Recommended Practices

R.P. No. 1-07 (May 18, 2007)
Permissible Load Concentration for Straight Floor Van Trailers - Establishes the minimum design criteria of non-specialized trailers up to 50 ft. in length to carry concentrated loads. It is intended as a guide to carriers and shippers when transporting heavy, concentrated loads to avoid damaging the trailer floor and structural members.

R.P. No. 4-08 (September 26, 2008)
Truck Trailer Landing Gear (Screw Type) - Provides a suggested hole pattern for trailer landing gear mounting brackets, crank handle location, and landing gear strength rating.

R.P. No. 6-07 (May 18, 2007)
Trailer Hitches and Connections for Interchange Service - Recommends the performance and physical inter-changeability of mechanical, pneumatic and electrical connections in tractor-trailer combination.

R.P. No. 9-10 (April 23, 2010)
Location of Lighting Devices for Trailers - Prepared to serve as a practical guide for positioning lighting devices on truck trailers over 80 inches in overall width in accordance with current regulations of the Department of Transportation. Although the drawings do not attempt to illustrate every type of trailer used in commercial service, a variety of types were chosen having different structural details so that the basic concepts might be applied to any specific design. This Recommended Practice is not intended to imply that it conforms to all state regulations. Each state's regulations if not preempted by Federal Regulations should be complied with in addition to the regulations of the DOT.

R.P. No. 12-07 (September 28, 2007)
Trailer Air Brake System Integrity Test - Intended for use in truck trailer production lines as a final air system integrity test before the vehicle is certified as ready for service.

R.P. No. 21-07 (September 28, 2007)
Tank Vehicles In Hot Products Service - Intended to serve as a guide for proper design and construction of non-pressure tank vehicles for transporting asphalts (Bitumens)or other hot commodities of similar characteristics in properly insulated tank vehicles.

R.P. No. 24-08 (May 2, 2008)
Classification of Weld Finishes for Stainless Steel Tank Vehicles - Establishes a uniform classification of weld treatments for use in specification writing.

R.P. No. 25-08 (May 2, 2008)
Design and Construction of Dry Bulk Pneumatic Trailers - A guide intended for use in designing and operating pneumatic trailers for highway transportation of dry bulk trailers.

R.P. No. 28-09 (May 1, 2009)
Flange And Emergency Valve Dimensional Information - Provides standard dimensions for cargo tank emergency valve inlet and outlet flanges.

R.P. No. 32-05 (May 13, 2005)
Method For Testing and Evaluating Trailer Steel Leaf Spring Fatigue Life - Determines a fatigue life of trailer leaf springs and offers an evaluation of the fatigue test life cycles in order to establish an acceptable minimum "life" standard.

R.P. No. 33-09 (May 1, 2009)
Clean-Out Nipples on Tank Trailers - Promotes uniformity and insures interchangeability of tank clean-out nipples which mate with the straight or tapered internal threads of caps, vents, cleaning equipment, etc.

R.P. No. 35-09 (September 2, 2009)
Permanent Safety Signs/Labels for Truck Trailers and Containers - Is intended as a guide for the design and display of product safety signs and labels for the protection of personnel and property. Requirements are set forth with the aim of achieving a uniform system to identify hazards for persons using, operating, servicing, or in proximity to, truck trailers and containers.

R.P. No. 36-04 (April 16, 2004)
Tank Trailer and Tank Container Nomenclature - Provides a nomenclature for tank trailer and tank container terms to facilitate communication. The nomenclature provided here is the preferred nomenclature of the majority of the trailer manufacturers.

R.P. No. 37-07 (May 18, 2007)
Rating of Van Trailer and Container Floors for Lift Truck Loading - Intended for use in determining and describing the strength of floor systems for closed van trailers and containers of monocoque construction in terms of the magnitude of lift truck front axle load that can be carried safely.

R.P. No. 38-07 (May 18, 2007)
Method for Testing and Rating Heat Transmission of Controlled Temperature Vehicles/Domestic Containers - Establishes standard test methods for determining rates of heat transmission and air leakage of controlled temperature vehicles and domestic containers and to establish a standard heat transmission rating method of controlled temperature vehicles and domestic containers.

R.P. No. 39-09 (May 1, 2009)
Method for Determining GAWR and GVWR for Truck Trailer Certification Describes a method for determining the Gross Axle Weight Rating (GAWR) based on the load-carrying capacity of the axle/wheel assembly components and the Gross Vehicle Weight Rating (GVWR) based on a uniformly distributed payload. Also describes a method for determining the GAWR and GVWR for the certification label prescribed by Title 49, Code of Federal Regulations, Part 567 (49 CFR 567).

R.P. No. 41-07 (May 18, 2007)
Splash Guard Attachments Where Mounting Holes Are Required - Establishes the hole size and locations for mounting 24 inch wide splash guards in order to facilitate replacement.

R.P. No. 44-08 (May 2, 2008)
Air Brake Application and Release Test - Establishes a procedure and test set up for production line testing and inspection of truck trailer air brake systems to determine compliance with requirements established by Federal Motor Vehicle Safety Standard S. 121 Air Brake Systems.

R.P. No. 45-07 (May 18, 2007)
Vapor Collection for MC 306 and DOT 406 Cargo Tanks - Establishes recommendations for vapor collection systems to be used with MC 306 and DOT 406 cargo tanks which are bottom loaded. (Reference TTMA R.P. No. 46)

R.P. No. 46-10 (April 23, 2010)
Bottom Loading MC 306 and DOT 406 Cargo Tanks Establishes recommendations for the design characteristics of MC 306 and DOT 406 Cargo Tanks that would be equipped with bottom loading systems.

R.P. No. 47-09 (May 1, 2009)
Testing, Rating, and Labeling Platform and Van Trailers for Cargo Securement Capability - Establishes test procedures and general performance specifications for tiedown anchor points, front-end structures, and sidewall structures. Doors are not considered cargo securement devices. Trailers manufactured on and after January 1, 2002 should be constructed in accordance with this R.P.

R.P. No. 49-07 (September 28, 2007)
FMVSS 121 Trailer Testing & Certification - Establishes minimum testing procedures for operational aspects of trailer air brake systems as integrated assemblies of trailers, as well as establishes requirements for certification of components relative to performance, the combination of which will allow trailer manufacturers to certify as required by FMVSS 121.

R.P. No. 51-09 (May 1, 2009)
Auxiliary Air Systems - Serves as a practical guide for the inter-connection of air systems for auxiliary equipment with the air brake systems of truck trailers, container chassis and converter dollies.

R.P. No. 53-10 (April 23, 2010)
U. S. Trailer Certification Label - Describes the information required by the National Highway Traffic Safety Administration (NHTSA) which must be placed on the information label of a newly manufactured trailer requiring no further manufacturing operations to perform its intended function other than the addition of readily attachable components such as tire and rim assemblies or minor finishing operations such as painting.

R.P. No. 54-08 (May 2, 2008)
External Work on Cargo Tank Motor Vehicles Which May Have Been in Service Establishes recommended safety precautions applicable to work on cargo tank motor vehicles which have handled flammable materials.

R.P. No. 55-07 (May 18, 2007)
Trailer Entry Securement - Intended as a guide for general design and installation of hardware for a trailer entry closing system to deter and to provide visible evidence of unauthorized entry into the trailer.

R.P. No. 56-03 (September 26, 2003)
Trailer Vehicle Identification Number - Describes the Vehicle Identification Number which must be placed on trailers according to 49 CFR 565 and 571.115 (Federal Motor Vehicle Safety Standard No. 115.) This Recommended Practice does not cover every detail of the federal regulations. 49 CFR 565 and 571.115 should be referred to for the legal require-ments of the VIN. A sample VIN code format is shown, but other code formats may be equally acceptable.

R.P. No. 57-10 (April 23, 2010)
Avoid Placement of Girth Seams (Circumferential Joints) in Voids on Self Supporting Tanks - Explains why girth seams should not be located in voids on self supporting tanks.

R.P. No. 58-08 (May 2, 2008)
FMVSS 121 Brake Requirements For Lowbed and Specialized Trailers - Intended as a guide to the Federal Motor Safety Standard (FMVSS 121) air brake system requirements for lowbed and other specialized trailers.

R.P. No. 59-10 (October 1, 2010)
Tank Trailer Ladders And Walkways - Intended to serve as a guide for the uniform design and construction of ladders and walkways on liquid tank trailers. May be applied to truck tanks and dry bulk trailers to the extent practicable.

R.P. No. 61-10 (April 23, 2010)
Performance of Manhole and/or Fill Opening Assemblies on MC 306, DOT 406, Non-ASME MC 312 and Non-ASME DOT 412 Cargo Tanks - Intended to serve as a guide for the design, construction, and testing of manhole and fill opening covers installed on DOT specification MC 306 and DOT 406 Cargo Tanks.

R.P. No. 62-05 (May 13, 2005)
Vibration Evaluation of Spring Brake Chamber on a Trailer Axle Mounting Establishes a uniform test procedure to provide maximum design criteria to mount spring brake chambers on trailer axles. The procedure is intended to verify the structural integrity of both the spring brake chamber mounting area and the mounting bracket of the trailer axle.

R.P. No. 64-05 (May 13, 2005)
Rolling Tail Pipes - Defines and shows location of rolling tail pipes.

R.P. No. 65-07 (September 28, 2007)
'Stretch' Van Trailers for Over-the-Road Service - Establishes applicable design and minimum testing procedures for 'stretching' van trailers for over-the-road service. It is not the intent of this Recommended Practice to provide a salvage system for damaged or junk trailers.

R.P. No. 66-08 (May 2, 2008)
Trailer Nomenclature - Provides a nomenclature of trailer terms to facilitate communication and define terms used in other TTMA Recommended Practices and Technical Bulletins.

R.P. No. 67-08 (May 2, 2008)
Rating of Platform Trailer Floors for Lift Truck Loading - Intended for use in determining and describing the strength of a platform trailer in terms of the magnitude of lift truck front axle load which can safely be carried.

R.P. No. 68-08 (May 2, 2008)
Urethane Foam Flammability and Safety Measures - Caution Signs - Serves as a guide to establish a caution sign regarding urethane foam flammability and safety measures.

R.P. No. 71-10 (May 13, 2010)
Trailer Axle Alignment - Intended as a guide for the alignment of axles on newly manufactured and rebuilt trailers. It describes one procedure for measuring trailer axle alignment with simple tools. Other more sophisticated procedures are also acceptable.

R.P. No. 72-10 (April 23, 2010)
Trailer Converter Dolly - Lists the requirements and recommendations for trailer converter dollies.

R.P. No. 73-10 (April 23, 2010)
Static Grounding or Bonding of Flammable Liquid Tank Trailers - Serves as a guide in the design and placement of external grounding studs and the internal bonding of the components such as capacity indicators and high level sensors on MC 306 tank trailers to reduce the hazard of static electrical sparks during loading and unloading.

R.P. No. 77-10 (April 23, 2010)
Baffle Emergency Drain Cut Outs for Cargo Tanks - Describes the need for and provides a guide to the location of auxiliary, emergency, baffle drain openings used to facilitate pumping off a baffled cargo tank which has overturned on its side or top.

R.P. No. 78-07 (September 28, 2007)
Design of Circumferential Reinforcing Members on Carbon Steel Cargo Tanks Where Internal Thickness Testing is Precluded by Lining or Product Heel - Intended as a guide to the design of circumferential reinforcements on lined MC 307, MC 312, DOT 407 and DOT 412 cargo tank vessels used for the transportation of corrosive materials and fabricated from mild and high tensile steels.

R.P. No. 80-09 (May 1, 2009)
Drive Shaft Protection on Trailers - Serves as a guide for installing power takeoff (PTO) shaft guards on tank trailers. The Practice only describes areas of the PTO assembly that should be protected and does not recommend specific guard design.

R.P. No. 81-07 (May 18, 2007)
Performance of Spring Loaded Pressure Relief Valves on MC 306, MC 307, MC 312, DOT 406, DOT 407 and DOT 412 Tanks - Intended as a guide for determining the reseating capability of MC 306, MC 307, MC 312, DOT 406, DOT 407 and DOT 412 cargo tank pressure relief valves in a rollover condition.

R.P. No. 83-04 (September 24, 2004)
Leak Testing Newly Manufactured DOT 406 Cargo Tanks and Cargo Tank Vapor Recovery Systems - Establishes procedures for the manufacturer's testing of newly manufactured DOT 406 cargo tanks and cargo tank vapor recovery systems.

R.P. No. 84-09 (May 1, 2009)
Emergency Valve Shear Device Impact Test Procedure - Intended as a guide for performing impact tests on emergency valves to show conformance with 49 CFR 178.345-8(b)(2) which states: "The failure of the sacrificial device must leave the protected lading retention device or part and its attachment to the tank wall intact and capable of retaining product."

R.P. No. 86-09 (May 1, 2009)
Emergency Valve Shear Section Strength Calculations - Recommends an acceptable method for calculating the strength of shear sections on Emergency Valves in accordance with 49 CFR 178.345-8(b)(2) and is intended for emergency valves protected by a shear section.

R.P. No. 88-08 (May 2, 2008)
Air Suspension Application Data - Describes the information required by air suspension and/or axle manufacturers from the trailer manufacturers to prevent misapplication.

R.P. No. 90-08 (September 26, 2008)
Side Turn Signal Lamps For Long Trailers - Recommends placement of side turn signal lamps on trailers longer than 45 feet (13.72 meters) to help alert motorists of impending turns by tractors pulling long semitrailers.

R.P. No. 94-07 (May 18, 2007)
Pressure Test Qualification of the Structural Integrity of DOT 406 and Low Pressure DOT 412 Cargo Tanks - Recommends a pressure proof test as an alternative to the calculated integrity of a cargo tank per 49 CFR 178.345(b), static pressure, and 178.345-8(e), longitudinal deceleration protection.

R.P. No. 95-06 (April 7, 2006)
Hazardous Materials Training for Manufacturers of DOT Specification Cargo Tanks Informs manufacturers of DOT specification cargo tanks of an acceptable training program, as required by 49 CFR, Subpart H-Training, Sections 172.700 through 172.704.

R.P. No. 96-09 (May 1, 2009)
Structural Integrity of DOT 406, DOT 407 and DOT 412 Cylindrical Cargo Tanks Recommends acceptable methods of calculating the structural integrity of DOT 406, DOT 407, and DOT 412 cylindrical cargo tanks in conformance with 49 CFR 178.345-3 and 178.345-8(e).

R.P. No. 97-05 (May 13, 2005)
Trailer Antilock Braking System Wiring - Specifies a method of wiring the antilock braking system (ABS) on a trailer intended to be used on public roads. This R.P. is compatible with TTMA T.B. No. 119 "Electrical Interface for Truck-Trailer Inter-connection." T.B. 119 provides the minimum design requirements for the cables, plugs, and receptacles for the truck-trailer interconnection.

R.P. No. 98-10 (April 23, 2010)
Cargo Tank to Truck Chassis Attachment - Provides items for consideration and recommendations for the mounting and attachment of cargo tanks to truck chassis by cargo tank manufacturers, distributors and re-mounters.

R.P. No. 100-07 (May 18, 2007)
Determination of Trailer Length and Width - Serves as a guide to the length and width limits of commercial trailers in truck tractor-semitrailer, truck tractor-semitrailer-trailer, and truck tractor-semitrailer combinations operating on the National Network.

R.P. No. 101-06 (April 7, 2006)
Verification of Finite Element Analysis - Recommends that the results from linear and nonlinear finite element analysis (FEA) be verified by some means.

R.P. No. 102-08 (May 2, 2008)
Vapor Recovery Line Configurations for DOT 407 and DOT 412 Cargo Tanks Establishes standard configurations for vapor recovery lines on DOT 407 and DOT 412 cargo tanks. These configurations provide for top (on the tank) and bottom (near the tank outlet) vapor recovery. This RP is not intended to address the retrofit of vapor recovery systems on existing cargo tanks.

R.P. No. 103-07 (May 18, 2007)
Trailer Tracking Installation - provides guidance for system component sizes and arrangement, interfacing and mounting for Trailer Tracking Systems intended for dry van semi-truck trailers. Specific components (hardware) and features, and actual operation of the individual devices are not covered by this recommended practice.