Railroad Brake System Tests

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Questions and Answers

What is the maximum allowable brake-pipe leakage for the second minute?

5 PSI

What must the air brakes be at when a train is originally made up?

100% operative

What percentage of operable air brakes is required on the entire train during Class 1A and Class 2 brake tests?

85%

What is the standard brake pipe pressure at the head end for freight and passenger trains?

90 PSI Signup and view all the answers

What is the maximum speed freight trains can exceed?

30 mph Signup and view all the answers

RFNOCOM is considered a failure message.

False Signup and view all the answers

At what brake cylinder piston travel must an air brake be considered inoperative?

10.5 inches Signup and view all the answers

While en route, what percentage of operative air brakes must each train have?

85% Signup and view all the answers

Who must accept the results of any inspection performed by the mechanical department?

The conductor Signup and view all the answers

What must a qualified employee do after completing the Class 1 brake test?

Notify the crew Signup and view all the answers

What is the leakage limit for brake pipe leakage tests?

5 PSI per minute Signup and view all the answers

When is a Class 1 brake test required?

When the train is originally made up. Signup and view all the answers

Under what conditions is a Class 1 brake test not required?

When a solid block of cars is removed or added. Signup and view all the answers

What is the required piston travel range for air brakes after a brake pipe reduction of 20 PSI?

7 to 9 inches Signup and view all the answers

What is the rule about trains previously tested prior to departure concerning further testing?

Requires no further testing. Signup and view all the answers

When does a Class II air brake test need to be conducted?

Unless directed by special instructions. Signup and view all the answers

What necessitates a Class III brake test?

When separated or changing locomotive. Signup and view all the answers

Define a transfer train.

A train that picks up or sets off at intermediate locations. Signup and view all the answers

What can happen to defective equipment during a transfer train air brake test?

Moved to the nearest location for repairs. Signup and view all the answers

What is the acceptable difference between readouts from the EOT and HTD?

3 PSI Signup and view all the answers

Freight trains can move on a 2% grade.

False Signup and view all the answers

What is a branch pipe cut-out cock?

A device for cutting in and out the control valve. Signup and view all the answers

Study Notes

Brake-Pipe Leakage Testing

Measure brake-pipe leakage for one minute; leakage must not exceed 5 PSI in the second minute.

Class 1 Brake Test

Requires air brakes to be 100% operative when the train is initially formed.

Class 1A and Class 2 Brake Tests

Entire train's air brakes must be at least 85% operable.
Tests performed only upon special or verbal instructions.

Standard Brake Pipe Pressure

Standard head-end pressure is 90 PSI; rear-end is 75 PSI for road freight, transfer, yard, freight, and passenger trains.

Telemetry En-route Restrictions

Freight trains limited to 30 mph and cannot exceed a 2% grade.

RFNOCOM Telemetry Message

RFNOCOM (rear to front no communication) is not classified as a failure message.

Inoperative Air Brake Criteria

Air brake considered inoperative if brake cylinder piston travel exceeds 10.5 inches.

En Route Air Brake Requirement

Each train must maintain at least 85% operative air brakes while en route.

Acceptance of Mechanical Inspections

Conductors must accept results from any inspections conducted by the mechanical department.

Class 1 Brake Test Notification

Qualified employees must notify the crew of successful Class 1 brake tests, documented by the engineer.

Brake Pipe Leakage Measurement

In leakage testing, brake pipe leakage must not exceed 5 PSI per minute to indicate proper function.

Conditions Requiring Class 1 Brake Test

Required when train is initially made up or if train consist changes, except with certain minimal adjustments.

Class 1 Test Exemptions

Not required for block car removals, addition of previously tested cars, or changing motive power.

Brake Pipe Leakage Inspection After Reduction

After a 20 PSI brake pipe reduction, verify that air brake cylinder piston travel is correct (7 to 9 inches on body-mounted brakes).

Previous Testing Validation

If a Class 1 test was conducted prior to departure on an outbound locomotive, no further testing is needed unless conditions change.

Class II Brake Test Requirements

Conducted only when specifically instructed; tests include verifying brake applications and compliance with specific retest rules.

Class III Brake Test Conditions

Required for separations or when a locomotive/caboose is changed at locations other than initial terminal, among other conditions.

Transfer Train Definition

A train with an engine and one or more cars that can pick up or drop off at intermediate points, within specified mileage limits.

Transfer Train Air Brake Protocol

Defective equipment may be moved for repairs if appropriately tagged.

Qualifying Telemetry Standards

EOT (End of Train) and HTD (Head of Train Device) readouts must not differ by more than 3 PSI.

Freight Train Speed and Grade Restrictions

Freight trains must not exceed 30 mph and cannot operate on grades greater than 2%.

Branch Pipe Cut-Out Cock Function

Device used to control the valve operation on a locomotive or car, allowing for cutting in and out.

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Description

This quiz focuses on critical concepts related to railroad brake systems, including testing procedures and operational standards. Master the definitions and requirements for various brake tests essential for train safety.