Rollover Events Research Articles

Evaluation of advanced curve speed warning system to prevent fire truck rollover crashes

Introduction: A disproportionately high number of deadly crash-incidents involve fire-tanker rollovers during emergency response driving. Most of these rollover incidents occur at dangerous horizontal curves (“curves”) due to unsafe speed. This study examined the effects of a curve speed warning system (CSWS) on fire tanker drivers’ emergency response behavior to develop system improvement suggestions. Method: Twenty-four firefighters participated in driving tests using a simulator. A fire tanker model, carrying a full tank of water, was used in emergency driving tests performed with and without CSWS. The CSWS was designed using the algorithm for passenger vehicles with a few initial modifications considering the unique requirements of heavy fire tanker and emergency driving. Results: The results indicated that the CSWS was effective in issuing preemptive warnings when the drivers were approaching curves with unsafe speed during emergency response. Warnings occurred more frequently at curves with smaller radius. Although the CSWS improved driving performance, it did not significantly reduce the number of rollover events. A detailed analysis of the rollover events provided suggestions for improvement of CSWS algorithms. Conclusions: To further improve the CSWS algorithm, the following may be considered: including increased safety speed margin below the rollover critical speed, moving the speed warning trigger from the curve apex to the curve entry point, extending the safe speed-control zone to cover the entire curve, and employing artificial intelligence to accommodate individual driving styles. Practical Applications: Fire tankers continue to be at increased risk of rollover during emergency response due to unsafe negotiation of dangerous curves. Development and use of advanced driver assist systems such as CSWS evaluated in this study may be an effective strategy to prevent deadly rollover crash-incidents. The knowledge generated by this study will be useful for system designers to improve the CSWS specifically designed for heavy emergency vehicles.

Evidence of Glacial Erratic Rollover Revealed by 10Be and 26Al Concentration Variations

AbstractCosmogenic nuclide exposure dating is one of the most intensively applied dating methods with which to study glacial geomorphology. Glacial erratics have been the major dating objective in many studies. Some research has proposed that glacial erratics may undergo rollover and re‐transportation during the late exposure stage, which can affect the dating results. However, there is no direct evidence to confirm this possibility. In this study, we collected seven samples from a vertical section inside a glacial erratic in the paleo‐Daocheng ice cap in the southeastern Tibetan Plateau, measuring their contents of the cosmogenic nuclides 10Be and 26Al. The results show that from the top to the bottom, the concentrations of 10Be were (1.21 ± 0.05) × 106, (1.00 ± 0.02) × 106, (0.88 ± 0.03) × 106, (0.77 ± 0.02) × 106, (0.75 ± 0.03) × 106, (0.95 ± 0.03) × 106 and (1.46 ± 0.04) × 106 atoms/g. The 10Be concentrations decreased from (1.21 ± 0.05) × 106 atoms/g to (0.75 ± 0.03) × 106 atoms/g and then increased to (1.46 ± 0.04) × 106 atoms/g, which is not consistent with the theoretical prediction of a gradual decrease. This phenomenon indicates that the glacial erratic may have rolled over at least once. The lower surface of the erratic could have been on top at some time in the past. Therefore, its exposure age was greater than the exposure age that was expected, based on its current orientation. This study provides numerical evidence for an erratic rollover event.

Analysis of Safety Requirements for Securing the Semi-Trailer Truck on the Intermodal Railway Wagon

The article presented the issue of securing semi-trailer trucks and trailers during their transport using intermodal railway wagons as a part of combined transport. This issue was analysed in different operational conditions related to loading level, cross-winds influence, inertia forces due to the emergency braking, and track curvature. According to general rules of loading and securing cargo, described in the internal and UIC regulations, the transported load should be positioned and secured with minimised risk of undesirable displacement or rolling over during transport. Basic analysis showed that adverse conditions such as strong winds or emergency braking may require adequate additional cargo protection. The lack thereof may result in a severe accident or damage to the transported vehicle or the nearby structures. The presented results for generic road and railway freight vehicles showed that the required anti-rollover torque for a semi-trailer mounted on the railway wagon platform may differ considerably (almost four times at the same maximum tested airflow speed) depending on the conditions related to aerodynamic and inertia influence. The potential weaknesses of the analysis relate to the impracticality of experimental tests for roll-over (or derailment) events under high levels of cross-wind, due to economic and safety reasons. The analysis can be extended in the future by including unsteady aerodynamic forces and a full-vehicle model based on the multi-body method for a specific design solution.

Energy Absorption in Actual Tractor Rollovers with Different Tire Configurations.

In order to better understand the complexities of modern tractor rollover, this paper investigates the energy absorbed by a Roll-Over Protective Structure (ROPS) cab during controlled lateral rollover testing carried out on a modern narrow-track tractor with a silent-block suspended ROPS cab. To investigate how different tractor set-ups may influence ROPS and energy partitioning, tests were conducted with two different wheel configurations, wide (equivalent to normal ‘open field’ operation) and narrow (equivalent to ‘orchard/vineyard’ operation), and refer to both the width of the tires and the corresponding track. Dynamic load cells and displacement transducers located at the ROPS-ground impact points provided a direct measurement of the energy absorbed by the ROPS cab frame. A trilateration method was developed and mounted onboard to measure load cell trajectory with respect to the cab floor in real-time. The associated video record of each rollover event provided further information and opportunity to explain the acquired data. The narrow tire configuration consistently subjected the ROPS cab frame to more energy than the wide tire arrangement. To better evaluate the influence of the ROPS cab silent-blocks in lateral rollover, static and dynamic tests were performed. The results confirm that tires influence the energy partition significantly and that further understanding of silent-blocks’ dynamic performance is warranted.

Forensic Engineering Analysis of a Failed ROPS

Agricultural, commercial, and some lawn and garden tractors have been known to tip and roll over. Roll-over protective structures (ROPS) are designed to assure seat-belted occupants can survive in a zone of clearance within the structure, during and following a roll-over event. Within the laboratory testing parameters established in the current standards, energy absorption is based on tractor mass alone, apart from any other forces that may be acting on the tractor. Current standards allow tractor manufacturers to determine the “reference mass” used for ROPS testing. Most manufacturers fail to include the mass of any attached implements. When implements remain attached to the tractor throughout the roll-over event, ROPS should still be designed to protect operators. In the past, tractors were mainly employed in soil-engaging or surface-grooming exercises. The center of gravity (CG) of these attached implements was relatively low. Today, however, tractors may tow larger, taller, and heavier implements with high CG on multiple axles, such as large liquid manure tank spreaders. The purpose of this paper is to investigate the physical issues associated with tractors towing high CG implements, such as geometrically tall, articulated steerable axle spreaders operating in sloped terrain that cause an ROPS to fail.

Factors influencing side air curtain deployment in rollover motor vehicle accidents

Objective: Recent changes in FMVSS have led to the utilization of side air curtains to provide occupant retention during rollover events. However, the safety advantage provided by the air curtains relies on the vehicle system’s ability to detect the rollover event and deploy the curtains. The purpose of this study is to identify crash and vehicle characteristics in motor vehicle rollovers that influence side air curtain deployment and occupant outcomes. The current study aims to improve the understanding of rollover events and inspire more robust air curtain deployment strategies.Methods: Study data were extracted from rollover cases documented in the NASS-CDS data set from 2011 to 2015. Vehicle model years of 2011 or later with side air curtains installed were examined. The presence of a rollover sensor in each vehicle was determined from vehicle content data available on the Insurance Institute for Highway Safety’s crash rating website. The resulting data set contained 14,003 weighted cases of rollover accidents in which the side air curtain did not deploy (40 raw count) and 23,178 cases of deployment (80 raw count).Results: Several crash event and vehicle characteristics were similar for the nondeployed and deployed groups, including number of quarter turns, primary location of damage, initiating event for the rollover, and vehicle model year. However, the nondeployed group included significantly more passenger vehicle body types (vs. SUV or truck) and had a significantly lower rate of rollover sensor presence. Presence of a rollover sensor increased the odds air curtain deployment by a factor of 36.5 (95% confidence interval [CI], 5.06–265). Cases in which both side air curtains deployed resulted in a higher frequency of injured occupants (Maximum Abbreviated Injury Scale [MAIS] ≥ 3). However, rollover events resulting in these injuries were also associated with higher rates of impact with another object or vehicle and damage to the roof of the vehicle, suggesting a higher energy event.Conclusions: Nondeployment of the side curtain airbags in rollovers occurred more frequently in vehicles without dedicated rollover sensors, which were most frequently passenger vehicles.

Rollover Phenomenon in Liquefied Natural Gas Storage Tank

Liquefied natural gas (LNG) rollover refers to the sudden mixing of stratified LNG layers, which can cause the generation of significant amounts of boil-off gas which create safety issues significantly in LNG storage tanks. Therefore, understanding of the phenomenon is very important for prevention purpose. Heat leak is a major challenge as it causes slow LNG boil-off leading to LNG stratification and LNG rollover phenomenon which has negative impact on people, environment, company asset and reputation. In this work, rollover phenomenon evolution is modeled and simulated using ANSYS FLUENT 16.0 software to study and analyze the effect of different ambient temperatures on the rollover phenomenon in LNG storage tanks and to study the stress distribution due to rollover and its effects on inner wall of the tank and determine the rollover time. This study examined the effect of different ambient temperatures ranged from 283 to 323 K on the LNG rollover inside a 5000 m3 LNG storage tank. Results show that higher temperature will cause higher heat transfer leaks to the LNG tank. The heat transfer through the tank walls is higher than the heat leaks to the tank through tank base. The pressure inside the LNG storage tank is strongly affected by the surrounding temperature. Higher temperature will cause higher pressure to build up in the tank especially along the area between the roof of the tank and the side walls. The simulations results show that significant initial density differences (∆ρ) between the stratified layers lead to late rollover events but last for longer time. At ∆ρ = 30, 15 and 7 kg/m3, the rollover will last for 3.1, 2.5 and 2.2 h, respectively.

Operator protection in rollover events of articulated narrow track tractors

Articulated steering arrangements, wheeled or tracked, are commonly used on agricultural tractors and earth moving machines. In Continental Europe and Italy in particular, this configuration is typical of narrow track tractors. Despite their widespread use, there is little research that specifically investigates articulated tractor rollover protective structure (ROPS) in-field performance with respect to the ROPS test procedures. The aim was to investigate the relevance of the standardised ROPS test procedures regarding articulation joint mobility. The shortcomings of the procedures concerning the Clearance Zone and ROPS testing are evidenced and discussed. It is a recommendation of this work that an update of the international testing procedure be developed for articulated tractor types. The paper indicates how this may be accomplished and presents remedial measures that can be implemented in the interim until this latter goal is achieved.

Assessing the influence of the road-tire friction coefficient on the yaw and roll stability of articulated vehicles

This article addresses the yaw stability of articulated vehicles by assessing the influence of the road-tire friction coefficient on the convergence region of a particular equilibrium condition. In addition, the boundaries of this region are compared to the boundaries of the non-jackknife and non-rollover regions to distinguish the instability phenomenon, jackknife or roll-over, responsible for this delimitation. The vehicle configuration considered in this analysis is composed by one tractor unit and one towed unit connected through an articulation point, for instance, a tractor-semitrailer combination. A nonlinear articulated bicycle model with four degrees of freedom is used together with a nonlinear lateral force tire model. To estimate the convergence region, the phase trajectory method is used. The equations of motion of the mathematical model are numerically integrated for different initial conditions in the phase plane, and the state orbits are monitored in order to verify the convergence point and the occurrence of instability events. In all cases, the longitudinal force on each tire, such as traction and braking, is not considered. The results show the existence of convergence regions delimited only by jackknife events, for low values of the friction coefficient, and only by rollover events, for high values of the friction coefficient. Moreover, the transition between these two conditions as the friction coefficient is changed is graphically presented. The main contributions of this article are the identification of the abrupt reduction of the convergence region as the value of the friction coefficient increases and the distinction of the instability events, jackknife or rollover, that define the boundaries of the convergence region.

Tractor rollover fatalities, analyzing accident scenario

IntroductionIn many countries, traditional data sources for collecting injuries of workers covered by compulsory accident insurance have recently been integrated by new observatories whose results may differ. A comparative analysis of the Italian data collection systems related to fatal tractor accidents in agriculture was performed focusing on tractor rollover fatalities with the aim of analyzing the accident scenario. MethodData from the Operational Archives of the Italian Workers Compensation Authority (INAIL), which collects injuries of workers covered by compulsory accident insurance and those of the National Surveillance System (INAIL_ASL), which provides narrative text reports of work-related fatal accidents have been analyzed and compared to the information collected by the INAIL Observatory. The INAL Observatory was recently set up to complement the collection of fatal accidents involving agricultural machinery. Italian data were then compared to data available at an international level. Fatal tractor accidents vary considerably with respect to fatal accidents in agriculture, being 10.6 and 43.7% for the Operational Archives and Surveillance System, respectively. National Surveillance System records, implemented with narrative texts allowed the accident scenario to be defined. Results71.7% of fatal tractor-related accidents refer to non-ROPS equipped vehicles and of these, 26.5% involved machines originally mounted with a ROPS that had been removed or was inoperative in the folded-down position during the rollover event. Just one fatal event from a collapsed ROPS on the overturned tractor was recorded. It is interesting that 16.6% of fatal accidents involved a clear environmental factor. Practical applicationA campaign to train tractor drivers on the correct use of the combination ROPS and seatbelt can contribute to decreasing rollover events with fatal outcomes. Contemporarily a strict requirement to install ROPS and a seatbelt on tractors, combined to an official inspection at the farm level, can increase the chance of survival in a rollover accident.

Lago Albano, the “anti-Nyos-type” lake: The past as a key for the future

On 21 August 1986 almost 1800 people were asphyxiated by a CO2 cloud violently released by Lake Nyos, Cameroon. Post-1986 monitoring of Lake Nyos revealed that CO2 steadily accumulates in bottom waters through recharge from soda-rich aquifers. The 1986 lake roll-over event triggered scientific research on volcanic lakes, creating “Nyos biased” interpretations: the search for dissolved CO2 in other lakes might have led to over-interpretations regarding hazard assessment. In this study, a thorough review of the historical literature on Lago Albano over the past approx. 2800 years shows no clear evidence of Nyos-type bursts, contrary to previous ideas. In 1989 Lago Albano was affected by a large CO2 pulse, concomitant with a seismic swarm below Colli Albani volcano. Tracing back in historical literature, at least two similar anomalous degassing episodes occurred out of five seismic crises between 1829 and 1927. Partial temperature- and density-driven roll-over of the top-9 m of Lago Albano commonly releases accumulated CO2 each winter (Chiodini et al., 2012). This degassing dynamics avoids long-term CO2 accumulation in bottom waters, as is the case at permanently stratified lakes in the tropics, such as Lake Nyos.Here we show that Lago Albano is an “anti-Nyos-type" lake: sudden recharge and regularly periodic release of CO2 (Lago Albano) vs. steady recharge and sudden release of CO2 (Lake Nyos). Despite past evidence of hazardous events, (1) the intensive well pumping from the Albano aquifer might lower lake level, and hence decrease the CO2 saturation pressure threshold, and (2) the absence of cold winters, hence avoiding yearly lake roll-over favoring CO2 accumulation at bottom layers, are modern factors that rise the need to revise hazard assessment and future monitoring strategies. Despite the fact that CO2 concentration in bottom waters was far from saturation conditions during the last survey (May 2010; Chiodini et al., 2012), making a limnic eruption highly unlikely, it is necessary to know the saturation state of CO2 in bottom waters and physical lake stability at any time, in order to be prepared for a next anomalous co-seismic CO2 degassing event of unknown quantity near Lago Albano.

Investigation of when quad bikes rollover in the farming environment

Quad bikes, referred to as All-terrain vehicles (ATVs) in North America, are the leading cause of fatalities and serious injuries on Australian farms and on–farms in many other countries. These fatal and injurious events have been associated with riding over bumps such as rocks, tree stumps, grass tufts, etc., specifically bumps positioned in-line with one wheel track of the quad bike that can result in a rollover trapping the rider. ObjectivesEarlier work presented Finite Element simulations showing how a quad bike and seated rider travelling over the bump on flat terrain can induce sudden steering and yawing that consequently triggers a rollover event. This study identifies which combination of speed, slope and bump size causes a quad bike with a seated rider to rollover. ResultsTwo different rollover mechanisms occur depending on the speed, slope angle and bump height: a rear wheel impact steering induced rollover mechanism; and a front wheel impact tip-over mechanism. When quad bike speed and the slope steepness are increased to typical values (e.g. 20 km/h and 12.5°), the bump size needed to cause a rollover quickly reduces (e.g. around 100 mm). ConclusionQuad bikes are particularly vulnerable to a rollover event when travelling around farming environments where they traverse relatively small bumps on typical grassy slopes at moderate speeds. This suggests that a quad bike should no longer be considered as a vehicle fit for farming tasks and alternate safer vehicles should be considered.

The biogeochemical vertical structure renders a meromictic volcanic lake a trap for geogenic CO2 (Lake Averno, Italy).

Volcanic lakes are characterized by physicochemical favorable conditions for the development of reservoirs of C-bearing greenhouse gases that can be dispersed to air during occasional rollover events. By combining a microbiological and geochemical approach, we showed that the chemistry of the CO2- and CH4-rich gas reservoir hosted within the meromictic Lake Averno (Campi Flegrei, southern Italy) are related to the microbial niche differentiation along the vertical water column. The simultaneous occurrence of diverse functional groups of microbes operating under different conditions suggests that these habitats harbor complex microbial consortia that impact on the production and consumption of greenhouse gases. In the epilimnion, the activity of aerobic methanotrophic bacteria and photosynthetic biota, together with CO2 dissolution at relatively high pH, enhanced CO2- and CH4 consumption, which also occurred in the hypolimnion. Moreover, results from computations carried out to evaluate the dependence of the lake stability on the CO2/CH4 ratios, suggested that the water density vertical gradient was mainly controlled by salinity and temperature, whereas the effect of dissolved gases was minor, excepting if extremely high increases of CH4 are admitted. Therefore, biological processes, controlling the composition of CO2 and CH4, contributed to stabilize the lake stratification of the lake. Overall, Lake Averno, and supposedly the numerous worldwide distributed volcanic lakes having similar features (namely bio-activity lakes), acts as a sink for the CO2 supplied from the hydrothermal/magmatic system, displaying a significant influence on the local carbon budget.

Dynamic ROPS Test for Tractors over 6,000 Kilograms

Abstract. OECD static tests (Codes 4, 6, 7, and 8) for agricultural rollover protective structures (ROPS) have become accepted standards for evaluating the ability of these structures to protect the operator during tractor rollover events. The strength properties of some materials typically used in ROPS change because of cold weather embrittlement at low temperatures. The static ROPS tests lack the ability to evaluate the strength of these structures during cold weather. The use of the dynamic ROPS test is well noted as a means for proving cold weather embrittlement resistance properties. Unfortunately, application of the OECD dynamic ROPS test (Code 3) is restricted to tractors with unballasted mass greater than 600 kg and generally less than 6,000 kg. The analyses presented in this technical note were undertaken to evaluate the extension of the OECD Code 3 dynamic ROPS test to tractors with unballasted mass of 6,000 kg or more. Tractor unballasted mass and wheelbase data from 47 wheeled tractors tested at the Nebraska Tractor Test Lab from 2014 to 2016 were used to explore the possibility of using a dynamic test method for evaluating the ability of ROPS on tractors with unballasted mass greater than 6,000 kg to meet the safety requirements of agricultural tractor ROPS. The data were graphed and analyzed to determine the required pendulum drop height and energy values to be applied to the ROPS by extending the existing equations to tractors over 6,000 kg. For tractors over 6,000 kg mass, it was determined that pendulum drop heights were too great for practical use. Three pendulum masses were proposed for the dynamic ROPS test: a 2,000 kg pendulum for tractors with mass less than 7,000 kg, a 4,000 kg pendulum for tractors with mass of 7,000 kg or more and less than 14,000 kg, and a 6,000 kg pendulum for tractors with mass of 14,000 kg or more and less than 23,000 kg. Alternate equations were developed for the drop height of each pendulum to meet the energy requirements that are expected to provide similar permanent deflections as those obtained when using the static ROPS test when considering the effect of strain rates on material properties. Tests should be conducted to determine how the results (permanent deflections) from the proposed dynamic ROPS test compare with results from the accepted static ROPS tests. It is further proposed that dynamic testing be conducted with the tractor rigidly restrained in a manner similar to the static test to better account for the wide variety of available tires and mountings for each tractor model. Keywords: Energy, Impact test, Pendulum, Reference mass, ROPS, Tractors.

Barrier-relevant crash modification factors and average costs of crashes on arterial roads in Indiana

The objective of this study was to develop crash modification factors (CMFs) and estimate the average crash costs applicable to a wide range of road-barrier scenarios that involved three types of road barriers (concrete barriers, W-beam guardrails, and high-tension cable barriers) to produce a suitable basis for comparing barrier-oriented design alternatives and road improvements. The intention was to perform the most comprehensive and in-depth analysis allowed by the cross-sectional method and the crash data available in Indiana. To accomplish this objective and to use the available data efficiently, the effects of barrier were estimated on the frequency of barrier-relevant (BR) crashes, the types of harmful events and their occurrence during a BR crash, and the severity of BR crash outcomes. The harmful events component added depth to the analysis by connecting the crash onset with its outcome. Further improvement of the analysis was accomplished by considering the crash outcome severity of all the individuals involved in a crash and not just drivers, utilizing hospital data, and pairing the observations with and without road barriers along same or similar road segments to better control the unobserved heterogeneity.This study confirmed that the total number of BR crashes tended to be higher where medians had installed barriers, mainly due to collisions with barriers and, in some cases, with other vehicles after redirecting vehicles back to traffic. These undesirable effects of barriers were surpassed by the positive results of reducing cross-median crashes, rollover events, and collisions with roadside hazards. The average cost of a crash (unit cost) was reduced by 50% with cable barriers installed in medians wider than 50ft. A similar effect was concluded for concrete barriers and guardrails installed in medians narrower than 50ft. The studied roadside guardrails also reduced the unit cost by 20%–30%.Median cable barriers were found to be the most effective among all the studied barriers due to the smaller increase in the crash frequency caused by these barriers and the less severe injury outcomes. More specifically, the occupants of vehicles colliding with near-side cable barriers tended to have less severe injuries than occupants of vehicles entering the median from median’s farther side. The near-side cable barriers provided protection against rollover inside the median and against a potentially dangerous collision with or running over the median drain; therefore, the greatest safety benefit can be expected where cable barriers are installed at both edges of the median.The CMFs and unit crash costs for 48 road-barrier scenarios produced in this study are included in this paper.

A review: Optimizing performance of Floating Storage and Regasification Units (FSRU) by applying advanced LNG tank pressure management strategies

Summary The demand for Floating Storage and Regasification Units (FSRU) has grown rapidly worldwide since the first unit was commissioned in 2005 and opened many new markets to LNG trade. Technology has evolved leading to a fleet of FSRU ranging from relatively cheap conversions from LNG carriers (LNGC) to larger-capacity, new-build vessels with higher-tank-pressure ratings. The different types of FSRU ideally require operating procedures tailored to their specific designs, capacities, and tank-pressure ratings. Currently, many of the operating practices developed for the lower-tank pressure ratings of LNGC are applied as a matter of routine across the FSRU fleet, leading to operating inefficiencies. There are therefore significant opportunities to improve operating efficiencies on many FSRU and thereby reduce onboard gas consumption and atmospheric emissions, particularly regarding ship-to-ship (STS)-transfer procedures and LNG cargo rollover-protection strategies. Additional non-standard use of recondensing equipment, recirculating condensed boil-off gas as warm LNG back to the cargo tanks, can also reduce unnecessary shipboard consumption of gas. These savings can be achieved without any capital investments or modifications. STS transfers for LNG were first performed in 2007 and are a relatively new, but now routine necessity for FSRU operations. The operating efficiency associated with STS transfers can be significantly improved by adopting 12 straightforward measures. Some of the STS transfer improvement measures recommended involve an increase (beyond current practices) of cooperation, planning, and coordination of tank pressures between discharging and receiving vessels. The adoption of proactive prevention and mitigation measures to limit the potential tank pressure increases associated with LNG cargo rollover events can also appreciably reduce shipboard gas consumption and improve FSRU operating efficiency at no additional cost. Other operating efficiency gains focused on tank-vapor-handling equipment are also attainable for the higher-pressure rated FSRU.

Protecting occupants during passenger vehicle rollover crashes

Protecting occupants during passenger vehicle rollover crashes

Rollover event simulation and optimizations of vehicle Design using Finite Element Analysis

Rollover event simulation and optimizations of vehicle Design using Finite Element Analysis

Injury Mechanisms of Aortic Ruptures to Vehicle Occupants and Vulnerable Road Users – An In-Depth-Investigation over Time

A rupture of the aorta was a common injury observed in the 60ies and 70ies regarding unprotected car occupants, reported in 10% to 15% of vehicle mortalities in the past. With this study it is investigated how often the Aortic Rupture can be observed in today´s traffic accident scene and what changes happened in the course of time history regarding different kinds of traffic participation and different kinds of injury mechanisms. Based on very well documented in-depth-accident cases by GIDAS (German-In-Depth-Accident-Study) a representative sample of all traffic accidents during a 40 year period (years 1973 to 2014) is available (n>100.000 involved persons) and the cases with Aortic ruptures AR (n=142) are analyzed in detail. The Aortic rupture can be observed in high speed accidents with high body deceleration and direct load to the thorax. Nearly always a high compression of the thorax is responsible for the load direction to the heart vessel. The analysis found load in most cases from caudal-ventral in 26.1% and from ventral 21.1%. Another high percentage could be registered from the left and the right (19.7% each) and 7.5% in roll-over events by vehicles with high thorax compression. The rupture was found mostly classical on the area of the aortic arch into pars descendens caused by a kind of scoop-mechanism and in few cases a hyper flexion mechanism, but never with deceleration effect only. Today the AR is very seldom registered for car occupants (0.1%) and also for cyclists (0.05%), more frequent for pedestrians (0.22%) and motorcyclists (0.23%). Related in the course of time history the focus of AR has to change from car occupants to vulnerable road users. Always the characteristic is linked with high thorax deformation mainly in accident situations under high impact speed, no seatbelt and direct body impact.

Development of an automatically deployable roll over protective structure for agricultural tractors based on hydraulic power: Prototype and first tests

An inadequate use of the deployable Roll Over Protective Structure (ROPS) in agricultural tractors contributes to fatalities in rollover events. To help to resolve this problem, an automatically deployable ROPS was designed, constructed and tested. The prototype, called HydraROPS, established two assistance levels for the elevation of the foldable ROPS. In the first level, the driver decides to change the ROPS’ position and this change is made using the manual activation on the board. In the second level, an automatic change to the operative position occurs in situations of impending rollover, without the intervention of the driver. In this level, it automatically sends a phone message with the GPS location to contact emergency response personnel. The tractor’s hydraulic power was used to move the protective structure. In order to increase the deployment speed of ROPS, a pressure accumulator was included in the hydraulic circuit. The deployment time of the ROPS without the pressure accumulator was 2.599s and with the pressure accumulator 0.743s. The results of the research show that the pressure accumulator assembled in the hydraulic circuit reduced the deployment time of ROPS by 71%; and that the electronic control system can correctly predict overturn. HydraROPS has the advantage compared to other automatic deployment devices of protective structures that can be installed on tractors equipped with a certified rollover protective structure. The installation in marketable tractor models does not modify the protection structure; therefore a new certification of the protection structure is not necessary.