Technical Bulletins

Technical Bulletins are issued principally to aid carriers or shippers in operation of truck trailers or to improve the serviceability or use.

T.B. No. 57 (May 1, 2009)
Guidelines on When to Use Stabilizing Devices on Semitrailers - Emphasizes the potential danger of trailer nose diving or tail diving under certain conditions of loading and unloading and provides guidelines for reducing this danger by the use of stabilizing devices whenever the trailer is not supported by a tractor or converter dolly.

T.B. No. 58 (May 18, 2001)
Cargo Tank Venting - Emphasizes the importance of proper venting to operators and to describe equipment problems that may result from inadequate venting.

T.B. No. 60 (April 7, 2006)
Corrosion Prevention for Aluminum Tanks - Advises users of means of corrosion prevention for aluminum tanks.

T.B. No. 61 (April 23, 2010)
Preheating of General Purpose Chemical Tanks - Advises operators of possible problems which may be encountered when preheating empty tanks.

T.B. No. 65 (May 2, 2008)
Wiring Diagram for Truck Trailers - Illustrates a typical wiring diagram for truck trailers.

T.B. No. 70 (May 13, 2005)
Spring Parking and Emergency Brakes on FMVSS 121 Equipped Trailers Emphasizes the reasons that spring brakes are installed on most trailers and the potential hazards that occur if the trailer is operated with the spring brakes caged or if servicing is attempted without caging the brakes.

T.B. No. 71 (April 23, 2010)
Fifth Wheel Pick-Up Ramps for Truck Trailers - Establishes a guide for the design of tractor pick-up ramps.

T.B. No. 74 (May 13, 2005)
End Dump Trailer Operation - Provides guidance for safe operation of end dump trailers.

T.B. No. 75 (April 7, 2006)
Hot Products Tank Vehicles - Suggests accepted operating procedures for hot product tank vehicles.

T.B. No. 76 (May 2, 2008)
Dry Bulk Receiving Piping Recommendations - Emphasizes the importance of good piping practices for dry bulk pneumatic trailer receiving installation.

T.B. No. 77 (May 18, 2007)
Cracked or Broken Main Beams on a Platform Trailer - Provides guidance for repairs to the main frame beams of a platform trailer that is cracked or broken.

T. B. No. 78 (May 18, 2007)
Upper Coupler Attachment Fasteners for Van Type Trailers - Establishes a guide for replacement of missing, damaged or loose upper coupler attachment fasteners on van trailers. It is of vital importance that attachment fasteners be replaced when damaged to insure safe operation of the trailer.

T.B. No. 79 (April 23, 2010)
Repair and Replacement of Damaged Body Members on Sheet & Post and FRP Van Trailers - Provides guidance for replacement or repair of van trailer main structural components for sheet & post and fiberglass reinforced plywood (FRP) side wall designs.

T.B. No. 80 (April 23, 2010)
Specification Cargo Tank Vehicle Usage - Suggests accepted operating procedures in the proper usage of MC 306, MC 307, MC 312, DOT 406, DOT 407 and DOT 412 cargo tank motor vehicles.

T.B. No. 83 (May 1, 2009)
Pneumatic Tank Vehicle Usage - Suggests accepted operating procedures in the proper usage of Pneumatic Tank Vehicles.

T.B. No. 84 (April 23, 2010)
Tractor Air Supplies for Pneumatic Trailers - Suggests features that should be incorporated when an air supply system is installed on a tractor.

T.B. No. 86 (May 1, 2009)
Modification of Used Vans for Hauling Wood Chips - Establishes certain guidelines for consideration when altering used closed vans for hauling wood chips, shavings, and related forest products to various mills, and to provide certain structural criteria for safe operation.

T.B. No. 87 (May 2, 2008)
Loading Hanging Meat In Meat Rail Trailers - Provides a guide for loading hanging meat in meat rail trailers so proper vehicle stability will be maintained and rollover hazard reduced.

T.B. No. 88 (September 26, 2008)
Broken Wood Floorboard Repair - Provides guidelines for repairing broken floorboards in trailers when the floor construction is of wood and is supported by and fastened directly through cross-members.

T.B. No. 89 (May 1, 2009)
Sliding Undercarriage Retention - Provides information, which will aid in the proper maintenance and safe operation of sliding under-carriages.

T.B. No. 92 (April 7, 2006)
Maintenance of MC 306 Manhole and/or Fill Assemblies - Provides guidelines for the inspection and maintenance of MC 306 cargo tank manhole and/or fill assemblies.

T.B. No. 94 (May 13, 2005)
Loading and Use of Lowbed and Industrial Trailers - Provides some general information about the loading and use of lowbed trailers.

T.B. No. 95 (May 2, 2008)
Trailer Specification - Offers a basic specification for new trailers, which may be adopted to purchase specifications.

T.B. No. 96 (May 18, 2007)
Identification of Openings in Voids and Vapor Return Systems Prior to Cleaning and Repairing MC 306, DOT 406, MC 307, DOT 407 and Insulated Tank Vehicles - Serves to emphasize the importance of properly identifying inspection openings and drains in voids and vapor return systems prior to cleaning and repairing MC 306, MC 307, DOT 406, DOT 407 and insulated tank vehicles.

T.B. No. 97 (May 2, 2008)
Urethane Foam Flammability and Safety Measures - Defines minimum precautionary measures, which should be taken to avoid fire and smoke when repairing foamed trailers.

T.B. No. 99 (April 23, 2010)
Disposition of Spring Brake Chambers - Provides a warning of potential danger in disposing of used or damaged spring brake chambers.

T.B. No. 100 (April 23, 2010)
Inspection of Reinforcing Members on Lined MC 312 and DOT 412 Vessels Emphasizes the need for regular inspection of reinforcing members on lined MC 312 and DOT 412 cargo tanks used for the transportation of corrosive materials. It is primarily intended for cargo tanks fabricated from mild and high tensile steels.

T.B. No. 101 (May 18, 2007)
Corrosion in General Purpose Stainless Steel Tanks - Points out some known factors which can cause corrosion problems in general purpose stainless steel tanks. This corrosion may show up as staining, pitting, etching, and/or stress corrosion cracking.

T.B. No. 102 (May 18, 2007)
Operation and Maintenance of MC 306 and DOT 406 Cargo Tank Bottom Loading Systems - Provides recommendations for the operation, maintenance, and safety of MC 306 and DOT 406 cargo tanks that are equipped with bottom loading systems.

T.B. No. 103 (May 2, 2008)
Liquid and Vapor Control During Loading/ Unloading MC 307 and DOT 407 Tanks Advises operators of the potential fire hazard from spills and health hazard from vapors associated with loading and unloading MC 307 & DOT 407 tanks, and recommendations on ways to alleviate these potential problems.

T.B. No. 104 (May 13, 2005)
Dimensions Affecting Interchange of Van & Platform Double Trailers - Provides guidance for operators and manufacturers in ordering and designing doubles trailers which may be interchanged with other similar equipment. Establishes guidelines for total combinations so that they may be satisfactorily and legally operated within the latest published size limitations for interstate and designated highways.

T.B. No. 105 (May 13, 2005)
Safe Use of MC 306 and DOT 406 Cargo Tank Vapor Collection Systems - Points out the design limitations, operational characteristics and safety considerations for a MC 306 or DOT 406 specification cargo tank subjected to conditions created by vapor collection systems during loading and unloading operations.

T.B. No. 107 (May 1, 2009)
Procedure for Testing In-Service Unmarked, and/or Uncertified MC 306 and Non-ASME MC 312 Type Cargo Tank Manhole Covers - The purpose of this test procedure is to qualify by means of a pressure test the structural integrity of in-service manhole and fill opening covers which are not marked as conforming to TTMA RP No. 61 nor so certified by the manufacturer.

T.B. No. 108 (April 7, 2006)
Spread/Steering Axle Specialty Trailers - Describes the proper and productive use of lowbed and other specialty trailers equipped with spread/ steering axles.

T.B. No. 109 (May 2, 2008)
Pressure Supply Manifold for Unloading Tank Vehicles - Establishes requirements for the air or gas supply manifold for permanent installation at an unloading site where a high-pressure supply is used to pressure unload tank trailers designed for low-pressure unloading.

T.B. No. 110 (May 18, 2007)
Upper Coupler Attachment Bolts for Trailers with Repositionable Upper Couplers - Establishes a guide for determining the number of upper coupler bolts on trailers using a repositionable bolted upper coupler arrangement. It provides a guide for field inspections to establish the adequacy of the bolting on a trailer.

T.B. No. 111 (April 7, 2006)
Electrical System Maintenance and Repair for Trailers Without Sealed Wiring Harness Systems - Intended as a guide for general maintenance and repair of trailer electrical systems other than those with sealed wiring harnesses. Use of this Technical Bulletin does not in any way relieve the user of the necessity of complying with Federal Motor Carrier Safety Regulations or applicable state and local motor vehicle regulations.

T.B. No. 112 (May 2, 2008)
Exhausting (Dumping) Air From One Air Suspension of a Spread Tandem Axle Trailer - Advises operators of the dangers in exhausting (dumping) the air from only one air suspension of a trailer equipped with spread tandem axles.

T.B. No. 113 (May 18, 2007)
Thickness Testing of Unlined Cargo Tanks in DOT Service - Establishes inspection methodology that conforms with the minimum requirements of 49 CFR 180.40(i), and illustrates one method of conducting a thickness test on a cargo tank vessel. This method meets the minimum requirement of the regulation. Other methods of conducting thickness testing may be equally acceptable.

T.B. No. 114 (May 1, 2009)
Wheel-End Separations - Advises operators of the dangers that occur if axle hubs and/or wheels of trailers separate due to improper maintenance procedures.

T.B. No. 115 (May 13, 2005)
Transportation of Food Grade Products in Dry Bulk Trailers - Provides guidelines for the transportation of food grade products in aluminum dry bulk (pneumatic) trailers.

T.B. No. 116 (May 1, 2009)
Determination of MC 300 Series Cargo Tank Minimum Thickness - Aids design certifying engineers, enforcement officials, and registered inspectors in determining the minimum thickness of MC 306, MC 307, and MC 312 cargo tanks when performing the test mandated by 49 CFR 180.407(i)

T.B. No. 117 (May 2, 2008)
Orientation of PAF Manholes with Integral Hinged 10 inch Fill Style Emergency Pressure Relief Valves - Provides guidelines for the orientation of manhole with integral hinged 10 inch fill style emergency pressure relief valves/fills on MC 306 and DOT 406 cargo tanks.

T.B. No. 118 (April 23, 2010)
Transportation of Liquid Food Products - Offers advice and suggestions on the transportation of liquid food products.

T.B. No. 119 (September 24, 2004)
Electrical Interface for Truck-Trailer Interconnection - Informs vehicle manufacturers, component suppliers, and carriers of the recommended electrical interface for truck-trailer interconnection for truck tractors, trucks designed to pull trailers and trailers equipped with antilock braking systems.

T.B. No. 120 (April 7, 2006)
Graphic Illustrations of Motor Carrier Tank Specifications MC 306, MC 307, and MC 312 - A visual aid illustrating construction details of tank trailers designed to comply with DOT Motor Carrier Tank Specifications MC 306, MC 307, and MC 312 for the carriage of hazardous commodities.

T.B. No. 121 (May 1, 2009) Inspection of Unwetted Circumferential Seam Welds, in a Self-Supporting Cargo Tank Motor Vehicle Where External Visual Inspection is Precluded - Provides guidance for inspection of the circumferential seam welds within the connecting structure joining multiple cargo tanks where, in a self-supporting cargo tank motor vehicle, external visual inspection is precluded by insulation, jacketing, doubler bands, etc. per FMCSA.

T.B. No. 122 (April 23, 2010)
Operation of Typical Vapor Recovery (VRL) Lines on DOT 407 and DOT 412 Cargo Tanks - This T.B. is intended to instruct personnel how to operate typical vapor recovery lines on DOT 407 and DOT 412 cargo tanks. These lines conform with TTMA R.P. No. 102.

T.B. No. 123 (May 18, 2007)
Vapor Recovery Retrofit of MC 307 and MC 312 Cargo Tanks - Guidelines for the retrofit of vapor recovery equipment on existing chemical and acid cargo tanks. Need for these systems may arise from requests to comply with the EPA's rule "National Emission Standards for Hazardous Air Pollutants: Organic Liquids Distribution (non-Gasoline)" or other carrier need. Care shall be exercised to familiarize yourself with any particular special needs of the commodity to be carried.

T.B. No. 124 (May 18, 2007)
Pressure Washing Precautions - Covers the power wash precautions to be taken for the trailer externals only. This bulletin does not address the precautions to be followed for power washing of cargo tank trailers.

T.B. No. 125 (September 23, 2011)
CTRMC General Ladders and Tank Access Equipment Maintenance - This Technical Bulletin is intended to suggest a general side access ladder configuration for use on new and used one compartment cargo tanks with a capacity of approximately 6000 to 8000 gallons, and a top walkway.