inbuilt elasticity. To test this theory, look what happens when a rope is tied an unmovable locomotive and to one to pull it: the rope will stretch and break. That stretching is why ropes and cables are only used under certain circumstances.
Another important factor in loading a car is keeping the brake wheel (which is on the “B” end of the car) free from the load so that it can be operated without interference. Rule 2.1 of the OTLRM stipulates the following clearances: refer to the diagram below for easy reference:
Red: 12” minimum clearance from the end of the car, extending from the center of the brake wheel to the side of the car and a 6’ clearance from the car floor to the bottom of the load.
Dark Blue: 6” clearance at the back, both sides and above the brake wheel.
Pink: A 4” clearance below the brake wheel.
When the free area around the brake wheel is looked at closer, the open area around the brake wheel in fact measures 6” X 6” X 10”
Rule 3.3 of the OTLRM deals with the weight and position thereof on the car. This rule does not apply to 85’ & 89’ flat cars, TOFC, COFC Auto racks.
The load weight of the car may not be exceeded. Similarly, the load must be centered on the car both end to end of the car as well as side to side. Where the load is of such a nature that the weight is distributed unevenly, ballast weight must be used to correct the load imbalance. (A wheel loader has its engine over the back axle so a ballast weight will have to be added to the bucket end of the car to level out the weight over the trucks). The ballast and the load may not exceed the car’s tonnage.
The load dimensions for a single car that has unrestricted clearance on all the roads is compiled in a section of the guide called “Plates”. These Plates are marked as Plate B, B-1, C, C-1, D, E, F and H. All cars are to be constructed to an extreme outside width of 10’-8”. This width must include outside body parts such as stake pockets and tie downs.
More information on the OTLRM can be found at the AAR website. As needed, I will refer to them in my construction articles.
