scholarly journals On the permissible speeds of empty freight cars mounted on 18-100 model bogies

2021 ◽  
Vol 80 (2) ◽  
pp. 65-75
Author(s):  
A. M. Brzhezovskiy ◽  
O. A. Krasnobaev ◽  
A. V. Spirov ◽  
I. E. Il’in
Keyword(s):  
Traffic Safety ◽  
Field Tests ◽  
Technical Condition ◽  
Potential Threat ◽  
Motion Stability ◽  
Rail Track ◽  
The North ◽  
Motion Speed ◽  
Circular Curves ◽  
Along Track

Problem of ensuring motion safety of empty freight cars is most acute in relation to cars on bogies of model 18-100, which is mainly due to operational wear of wheelsets, side frames and bolsters, as well as spring suspension elements. A potential threat to traffic safety arises when a train, composed of mostly empty and lightly loaded cars, moves along track sections that have deviations in the geometry of rail track of III and higher degrees or combinations and sequences of deviations of II degree. The article presents the main results of complex studies: mathematical modeling of the dynamic interaction of the track and empty freight cars of various types of bogie wear based on the Universal Mechanism software and field tests of cars on measuring sections of tangent, easement and circular curves with a radius of 350, 650, 800, 1000 and 2050 m on the section Belorechenskaya — Maykop of the North Caucasian railway. Dynamic qualities and motion stability of empty freight cars of various types are investigated depending on the parameters of the technical condition of the running gears and the deviations of the geometry of the rail track of II and III degrees of various types and combinations when moving in tangent and curved track sections. Authors provide tables and graphs of the dependences of indicators of dynamic qualities and motion stability of universal empty freight cars of various types on the motion speed in tangent sections of the track and circular curves of various radii and easement curves containing artificial deviations of the geometry of the rail track, most negatively affecting traffic safety. Recommendations are given for correcting the regulatory documents of the Russian Railways, which regulate the permissible speed of motion of empty freight cars, depending on the technical condition of the running gear.

Assessment of the technical condition of underground structures of the largest hydroelectric power station in the North Caucasus, the Chirkeyskaya HPP

2021 ◽  
Vol 18 (3) ◽  
pp. 410-420
Author(s):  
Vladimir N. KAVKAZKY ◽  
◽  
Yana V. MEL’NIK ◽  
Alexey P. LEIKIN ◽  
Andrey V. BENIN ◽  
...  
Keyword(s):  
Large Scale ◽  
Practical Importance ◽  
Hydroelectric Power Plant ◽  
Technical Condition ◽  
Hydroelectric Power Station ◽  
Hydroelectric Power ◽  
Underground Structures ◽  
North Caucasus ◽  
The Caucasus ◽  
The North

Objective: Chirkeyskaya HPP is by far the most powerful hydroelectric power plant in the North Caucasus with the highest arched dam in Russia and the second highest dam in the country after the Sayano-Shushenskaya HPP. This explains why it is called the pearl of the Caucasus. Methods: For the operation and maintenance of this unique structure, a large-scale complex of underground structures for various purposes was built, the technical condition of which must be constantly monitored. To carry out work on the survey of underground structures, the management of the design and survey institute of JSC “Lengidroproekt” decided to attract specialists from the Department of Tunnels and Subways and the Test Center “Strength” of Emperor Alexander I Petersburg State Transport University. The work was successfully carried out at the end of 2015. Results: The safety of underground structures was objectively assessed. Recommendations for the repair and further comprehensive reconstruction of the Chirkeyskaya HPP have been developed. Practical importance: Carry out work on the survey of underground structures of Chirkeyskaya HPP is allowes elaborate of complex measures on safety from Chirkeyskaya HPP.

Investigation of the interaction of car wheels with the stand rollers during braking

2021 ◽  
Vol 13 (1) ◽  
pp. 68-77
Author(s):  
Igor Мarmut ◽  
◽  
Andriy Kashkanov ◽  
Vitaliy Kashkanov ◽  
◽  
...  
Keyword(s):  
Traffic Safety ◽  
Technical Condition ◽  
The Body ◽  
Power Model ◽  
Equilibrium Equations ◽  
Design Features ◽  
Complex Objects ◽  
Passenger Cars ◽  
Wheel Drive ◽  
Four Wheel Drive

The article discusses the issues of modeling conditions for obtaining diagnostic information about complex objects. As an example, the study of the braking qualities of four-wheel drive cars on an inertial roller stand is considered. Diagnosing the technical condition of cars from the point of view of traffic safety is one of the most important problems. This is especially important for systems whose technical condition affects traffic safety: especially braking systems. Foreign and domestic experience testifies to the effectiveness of instrumental control. The diagnostic equipment includes roller stands, on which you can check the braking properties of cars. As shown by many studies, in particular, carried out at the Department of Technical Operation and Service of Automobiles, KhNADU (HADI), inertial stands provide more reliable information about the technical condition of the car. Such stands allow you to reproduce the real speed and thermal modes of the brakes (especially those equipped with ABS). To improve the accuracy of diagnosing a car on a roller stand, it is necessary to have an idea of the nature of the interaction of the car wheels with the rollers. The studies of wheel rolling on the stand rollers have been carried out by many authors since the 80s of the last century. However, all these studies were carried out on uniaxial stands and for mono-drive vehicles. Nowadays, a large number of passenger cars have four-wheel drive. Rolling of the wheels of such cars on rollers and their interaction has practically not been studied. Therefore, a return to the study of this issue is relevant. A power model of the system of interaction between the car and the stand has been developed, taking into account the design features of the stand and the design features of the car's suspension. The power model of the system under consideration contains the equilibrium equations of the body and two bridges and the equations of motion of the rollers and wheels of the car. Based on the results of the analysis of the acting forces in the "car-stand" system, the braking moments on the wheels M and the coefficients of the use of the load q during the braking tests of a 4x4 vehicle were determined. The obtained research results allowed to improve the theory of interaction of a car wheel with the rollers of an inertial diagnostic stand.

Maintaining Technical Integrity of Petroleum Flowlines on Offshore Installations: A Decision Support System for Inspection Planning

2010 ◽  
Author(s):  
R. M. Chandima Ratnayake ◽  
Tore Markeset
Keyword(s):  
Ad Hoc ◽  
Oil And Gas ◽  
Formal Model ◽  
Technical Condition ◽  
Inspection Planning ◽  
Analytic Hierarchy ◽  
Plant Strategy ◽  
The North ◽  
Critical Components ◽  
Inspection Data

Oil and Gas (O&G) platforms in the North Sea are facing aging problems as many of the installations have matured and are approaching their design lifetime. Flowlines are used to transport oil and gas well stream from the wellhead to the production manifold. They are categorised as one of the most critical components on a production facility. Flowline degradation takes place due to corrosion and erosion. The deterioration of a flowline may increase the risk of leakages, ruptures, etc., which shall lead to serious HSE (health, safety and environmental) and financial consequences. Any such risks have a direct impact on the O&G installation’s technical integrity as well as the operator’s sustainability concerns. Conventionally, pipelines are designed with safety provisions to provide a theoretical minimum failure rate over the life span. Furthermore, to reduce the risk of failure various techniques are routinely used to monitor the status of pipelines during the operation phase. The existing methods of flowline health monitoring planning requires one to take into consideration the operator’s plant strategy, flowline degradation mechanisms, historical data, etc. A technical condition report is made based on findings’ reports and degradation trends. This report recommends the inspection of a number of points on the flowlines in a certain year using non-destructive evaluation methods such as visual inspection, ultrasonic testing, radiographic testing, etc. Based on the technical condition report, in general for a certain preventive maintenance shutdown, 10 to 15 flowline inspection openings are accommodated as finance, time and resource availability are taken into consideration. However, it is customary to plan to open more locations in a certain inspection package than can be inspected and minimization of such points is at present done on an ad hoc basis. This paper suggests a formal model and a framework to formally minimize the number of visual inspections by executing the plant strategy as well as HSE concerns. The model is derived using analytic hierarchy process (AHP) framework, which is a multi-criteria decision-making approach. The model is developed based on literature, industrial practice, experience as well as real inspection data from a mature offshore O&G installation located on the Norwegian Continental Shelf.

scholarly journals Impact of High-Altitude on Truck’s Climbing Speed: Case study in Qinghai-Tibet Plateau Area in China

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Tian Lei ◽  
Jinliang Xu ◽  
Xingli Jia ◽  
Leyu Wei ◽  
Lin Tian
Keyword(s):  
High Altitude ◽  
Traffic Safety ◽  
Field Tests ◽  
Tibet Plateau ◽  
Infrastructure Development ◽  
Plateau Area ◽  
Negative Effect ◽  
High Altitude Area ◽  
The Impact ◽  
Different Altitudes

Truck’s climbing performance is an important consideration in traffic safety, efficiency, and highway geometric design. With the infrastructure development in high-altitude area in China, more attention needs to be paid on truck’s climbing performance in such area. In this article, truck’s climbing speed in high-altitude area was examined through field tests on different grade sections at different altitudes. Truck’s speed-distance curves were built at different altitudes and the impact of altitude on truck’s climbing speed was explored based on the test results. It was shown that, within the altitude range of 3000~5000m, altitude had an obvious influence on test truck’s decelerating and accelerating performance. Truck’s speed decreased faster on steep grades and increased slower on gentle grades with the increase of the altitude. Also, the stable speed that test truck could maintain on a certain grade was lower at a higher altitude. In addition, test truck’s theoretical speed-distance curves at the sea level were estimated through truck’s dynamic model. Compared with the theoretical crawl speed, a negative effect of altitude change (from 0 to the altitude above 3000 m) was found on truck’s climbing performance.

scholarly journals A Cost-Effective Method to Reproduce the Morphology of the Nearshore and Intertidal Zone in Microtidal Environments

2020 ◽  
Vol 12 (11) ◽  
pp. 1880
Author(s):  
Stefano Furlani ◽  
Valeria Vaccher ◽  
Vanja Macovaz ◽  
Stefano Devoto
Keyword(s):  
Intertidal Zone ◽  
Field Tests ◽  
Cost Effective ◽  
Time Lapse ◽  
3D Models ◽  
The North ◽  
Cost Effective Method ◽  
Photogrammetric Method ◽  
The Difference ◽  
Sea Wall

The photogrammetric method is widely used in coastal areas and in submerged environments. Time-lapse images collected with unmanned aerial vehicles are used to reproduce the emerged areas, while images taken by divers are used to reproduce submerged ones. Conversely, 3D models of natural or human-made objects lying at the water level are severely affected by the difference in refractive index between air and seawater. For this reason, the matching of 3D models of emergent and submerged coasts has been very rarely tested and never used in Earth Sciences. The availability of a large number of time-lapse images, collected at the intertidal zone during previous snorkel surveys, encouraged us to test the merging of 3D models of emerged and submerged environments. Considering the rapid and effective nature of the aforementioned program of swim surveys, photogrammetric targets were not used during image acquisition. This forced us to test the matching of the independent models by recognizing prominent landforms along the waterline. Here we present the approach used to test the method, the instrumentation used for the field tests, and the setting of cameras fixed to a specially built aluminum support console and discuss both its advantages and its limits compared to UAVs. 3D models of sea cliffs were generated by applying structure-from-motion (SfM) photogrammetry. Horizontal time-lapse images, collected with action cameras while swimming parallel to the coastline at nearly constant velocity, were used for the tests. Subsequently, prominent coastal landforms were used to couple the independent models obtained from the emergent and submerged cliffs. The method was pilot tested in two coastal sites in the north-eastern Adriatic (part of the Mediterranean basin). The first site was a 25 m sea wall of sandstone set within a small harbor, while the second site was a 150 m route below plunging limestone cliffs. The data show that inexpensive action cameras provide a sufficient resolution to support and integrate geomorphological field surveys along rocky coastlines.

scholarly journals Assessment of an ensemble system that assimilates Jason-1/Envisat altimeter data in a probabilistic model of the North Atlantic ocean circulation

Ocean Science ◽  
2015 ◽  
Vol 11 (3) ◽  
pp. 425-438 ◽  
Author(s):  
G. Candille ◽  
J.-M. Brankart ◽  
P. Brasseur
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic ◽  
Gulf Stream ◽  
North Atlantic Ocean ◽  
Altimeter Data ◽  
Stochastic Perturbations ◽  
The North ◽  
Altimetric Data ◽  
The North Atlantic ◽  
Along Track

Abstract. A realistic circulation model of the North Atlantic ocean at 0.25° resolution (NATL025 NEMO configuration) has been adapted to explicitly simulate model uncertainties. This is achieved by introducing stochastic perturbations in the equation of state to represent the effect of unresolved scales on the model dynamics. The main motivation for this work is to develop ensemble data assimilation methods, assimilating altimetric data from past missions Jason-1 and Envisat. The assimilation experiment is designed to provide a description of the uncertainty associated with the Gulf Stream circulation for years 2005/2006, focusing on frontal regions which are predominantly affected by unresolved dynamical scales. An ensemble based on such stochastic perturbations is first produced and evaluated using along-track altimetry observations. Then each ensemble member is updated by a square root algorithm based on the SEEK (singular evolutive extended Kalman) filter (Brasseur and Verron, 2006). These three elements – stochastic parameterization, ensemble simulation and 4-D observation operator – are then used together to perform a 4-D analysis of along-track altimetry over 10-day windows. Finally, the results of this experiment are objectively evaluated using the standard probabilistic approach developed for meteorological applications (Toth et al., 2003; Candille et al., 2007). The results show that the free ensemble – before starting the assimilation process – correctly reproduces the statistical variability over the Gulf Stream area: the system is then pretty reliable but not informative (null probabilistic resolution). Updating the free ensemble with altimetric data leads to a better reliability with an information gain of around 30% (for 10-day forecasts of the SSH variable). Diagnoses on fully independent data (i.e. data that are not assimilated, like temperature and salinity profiles) provide more contrasted results when the free and updated ensembles are compared.

scholarly journals The unperceived risk to Europe's coasts: tsunamis and the vulnerability of Cadiz, Spain

2010 ◽  
Vol 10 (12) ◽  
pp. 2659-2675 ◽  
Author(s):  
J. Birkmann ◽  
K. v. Teichman ◽  
T. Welle ◽  
M. González ◽  
M. Olabarrieta
Keyword(s):  
Early Warning ◽  
Emergency Preparedness ◽  
Local Population ◽  
Warning System ◽  
Potential Threat ◽  
Adaptation Measures ◽  
Tsunami Early Warning ◽  
Tsunami Waves ◽  
The North ◽  
Reduction Strategies

Abstract. The development of appropriate risk and vulnerability reduction strategies to cope with tsunami risks is a major challenge for countries, regions, and cities exposed to potential tsunamis. European coastal cities such as Cadiz are exposed to tsunami risks. However, most official risk reduction strategies as well as the local population are not aware of the probability of such a phenomenon and the potential threat that tsunami waves could pose to their littoral. This paper outlines how tsunami risks, and particularly tsunami vulnerability, could be assessed and measured. To achieve this, a vulnerability assessment framework was applied focusing on the city of Cadiz as a case study in order to highlight the practical use and the challenges and gaps such an assessment has to deal with. The findings yield important information that could assist with the systematic improvement of societal response capacities of cities and their inhabitants to potential tsunami risks. Hazard and vulnerability maps were developed, and qualitative data was obtained through, for example, focused group discussions. These maps and surveys are essential for the development of a people-centred early warning and response system. Therefore, in this regard, the Tsunami Early Warning and Mitigation System in the North Eastern Atlantic, the Mediterranean, and connected seas promoted by the UNESCO-Intergovernmental Oceanographic Commission (IOC) should encompass these assessments to ensure that action is particularly intensified and fostered by those potentially exposed. That means that besides the necessary technical infrastructure for tsunami detection, additional response and adaptation measures need to be promoted – particularly those that reduce the vulnerability of people and regions exposed – in terms of national systems. In addition, it is important to develop emergency preparedness and awareness plans in order to create an integrated regional Tsunami Early Warning System (TEWS) by 2011. The findings of the paper are based on research conducted within the framework of the EC funded project TRANSFER: "Tsunami Risk ANd Strategies For the European Region", a project that aims to improve the understanding of tsunami processes in the Euro-Mediterranean region, to develop methods and tools to assess vulnerability and risk, and to identify strategies for the reduction of tsunami risks.

scholarly journals How could the Viking Sun compass be used with sunstones before and after sunset? Twilight board as a new interpretation of the Uunartoq artefact fragment

2014 ◽  
Vol 470 (2166) ◽  
pp. 20130787 ◽  
Author(s):  
Balázs Bernáth ◽  
Alexandra Farkas ◽  
Dénes Száz ◽  
Miklós Blahó ◽  
Ádám Egri ◽  
...  
Keyword(s):  
North Atlantic ◽  
Eleventh Century ◽  
Field Tests ◽  
Baffin Island ◽  
Sun Compass ◽  
The North ◽  
Skylight Polarization ◽  
Before And After ◽  
Birefringent Crystals ◽  
New Interpretation

Vikings routinely crossed the North Atlantic without a magnetic compass and left their mark on lands as far away as Greenland, Newfoundland and Baffin Island. Based on an eleventh-century dial fragment artefact, found at Uunartoq in Greenland, it is widely accepted that they sailed along chosen latitudes using primitive Sun compasses. Such instruments were tested on sea and proved to be efficient hand-held navigation tools, but the dimensions and incisions of the Uunartoq find are far from optimal in this role. On the basis of the sagas mentioning sunstones, incompatible hypotheses were formed for Viking solar navigation procedures and primitive skylight polarimetry with dichroic or birefringent crystals. We describe here a previously unconceived method of navigation based on the Uunartoq artefact functioning as a ‘twilight board’, which is a combination of a horizon board and a Sun compass optimized for use when the Sun is close to the horizon. We deduced an appropriate solar navigation procedure using a twilight board, a shadow-stick and birefringent crystals, which bring together earlier suggested methods in harmony and provide a true skylight compass function. This could have allowed Vikings to navigate around the clock, to use the artefact dial as a Sun compass during long parts of the day and to use skylight polarization patterns in the twilight period. In field tests, we found that true north could be appointed with such a medieval skylight compass with an error of about ±4° when the artificially occluded Sun had elevation angles between +10° and −8° relative to the horizon. Our interpretation allows us to assign exact dates to the gnomonic lines on the artefact and outlines the schedule of the merchant ships that sustained the Viking colony in Greenland a millennium ago.

Advances in marine electromagnetic (EM) efficiency with a towed acquisition system

2012 ◽  
Vol 52 (2) ◽  
pp. 699
Author(s):  
Folke Engelmark ◽  
Johan Mattsson ◽  
John Linfoot
Keyword(s):  
Oil And Gas ◽  
Field Tests ◽  
Repeated Sequence ◽  
Dipole Source ◽  
Surface Sampling ◽  
Gas Field ◽  
The North ◽  
Simultaneous Acquisition ◽  
Oil And Gas Field ◽  
Source Signal

A towed marine EM system has been developing since 2004 where both source and receivers are towed behind the same vessel in an arrangement similar to 2D streamer seismic. This is an ideal technology for reducing risk in hydrocarbon targets in general and low saturation gas in particular, as well as the monitoring of CO2 sequestration. The dipole source is 400 or 800 m long and towed at 10 m below the sea surface. The receiver cable is towed at 100 m depth and has receiver offsets between 500 and 8,000 m. A transient source signal is used, allowing deterministic deconvolution of the source signature, which can be of any shape; for example, square wave, PRBS, or optimised repeated sequence (ORS). There are multiple benefits of the towed EM system: Similar in operation to a marine streamer seismic. Improved survey efficiency with source and receivers towed by the same vessel. Real-time monitoring of source and receivers, and quality control of incoming data. Onboard pre-processing. Dense sub-surface sampling. Receivers towed above the seafloor—the influence of strong local anomalies at the seabed is thus minimised. Facilitates simultaneous acquisition of EM and 2D seismic. Successful field tests were conducted in mid-2010 over the Peon gas field and the Troll oil and gas field in the Norwegian sector of the North Sea. A total of 615 line km were acquired during 138 hours, and the data has been successfully processed and inverted to delineate all targets.

Determination of Technical Condition of a Bridge Structure Based on Survey Results

2018 ◽  
Vol 931 ◽  
pp. 643-648 ◽  
Author(s):  
Marina O. Karpushko ◽  
Igor L. Bartolomei ◽  
Elena N. Karpushko
Keyword(s):  
Traffic Safety ◽  
Carrying Capacity ◽  
High Performance ◽  
High Water ◽  
Technical Condition ◽  
Safety Requirements ◽  
The Road ◽  
Ice Drift ◽  
Load Carrying ◽  
Survey Results

Nowadays, the age of most transport facilities in Russian Federation is estimated in many decades. Consequently, there is an urgent need for periodic surveys and monitoring of the state of each structure, its individual structural elements. The main purpose of these measures is to maintain the high performance indicators of the transport structure, the achievement of which is impossible without examination, analysis and evaluation of parts of the structure that are in the aquatic environment and, as a consequence, the occurrence and development of various types and degrees of defects and damages. The most important conditions for ensuring uninterrupted and safe traffic along the bridges of vehicles and pedestrians are: the normative load-carrying capacity of the structure; required clearance of the roadway and sidewalks; compliance with traffic safety requirements for bridges; observance of characteristics and maintenance of the bridge capacity for the period of ice drift and high water; timely performance of work on the care, maintenance and repair of the elements of the bridge. Technically sound structures and their reliability can be ensured if all the parameters of the road category structure and the requirements of regulatory documents are met. The work presents the survey materials of the bridge. Classification of defects by group and class of danger. The results of determining the carrying capacity on the basis of the survey are given.

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