Railway Accident Investigation Chapter 2

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Questions and Answers

What may cause the amplitude of oscillations to increase when a train is coasting?

Improper loading of goods

Presence of factors amplifying the oscillations (correct)

The application of brakes

The train moving at a lower speed

What is the primary purpose of a site investigation after a derailment?

To identify the speed of the train at the time of derailment

To ascertain the actual cause of derailment (correct)

To monitor the weather conditions during the incident

To restore the track and vehicles immediately

What is a potential consequence of irregular or excess loading of a vehicle?

Increased stability

Wheel floating due to off-loading (correct)

Improved performance during travel

Reduction in maintenance costs

Which of the following is NOT a main purpose of the site investigation?

To repair damaged tracks Signup and view all the answers

Which factor is NOT considered in the investigation of a derailment?

Weather conditions Signup and view all the answers

In what order should the site investigation sequence be conducted?

First considerations, Site sketch, Flange marks Signup and view all the answers

What might occur if empty stock is marshalled between two loaded wagons?

Derailment due to impact of drawbar forces Signup and view all the answers

Which of the following factors is crucial to check if derailment occurs due to mismanipulation of a point?

Length of tongue rail Signup and view all the answers

Why is it essential to record the position of vehicles after a derailment?

To establish the category of derailment Signup and view all the answers

What key evidence must be drawn from the initial point of derailment during an investigation?

The wheel mounting marks Signup and view all the answers

What kind of failures may lead to derailments by the operating staff?

Loose couplings and undetected obstructions Signup and view all the answers

When should a survey of the site be completed in relation to track restoration?

Before restoration work commences Signup and view all the answers

How can sudden applications of brakes lead to derailment?

Through bunching and off-loading of lightly loaded wheels Signup and view all the answers

Which of the following is essential for ensuring points work correctly?

Proper setting and locking of points Signup and view all the answers

What information is included in a site sketch during an investigation?

The position of derailed vehicles relative to the rails Signup and view all the answers

Which issue is a result of improper train operation by the driver?

Off-loading of light loaded wheels during sudden braking Signup and view all the answers

What should be done first during a site investigation?

Record the sequence of events leading to derailment Signup and view all the answers

What can examining flange marks help determine?

Whether the derailment was sudden or gradual Signup and view all the answers

What should NOT be checked when examining the point operation?

Length of the track Signup and view all the answers

Which aspect is NOT part of the site investigation process?

Repairing the damaged track immediately Signup and view all the answers

What factors should be recorded when analyzing wheel mounting marks?

Length, profile, and strength of marks Signup and view all the answers

What is the consequence of exceeding the permissible speed during a train operation?

Increased risk of flange mounting and derailment Signup and view all the answers

Why is it important to photograph mounting marks on the sleeper fastenings and ballast?

To document the condition of the track post-derailment Signup and view all the answers

What happens to the range of permissible imperfections on the track as train speed increases?

It decreases, leading to higher risk of derailments Signup and view all the answers

How can the initially derailed wheel set be identified after a derailment?

By matching trail marks left by wheels with vehicle orientation Signup and view all the answers

What is the effect of the train's speed on the rolling stock?

It causes exciting oscillations based on disturbances Signup and view all the answers

What is meant by 'flange mounting' in the context of train derailments?

A situation where the wheel flanges go over the rail edge Signup and view all the answers

Which element is NOT considered a major operational defect in derailments?

Weight of the cargo Signup and view all the answers

What should be done if it is challenging to ascertain the first vehicle that derailed?

Detail the damage sleeper by sleeper Signup and view all the answers

What is a key consideration when analyzing flanged wheel marks?

Whether they are continuous or broken Signup and view all the answers

What is the primary method used to establish the category of derailment?

Examining flange marks at the initial point of derailment Signup and view all the answers

Which of the following steps should be completed before restoring any track after a derailment?

Completing a site sketch of the crash location Signup and view all the answers

What is the significance of the sequence of events recorded during an investigation?

To ascertain how the derailment occurred from initiation to halt Signup and view all the answers

What aspect is critical when preparing the site sketch after a derailment?

Illustrating the position of derailed vehicles relative to the rails Signup and view all the answers

Which action is considered first during the site investigation process?

Locating the initial point of derailment Signup and view all the answers

Why is the examination of wheel marks essential in derailment investigations?

To differentiate between gradual and sudden derailments Signup and view all the answers

Which of the following factors significantly influences the possibility of a train derailment?

Operational speed of the train Signup and view all the answers

What is at risk if site sketches are not prepared during an investigation?

Accurate correlation of the event data later on Signup and view all the answers

When analyzing wheel mounting marks after a derailment, which detail is NOT typically recorded?

Type of wheels used Signup and view all the answers

What must be assured before proceeding with the survey of the site?

Initial observations should be documented Signup and view all the answers

Which of the following is NOT a main purpose of conducting a site investigation?

Planning future route improvements Signup and view all the answers

What characteristic of the rolling stock is essential in understanding how derailments occur under dynamic conditions?

Spring and suspension system response Signup and view all the answers

Which aspect of the marks left by derailed wheel sets is crucial for tracing the initial point of derailment?

Length and nature of trail marks Signup and view all the answers

How is the condition of the track examined during the site investigation?

By conducting a comprehensive track survey Signup and view all the answers

How does increased train speed affect the permissible imperfections on the track?

It decreases the range of permissible imperfections. Signup and view all the answers

What must be done if it is challenging to determine the first vehicle to derail?

Record damage sleeper by sleeper. Signup and view all the answers

What type of marks must be noted and measured following a derailment?

Mounting marks on the rails and sleep fastenings Signup and view all the answers

In terms of operational defects leading to derailments, which of the following is NOT considered significant?

The engineer's experience level Signup and view all the answers

What characteristic of the marks made by derailed wheels can indicate the severity of the incident?

Faintness or strength of the marks Signup and view all the answers

Which operational feature is likely to produce increased lateral forces on the flange, leading to derailment?

Excessive train speed Signup and view all the answers

Which factors can primarily amplify oscillations in a train's movement?

Degree of track imperfections and maintenance of rolling stock Signup and view all the answers

What is the most significant result of marshalling empty stock between loaded wagons?

Risk of the empty stock derailing under draw bar forces Signup and view all the answers

What should be checked to determine if a derailment resulted from mismanipulation of a point?

The alignment of tongue rail and stock rail Signup and view all the answers

What specific issue may occur if points are not set correctly during operational procedures?

Derailment of the leading wheel or trolley Signup and view all the answers

Which operational failure could contribute to derailment due to improper manipulation of controls?

Points not being locked during wheel movement Signup and view all the answers

What can be a consequence of the sudden application of brakes during train operation?

Bunching and off-loading of the light loaded wheels Signup and view all the answers

Which aspect is NOT crucial when investigating a potential derailment?

Condition of other trains on adjacent tracks Signup and view all the answers

What potential effect does irregular loading have on train behavior?

Increased likelihood of wheel floating Signup and view all the answers

In case of derailment, what item is essential to check at the points?

Gap between the toe of switch and stock rail Signup and view all the answers

Which factor is least likely to contribute to train derailment during normal operations?

Well-maintained track conditions Signup and view all the answers

What detail is NOT typically recorded when analyzing wheel mounting marks?

Material of the wheel Signup and view all the answers

How can the initial wheel set that derailed be identified?

By matching the trail marks left by wheels against vehicle orientation Signup and view all the answers

What effect does excessive train speed have during operation?

It increases lateral forces on the flange Signup and view all the answers

What type of photographs should be taken after a derailment?

Of mounting marks on rail, sleeper fastenings, and ballast Signup and view all the answers

What is the consequence of a train's speed exceeding permissible limits?

Increased likelihood of flange mounting or derailment Signup and view all the answers

Which of the following describes a key feature to analyze during derailment investigation?

The nature of marks on the wheel tread and flanges Signup and view all the answers

What typically happens to the range of permissible imperfections on the track as train speed increases?

It decreases Signup and view all the answers

Why is it important to analyze the profile of the path followed by mounting marks?

To identify changes in wheel alignment during travel Signup and view all the answers

What aspect of the rolling stock is crucial to understanding derailments under dynamic conditions?

The speed of the train Signup and view all the answers

Which of the following could potentially contribute to increased derailment risk?

Inadequate speed regulation Signup and view all the answers

What can cause derailments due to improper train operation by the driver?

Bunching and off-loading of light loaded wheels Signup and view all the answers

What is one of the main purposes of a site investigation after a derailment?

Locating the initial point of derailment Signup and view all the answers

Which factor is least likely to cause derailment due to a mismanipulation of a point?

Weight distribution of cargo Signup and view all the answers

What should be the first step during a site investigation?

Recording initial considerations Signup and view all the answers

Which of the following conditions can amplify oscillations that lead to derailments?

Higher speeds with existing causative factors Signup and view all the answers

What is a common consequence of irregular loading of a vehicle?

Floating of wheels due to off-loading Signup and view all the answers

Why is it important to examine wheel marks at the initial point of derailment?

To establish whether the derailment was sudden or gradual Signup and view all the answers

What should be carefully examined if a derailment occurs due to operating staff failure?

Setting and locking of points during operations Signup and view all the answers

What must be done before restoration work begins at a derailment site?

Record the position of vehicles Signup and view all the answers

What does the site sketch during an investigation illustrate?

Relationship of derailed vehicles to rails and track damage Signup and view all the answers

Which factor does NOT significantly contribute to the investigation of a derailment?

Track color and design Signup and view all the answers

What is indicated by examining flange marks left by derailed wheels?

The nature of derailment - sudden or gradual Signup and view all the answers

What type of train configuration can lead to derailments when marshalled incorrectly?

Empty stock positioned between loaded wagons Signup and view all the answers

Which of the following is NOT a step in the site investigation sequence?

Assessing crew fatigue Signup and view all the answers

Which of the following is essential to check for proper point operation during a derailment investigation?

Freedom and correctness of point operation Signup and view all the answers

What is the potential effect of increased speed on permissible track imperfections?

Decreased tolerance for imperfections Signup and view all the answers

What type of investigation is emphasized as critical immediately after a derailment?

Identification of the first derailed vehicle Signup and view all the answers

Which aspect of the site investigation helps clarify the cause of the derailment?

Establishing a timeline of events leading to derailment Signup and view all the answers

What must happen if the position of vehicles is not recorded during the site investigation?

Future correlations between vehicles and track events will be complicated Signup and view all the answers

Study Notes

Chapter 2: Site Investigation

Comprehensive investigation is needed if the cause of derailment isn't immediately obvious.
The process follows a logical sequence focused on identifying evidence before restoring the track and vehicles.
Key purposes include:
- Locating the initial point of derailment
- Identifying the first derailed vehicle and wheel
- Determining the events leading up to the derailment halt
- Explaining the initial derailment cause

Sequence of Site Investigation

First Considerations: Document the sequence of the derailment from start to halt. Record the position of vehicles after the derailment. Importance of rapid observations.
Site Sketch: Produce a sketch of the entire derailment site with derailed vehicles, rails, other evidence and track damage (showing relative positions).
Flange Marks: Examine wheel mounting marks for sudden or gradual derailment. The details (e.g. Length, Profile/path followed, Strength/faintness, continuous/broken, single/multiple) of the marks are crucial.
Operational Defects/Failures: Assess operational factors, including speed (exceeding permissible limits, dynamic conditions), irregular or excessive loading, improper marshalling. Investigate whether a speed was in excess of the permissible limits (resulting in higher lateral forces on flanges). Consider whether dynamic conditions contributed to vehicle derailment at higher speeds.
Track Survey and Examination: Assess the track for damage and imperfections.
Vehicle Examination: Examine the vehicles for any damage or defects that contributed to the derailment.

Additional Factors

Photographs: Include photographs of mounting marks on rails, sleepers, ballast, and any other relevant evidence. The marks must be carefully noted and measured.
Multiple Derailments: Often multiple vehicles derail before the train stops. Identifying the initial derailed set is critical. Identifying the particular wheel set which derailed first is crucial; match length and nature of marks to positions.
Operational Defects: Factors like speed, loading, and marshalling significantly contribute to derailments.
Improper Train Operation: Sudden braking can bunch and unload light cargo cars, potentially leading to additional derailments (sudden application of brakes).
Point Mismanipulation: Problems with points (switches) during operation can lead to derailments, particularly when they aren't correctly set or locked. Important to check tongue rail length, wheelbase of stock, gap between switch and stock rail. Ensure that the point is working freely and correctly before and during movement.
Operating Staff Failure: Assess if operational errors such as improper point setting or undetected obstructions were implicated. Loose couplings are another potential issue.
Wheel load changes: Changes in wheel load due to oscillations, track imperfections, maintenance state, suspension characteristics, and train speed are critical aspects in assessing derailments.
Loading: Irregular or excessive loading could cause a vehicle's wheel to float off the track resulting in derailment.

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Description

Explore the key aspects of site investigation following a derailment in this comprehensive quiz. Learn the logical sequence for documenting evidence, locating the derailed vehicle, and understanding the initial cause of the accident. This assessment will help reinforce your understanding of the investigatory process in railway incidents.