Fault Tree Analysis: Tay Rail Bridge Disaster of 1879

This report discusses the Tay Rail Bridge disaster of 1879, including the system and its working environment, the top event and its effects, failures and their causes, similar catastrophic events, and recommendations to prevent future disasters.

FAULT TREE
ANALYSIS

Contents
INTRODUCTION...........................................................................................................................3
MAIN BODY..................................................................................................................................3
Description of the system and its working environment.............................................................3
Description of the top event and the effect it had on the surrounding environment...................4
Failures and their causes which contributes to the catastrophe...................................................5
similar less catastrophic events had or have taken place.............................................................5
Recommendation related to making these events stop................................................................6
CONCLUSION................................................................................................................................7
REFERENCES................................................................................................................................8

INTRODUCTION
Fault tree analysis can be defined as that system in which top-down deductive failure are
being analyzed during the undesired state. It makes use of Boolean logic in order to combine a
series of lower level events. This method is basically used in safety engineering and reliability
engineering system so that the risk related to system failure can be reduced. FTA is basically
been used in nuclear power, chemical, and other areas of industries. In this if the conditions are
being severe than it will require more extensive Fault tree analysis. Present report will lay
emphasis on the Tay rail bridge disaster of 1879. It will lay emphasis on the system and its
working environment. It will focus on description of the top event and the effect it had on the
surrounding environment. Report will lay emphasis on the failures and their causes which
contributes to the catastrophe. Assignment will also make clear of similar less catastrophic
events had or have taken place. It will also recommend strategies so that these type of event
cannot occur.
MAIN BODY
Description of the system and its working environment
System
Tay Bridge construction began in 1871 and was completed within February 1878.
Thomas Bouch was accountable for the construction, design and maintenance of the bridge. The
most past of the Bridge were lattice girders that are supported through the columns that are
braced with iron ties and Struts. Trial Boring has the bedrock to lie under the depth of the river.
Within one end of the bridge were Deck trusses while tops were levels with piers tops
accompanied by the single railway track running on top (Choudhury. and Hasnat, 2015). Thus
within center section the girders ran through trusses within order to get the needed clearance to
enable passage of the ships to the Perth. Regarding the higher portions of the bridge there are
also 13 spans of girder. For the thermal expansion there is only 3 of their 14 piers that has the
fixed connection. There are also have the 3 divisions regarding the high girder spans are
connected to each division with each other but not with the other divisions.
Its working environment
Ex- Provost Robertson had timed in his pocket watch as well as gives the benefit to the
railway as he has rounded up to 5 seconds. The time can be measured by the graders and was
around 60 seconds but it had been in 50 seconds. If observing from shore it has measured around

80 seconds for trains that are traveling by girders, but he had never experienced of train travelled.
Through gradient the high speeds on south bound locals can be prevented at the end of the
northern end of the bridge(Swinfen, 2016). As per the Robertson the moment observed by him
was hard to quantify as lateral movement was around 2 inches was because of the bridge not
due to the train and also the effect was also more marked within a high speed. Although there are
four other train that was supported by the timings of the Robertson but there is only one had
noticed any kind of the movement within bridge. At that time the stationmaster has complaint
regarding the speed as he was unaware regarding the oscillation and then checked the times from
cabin to cabin. Thus he had never checked the speed by the help of the high girders.
Description of the top event and the effect it had on the surrounding environment
On 28 Dec 1879 there is a violent storm that was virtually blow bridge's right angles. As
per the witness it was said that storm was a bad and also seen within 20-30 years within that
particular area, also called it a typhoon, hurricane within the china Sea. The speed of the wind
was measured at Aberdeen and Glasgow. At that time that use of the bridge was restricted, only
one train at a time by the help of the signalling block system by the baton taken as a token. At
7.13 pm a train slowed to pick up the signal cabin within the bridge south end and the cabin
catches fire.
The sparks continuous not for more than three minutes through which train girders was
high as that specified point there was a quick flash of light and after that there is a total darkness,
as the tail lamps of the train was also disappearing within the same time (Lawrence, 2017). As
signalman was seen none and train was failed to appear on the bridge, due to this not only the
Bridge failure
Process analysis
Case analysis Technical analysis
Strategic analysis Indirect reason: effective
mamagement
Fault tree analysis
Perspective communication
Management guidelines

train was into the river but also the girders and also its supporting piers and ironwork. No
survivors were there and only about 46 bodies were recovered.
Failures and their causes which contributes to the catastrophe
There were various reasons because of which this disaster of Tay rail Bridge has bene
taken place. It has been analysed that law has given that bridge was not designed perfectly which
was the main reason of Bridge failing. In this the thickness of the columns that has been placed
in Bridge was not being examined at initial stage. It has also been analysed that the cast iron that
is being used in making up of Bridge was of poor quality, vulnerable and was considered as one
of the main reason of shock loadings. It was analysed that Bridge was unable to take the wind
pressure it was assisted by different low quality mechanism. Yolland Barlow has figured out the
reason for the failure of Tay rail bridge, they found out that cross bracings that was put upon the
bridge was insufficient(Schultz. and Gastineau, 2016). It was analysed that the bridge was unable
to keep up the pace with pressure of wind as it was badly structured and was also built form the
low quality of materials. It was also maintained ineffectively. The main cause of Tay Rail bridge
was structural failure. It was estimated that 75 people died and also 60 of the people suffer severe
injury. It was analysed that the wrought iron which was used in building of bridge was of low
quality. There are various caused for the collapse of Tay rail Bridge collapse like fundamental
design, derailment of the train, poor materials used for constructing the Bridge. Also the material
that has been used in building the bridge was of poor appreciation related to wind
loading(Choudhury. and Hasnat, 2015).
The Bridge has been collapsed during a violent storm on the evening of 28 December
1879. The disaster was really severe. It has been analysed that in year 1877, some of the
engineers have analysed the problems but there was delay from them to find solution to issues.
The change in design procedure also get delayed. It has been analysed that there were so many
flaws and consequences in designing of the Bridge. The engineer who has designed the Tay rail
Bridge his reputation was ruined and also he died within the year when disaster appeared.
Several people were killed in this Collapse.
similar less catastrophic events had or have taken place
There are so many catastrophic events that had taken place because of the failure in system
design. One of the example includes Hyatt Regency Walkway Collapse. This incident took place
in year 1981. It was considered as one of the dangerous structural failure in the history of

America. The main reason of this collapse was structural overload which results because of the
flaws in design. There were 114 people who died in this disaster. Also 216 was injured during
this catastrophic collapse. It was analysed that the fourth floor walkway was supported from the
nuts that was made of steel rods. These nuts and steel rods was of low quality that led to collapse
of Hyatt Regency.
The other example of similar catastrophic event included Sampoong Department Store
Collapse in South Kora. It was one of the mot sever disaster that took place in Seoul. It killed
around 502 people and also 937. The main reason of this Collapse was structural overload and
Punch Shear. It was analysed that the completed building was, made up of flab slab structure.
The building does not have steel skeleton. Also the materials that has been used in building up
the Department store was of low Quality. (Hough Jr, 2018) The engineers were not engaged in
keeping up a check upon what Quality of material has been used. This was the major reason of
this Collapse. It was analysed that the department store was over Built and the floor cannot
support one more floor. he fifth floor were not aligned with the ones supporting lower floors,
causing the load of the 5th floor to be transferred through the slab.
The other similar event that took place was of Versailles wedding hall. The charges were
made related to negligence. This building was collapsed because of flawed structural design and
insufficient load capacity (Lawrence, 2017). There were 23 people who died in this incident and
also 380 was being injured. It was analysed that engineers made use of light weight method of
constructing which was proven to be unsafe and resulted in this disaster. During the wedding
event in 2001, this significantly overstressed floor section failed, resulting in the catastrophe. The
Engineer who was engaged in building this, was arrested and also it was analysed that
construction did not take place in an efficient manner.
Recommendation related to making these events stop
It has been recommended in order to stop these events is that engineers needs to be engaged
in checking out the area of construction. They also need to keep a check upon the foundation.
Also it has been analysed that engineers need to make use of better design and engineering
process. This will assist them in overcoming the risk of collapse and will also lead to stop of
these disaster( Smith, 2015). They can also have engaged in making use of Hugh quality of
materials so that this disaster can be stopped. Also engineers can have engaged in allowing large
debris to pass through Bridges so that it can be protected from flood. Engineers also needs to

proper design the structure so that bridge does not flow down during the time of uncertain
situation. They also need to set up engineering standards that can cope with extraordinary
loadings which are being caused by caused by extreme weather events and also prevent bridge
form falling down. They must also make sure that structure of buildings and bridge is not been
overloaded. Also speculation from time to time basis needs to be done by engineer. They also
must not have engaged in checking upon the adequacy of steel plates and nuts which is being
used in building up the Bridge. This will help in reducing the bridge collapsing and disaster.
CONCLUSION
From the above study, it has been summarized that Tay Rail Bridge got collapsed in the year
1879. It has been analyzed from the report that one of the major reason for this disaster was
flaws in structural design. Also it has been depicted that low quality of material were being used
in building up this Bridge. In order to build the Bridge, it took 8 years, the construction got
started in year 1879. It was analyzed that Bridge got collapsed because of heavy storm that occur
in the evening. Several people have died when this collapse took place. It was also analyzed that
the engineer who designed the Tay rail Bridge faced severe consequences and also his reputation
was ruined. It has also been analyzed from event that there are several similar events that has
taken place because of the flaws in engineering design. The re-designing process related to
Bridge was delayed that has ultimately led to this disaster.

REFERENCES
Books and Journals
Choudhury, J.R. and Hasnat, A., 2015, August. Bridge collapses around the world: Causes and
mechanisms. In IABSE-JSCE Joint conference on advances in bridge engineering-III (p.
34).
Hough Jr, G.A., 2018. Disaster on Devil's Bridge. Rowman & Littlefield.
Lawrence, J.C., 2017. Steel frame architecture versus the London Building Regulations:
Selfridges, the Ritz, and American technology. In Structural Iron and Steel, 1850–
1900(pp. 339-362). Routledge.
Schultz, A.E. and Gastineau, A.J., 2016. Bridge collapse. In Innovative Bridge Design
Handbook (pp. 795-815). Butterworth-Heinemann.
Smith, N., 2015. Classic Project: Forth Bridge. Engineering & Technology, 10(4), pp.100-1.
Swinfen, D., 2016. The fall of the Tay Bridge. Birlinn Ltd.

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