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From page 8... ... 8S e c t i o n 2 The first objective of this study, a review of the nature and quality of the data currently being collected, was achieved through a literature review, a review of relevant definitions used in analyzing bulk package accident performance, an investigation of existing data collection strategies, and an extensive interview process. The literature review focuses on studies and reports in the following categories: • Cargo tank and portable tank classification and specifications. Read the entire page →
From page 9... ... 9 The review focused on studies and reports in the following categories: • Bulk package classification and specifications. • Cargo tank motor vehicle assembly and repair. Read the entire page →
From page 10... ... 10 and 8,000 gallons of flammable liquids and mild corrosives with vapor pressures not more than 40 psi at 70°F. Figure 2 illustrates an MC 307/DOT 407 cargo tank. Read the entire page →
From page 11... ... 11 aluminum; and are equipped with rollover protection and splashguards that also provide rollover protection. Figure 3 illustrates an MC 312/DOT 412 cargo tank. Read the entire page →
From page 12... ... 12 Volume Capacity (gallons per inch) Lading Density (pound per gallon at 60°F) Read the entire page →
From page 13... ... 13 and covered with a steel jacket while steel tanks need to be insulated and covered with a steel jacket only when carrying a flammable gas. Insulation must be non-combustible if used for tanks carrying nitrous oxide refrigerated liquid and must be corkboard, polyurethane foam, or ceramic fiber/ fiberglass if used for tanks carrying chlorine. Read the entire page →
From page 14... ... 14 Compressed Gas Tube Trailer Tube trailers transport bulk non-liquefied compressed gases such as helium, hydrogen, nitrogen, and oxygen at pressures ranging between 3,000 and 5,000 psi. A group of cylinders, meeting standards outlined in 49 CFR 178.35 are stacked and banded together in a modular or nested shape. Read the entire page →
From page 15... ... 15 pressure relief device continues to function in the event of a collision. Stop valves, or other suitable means of closure, are located close to the shell at all openings except for openings leading to venting or pressure relief devices. Read the entire page →
From page 16... ... 16 scenario. To understand this aspect further, information was obtained from the FMCSA report entitled Guidelines for the Operation, Assembly, Repair, Testing, and Inspection of Hazardous Material Cargo Tanks (Bowman et al. Read the entire page →
From page 17... ... 17 tors involved in the certification of repairs to cargo tanks. Individuals with National Board Inspection Code certification are ideal candidates for providing information as to the location and extent of damage sustained by the lading retention system of vehicles involved in accidents. Read the entire page →
From page 18... ... 18 • Driver factors including driver age, vehicle speed, and driver errors or distractions. The analysis resulted in some unexpected findings. Read the entire page →
From page 19... ... 19 Cargo Tank Accident Investigations Accident investigations were also reviewed to identify key factors for inclusion in a database enabling statistical analyses of container performance. The following sources represent serious, relatively unique accidents that could have been avoided. Read the entire page →
From page 20... ... 20 Facility A -- Single-Stage Manufacturer Facility A is a single-stage trailer manufacturing facility in which the tank is manufactured and mounted on a truck chassis or trailer frame. Facility A produces an average of 7,000 tanks per year (over the past 30 years) Read the entire page →
From page 21... ... 21 Additionally, when fatigue cracks develop in the shell, such as what might occur around support appendages, the influence of repair, maintenance, and qualification practices on the performance of cargo tanks that are later involved in crashes deserves more analysis. In addition to examining tank maintenance practices and structural integrity histories in an accident damage database, Facility B representatives indicated that it would be useful to include the year the trailer was manufactured as well as whether the vehicle was equipped with RSC. Read the entire page →
From page 22... ... 22 single-stage manufacturers while one was an incomplete vehicle manufacturer. They mostly manufactured trailer-mounted tanks although some MC 306/DOT 406 and MC 331 tanks were truck-mounted. Read the entire page →
From page 23... ... 23 Stakeholder Number of Stakeholder Companies % of Stakeholder Respondents Quantity of Tanks per Year Bulk Tank Manufacturers 2 67% 10–99 Repair Facilities 4 50% 1–199 (< 25% damaged in accidents) 1 13% 200–499 (< 25% damaged in accidents) Read the entire page →
From page 24... ... 24 Stakeholder Number of Stakeholder Companies % of Stakeholder Respondents Quantity of Tanks per Year Bulk Tank Manufacturers 1 33% 10–99 1 33% 100–1,000 Repair Facilities 1 13% 1–199 (< 25% damaged in accidents) 1 13% 200–499 (< 25% damaged in accidents) Read the entire page →
From page 25... ... 25 America, while one shipper reported making between 1,000 and 9,999 shipments, and two others reported making over 50,000 shipments. The types of hazardous materials shipped by these companies represent all classes of materials. Read the entire page →
From page 26... ... 26 Researcher experience ranged from 3 years to 35 years, with a median of 20 years. Only one of the researcher survey respondents was employed by an organization that maintained data regarding cargo tank accident performance measures. Read the entire page →
From page 27... ... 27 The accident prevention measures that have been incorporated into standard tank design by at least one manufacturer include lowered center of gravity, electronic stability control or trailer-mounted RSC, and truck conspicuity and enhanced lighting/signaling beyond what is required by regulation. The other accident measures included in the survey (wider wheel feature on our bulk tanks" for the following accident damage protection measures: • Fitting protection beyond federal standards. Read the entire page →
From page 28... ... 28 minimum federal requirements for bulk tanks used to transport hazardous materials. These additional requirements include the following accident damage protection: • Fitting protection beyond federal standards. Read the entire page →
From page 29... ... 29 Identified By: Measure Bulk Package Manufacturer Repair Facility Carrier Shipper Researcher / Government For Improved Accident Protection Top-fitting protection enhancements (enlarge and increase robustness of "spill boxes") Improved bottom fittings protection / protective cages around any piping Remove bottom fittings Locate manual valves close to the tank Use the trailer frame to provide valve and piping protection Provide fitting securement of all closures Reduce unnecessary fittings Ensure piping, vents, piping protection, dolly legs, and rear tires do not extend beyond the profile of the tank Use a "wheels back" trailer design to add additional protection in rear-end collisions Install under-ride protection Continuous frame rails Better dome lids Better internal valves Self-closing stop valves / Emergency valves Stronger bulkheads Increase material thickness (shell and head) Read the entire page →
From page 30... ... 30 Manufacturers. With regard to the most effective means to improve accident damage protection, the general opinion is summarized in the words of one manufacturer, "the current requirements of 49 CFR 178-345-8 are very effective in protecting against accident[s] Read the entire page →
From page 31... ... 31 :yB deifitnedI Tank Part Bulk Package Manufacturer Repair Facility Carrier Shipper Researcher / Government Tank shell Tank heads Support structure: rings, bolsters, baffles, and bulkheads Jacket material Top fittings: valves, pipe nozzles, piping, hydraulic assemblies, pressure relief devices, clean out caps, domes, etc. Rupture disc (on cryogenic trailers) Read the entire page →
From page 32... ... 32 • Tank wall thickness and material strength/toughness. • Baffle and bulkhead location. Read the entire page →
From page 33... ... 33 shape, tank wall thickness, and baffle and bulkhead location. Presence of wet lines, type of wet line construction, and valve design and location were data fields judged to be not as useful to researchers focusing on bulk package performance. Read the entire page →
From page 34... ... 34 Manufacturers. The bulk package manufacturers who responded to the survey had varying opinions on what would be most useful; however, they all agreed that the categories of information listed above would be at least somewhat useful. Read the entire page →
From page 36... ... 36 or a non-release accident) , MCMIS only provides an indication of whether or not the incident is federal or state recordable. Read the entire page →
From page 37... ... 37 non-motorists involved in the crash. If the number of injuries or fatalities is used as a measure of the severity of the accident, the total number of people involved in the accident could be used as the denominator to establish the rate of injury for a given accident. Read the entire page →
From page 38... ... 38 Vehicle Role GES examines each vehicle involved and identifies the following variables: • Travel speed of each vehicle involved. • Travel path of the vehicle involved both before and after a driver made a corrective action to avoid an accident. Read the entire page →
From page 39... ... 39 the VIN, but also contains fields for vehicle license number and state. TIFA records include VIN, truck fuel code, weight code, series, and length. Read the entire page →
From page 40... ... 40 • Design pressure. • Shell thickness. Read the entire page →
From page 41... ... 41 Damage cause. GES records what vehicle factors may have contributed to the cause of the crash. Read the entire page →
From page 42... ... 42 of damage. TIFA records include the principal impact point in terms of degrees around the vehicle and bulk package (no distinction is made between the vehicle and trailer) Read the entire page →
From page 43... ... 43 • The number of general public fatalities due to a hazardous material release. • The number of non-hazardous material fatalities. Read the entire page →
From page 44... ... 44 Pre-Crash Package Descriptors Suitable adaptations of the following fields are some possible additional data to collect in HMIRS: • Tank shape (e.g., cylindrical, oval, etc.) Read the entire page →
From page 45... ... 45 Design Characteristics Affecting Package Resistance to Damage and Tank Stability Package Specification. The inclusion of bulk tank specification enables the evaluation of specification-specific conditional probability of release. Read the entire page →
From page 46... ... 46 Figure 11. Conditional probability of release influence diagram. Read the entire page →
From page 47... ... 47 placement of baffles would allow the following questions could be addressed: • How does spacing of baffles affect bulk package performance? • How does the performance of baffles or baffle attachment rings compare in accident scenarios? Read the entire page →
From page 48... ... 48 a substantial amount of the variability in the conditional probability of release for railroad tank cars (Treichel et al. Read the entire page →
From page 49... ... 49 the presence of existing stress fractures or other such flaws are recorded, the following questions could be addressed: • Does the presence of pre-existing stress flaws affect bulk package performance? • Is there a relationship regarding the proximity of stress fractures or other flaws to accident damage with regard to susceptibility of lading loss? Read the entire page →
From page 50... ... 50 • What is the nature of the relationship between package motion and the CPR? For example, if a package is both rolling and sliding along the ground, is it more susceptible to lading loss than if it were only rolling or only sliding? Read the entire page →
From page 51... ... 51 • 16 represents damage at the bottom middle passenger-side of the cargo tank. • 17 represents damage at the bottom rear passenger-side of the cargo tank. Read the entire page →
From page 52... ... 52 Variablea, b Importance of Inclusion in Accident Damage Databasec Ease of Obtaining Informationd Commodity Characteristics Proper Shipping Name E 1 Hazardous Class/Division Code E 1 Identification Number E 1 Amount E 1 Package Design Characteristics Package Specification E 1 2 3 epahS noitceS-ssorC egakcaP Number of Compartments in Package E 1 Capacity of Each Tank E 1 5 4–2 egatuO knaT 1 4–2 egakcaP eht ni tnemecalP knaT fo redrO 4 4–2 thgieH mumixaM noitceS-ssorC 4 4–2 thgieH muminiM noitceS-ssorC 6 4–2 htdiW mumixaM noitceS-ssorC 6 4–2 htdiW muminiM noitceS-ssorC 8 1 ytivarG fo retneC dedaoL llarevO 1 E noitcetorP egamaD tnediccA mottoB If Not Sacrificial, Extension Beyond Lading Retention Components 2 3 If Sacrificial, Distance from the Major Radius of the Cargo Tank Shell 2 3 1 E noitcetorP egamaD tnediccA revolloR 2 selffaB fo rebmuN 1 if not jacketed, 8 if jacketed 2 selffaB fo tnemecalP 1 if not jacketed, 8 if jacketed 2 sreneffitS gniR fo rebmuN 1 if not jacketed, 8 if jacketed 2 sreneffitS gniR fo tnemecalP 1 if not jacketed, 8 if jacketed 1 E tekcaJ fo ecneserP 1 E lairetaM tekcaJ 6 E ssenkcihT tekcaJ 6 E epyT noitalusnI 1 E lairetaM daeH 1 E ssenkcihT ngiseD daeH tnorF 1 E ssenkcihT ngiseD daeH raeR 1 E lairetaM llehS 1 E ssenkcihT ngiseD llehS po 1 E ssenkcihT ngiseD llehS ediS 1 E ssenkcihT ngiseD llehS mottoB 1 7–5 lairetaM dleW 1 7–5 egnaR erutarepmeT ngiseD 1 1 erusserP gnikroW elbawollA mumixaM 2 1 ngiseD evlaV feileR erusserP 1 7–5 tnemecalP evlaV feileR erusserP Pressure Relief Valve Distance From Bulk Package Stiffeners 6 7–5 2 01 ngiseD tneV ecapS dioV 1 7–5 erusserP tseT elohnaM T 1 7–5 epahS elohnaM 1 7–5 tnemecalP elohnaM Table 35. Variable evaluation. Read the entire page →
From page 53... ... 53 Variablea, b Importance of Inclusion in Accident Damage Databasec Ease of Obtaining Informationd Maintenance/Repair Characteristics 8 8–6 dedorroC tnuomA 8–6 ssenkcihT daeH tnorF lautcA 8 8–6 ssenkcihT daeH raeR lautcA 8 8–6 ssenkcihT llehS poT lautcA 8 8–6 ssenkcihT llehS ediS lautcA 8 8–6 ssenkcihT llehS mottoB lautcA 8 Presence of Pre-existing Stress Flaw(s) in Damage Location 6–8 6 Presence of Pre-existing Stress Flaws(s) Read the entire page →
From page 54... ... 54 • Damaged components (replaces "What Failed" on Form DOT F 5800.1) Read the entire page →

From page 8...

... 8S e c t i o n 2 The first objective of this study, a review of the nature and quality of the data currently being collected, was achieved through a literature review, a review of relevant definitions used in analyzing bulk package accident performance, an investigation of existing data collection strategies, and an extensive interview process. The literature review focuses on studies and reports in the following categories: • Cargo tank and portable tank classification and specifications.