ELECTRIFICATION OF THE SUBURBAN 
NETWORK OF THE SRI LANKA RAILWAY 
ECONOMIC STUDY 
 
 
 
 
 
Gallage Maheel Prasanta 
 
A dissertation submitted in the partial fulfillment of the requirements  For the degree of Master 
of Engineering in Electrical Engineering 
 
 
Department of Electrical Engineering 
University of Moratuwa 
Sri Lanka 
December 2002 
 
 
 
 
78480 
ABSTRACT 
 
Rapidly increasing congestion of traffic in urban and suburban roads raises the necessity 
of better and quicker railway service urgently. Electrified railway system is a better 
solution for that. 
The prime objective of this electrification economic study is to determine Whether 
electrical operation of the Sri Lanka suburban railway is economically viable and more 
advantageous than that of the existing diesel  operation system with further improvement. 
 
According to present railway passenger flow , geographical data of railway tracks and 
other railway statistics and population of Sri Lanka, the network of suburban railway 
stations Kalutara North- Colombo-;· Polgahawela, Colombo - Homagama and  Ragama  
Negombo (Colombo International Airport ) was selected as high passenger density area. 
 
In the selected suburban area, railway and road passenger flow was studied by us in g 
train formation , railway time table , tickets issued at railway stations (daily and season 
tickets) and survey details of major railway stations and bus stand s. 
 
According to above data peak hour and daily pass enger  flow for one day was calculated. 
Some technical detail s were selected as to be compatible with the existing system with 
few modifications, to retain the ability of continued operation o f the present diesel 
locomotives. 
Other technical data was selected by studying established electrification systems in other 
countries. 
Finally, total electrical multiple unit s, clearance specifications , specific energy 
consumption, power requirement , power generation and distribution were determined. 
Total cost of electrification system and improved existing diesel system was calculated 
separately and compared . Electrification system was found to be economically viable for 
3 0 years and the cost was less than that of the improved existing diesel system. 
 
AKNOWLEDGEMENTS 
The author wishes to express his deep gratitude to Prof L. Lucas, head of the 
Electrical Department of University of Moratuwa and Dr H.J.C. Peiris, 
course coordinator and supervisor of this project for guidance and 
encouragement given during the period of this project. Author also wishes to 
extend his sincere thanks to Dr. Naleen Wikramarachchi , the present course 
coordinator. 
The author acknowledges the corporation given by the stationmasters and 
their staff of the railway stations in the selected suburban areas during the 
survey period. 
The author gratefully appreciates the Department of Sri;Lanka Railway for 
the financial assistance given and the University of Moratuwa for the 
facilities provided during the study period. 
Finally, I wish to thank my wife Sujeeva for her patience, understanding and 
also assistance given to me to complete this thesis . 
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LIST OF FIGURES 
Sri Lanka Railway Network 
Typical speed/time curve for electric trains 
operating on passenger services 
Speed/time curve for suburban service 
Simplified (trapezoidal shape) Speed /Time curve 
Percentage gradient 
Mechanism of train movement 
Diesel Multiple Unit 
Electric M ultiple Unit 
General arrangement of four car nonnal E .M.U. 
General arrangement of four car special E.M.U. 
25kv 50Hz simple feed catenary system 
Types of catenary 
Traction overhead equipment 
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LIST OF TABLES 
Page No 
Table 1.1 Description of rail routes 04 
Table 3.1 Proposed track system 14 
Table 3.2 Expected peak hour one direction passenger flow 15 
(suburban area) 
Table 3.3 Expected daily one direction passenger flow 16 
(suburban area) 
Table 3.4 Expected peak hour one direction passenger flow 16 
(from non-suburban area) I 
Table 3.5 Expected daily one direction passenger flow 16 
(from non-suburban area) 
Table 4.1 Requirements of normal E.M.U.s 19 
Table 5.1 Power supply arrangement 35 
Table 5.2 Power stations capacity 38 
Table 6.1 Cost of energy per day 39 
Table 7.1 Total normal E. M. U. passenger kilometres 46 
Table 7.2 Total special E.M.U. passenger kilometres 46 
Table 8.1 Cash flow analysis of the electrification project 50 
Table 8.2 Cash flow analysis of the improved diesel project 51 
Table A1.1 Present rail passeng<;.r traffic flow 
(Colombo Fort- Kalutara South suburban service) 57 
Table Al.2 Present rail passenger traffic flow 
(Colombo Fort- Polgahawela suburban service) 58 
Table Al.3 Present rail passenger traffic flow 
(Colombo Fort - Homagama suburban service) 59 
Table Al.4 Present rail passenger traffic flow 
(Colombo Fort- Negombo suburban service) 60 
Table A1.5 Present rail passenger traffic flow 
(from non-suburban area) 61 
Table Al.6 Road passenger traffic flow 61 
Table A8.1 Basis for lateral displacements (locomotives) ·- 75 
Table A8.2 Basis for lateral displacements (multiple unit cars) 75 
Table A8.3 Altitude compensation 75 
Table A8.4 Air clearances 76 
Table A8.5 Supper elevation allowance 76 
IV 
TABLE OF CONTENTS 
ABSTRACT 
AKNOWLEDGEMENTS 
LIST OF FIGURES 
LIST OF TABLES 
TABLE OF CONTENTS 
CHAPTER 1 
1.0 Introduction 
1 .1 Electric Traction 
1.2 Sri Lanka Railway 
1.3 Electrification Studies in Sri Lanka 
1.4 Proposed Project 
CHAPTER 2 
2.0 Objectives and Methodology 
2.1 General 
2.2 Traffic 
2.3 Capital Equipment Cost 
2.4 Annual Operating Expe_Dses 
2.5 Maintenance of Way Changes 
2.6 Intangible Benefits and Liabilities 
CHAPTER 3 
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3.0 Proposed Operating System of Suburban Area 
3.1 Electrification Area 
3.2 Rail Track System And Operating System 
3.3 Passenger Flow 
CHAPTER4 
4.0 Electrical Multiple Units 
4.1 Requirements ofNorrnal E.M.U.s 
4.2 Requirements of Special E.M.U.s 
4.3 Technical Details 
4.4 Specific Energy Consumption 
4. 5 Energy Returned to the Line 
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CHAPTER 5 
5. 0 Railroad Electrification System 
5.1 Power Distribution 
5.2 Electrical Clearances 
5.3 Catenary System 
5.4 Power Stations and Substations 
CHAPTER 6 
6.0 Cost of the Project 
6.1 Electrical Multiple Unit System 
6.2 Improved Diesel Multiple Unit System 
CHAPTER 7 
7.0 Cost of the Project 
7.1 Electrical Multiple Unit System 
7.2 Improved Diesel Multiple Unit System 
CHAPTERS 
8.0 Project Evaluation 
CHAPTER9 
9. 0 Discussion 
CHAPTER 10 
10.0 Conclusion 
CHAPTER 11 
11 .0 References 
APPENDIX - A 
Annexes 
APPENDIX-B 
Diagrams and Pictures 
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