Abstract: A pressure equalization valve arrangement for a rail brake system includes a hold valve and a membrane vent valve each having a control chamber. The hold valve and vent valve are piloted by a respective solenoid valve. A further solenoid valve is connected to the control chamber of the vent valve to allow the pressure across the vent valve membrane to be equalized with the brake cylinder pressure to decrease the pressure difference across the membrane. This results in an improved vent time.

Abstract: A brake control valve arrangement for controlling application of a braking force includes an electro-pneumatic brake control valve block including a hold valve and a vent valve (PRESSURE CONTROLLER), a main regulator valve (RELAY VALVE) and an emergency and a variable load control pressure regulator. The valve block has an inlet for a brake supply pressure, and an outlet in pneumatic connection with a brake cylinder. A pilot pressure into the main regulator valve from the variable load control pressure regulator is controlled by a remote release solenoid valve (CONTROL CHAMBER VENT MAGNET VALVE). The remote release solenoid valve adapted to vent brake cylinder pressure to atmosphere when de-energized thereby enabling release of the wheel braking force via the main regulator valve.

Abstract: An electropneumatic rail brake system configured to provide emergency braking including an emergency magnet valve which controls air flow into an emergency regulator valve, which valve has an emergency back-up chamber. The emergency regulator provides an output pressure nominally equal to the variable load pressure and no lower than the tare back-up. The magnet valve is closed when energized and when de-energized, pressure is allowed into the emergency back-up chamber, Regulation of the brake cylinder pressure continues during an emergency application such that the brake cylinder pressure applied during an emergency stop does not drop below a predetermined level. In the event of power-loss during an emergency brake stop, the nominal emergency brake pressure is applied to the brake cylinders.

Abstract: A brake system has prime functions involving active control of equipment by a brake ECU, which brake ECU comprises a microcontroller and a non-volatile memory. The non-volatile memory is adapted to store the result of tests on the safety circuits carried out during, before or after operation of the brake system, the result of the tests being assigned one of at least two statuses, at least one of the said statuses being indicative of an unhealthy test. At start-up of the brake system self-tests are carried out on the circuits or components of the brake system for which an unhealthy status has been stored in the non-volatile memory, thereby enabling the brake system to operate prime functions without prior self-test.

Abstract: A brake system has prime functions involving active control of equipment by a break ECU, which brake ECU comprises a microcontroller and a non-volatile memory. The non-volitile memory is adapted to store the result of tests on the safety circuits carried out during, before or after operation of the brake system, the result of the tests being assigned one of at least two statuses, at least one of the said statuses being indicative of an unhealthy test. At start-up of the brake system for which an unhealthy status has been stored in the non-volitile memory, thereby enabling the brake system to operate prime functions without prior self-test.

Abstract: A brake control unit for a railway vehicle having first and second cores. The first core is responsible for brake control functions and the second core is responsible for communications. A switch controls communication between the second core and a communication bus on the railway vehicle to safeguard the braking function of the first core. The second core only has write access to the communication bus when enabled by the first core, which first core determines whether the system is in a defined safe state to safeguard the braking function. This reduces the testing requirements for new communications software.

Abstract: A brake control unit for a railway vehicle having first and second cores. The first core is responsible for brake control functions and the second core is responsible for communications. A switch controls communication between the second core and a communication bus on the railway vehicle to safeguard the braking function of the first core. The second core only has write access to the communication bus when enabled by the first core, which first core determines whether the system is in a defined safe state to safeguard the braking function. This reduces the testing requirements for new communications software.

Abstract: A brake system for a railway vehicle (10), wherein the axles (3, 6) of the vehicle are provided with axle speed sensors (1, 2, 4, 5) adapted to measure the speed of rotation of the respective axle. The output of the axle speed sensor being fed to a data processor (7), which is provided with local intelligence so as to permit individual control of brake pressure on each axle or, alternatively on each bogie or car. The data processor (7) communicates, in use, with a brake control unit via a databus (18), the sensor outputs being processed so that the data can be communicated between the data processor (7) and further data processors (17), which further data processors are adapted to process sensor outputs on further axles or bogies.

Abstract: A brake system for a railway vehicle (10), wherein the axles (3, 6) of the vehicle are provided with axle speed sensors (1, 2, 4, 5) adapted to measure the speed of rotation of the respective axle. The output of the axle speed sensor being fed to a data processor (7), which is provided with local intelligence so as to permit individual control of brake pressure on each axle or, alternatively on each bogie or car. The data processor (7) communicates, in use, with a brake control unit via a databus (18), the sensor outputs being processed so that the data can be communicated between the data processor (7) and further data processors (17), which further data processors are adapted to process sensor outputs on further axles or bogies.

Abstract: A method for interpolating the environment and geological age at all levels in a borehole from information provided by a limited number of depths and the use of a synthetic stratigraphic cross-section for the interval between these depths. In hydrocarbon exploration, a borehole provides a suite of logs, plus estimates of geologic age at a number of spaced markers. This method uses a sea-level cycle chart, a calculation of subsidence from the thickness of the interval, and postulated values for several variables. If it is known that the supply of sediment always exceeded the available accommodation during deposition, the corresponding synthetic cross-section may then be optimized for geological plausibility (as gauged by visual observation or quantitative criteria) by perturbing the postulated variables and iterating the calculations.

Abstract: A method for interpolating the environment and geological age at all levels in a borehole from information provided by a limited number of depths and the use of a synthetic stratigraphic cross-section for the interval between these depths. In hydrocarbon exploration, a borehole provides a suite of logs, plus estimates of geologic age at a number of spaced markers. This method uses a sea-level cycle chart, a calculation of subsidence from the thickness of the interval, and postulated values for several variables. If it is known that the supply of sediment always exceeded the available accommodation during deposition, the corresponding synthetic cross-section may then be optimized for geological plausibility (as gauged by visual observation or quantitative criteria) by perturbing the postulated variables and iterating the calculations.

Abstract: A method for identifying the boundaries between sequences of rocks laid down in different depositional regimes. The approach used is to search, in well logs or seismic data, for a statistic characteristic of such regimes, and for breaks in that statistic. The preferred statistic used in the method of the present invention is the first moment of the power spectrum of the wavenumber of a suitable physical property as a function of depth. This statistic is calculated rapidly and with excellent depth resolution from the complex-valued autocorrelation function at its zero and unit lag values, respectively, and displayed as a single variable in black-and-white or color. The method of the present invention further includes manipulations that achieve the approximate conversion of the scale (and corresponding display) from its initial dependence on depth to one that is displayed as a function of geologic time.

Abstract: A rotary vibrating system is used in surveys of the acoustic properties of the shallow earth. The vibrator itself is of eccentric-mass (or "swinging-weight") form. Coupled to a flywheel, it decelerates freely from a selected high frequency to a selected low frequency. The observed deceleration rate is manipulated to give a measure of the acoustic properties of the near-surface. The eccentricity of the vibrator is then annulled, and the flywheel and vibrator accelerated back to the selected high frequency for another measurement at another location. A display in map form is provided to facilitate visual interpretation of the results.

Abstract: Seismic exploration for hydrocarbons may use an eccentric-mass (or "swinging-weight") vibrator as the seismic source. According to the invention, a vibrator undergoes alternate periods of acceleration and deceleration, during one of which the vibration may be annulled. For example, the rotating mass may be formed in a plurality of parts; then the several parts are disposed in a manner that rapidly and automatically balances their vibratory forces during the period when the vibration is to be annulled, and that adds their vibratory forces during the other period. The invention further provides for modulation of the frequency-time relation during deceleration, for synchronization of several vibrators, and for modulation of the effective output force by controllable variation of the mass, eccentric radius or relative phase of the several parts of the rotating mass; in such modulation, only resultant forces are applied to the vibrator bearings.

Abstract: In a method of seismic exploration using swept-frequency signals, compressional and shear waves are emitted simultaneously. Typically the waves are generated by swinging-weight vibrators acting through a single baseplate. If the frequency of the shear vibration is one-half that of the comopressional vibration, the downward vertical forces can be phased to minimize the horizontal slippage of the baseplate. The sensitive axis of the geophones is inclined to the vertical for detecting both compressional waves and shear waves. For defined ranges of sweep rate, separate compressional and shear records are obtained by cross-correlating the geophone signal separately against the vertical and horizontal emissions.

Abstract: A swinging-weight seismic vibrator is driven by the energy stored in a flywheel. Since the sweep rate is large near the resonance of the vibrator-ground coupling, and small away from resonance, a measure of compensation of the resonance is automatically obtained. Weights of variable eccentricity may be provided. Multiple vibrators may be used, provided that no two vibrators generate the same frequency at times separated by less than the maximum reflection time of interest.

Abstract: A method of seismic exploration by which substantially plane or substantially cylindrical seismic energy waves are simulated by combining reflectional signal traces of conventional spherical seismic waves. Seismic sources and receivers are established in sets at positions such that at least one of the sets includes a plurality of positions spaced over an extent of the area being explored having either one or two dimensions which are large relative to a seismic energy wavelength. Seismic energy is imparted into the earth from the sources and signals are generated in response to seismic energy received at the receivers. The generated signals are then combined into a form simulating the reflection response of the earth to seismic energy having a substantially continuous wavefront in either one dimension, simulating a cylindrical seismic energy wave, or two dimensions, simulating a plane seismic wave.

Abstract: Apparatus for conducting seismic reflection surveys from oil tankers or other bulk liquid carriers in the course of their normal journeys. Seismic sources and detector apparatus are mounted in the ballast tanks. Pulse compression techniques may be used, and may take the form of a mechanical flail acting on the hull of the ship.

Abstract: A color dot display and method of forming same by applying colors to dot areas within a matrix of cells in accordance with a color code defining the number of dot areas in the cells, and their locations in the cells, to receive the colors. The proportion of dots of a particular color in a cell defines the representation or saturation of that color in the cell, while the superposition, whether visual or physical or both, of the dots of the various component colors in a cell defines the apparent or resulting color of the cell.

Abstract: A new and improved method of forming color graphic displays from input data is disclosed. In the displays so formed differing colors quantitatively identify and indicate differing values or ranges of values of the data. The input data are processed to determine sample values for data display points, and numerical codes from an assignment table are assigned according to the sample values. The assigned codes are arranged into output sequences for each of plural component displays of the final display, and the component displays formed and displayed in superposition to form the color graphic display with colors therein graphically indicating the data.