For Signals Training Consortium Use Only

Transcription

1 Introduction and Overview to Highway Grade Crossings Course 104 PARTICIPANT GUIDE

2 Introduction and Overview to Highway Grade Crossings Participant Guide Signals Maintenance Training Consortium COURSE 104

3 Disclaimer: This course is intended to educate employees of transit agencies that have agreed to voluntarily participate in the Signals Maintenance Consortium. It is intended only as informal guide on the matters addressed, and should not be relied upon as legal advice. Anyone using this document or information provided in the associated training program should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of care in any given circumstances. The Signals Consortium, it s participating agencies and labor unions, as well as the Transportation Learning Center, make no guaranty or warranty as to the accuracy or completeness of any information provided herein. The Signals Consortium, its participating agencies and labor unions, as well as the Transportation Learning Center, disclaims liability for any injury or other damages of any nature whatsoever, directly or indirectly, resulting from the use of or reliance on this document or the associated training program.for Signals Training i

4 TABLE OF CONTENTS PAGE HOW TO USE THE PARTICIPANT GUIDE... iv 1-1 Overview Highway Grade Crossing Regulation Highway Grade Crossing Warning System Devices Highway Grade Crossing Control Circuits Warning System Malfunction Traffic Signal Preemption Summary ii

5 LIST OF FIGURES Figure A Wigwag Signal in Southern Oregon Courtesy Wikipedia.org... 4 Figure A Standard Crossbuck and Required Size - MUTCD... 7 Figure Crossbuck with a Number of Tracks Plaque... 7 Figure Highway Grade Crossing Sign Indication Crossing Identification Number and Phone Number for Emergencies MDysart Figure Passive highway grade crossing with a crossbuck mounted on an mast and with optional yield sign, Courtesy Oregon.gov... 8 Figure Pavement Markings and an Advanced Warning Sign - Department of Transportation... 9 Figure Active Highway Grade Crossing - Courtesy San Diego Trolley, Inc Figure Flashers Showing Alternating Lights - Courtesy New Jersey Transit Figure Highway Grade Crossing with Both Front Flashers and Backlights - Courtesy New Jersey Transit Figure Flashing Light Unit Diagram Including Backlights - Safetran Figure Flashers Mounted on a Cantilever with Side Flashers Aimed at a Parking lot Courtesy MClark Figure Electro-mechanical Bell Atop a Mast - Courtesy San Diego Trolley Figure Electronic Bell - Safetran Figure Gate Arm, Gate Lights and Gate Mechanism - Courtesy New Jersey Transit Figure Four Quadrant Gate System with Entrance Gates Lowered and Exit Gates Raised - Courtesy New Jersey Transit Figure Four Quadrant Gate System with Both Entrance Gates Lowered and Exit Gates Lowered Creating a Sealed Corridor - Courtesy New Jersey Transit Figure Gate Mechanism at a Highway Grade Crossing MDysart Figure Gate Arm Counterweight MDysart Figure Western-Cullen-Hayes Gate Mechanism Circa 1980's - Courtesy San Diego Trolley, Inc Figure Safetran S60 Gate Mechanism Circa Approximately Courtesy NJ Transit. 1 Figure Active "No Left" turn signal at a Metra crossing in Chicago, IL... 2 Figure Track Circuits at a Highway Grade Crossing... 3 Figure Approach Circuits with Basic Wiring Diagram Including a Flasher Relay - Courtesy Metro-North Railroad... 4 Figure Highway Grade Crossing Electrical Diagram Showing Directional Stick Circuits - Courtesy Metro-North Railroad... 5 Figure Highway Grade Crossing Electrical Diagram - Courtesy Metro-North Railroad... 6 Figure Key Cut-out - Courtesy Long Island Railroad Figure Highway Grade Crossing Electrical Diagram Showing a Push Button Cutout - Courtesy New Jersey Transit Figure Highway Grade Crossing with Traffic Signal Preemption MClark Figure Complex Highway Grade Crossing with Traffic Signal Preemption in LACMA - MClark iii

6 How to Use the Participant Guide Purpose of the Course The purpose of the Introduction and Overview to Highway Grade Crossings course is to provide the participant with an introduction to highway grade crossings. This introduction will include basic terminology, regulations and oversight specific to highway grade crossings, general highway grade crossing components, control circuits and warning systems. Approach of the Book This course begins with an outline, a statement of purpose and objectives, and a list of key terms. The outline will discuss the main topics to be addressed in the course. A list of key terms identifies important terminology that will be introduced in this course. Learning objectives define the basic skills, knowledge, and abilities course participants should be able to demonstrate to show that they have learned the material presented in the course. A list of key terms identifies important terminology that is introduced in this course. Review exercises conclude this course to assist the participants in reviewing key information. iv

7 INTRODUCTION AND OVERVIEW TO HIGHWAY GRADE CROSSINGS Outline 1-1 Overview 1-2 Highway Grade Crossing Regulation 1-3 Warning System Devices 1-4 Highway Grade Crossing Control Circuits 1-5 Warning System Malfunction 1-6 Traffic Signal Preemption 1-7 Summary Purpose and Objectives: The purpose of this module is to provide the participant with an introduction to highway grade crossings. This introduction will include basic terminology, regulations and oversight specific to highway grade crossings, general highway grade crossing components, control circuits and warning systems. Following the completion of this module, the participant should be able to complete the exercises with an accuracy of 70% or greater: Identify key highway grade crossing terminology & nomenclature Describe regulations pertaining to highway grade crossings Describe the principles of highway grade crossing operation Identify and describe highway grade crossing warning equipment Identify and describe highway grade crossing control circuits Describe highway grade crossing warning systems Identify three types of warning system malfunctions Coursebook Not for Distribution: For Consortium Use ONLY 1

8 Key Terms Activation Failure Active No Left Turn Active No Right Turn Advanced warning sign Approach circuit Backlights Battery Cantilever Circuit controller Constant warning time Conventional circuit Crossbuck Crossing controller Crossing gates Directional stick Emergency signage Entrance gate Exit gate False activation Flashing light unit Four quadrant gate Gate arm Gate arm adapter Gate arm counterweight Gate mechanism Gear train Gate heater element Hold Clear Device Island circuit Motion sensor Motor Number of track plaque Overlay detection circuit Partial activation Traffic signal preemption Warning bell Warning systems Warning system cut-out Warning time Wind bracket Coursebook Not for Distribution: For Consortium Use ONLY 2

9 1-1 OVERVIEW When a highway and railroad cross or intersect at the same grade or height, it is called a highway-rail grade crossing. The Federal Railroad Administration defines a highway-rail grade crossing as a location where a public highway, road, street or private roadway, including associated sidewalks and pathways, crosses one or more railroad tracks at grade. Highway grade crossings present the potential of highway and/or pedestrian traffic intersecting at the same time with a train. As a result of this, warning systems have been developed and revised over the years to alert motorists and pedestrians to the approach of oncoming trains and rail vehicles. The first attempts at providing highway grade crossing safety through warning systems date back to the late 1800 s. These early warning systems were used to alert motorists and pedestrians of an oncoming train and were known at that time as protection systems. These early protection systems included hand-painted railroad crossing warning signs in less traveled areas and watchmen with red flags stationed in busier areas. Soon after, the industry adopted the practice of installing a mechanically man-operated crossing gate to be lowered across the roadway during train movement. The assigned gate keeper (or crossing guard), as they were called, would be stationed in a gate keeper s shanty immediately next to the crossing. Upon hearing the whistle of an approaching engine, the gate keeper would come out of his shanty to manually lower the crossing gate to stop traffic for the train and then crank it gate back up into the air again to allow people to resume travel. Over time, both road and rail have seen increases in traffic in terms of volume and speeds. Consequently, additional highway grade crossings emerged as well as a need for more efficient and affordable warning systems. Beyond the earlier mentioned protection systems, track circuit installations provided the means for the trains to activate a warning system. The development and use of the wigwag signal, the first mechanical warning device, came into play next. Wigwag means to move back and forth in a rhythmic fashion. Thus, a wigwag signal provided a swinging banner equipped with a light in the middle to caution motorists. An audible warning bell was also typically included as an adjunct to wigwag signal. The wigwag was either placed above or to the side of the road and was intended to replicate a crossing watchman and his swinging red lantern. Some of these wigwags are still in use in the United States today as seen in Figure 1. Coursebook Not for Distribution: For Consortium Use ONLY 3

10 Figure A Wigwag Signal in Southern Oregon Courtesy Wikipedia.org As road systems and their use continued to grow, the need to standardize signage and warning systems became increasingly important. In 1923, the first standardization of highway grade crossing signals in the United States occurred during the annual meeting of the American Railway Association (now the Association of American Railroads). While highway grade crossing systems have been improved over the years, the basic idea of providing a train-based warning system to allow for an effective amount of warning time and minimal inconvenience to the motorist have remained the same. This module is intended to explore the modern grade crossing in terms of regulations, warning devices, basic operation, and warning system logic circuits. Warning: Safety Precautions! As with all work on train tracks, the signal maintainer must strictly adhere to the worker safety policies of the transportation agency. Coursebook Not for Distribution: For Consortium Use ONLY 4

11 Figure Active Highway Grade Crossing - Courtesy San Diego Trolley, Inc. While the activation of these warning devices is based on sophisticated train detection and crossing signal control circuitry, the proper functioning of these warning devices is dependent on FRA required testing, diligent monitoring of operation, and conscientious maintenance. Flashing Light Unit or Flashers Flashing Light Units, or Flasher signal, are pairs of red lights displayed in one or more direction to provide a visual warning to motorists and pedestrians that a train is approaching the crossing. Flashers are aligned to face the direction of approaching traffic and are mounted to the mast just under the crossbuck sign as per MUTCD and AREMA standards. As the train approaches the highway grade crossing, train detection circuits initiate the start of the flashers. According to FRA regulation, the flashers must alternately flash red lights in a synchronized manner for not less than 35 or more than 65 operations per minute, as seen in Figure 8. After the train clears the highway grade crossing, train detection circuits will cause the flashers to cease operation. Coursebook Not for Distribution: For Consortium Use ONLY 10

12 Directional Stick Circuits Previously mentioned a conventional highway grade crossing control circuit also needs a directional stick circuit. Directional stick circuits are required to cease crossing warning system operation when the train clears the highway (island circuit recovers) and the opposing approach is occupied by the trailing end of the train. The directional stick circuit also indicates, as the name states, the direction of the train movement. An example of a directional stick circuit in an electrical diagram is shown in Figure 24. Figure Highway Grade Crossing Electrical Diagram Showing Directional Stick Circuits - Courtesy Metro-North Railroad Understanding the Highway Grade Crossing Sequence of Operation and a Directional Stick Circuit Given the earlier mentioned crossing train detection circuits and directional stick circuits, let s explore an example sequence of operation of a highway grade crossing with the passage of a train. Table 1 Sequence of Operation Nomenclature TB RB TR ESR WSR XR ZR Sequence of Operation Nomenclature Transmit Battery Wires Relay Receive Wires Track Relay East Stick Relay West Stick Relay Crossing Relay Flasher Relay Coursebook Not for Distribution: For Consortium Use ONLY 5

13 STEP 1 The train proceeds in the west approach track circuit. The 1TR relay drops. With the 1TR relay down, power to XR is taken away causing gates to start down and lighting to start. Putting power to the ZR causes lights to flash. Highway Grade Crossing Sequence of Operation STEP 2 Train enters the island circuit (2TR) while still on approach circuit. Both 1TR and 2TR are down. At this time, the east directional stick relay (ESR) is picked up showing direction of traffic through crossing. Coursebook Not for Distribution: For Consortium Use ONLY 7