Shaft Line Research Articles

Producing antifriction babbitt В83 layer by gas-dynamic cold spraying

The technological processing of antifriction layer from Babbitt by gas-dynamic cold spraying was carried out on the DIMET-403. The coating was sprayed on plain bearings for marine low- and medium-speed diesel engines, turbines, and shaft lines. Technical requirements for antifriction layer materials, standard technological processes of preparation, spraying, heat treatment, and quality control are also considered.

Forced vibrations of the shaft line based on the model of a two-stage rod with an elastic connection of sections

The paper considers a method for solving the problem of dynamics of forced vibrations of a wall line based on a model of an equivalent elastic two-stage rod with a pliable connection of sections. The model is represented by a system of partial differential equations. The solution of the equations is obtained by the Fourier method for eigenfunctions orthogonal with weight. It is established that the presence of an elastic element at the junction of the sections does not affect the orthogonality of the eigenfunctions. The influence of the elastic coupling compliance coefficient on the natural frequency spectrum of the shaft line is estimated. The obtained forms of natural vibrations of an equivalent elastic two-stage rod are consistent in appearance with the corresponding forms known in the literature for a discrete model of a similar torsional circuit. A partial solution of the equations is found for the case of the action of the harmonic load on the engine and the averaged torque on the propeller. As an example, the dynamics of forced vibrations of the shaft line of a barge of the Sosnovka type is studied. The results of calculating the natural frequencies of the considered model are compared with the classical discrete mass method. The analysis of the obtained plots of the twisting angles and torques showed that the angles are satisfactorily approximated by the first proper oscillation shape, and for moments, high shapes must be taken into account. The comparison of the simulation results with the data of the torsiogram obtained under production testing conditions indicates the need for further development of the model. Further improvement of the torsional circuit, as well as a more detailed study of the nature of the operating loads, are considered as promising areas of research.

Nonlinear dynamics analysis of hydraulic turbochargers in reverse osmosis desalination plants

The hydraulic turbocharger plays a vital role in harnessing the energy stored in brine within reverse osmosis desalination plants. To optimize the efficiency and durability of this equipment, it is crucial to develop accurate dynamic models of the turbocharger rotor. An improved understanding of rotor dynamics enables the integration of innovative technologies such as Hydraulic Energy Management Integration, effectively enhancing efficiencies in systems characterized by small capacities and high rotational speeds. This study presents a dynamic modeling methodology for the hydraulic turbocharger. The analysis involves approximating the turbocharger rotor with an equivalent finite element shaft line model. Verification of the model’s natural frequency is conducted using three-dimensional finite element analysis, employing the ANSYS modal analysis module. Computational fluid dynamics is employed to evaluate the fluid forces, while the Reynolds equation is utilized to assess the journal bearing forces. The resulting model is employed to investigate the nonlinear dynamics of the rotor, examining the impact of various system parameters, including rotational speed, unbalance forces, and shaft geometrical parameters. The results highlight the significance of balancing the turbine and pump disks for optimal performance. Furthermore, the research demonstrates that increasing the shaft length reduces the rotor’s threshold speed, while increasing the shaft diameter initially raises the threshold speed until it reaches a critical value. Beyond this critical value, further increases in shaft diameter lead to a decrease in the threshold speed.

Utjecaj ekscentrične porivne sile na odabir statvenog kliznog ležaja

Stern tube slide bearing of the shaft line of the ship's propulsion system causes losses during operation. Friction and material wear of the tribosystem occur. One of the reasons is the different navigating regimes of the ship, which have an influence on the formation of the velocity field on the ship's propeller. The variable velocity field defines the magnitude and the position of the thrust force. The methodology presented in this paper is based on the fact of the existence of the eccentricity of the thrust force, i.e. loads due to the action of the moment of the eccentric thrust force. Due to the changing position of the thrust force, the curvature of the elastic line of the sleeve inside the stern tube bearing, which is mostly spatial, changes. Spatial elastic line of the sleeve has an influence on the working area of the slide bearing. Therefore, the importance of a sufficient thickness of the lubricant layer for lubrication in relation to these changes was highlighted. In this paper, this is the initial criterion for the selection of materials and lubricants of the stern tube bearing. An equally important criterion would be to define the possible harmful impact of lubricant leakage with particles of bearing bush material on the ecosystem. In order to facilitate the whole process, the simplified analytical model is presented, which can be used in the initial stage of stern tube bearing selection. Such a model allows a simpler analysis of the influence of the elastic line on the condition of the stern tube bearing due to the loading by the weight of the ship's propeller and by the moment of the eccentric thrust force. The procedure for the initial selection of the stern tube bearing created by this methodological approach could have its practical application. For this reason, the paper analyzed different navigating regimes and their influence on the working area of the stern tube slide bearing. The obtained results can be useful in the selection of materials and lubricants for the stern tube bearing tribosystem.

РЕМОНТ КОРЕННЫХ И ШАТУННЫХ ШЕЕК КОЛЕНЧАТЫХ ВАЛОВ ДИЗЕЛЬНЫХ ДВИГАТЕЛЕЙ ПРИ ПОМОЩИ ДИСКРЕТНОГО УПРОЧНЕНИЯ

Studies to assess the effect of discrete hardening of the crankshaft journals on its fatigue strength have been carried out. For this purpose, fatigue tests were carried out on two control parts of the D80 type crankshaft. It was established that the destruction of control part No. 1 occurred after 322,000 cycles, control part No. 2 after 201,000 cycles. The destruction zone of both control parts passes along the R8 mm transition fillet of the connecting rod journals. This allows us to conclude that the discrete hardening factor is not associated with fatigue failure of the control parts. In order to determine the service life of the crankshaft of the KamAZ 740 engine, strengthened in a discrete way (shaft of the fourth repair size), it was installed on a KamAZ 5320 vehicle. As a result of the tests, it was found that during the entire testing cycle the vehicle's mileage was 109,000 km. Moreover, at the time of completion of the tests, all parameters of the car’s engine met the technical requirements. The KamAZ 5320 vehicle is in operation to this day. Its mileage was 269,000 km without stopping for major repairs. To conduct operational tests of a cast iron crankshaft with discrete hardening of a D80 type engine, a 1D80B diesel generator engine was taken, which after assembly was subjected to full-scale testing. These tests included a 100-hour engine run-in, determination of the vibration level and amplitudes of torsional vibrations of the diesel generator shaft line in the operating speed range. The analysis of the vibration state of the engine showed that in all test modes the vibration level at the points under study does not exceed the norms (0.350 mm on the turbocharger housing and 0.150 mm on the generator foot). The maximum stresses from torsional vibrations were: 8, about 17.5 MPa; 4, 5 order 10.5 MPa; 1.5 order 10.0 MPa. The resulting stress levels are significantly lower than permissible. Tests of the 1D80B diesel generator showed its full compliance with the technical requirements for the operation of this engine.

СРАВНЕНИЕ ТЯГОВЫХ ПРИВОДОВ С ОПОРНО-ОСЕВЫМ И ОПОРНО-РАМНЫМ ПОДВЕШИВАНИЕМ ДВИГАТЕЛЯ

The problem of finding criteria for choosing between axial support and frame support drives for locomotives in the conditions of import substitution is considered. The changes in the criteria for choosing a traction drive design depending on the changes in requirements for locomotives are analyzed. The types of drives are compared according to their technological simplicity, weight and size indicators, the effect on the coupling properties of the locomotive and the damage to the track structure, taking into account the production of new traction drive designs of an integrated type with collector-free traction electric motors having an increased rotation frequency. It was found that for locomotives with collector traction motors, it is advisable to use a frame support drive with an axial gearbox or a hollow driveshaft, and when using collector-free traction motors , the axial support traction drive of an integrated layout on freight locomotives with 1250 mm wheel diameter to improve coupling properties by 12...15%, it is advisable to replace it with the one proposed by the authors, which is an aggregate-type drive with an elastic link in the shaft lines, or with frame support drives with an axial gearbox, and with a wheel diameter of 1050 mm – frame support drives with a hollow shaft on the axis. An application for a patent has been submitted for the proposed solutions.

Study of high power steam turbine forced oscilla-tions near operating frequency

Problem. Forced oscillations of the turbine unit-foundation-base system near the operating frequency are considered. Goal. The purpose of the work is to study forced vibrations of the turbine unit-foundation-base system near the operating frequency range to assess the vibration state of the system and determine the causes of increased vibrations. The object of the study is the turbine unit-foundation-base system. The system consists of a single reinforced concrete foundation on which a steam turbine and generator are installed. The subject of the study is the amplitude-frequency dependences of forced oscillations of the turbine unit-foundation-base system. Methodology. The study was carried out using vibration methods and the finite element method. Also worth noting is the use of original methods developed directly by the author for constructing models of complex mechanical engineering systems. Results. As a result of the research, three-dimensional finite element models of low-pressure cylinder housings, the foundation and the entire turbine unit-foundation-base system were built. The conducted research allows us to draw a conclusion regarding the reasons for the increased level of vibration near the operating frequency and directions for their prevention. Originality. Regarding the methods for constructing a model of the turbine unit-foundation-base system, it should be noted that they are unique. The features of the applied modeling method make it possible to take into account the variable interaction between the low-pressure cylinder bodies and the foundation. Fixpoints are also taken into account. Previous studies of the turbine unit-foundation-base system did not allow us to determine the causes of increased vibrations of the shaft line supports. Practical significance. The results of the work relate to direct practical application. As a result of the work, conclusions were drawn about the ways to increase the vibration reliability of the turbine unit-foundation-base system and further directions for research.

The risk matrix application to assess the installation of torsional vibration monitoring systems on ships

According to statistics, the number of accidents related to the failures of ship engine and propulsion systems remains in second place among the total number of accidents. One of the reasons for the destruction of diesel crankshafts, intermediate and propeller shafts, elastic couplings and other elements of shaft lines are torsional vibrations in combination with other types of fluctuations and vibrations. The main method for monitoring the level of torsional vibrations in ship’s shaft lines remains periodic torsiography or strain measurement. The widespread introduction of diagnostic and control systems on ships leads to the technical possibility of constant monitoring of the level of torsional vibrations, which will allow you to reduce the risks of accidents in the periods between torsiography. Like any new technical solution, the introduction of torsional vibration monitoring systems requires a scientific justification of the need for their application, which can be carried out with using risk theory. The results of applying the risk matrix to justify the installation of torsional vibration monitoring systems in marine propulsion systems are presented in the paper. As a result, a risk matrix with quantitative parameters is obtained to justify the installation of torsional vibration monitoring systems and reduce the risks of ship’s shaft line breakdowns. As an example, the application of the risk matrix for “OT” type tugs, which are widely used for various operations on the Russian waterways, is considered. It is established that for these types of vessels, the use of a monitoring system will be justified to reduce the risks of accidents, serious accidents and catastrophes that may arise from the development of dangerous torsional vibrations. A method for applying the assessment of the damage degree from an accident occurrence to determine the reduction of economic costs when using torsional vibration monitoring systems is proposed in the paper. It is found that for the “OT” type tugs, the installation of torsional vibration monitoring systems will be justified, both from the point of view of economics and reducing the accidents risks of ship engine and propulsion systems.

Сравнительная оценка применения микроэлектромеханических акселерометров для измерения крутильных колебаний судовых машинно-движительных комплексов

Microelectromechanical accelerometers are investigated, and their applicability to measuring torsional vibrations occurring in marine propulsion systems is evaluated. The calculated and experimental assessment of the applicability of accelerometers of the ADXL345, ADXL375 and H3LIS331DL models for measuring torsional vibrations of marine shaft lines has been carried out and recommendations for their practical application have been developed. The materials used were the rules of the Russian Classification Society, scientific and technical literature in the field of torsional vibrations and the authors' own research. The methods used were analysis, numerical and physical experiment. Recommendations on the use of accelerometers of the ADXL345, ADXL375 and H3LIS331DL models depending on the rotational speed and diameter of the torsiographed shaft are obtained. The results obtained give grounds to recommend the ADXL375 accelerometer as the basic basic model for measuring torsional vibrations of most marine propulsion systems with rotation frequencies up to 1,025 min–1. At rotational speeds of less than 135 min–1, the use of the ADXL345 accelerometer with a measuring range of ±2g is recommended, and when setting the range of ±16g, it can be used at rotational speeds up to 380 min–1. If it is necessary to measure torsional vibrations at a rotational speed of more than 1,025 min–1, it is recommended to use a less accurate, but more reliable accelerometer model H3LIS331DL in terms of overload shutdown threshold.

ИССЛЕДОВАНИЕ РЕЗОНАНСНЫХ ЯВЛЕНИЙ КРУТИЛЬНЫХ КОЛЕБАНИЙ ВАЛОПРОВОДОВ ГРЕБНЫХ ВИНТОВ

The problem of torsional vibrations of propeller shaft lines is considered in the work. A two-stage rod model with distributed parameters has been adopted for the study of dynamic processes in contrast to the traditional method based on discrete masses. The active load on the engine side, as in the classical approach, is approximated by the partial sum of the Fourier series. The comparison of the calculation results according to the proposed model with the results known in the literature has been performed. It is established that both calculation methods give excessive values of forces and deformations in resonance with harmonics, for which the phase component is a multiple of the engine cycle.

ЭКСПЕРИМЕНТАЛЬНОЕ ИССЛЕДОВАНИЕ РАСХОДНЫХ ХАРАКТЕРИСТИК ЯЧЕИСТО-ЛУНКОВОГО УПЛОТНЕНИЯ ДЛЯ ПАРОВЫХ ТУРБИН

In this paper, a study of the flow characteristics of a seal with a cellular stator is carried out. The rotor had a well surface with a diameter of d = 10 mm and a depth of h = 1 mm. The stator part is made of stamped rings and radial plates, forming a cellular structure with a rectangular cross section. Holes were made on the outer plate to separate moisture into the sealing chamber behind the stator. A series of experiments were carried out with a fixed disk and rotating at different speeds (1000; 2000; 3000 rpm). The results of the construction of consumption characteristics showed that the effect of rotation is negligible. Numerical research at Ansys revealed the complex spatial nature of the gas flow in the flow part of the seal with the formation of reverse vortex flows. In a seal with wells, the vortices in the cells, on the contrary, have a more gentle structure. The strengthening of vortex structures is associated with a changing gradient of the area of the wells, where local acceleration of the main flow occurs, which, in turn, pumps the perturbed flow into the cells. The numerical calculation and field experiment performed have shown the effectiveness of using this seal design for steam turbines, especially in nodes of large axial displacements of the shaft line relative to the housing.

Gas lifting design and application in geothermal wells: A case study from West Anatolia, Turkiye

The gas content of the producing fluid has crucial effects on the production performance of geothermal wells. The decline of non-condensable gases (NCG) could result in significant performance reduction of the wells. Artificial production techniques such as pumps (i.e., Line Shaft Pump and Electrical Submersible Pump) and gas lifting are the widely known methods for enhancing the production performance of wells. Due to the high-temperature working environment and the well's inclination, pumps might be inconvenient for geothermal wells. Continuous injection of gases such as nitrogen (N2) and carbon dioxide (CO2) serving as gas lifting might be the appropriate method to enhance production from geothermal wells suffering from low gas content and reservoir pressure. This study investigates production enhancement with gas lifting in a geothermal field in Turkiye. The study aims to fill the gap of gas lifting in the geothermal industry as an alternative to downhole pumps such as ESP and LSP. The sensitivity analyses were performed on the design parameters such as injection depth, rates, tubing size, number of valves, and injectate gas type influencing the production performance of gas lifting. The study found that gas lifting is an optimization problem that needs to be solved by considering gas sources, infrastructure sizes, wellbore geometry, and operating parameters.

Effect of Air-Liquid Homogeneous Mixture on the Linear Dynamic Characteristics of a Hydrostatic Journal Bearing

Abstract Water lubricated hydrostatic journal bearings are widely used to support radial load of pumps in nuclear power plants. In some situations, these pumps may be required to operate with a mixture of water and air. This compressible air–water mixture will alter the dynamic characteristics of the hydrostatic journal bearings and can have a significant impact on the vibration behavior of the entire pump shaft line. This work is a parametrical investigation of the rotordynamic characteristics of these bearings relative to the volume fraction of the ingested air. The compressibility, the density, and the viscosity of the air–water mixture depend on this volume fraction. In order to evaluate this influence, a homogeneous air-liquid mixture model were developed. Moreover, for low viscosity lubricants, inertia effects can also have an important impact on bearing rotordynamic coefficients. Therefore, the flow is modeled first with the Reynolds equation and then with the bulk flow system of equations to evaluate this impact. The results show the variation of the direct and cross-coupling stiffness and of the direct damping with the evolution of inertial effects and of the level of air contamination.

Study Case of Marine Propulsion Shaft Measurements by the Strain Gage Method: before and after a ship hull grounding accident

The strain gage method for propulsion shaft bending moment verificationhas been in use since the 80’s. In this work, the authors present theirprocedure and results of this method to an Anchor Handling Tug Supply(AHTS) ship. The method was applied in this ship in two occasions: afterdelivery in 2018 and after a grounding accident in 2019. After a period ofhull repair, the bearing reactions were verified at the same time by Jackupand Strain Gage methods. The results by the Strain Gage techniqueare considered more accurate and complete than those of the Jack-up.Based on the Strain Gage results, it was concluded that the groundingaccident caused a change in the alignment of the shaft lines, mainly onstarboard side. The comparison between the methods presented thesame graphic shape, however the Jack-up measurements differed fromthe Strain Gage ones at some points due to some factors noted anddiscussed by the authors.

Can the reduction quality of distal humeral transphyseal fractures be determined using reference measurements on conventional radiography?

Our objective was to compare the radiological outcomes of transphyseal fractures treated using closed reduction and percutaneous fixation, without arthrography, with those of supracondylar humerus fractures treated using the same method within a similar age group. Additionally, we aimed to assess the efficacy of the reference points in the lateral and anteroposterior radiographs utilized for the evaluation of reduction. The study included patients aged 0-3 years who underwent surgery for supracondylar and transphyseal fractures between 2013 and 2022. All the patients were diagnosed using anteroposterior (AP) and lateral elbow X-rays. No arthrographic intervention was used either in the diagnosis or treatment phase. On the AP X-rays, we assessed the alignment between the humeral shaft line and the ulnar long axis line to determine the positioning of the distal humeral physis segment in relation to the humerus. Additionally, we evaluated the relationship between the anterior cortex line of the humerus and the coronoid process on lateral radiographs. At the final follow-up visit, Flynn criteria were used for functional assessment. The study comprised 24 patients with supracondylar humerus fractures and 24 patients with transphyseal fractures. In the early post-operative radiographs, the humero-ulnar angle measured 6.43° (-7° - 16.6°) in the supracondylar group and 9.8° (-4.3° - 25.3°) in the transphyseal group (p = 0.087). The distance between the coronoid and the anterior humeral line was 9.19 mm (4.27 - 16.08) for the supracondylar fracture group and 8.05 mm (3.29 - 14.85) for the transphyseal fracture group (p = 0.513). The current study's findings suggest that both the humero-ulnar angle and the distance between the coronoid and the anterior humeral line are valuable indicators for assessing the quality of reduction in transphyseal distal humerus fractures.

Modeling the deadwood bearings wear surface by optical scanning

The development of a methodology for modeling the wear surface of deadwood bearings based on optical scanning is considered in the paper. It is noted that the deadwood bearings of the ship’s shaft line wear out unevenly during operation, which affects the stress-strain state of the shaft and the system parameters responsible for the occurrence of resonance of transverse, torsional and longitudinal vibrations. The methodology and results of an experimental study of bearing wear surfaces are presented. The applied optical scanning scheme makes it possible to obtain high-precision digital models of objects due to synchronous shooting of an object with two cameras. The measurement results are obtained by processing with specialized software. The results obtained are an addition to the methodology for determining the elastic force acting on the shaft from the side of a bearing that is unevenly worn along the length with a non-constant gap. Based on the obtained wear values, a solid-state model is constructed and the natural frequencies of transverse, torsional and longitudinal vibrations are determined. For the constructed model, the forms of natural oscillations for practically significant frequencies are obtained. It is noted that bearing wear affects not only the displacement of the natural frequencies values, but also the oscillations shape. The impact of the wear of the aft bearing on the bearing capacity of the shaft line, taking into account the contact interaction, is evaluated. The simulation has shown that the bearing wear surface forms an area of increased contact pressures that arise from the impact of the propeller shaft. Analysis of the propeller shaft tip has revealed the presence of an area of increased concentration of equivalent stresses formed at the place of bearing wear formation. The proposed method of modeling the deadwood bearings wear allows us to evaluate its effect on the magnitude of the displacement of natural frequencies and the change in the bearing capacity of the shaft line. The results obtained in this work are an addition to the existing calculations in the design and evaluation of the ship’s power plant reliability.

Assessment of Fiber Bragg Grating Sensors for Monitoring Shaft Vibrations of Hydraulic Turbines.

The structural dynamic response of hydraulic turbines needs to be continuously monitored to predict incipient failures and avoid catastrophic breakdowns. Current methods based on traditional off-board vibration sensors mounted on fixed components do not permit inferring loads induced on rotating parts with enough accuracy. Therefore, the present paper assesses the performance of fiber Bragg grating sensors to measure the vibrations induced on a rotating shaft-disc assembly partially submerged in water resembling a hydraulic turbine rotor. An innovative mounting procedure for installing the sensors is developed and tested, which consists of machining a thin groove along a shaft line to embed a fiber-optic array that can pass through the bearings. At the top of the shaft, a rotary joint is used to extract, in real time, the signals to the interrogator. The shaft strain distribution is measured with high spatial resolution at different rotating speeds in air and water. From this, the natural frequencies, damping ratios, and their associated mode shapes are quantified at different operating conditions. Additionally, the change induced in the modes of vibration by the rotation effects is well captured. All in all, these results validate the suitability of this new fiber-optic technology for such applications and its overall better performance in terms of sensitivity and spatial resolution relative to traditional equipment. The next steps will consist of testing this new sensing technology in actual full-scale hydraulic turbines.

Case study on the shaft line alignment for a 180 000 tdw bulk carrier vessel

Alignment means the determination of displacements and breaks between two shafts and their elimination so that the geometric axes of the shafts become approximately collinear, and the deviations are within the permissible limits. This paper presents the methodological steps of the shaft line alignment (as a case study for a bulk carrier vessel of 180 000 tdw) through two classic approaches: with the help of a ruler and feeler gauge (templet) respectively with the help of dial gauge. Comparative analysis of the performances of the two methods, can provide essential information to an engineer in choosing the optimal option for alignment of the shaft lines both in the case of vessels in service and, mainly, in the case of new building’s. The originality of the work consists in carrying out the detailed calculations for displacements and breaks, with the graphical highlighting of the calculated values in the limit allowed intervals. Also, for each method are presented and commented the advantages and disadvantages.

Development and Preliminary Application of Temperature Stress Test Machine for Cast-in-Place Inner Shaft Lining.

Over the past 20 years, as the depth and diameter of shaft lines increased in China, the cracking and water leakage of the inner walls of frozen shafts have become increasingly severe, resulting in significant safety threats and economic losses. Understanding the stress variation patterns of cast-in-place inner walls under the combined effects of temperature and constraint during construction is a prerequisite for evaluating the crack resistance performance of inner walls and preventing water leakage in frozen shafts. The temperature stress testing machine is an important instrument for studying the early-age crack resistance performance of concrete materials under the combined effects of temperature and constraint. However, existing testing machines have shortcomings in terms of applicable specimen cross-sectional shapes, temperature control methods for concrete structures, and axial loading capacity. In this paper, a novel temperature stress testing machine suitable for the inner wall structure shape, capable of simulating the hydration heat of the inner walls, was developed. Then, a reduced-scale model of the inner wall according to similarity criteria was manufactured indoors. Finally, preliminary investigations of the temperature, strain, and stress variations of the inner wall under 100% end constraint conditions were conducted by simulating the actual hydration heating and cooling process of the inner walls. Results show that the hydration heating and cooling process of the inner wall can be accurately simulated. After approximately 69 h of concrete casting, the accumulated relative displacement and strain of the end-constrained inner wall model were -244.2 mm and 187.8 με, respectively. The end constraint force of the model increased to a maximum value of 1.7 MPa and then rapidly unloaded, causing the model concrete to crack in tension. The temperature stress testing method presented in this paper provides a reference for scientifically formulating technical approaches to prevent cracking in cast-in-place concrete inner walls.

Проблема определения ледового момента на движителе

Object and purpose of research. This paper discusses the methods for determination of propeller anti-torque in ice milling conditions. The purpose of the study was to investigate existing methods for propeller anti-torque determination, analyse their respective pros and cons and to trace out the paths of further studies towards a satisfactory description of propeller anti-torque. Materials and methods. This study relies on previous publications and experimental ice milling data from both laboratory tests and field measurements, as well as on full-scale measurement data obtained on propulsion shafts of real icebreakers and ice-going ships. Main results. Currently, there is a wide variety of methods for obtaining anti-torque data: regulatory, theoretical, model testing and full-scale measurements on ship shafting. Analysis of the regulations given in the recommendations of various class societies has shown considerable drawbacks in the calculation formulae used in them. This paper proves that the most viable method for propeller anti-torque determination is its reconstruction as per the results of full-scale measurements on shaft line. Conclusion. Current methods for determination of anti-torque do not describe this phenomenon exhaustively. The most promising solution here would be to perform full-scale trials and analyse their results.