Study on factors for train derailments in Bangladesh

Abstract

Safe transport of passengers and goods is the key business objective of any transportation system around the world. Bangladesh Railway though stated as the principle and safest mode of transportation but it has been experiencing a large number of train accidents since its development in 1972. Over the past 10 years from 2001-2010, a total 5938 numbers of accidents (average 594 incidences each year) have occurred in Bangladesh railway among which 5461 numbers (approximately 92%) due to derailments. The rate of derailments reduced around 50% from 51.87 to 25.50 within the period 2005-06 to 2009-10, but the figure is still high. This high rate of derailments involves substantial financial losses and disruption to services, as well as posing an obvious safety risk to staff and passengers thus need study to determine the possible causes of derailment. The purpose of this study was to identify several factors contribute to derailment accidents and to recommend suitable countermeasures based on common patterns of probable cause.

The objective of the study was accomplished using four systematic approaches. Firstly, extensive literature review was conducted on derailment mechanism, various factors & causes of derailment, preventive measures of derailment etc. to establish a clear understanding on this issue. Secondly, status of tracks, rolling stocks & manpower of Bangladesh Railway was assessed providing various data and also with the help of photographs. Thirdly, six years accidents data from 2005 to 2010 of BR was collected for the purpose of analysis mainly to determine factors and causes of derailments. Quantitative analysis of derailments for east and west zone of BR was also done separately including various issues, like trend of derailments, rates of derailments, distribution of derailment respect to line types, monthly distribution of derailments, distribution of derailment respect to numbers of vehicles derailed, average block time etc. Frequency of derailments at different locations was calculated and a map of Bangladesh railway also prepared showing intensity of derailment at various sections and stations. Derailment prone sections and stations were also identified from this study. Fourthly, field investigation was done at two major derailment prone locations including a station & a section to correlate the findings from analysis. Finally, some recommendations were made for future improvements.

From the study, status of tracks, rolling stocks and man power reveals the rundown situation of BR. All of these aspects are declining continuously over the years after the independence. Lack of manpower and negligible allocation for maintenance are the main impediments which results age old track more vulnerable. Old rail, defective sleeper, inadequate ballast, insufficient fittings-fastenings, expired bridges etc. are the major constraints of permanent way. Loop lines and branch line are more exposed to such condition than the main lines. Several stations have been closed permanently due to dilapidated loop lines and station master crisis. Acute shortage of locomotives, coaching vehicles and freight wagons makes railway transport unpleasant, inefficient and almost unreliable.

Analysis of six years derailment data has explored several important aspects including factors and causes of derailments. A total 3464 numbers of derailment was occurred in BR among which east zone and west zone comprises 66.25% (2295 nos.) and 33.75% (1169 nos.) respectively. Distribution of derailments on various lines shows that maximum derailments were took place on branch line (46.16%) while minimum on loop line (8.11%). Study on factors indicates that large share (about 64%) of derailments were the result of track defects and the topmost cause of derailment was ‘spread of gauge’ which accounts about 39.5% of total derailments. Derailments on passenger train were found higher in both east and west zone. Monthly distribution of derailments shows that more than 50% of derailments were occurred in 5 months of summer season from June-September. Calculation on numbers of vehicles derailed shows that about 31.6% of incidents involve derailment of 3 to 7+ vehicle which can be stated as major derailment. Average block time per derailment was very high in west zone than east zone and the value was 10 hours 43 minutes for west zone while 6 hours for east zone.

Field investigation at Mymensingh station and Rajapur-Sadar Rasulpur section unveils several problems particularly in tracks which clearly testify the study findings mentioned above. Several recommendation are proposed to minimize train derailments which includes fitness evaluation and improvements of existing tracks, use of concrete sleepers, conversion of MG track into BG system, computer based interlocking system, regular track maintenance, introduction of modern tools for quick and proper track inspection, sufficient fund allocation, emphasize institutional research etc.