Abstract: A multi-use wayside railway control system for installation and use in operating wayside railway equipment in a railway wayside application selected from among a plurality of differing railway wayside applications usable in the control system. The system includes detectors responsive to and generating data indicative of operating conditions of the selected wayside application A controller receives data from the detectors and is responsive to the data for operating the wayside equipment. A programmed processor associated with the controller includes a software program storage device for storing a plurality of separately selectable operating programs, each of the operating programs comprising application specific information for a selected wayside application and corresponding configuration of wayside equipment.

Abstract: An autonomous personal transportation system for moving passengers and light freights is constructed with a track network and small vehicles on the track network. There are a number of stations and stops for loading and unloading on side tracks off the mainline of the track network. The vehicle width is limited to a dimension for one seat. The vehicles can be coupled statically or dynamically to form a train. The track has side rails for the rigid wheels of the vehicle and a central rail for centering the vehicle on the guideway and providing additional acceleration and braking capability. The control system for the movement of vehicles is divided into three levels: the central control system, the wayside control system and the vehicle control system.

Abstract: A train control system includes a positioning system and consults a database to determine when the train is approaching a configurable device such as a switch or grade crossing gate. The system continuously interrogates the device to determine its status as the train approaches the device, and forces an engineer/conductor to acknowledge any detected malfunction. The train is forced to come to a complete stop before proceeding past the device or may be slowed down to a speed that will allow the engineer/conductor to visually determine whether it is safe to proceed past the device if the engineer/conductor acknowledges a message warning of the malfunction and will stop the train if the engineer/conductor fails to acknowledge the warning message.

Abstract: A system which operates a digitally controlled model railroad transmitting a first command from a first client program to a resident external controlling interface through a first communications transport. A second command is transmitted from a second client program to the resident external controlling interface through a second communications transport. The first command and the second command are received by the resident external controlling interface which queues the first and second commands. The resident external controlling interface sends third and fourth commands representative of the first and second commands, respectively, to a digital command station for execution on the digitally controlled model railroad.

Abstract: A control apparatus for an electric railcar that provides control so that when rotational speed of a motor decreases below a required value, torque of the motor will decrease at a required rate of change, a current limiter for limiting a torque current command “(A)Iqp” output from a current command arithmetic unit is provided to ensure that when the rotational speed of the motor decreases below the required value, the torque current command will be limited to a command value “(B)Iqp” smaller than that command value, and to ensure that a carrier frequency at which PWM signals are created when switching elements of the electric power converter are controlled by carrier generator is controlled to become lower than a carrier frequency existing when the rotational speed of the motor decreases below the required value.

Abstract: An automatic coupling system (10) for a locomotive (11). The automatic coupling system includes a means for detecting a coupling contact and for controlling locomotive systems such as throttle and brakes in response to such contact. The means for detecting contact may be a speed sensor (24), an accelerometer (26), a distance detector (28), and/or a wheel slip detector (30). The automatic coupling system may be integrated with a locomotive remote control system (22) to facilitate the coupling of a locomotive to a railcar (40) when the operator is not located in the locomotive cab.

Abstract: A system which operates a digitally controlled model railroad transmitting a first command from a first client program to a resident external controlling interface through a first communications transport. A second command is transmitted from a second client program to the resident external controlling interface through a second communications transport. The first command and the second command are received by the resident external controlling interface which queues the first and second commands. The resident external controlling interface sends third and fourth commands representative of the first and second commands, respectively, to a digital command station for execution on the digitally controlled model railroad.

Abstract: This invention relates to a method and apparatus for assessing quality of service for communication networks. More particularly, the invention is directed to assessing quality of service in circuit and packet switched networks by way of a computer simulation. Preferably, the information necessary to conduct the assessment activity is available via the internet from a web server that also compiles statistical data on the resultant quality of service assessments.

Abstract: An apparatus for controlling a railway consist, the apparatus comprising: a consist model adapted for computing an objective function from a set of candidate driving plans and a set of model parameters; a parameter identifier adapted for calculating the model parameters from a set of consist measurements; and a trajectory optimizer adapted for generating the candidate driving plans and for selecting an optimal driving plan to optimize the objective function subject to a set of terminal constraints and operating constraints.

Abstract: A remote locomotive control system includes a slave controller configured to receive data strings from remote transmitters. The slave controller is responsive to an acquire signal received from one of the remote transmitters for configuring the slave controller to control one or more control functions of the locomotive as a function of one or more data strings received exclusively from the one remote transmitter. However, the slave controller is configured so that any remote transmitter can control safety functions of the locomotive via the slave controller.

Abstract: In order to propose a method of promptly judging movement of a train between block sections with a minimum number of transponders, an on-ground train control part for controlling operation of a train; an on-ground communication means capable of performing communication of information by coming within a specified range; and a sending-and-receiving part capable of sending the information received by the on-ground communication device to the on-ground train control part and receiving the information sent from the on-ground train control part, are provided, thereby, a position of presence of train is grasped by receiving a speed of the train using the on-ground communication means when the on-train communication means attached to the train comes near.

Abstract: An end of train unit includes a positioning system such as a GPS receiver and is configured to transmit a message including the EOT unit's location when the EOT unit detects a loss of air pipe pressure and/or it is tipped over and/or a low battery condition is detected. In highly preferred embodiments, the EOT unit periodically re-transmits the message until an acknowledgment message is received. In some embodiments, information from the positioning system is used to create a signal as a substitute for a motion sensor. In other embodiments, information from the positioning system is used to determine the speed of the end of the train. End of train unit tracking is also performed.

Abstract: A train control system and method uses signal information from a next block to change a restrictive signal in a block currently occupied by the train to a less restrictive signal if it can be ascertained that the condition causing the more restrictive signal has changed. This may be accomplished by receiving signal information from the next block while still in the current block and, if the signal information from the next block is no more restrictive than the signal information in the current block, and the signal in the current block is of a type that can safely be modified, allowing the train to operate as if the signal information for the current block were less restrictive than the actual, previously received signal information for the current block.

Abstract: The invention relates to a method and apparatus for controlling trains, in which method and apparatus, the location and the speed of a train on the line are acquired. A location specification is generated as a function of the acquisition, so that a movement control magnitude is delivered for controlling movement of the train. In the invention, a braking distance for the preceding train and the control magnitude are computed on the basis of the location specification plus the computed braking distance. Application in particular to ERTMS/ETCS systems.

Abstract: A method of controlling operation of a train (T) for passage of the train through a tunnel. The train has a plurality of locomotives (L1-Ln) pulling the train. The position of the lead locomotive relative to the tunnel entrance is determined, as is the amount of time before the train enters the tunnel. Each locomotive is separately configured for passage through the tunnel as a function of performance characteristics of the locomotive and the locomotive's current operating status, as the train approaches the tunnel. Once the train enters the tunnel, the performance characteristics of each locomotive are continually monitored. The performance requirements for one or more of the locomotives are then dynamically changed as a function of conditions within the tunnel and the current performance characteristics of each locomotive. This is done to maintain a sufficient combined performance capability from the locomotives to move the train through the tunnel.

Abstract: A locomotive control system includes an on-board controller responsive to a time signal received from a remote source for outputting a first polling signal at a time determined with reference to the time signal. A first remote controller is responsive to the polling signal for outputting a first control signal during a first interval of time. The on-board controller is responsive to the first control signal for controlling one or more functions of the locomotive. The locomotive control system can also include a second remote controller responsive to a second polling signal output by the on-board controller at a time after the first interval of time determined with reference to the time reference signal for outputting a second control signal during a second interval of time. The on-board controller is also responsive to the second control signal for controlling one or more functions of the locomotive.

Abstract: A method of locating nodes in train having at least one node per car and includes enabling each node; querying each enabled node to respond during a response interval; disabling each node which responded; and re-querying the enabled nodes until no further responses are received during a response interval. The method further includes disabling the responding nodes before the expiration of the response interval if the interval is under utilized and after the expiration of the response interval if the interval is fully utilized. The method further includes determining the number of responses during a present response interval and setting the length of a subsequent response interval as a function of the determined number of responses. The number of responses may be determined for a whole interval or for a portion of the present response interval, and the length of the subsequent response interval is set based on the response rate determined for the portion of the present response interval.

Abstract: A system used to detect and annunciate a loss of occupancy detection in transit systems normally operating under automatic train control operation is disclosed. Upon manual or automatic engagement of operation the system, in collaboration with the existing automatic train control electronics, detects and annunciates the loss of occupancy detection by querying the train's trailing speed control blocks for any valid nonzero speed command that would allow other trains to enter that already occupied block—causing a collision! Additionally, in the present invention the system's self checking error and failure detection operation is automatically checked during normal running mode of operation and as such each individual component of the entire automatic train operation is checked for failure in its entirety and the system is void of undetected latent failures owing to its design, stability, and simplicity of operation.

Abstract: A mass transit vehicle traction motor control system includes an automatic control block for receiving and processing a tachometer signal having a first resonance signal superimposed thereon to produce a rate request signal having a corresponding second resonance signal superimposed thereon. A filter is provided for decreasing an amplitude of the second resonance signal whereupon the rate request signal is isolated therefrom. A communication and control block and a propulsion and control block co-act to process the isolated rate request signal to produce a speed control signal that is configured to cause a traction motor of a mass transit vehicle to provide motive force to the mass transit vehicle at a rate related to the value of the speed control signal.

Abstract: A system for controlling, a response to an operator, a consist of at least first and second locomotives having discrete operating modes. The system comprises an operator control, a first controller, a second controller, and a communication link. Alternatively, the system and method includes control modules which may be retrofitted to an existing consist control. The power operating modes of the locomotives within a consist are selected to optimize the operation of the consist. The operation of the consist may be optimized for any number of factors including optimizing for braking capacity, as a function of the location, base on a performance parameter which is a function of a performance profile or the location of a crew member.

Abstract: The system and method for controlling a consist of at least first and second locomotives having discrete operating modes. The method comprises receiving a control command and determining a power operating mode of the first locomotive and a power operating mode of the second locomotive as a function of the control command and an optimization parameter. The power operating mode of the second locomotive is different as compared to the power operating mode of the first locomotive in at least one mode of operation of the method. The method further comprises controlling the first locomotive responsive to the power operating mode of the first locomotive and controlling the second locomotive responsive to the power operating mode of second locomotive.

Abstract: In an automatic train stop system in which a track circuit 3 is divided into track circuit sections 1T, 2T and 3T, and a digitized train control information telegram (ATS telegram) 8 is transmitted through the track circuit sections on carriers having different frequencies, a carrier sensor 12 mounted on a train 5 receives a carrier in the track circuit 3 and detects a track circuit boundary 31 by detecting a level change of the carrier, whereby an onboard system grasps the position thereof and controls the train 5 based on the information of the ATS telegram 8.

Abstract: A train control system includes a positioning system and consults a database to determine when the train is approaching a configurable device such as a switch or grade crossing gate. The system continuously interrogates the device to determine its status as the train approaches the device, and forces an engineer/conductor to acknowledge any detected malfunction. The train is forced to come to a complete stop before proceeding past the device or may be slowed down to a speed that will allow the engineer/conductor to visually determine whether it is safe to proceed past the device if the engineer/conductor acknowledges a message warning of the malfunction and will stop the train if the engineer/conductor fails to acknowledge the warning message.

Abstract: The present invention provides methods for preventing low train voltages and managing interference, thereby improving the efficiency, reliability, and passenger comfort associated with commuter trains. An algorithm implementing neural network technology is used to predict low voltages before they occur. Once voltages are predicted, then multiple trains can be controlled to prevent low voltage events. Further, algorithms for managing inference are presented in the present invention. Different types of interference problems are addressed in the present invention such as “Interference During Acceleration”, “Interference Near Station Stops”, and “Interference During Delay Recovery.” Managing such interference avoids unnecessary brake/acceleration cycles during acceleration, immediately before station stops, and after substantial delays. Algorithms are demonstrated to avoid oscillatory brake/acceleration cycles due to interference and to smooth the trajectories of closely following trains.

Abstract: A transmitter for remotely controlling a locomotive entity. The transmitter has a control entity capable of acquiring a plurality of states, including a linked state. The transmitter also has an interface in communication with the control entity for receiving an identifier of the locomotive entity via a communication link. The transmitter also has a proximity detector having a detection field, the proximity detector being in communication with the control entity to enable the control entity to switch to the linked state at least when the locomotive entity is in the detection field.

Abstract: A method and system for compensating for wheel wear uses position and/or speed information from an independent positioning system to measure some distance over which the train has traveled. Wheel rotation information and/or distance and speed from a wheel sensor over the distance is also collected. The wheel rotation information and distance and/or speed information are then used to determine the size of the train wheels and/or a correction factor that can be used to correct the information from the wheel sensor for wheel wear. The method is performed periodically to correct for changes in wheel size over time due to wear so that the wheel rotation information can be used to determine train position and speed in the event of a positioning system failure.

Abstract: A positive signal comparator system includes a transceiver located on a train for transmitting an interrogation signal to a wayside signal device and receiving a response signal from the wayside signal device, an input device through which an operator enters a signal in response to the signal received from the wayside signal device, and a controller including a signal comparator for determining if the signal input by the operator matches the signal received from the wayside signal device and taking corrective action if the operator fails to enter the proper signal. In some embodiments, the corrective action comprises activating a warning device and/or activating the train's brakes. In some embodiments, the invention further comprises a display for displaying the signal received from the wayside signal generator to the operator.

Abstract: An electronic control system (20) for an electropneumatic brake for a rail vehicle having a power trainline (18), comprising a battery (34); a functional control module (30) and a power management module; wherein the functional control module (30) includes a brake controller for the electropneumatic brake, an interface to the power trainline, a transceiver for receiving brake signals, a power supply circuit deriving a power supply from the power trainline (18), and a control management controller for the transceiver and the power supply circuit; and wherein the power management module includes a battery charging circuit connected to the power supply and a power controller for the battery charging circuit and the power supply circuit.

Abstract: A method and apparatus for determining a model vehicle layout by moving a vehicle around the track and noting when the vehicle passes track position detection elements. The vehicle can either detect the position detection elements, or the position detection elements can be sensors which detect the vehicle. By noting the order of the position detection elements as detected, and the direction of the vehicle, the layout of the track can be determined. In one embodiment, the position detection elements are sensors along the track which detect an emitted ID from the vehicle, and also detect the speed and direction of the vehicle. This information is then relayed to a control system. In another embodiment, the vehicle detects the position detection element, and relays this information, along with the train ID, speed and direction, to the control system.

Abstract: A method for controlling locomotive consists at slow speeds by independently controlling each locomotive is provided. The method comprises controlling the throttle settings and main generator excitation of a control locomotive, independently controlling, from the control locomotive, the throttle setting of each of the controlled locomotives, and compensating for a combined consist tractive effort change induced by a change in the throttle setting of each of the controlled locomotives by adjusting the main generator excitation of at least one of the locomotives to maintain a preset consist speed. The method further includes changing the throttle settings concurrently in the control and controlled locomotives, changing the throttle settings of the controlled locomotives only after the control locomotive reaches a maximum generator excitation, and changing the throttle settings according to a rule base.

Abstract: A remote control unit for controlling a locomotive by transmitting signals to a remote receiver mounted onboard the locomotive is provided. The remote control unit includes an input for receiving a signal indicative of a command selected from a set of available commands. A signal transmitting unit transmits a signal indicative of the selected command repetitively to create a succession of signal transmission events. In a first example, each signal transmission event is spaced in time from a previous signal transmission event by a certain time interval having a duration conditioned at least in part on the basis of the selected command. In a second example, each signal transmission event includes a message portion and a header portion and the message portion of the signal has a length conditioned at least in part on the basis of the selected command. In a third example, each signal transmission event is characterized by a signal level conditioned at least in part on the basis of the selected command.

Abstract: Method for controlling the level of tractive efforts in a train having a first locomotive at a head end of the train, constituting a lead locomotive, and a second locomotive positioned in the train behind the lead locomotive, constituting a remote locomotive, with the remote locomotive being configured to selectively operate in either of two modes of operation, such as a first mode in which the locomotive operates at a full tractive effort level of operation and a second mode in which the locomotive operates in a partial tractive effort level of operation producing a tractive effort which is less than the full tractive effort of the locomotive. The method allows selecting (e.g., at the lead locomotive) one of the two modes of operation for producing a level of tractive effort appropriate for conditions as the train moves along a length of track. The method further allows transmitting a signal indicative of the selected mode of operation from the lead locomotive to the remote locomotive.

Abstract: A system which operates a digitally controlled model railroad transmitting a first command from a first client program to a resident external controlling interface through a first communications transport. A second command is transmitted from a second client program to the resident external controlling interface through a second communications transport. The first command and the second command are received by the resident external controlling interface which queues the first and second commands. The resident external controlling interface sends third and fourth commands representative of the first and second commands, respectively, to a digital command station for execution on the digitally controlled model railroad.

Abstract: A process for scheduling the travel of trains on a rail corridor. The rail corridor includes a plurality of siding tracks onto which trains can be sided when a meet or pass occurs with another train on the corridor. A gradient search process is used with a cost function to determine the optimum schedule by moving each meet and pass to a siding. The individual train schedules are varied by changing train speed and/or the train departure time (i.e., the time at which the train enters the corridor).

Abstract: In a railroad locomotive having a diesel engine and an electro-motive propulsion system for transforming and transmitting power from the engine to wheels of the locomotive for propelling the locomotive, a method of reducing the time required to transmit power at a predetermined level of power to the wheels to propel the vehicle comprising increasing engine speed to approximately a maximum engine speed prior to transmitting power generated by the engine to propel the locomotive, and thereafter controlling the electro-motive propulsion system to transfer power from the engine to the locomotive wheels to propel and accelerate the locomotive.

Abstract: A system and method for removing cross-talk in measured forces between a railway wheel set and the railhead of underlying track such as found in angle of attack measurements for shallow curvature track. The angle of attack for the leading and trailing sets of wheels in trucks of rail vehicles is measured traveling over track in a wayside system. At a first point on the outside rail of a track vertical force is measured with a first vertical strain gage, lateral force is measured with a first lateral strain gage and an outside angle of attack timing signal is measured with a first angle of attack strain gage. This process is repeated on the inside track so that a raw angle of attack for each set of wheels can be determined based upon speed and time difference. Position signals obtained from position strain gages are used to remove cross-talk thereby improving accuracy. The sensed position signals are calibrated to known forces on the railhead.

Abstract: A train control system and method uses signal information from a next block to change a restrictive signal in a block currently occupied by the train to a less restrictive signal if it can be ascertained that the condition causing the more restrictive signal has changed. This may be accomplished by receiving signal information from the next block while still in the current block and, if the signal information from the next block is no more restrictive than the signal information in the current block, and the signal in the current block is of a type that can safely be modified, allowing the train to operate as if the signal information for the current block were less restrictive than the actual, previously received signal information for the current block.

Abstract: The present invention relates to a remote control system for a locomotive having a control interface. The remote control system comprises a portable remote control device and a locomotive control device. The portable remote control device receives command data indicative of speed information, and generates digital command signals for transmission to the locomotive control device for conveying the command data. The locomotive control device is adapted to be mounted on board a locomotive, and is operative for receiving the command signals conveyed by the portable remote control device. The locomotive control device includes a control entity that is responsive to the signal conveyed by the remote control device for deriving a specific speed associated to the command data, wherein the specific speed is a configurable parameter. Finally the control entity is operative for issuing local control signals to the locomotive control interface for causing the locomotive to implement the specific speed.

Abstract: A method and apparatus for transmitting an information carrying signal, such as an electromagnetic frequency signal or an acoustic signal, through the tracks of a railroad to a remote position on the track where the information is extracted. The extracted information can be used to relate speed and location of trains, location of obstructions, and/or track conditions. The in situ track (10) is evaluated using an autoranging digital multimeter which establishes the resistance between two opposite rails (12, 14).

Abstract: A system which operates a digitally controlled model railroad transmitting a first command from a first client program to a resident external controlling interface through a first communications transport. A second command is transmitted from a second client program to the resident external controlling interface through a second communications transport. The first command and the second command are received by the resident external controlling interface which queues the first and second commands. The resident external controlling interface sends third and fourth commands representative of the first and second commands, respectively, to a digital command station for execution on the digitally controlled model railroad.

Abstract: A remote control system for a locomotive. The remote control system includes a lead controller and follower controller connected to one another over a wireless communication link. The lead controller issues commands over the wireless communication link and those commands are implemented by the follower controller mounted on-board the locomotive. The lead controller is responsive to voice commands uttered by the operator.

Abstract: The invention is a communication system having a series of output modules that provide continuous synchronization output signals. Each output module has a driver assembly has a driver output and a backup selector output that is capable of driving a failed next driver assembly. A sensor detects the failure of the driver output and generates a select signal in the failure state. A selector receives the driver output, a backup driver output, the select signal, and a select signal from the next driver assembly. The selector normally selects the driver output, but in response to a failure state from the select signal, isolates the failed driver output. The previous driver assembly transmits a backup selector output to the failed driver assembly to maintain a continuous driver output. The transformers are preferably placed on a separate card to reduce the thermal degradation of nearby electronics. As transformers rarely fail, replacing them when a card fails is wasteful.

Abstract: A system for automatically detecting the presence of a train located within a detection or surveillance area of a railroad track associated with a railroad grade crossing. The system includes a transmitter unit that transmits a detection signal. The system also includes a receiver that receives a detection signal. A receiver unit receives one or more signals. A processor coupled to the receiver unit is configured to process the received signals and determine the presence, absence or movement of a train or signal within the detection or surveillance area. The processor unit is configured to initiate an action when the processor determines the presence or the absence of the train or one or more detection signals. The current invention also includes a method for automatically detecting the presence of the train located within a surveillance area associated with a railroad grade crossing area.

Abstract: A system of controller modules allowing to remotely control a train having a first locomotive and a second locomotive separated from one another by at least one car is provided. The system of controller modules comprises a first controller module associated to the first locomotive and a second controller module associated to the second locomotive. One of said controller modules has a lead operational status and the other has a trail operational status. The controller module having the lead operational status receives a master control signal for signaling the train to move in a desired direction and releases in response to the master control signal a first local command signal. The first local command signal is operative to cause displacement of the locomotive associated with the controller module having the lead operational status.

Abstract: A remote control system for a locomotive. The remote control system includes a lead controller and follower controller connected to one another over a wireless communication link. The lead controller issues commands over the wireless communication link and those commands are implemented by the follower controller mounted on-board the locomotive. The lead controller is responsive to voice commands uttered by the operator.

Abstract: This management system for managing the route of a rail vehicle travelling on a rail network between a departure point and an arrival point includes a central processor unit configured to cause a change in the route of the rail vehicle between a route-change node and a convergence node at which the changed route converges back on the initial route. The central processor unit is further configured to determine a set of routes comprising all of the possible routes between the route-change node and the convergence node, and compare the set of routes with the initial route so as to cause the route change to be made along the route that is closest to the initially-planned route.

Abstract: An apparatus for controlling a plurality of locomotives, the locomotives being responsive to a plurality of discrete actual commands, the apparatus comprising: a combination generator adapted for generating combinations of the discrete actual commands to yield a command combination set; a performance calculator adapted for calculating a performance parameter set from the command combination set; a feasible combination selector adapted for selecting a feasible combination subset from the command combination set as a function of a discrete performance setpoint, a performance tolerance, and the performance parameter set; an objective function calculator adapted for calculating an objective function set from the feasible combination subset; and an optimal command selector adapted for selecting an optimal command combination from the feasible combination subset corresponding to an optimum value of the objective function set.

Abstract: An automatic train handling controller. In one embodiment, there is disclosed a system and method for tracking a velocity profile in a rail-based transportation system. A fuzzy logic controller is used to ensure that a train simulator complies to the velocity profile over a specified track profile while providing a smooth ride. A safety constraint enforcer is used to minimize sudden slack movements by ensuring that the control action provided by the fuzzy logic controller is kept in compliance with a set of predetermined safety constraints. In a second embodiment, there is an automatic train handling controller that smoothly manages the slack of the couplers while keeping the train within prescribed speed limits over a varying terrain.

Abstract: A train control method and apparatus for controlling the movement of trains with high safety by detecting trains on sections of track by an electronic blocking system. A wayside communication element (wayside transponder) 5 is placed in each block section on a track on which a train 1 runs. A cab communication element (cab transponder) 3 which can communicate with the wayside communication elements on the track is placed on the train 1. When receiving a train identifier (ID) from a train, a wayside control device transmits the current position information and the stop position information to the train. The cab communication element of the train 1 receives the current position information and the stop position information, creates a protection speed pattern between the current train position and the stop position from the received information, and limits the speed of the train 1 by the protection speed pattern.

Abstract: A diesel locomotive includes a number of auxiliary subsystems operating in conjunction with the locomotive diesel engine and deriving their energy, from the diesel engine. Included among the subsystems are various cooling systems, the battery charging system, and the electrical generation system, comprising one or more alternators drivingly coupled to the engine shaft. Each of the subsystems includes a component that is activated when one or more operational conditions associated with the subsystem are met. For instance, an engine cooling system fan motor is activated when the coolant temperature exceeds a predetermined value. Similarly, a battery charger is activated when the battery voltage falls below a predetermined value, and an alternator blower is activated when the main or auxiliary alternator temperature exceeds a predetermined value.