merits of ac vs dc locomotives

1Contains proprietary Electro-Motive information that shall not be disclosed to third parties.

The Merits of AC vs DC Locomotives

November 13, 2008


The Merits of AC vs DC Tractiom

1. EMD Historical Perspective

2. Development of AC Traction

3. Performance and Maintenance Benefits of AC Traction

4. The Market- What are Railways Purchasing

5. Summary


• Market, Design, Sell and Manufacture diesel-electric locomotives, component sets and aftermarket products

EMD


• Providing value to our marketsby continuously developing our core competencies

Locomotive DesignLocomotive Systems IntegrationMarketing and SellingFinancingManufacturingProduct Support Services

• Developing and supporting global partners

Fully Integrated Locomotive Supplier


Electro-Motive Engineering Corporation

• “The successful application of internal combustion engines to rail service”– Over 500 railcars produced by 1930

• Incorporated in August of 1922


1st Diesel-Electric Locomotive

1930 1940 19601950 19801970 1990 20001934

EMD Significant Milestones


0

10,000

20,000

30,000

40,000

50,000

60,000

1930

1935

1940

1945

1950

1955

1960

Dieselization of the American Railroads

Steam

Diesel

Locomotives in Service

In 1939, EMD introduced the FT103


1st Overseas Manufacturing Associate

1930 1940 19601950 19801970 1990 20001948

EMD Significant Events


Fully Integrated Locomotive Supplier

• Locomotive Assembly Affiliates

– EDI Rail - Australia– Rotem – South Korea– Vossloh - Spain– Tulomsas - Turkey– Indian Railways - India– ETP – Egypt– ELMOTEC – Argentina– D-LOCO - China


Global Presence with Broad International Customer Base

EMD has delivered approximately 11,300 locomotives in 71 countries outside North America

North America48,750

South America1,800

Western Europe1,650

Eastern Europe500

Middle East1,000

Africa2,650

Australia1,500

Asia1,400


EMD Development of AC Traction SD70MACSD60MAC

SD90MACSD80MAC


Development of AC Traction in North America

• In the 1980s, EMD invested in developing AC traction for the special requirements of heavy haul– High axle loads of 32 metric tonnes – Sustained high tractive effort levels for pulling long,

heavy freight trains - up to 18,000 metric tonnes• Many declared that AC was not the right

technology for North America– EMD went ahead with development and tests– EMD was the first North American supplier to market

AC traction locomotives


Evolution of Inverter Control

• 1987 - EMD tested the first AC locomotive in North America with six powered axles– one inverter per axle

• 1989 - EMD built the first new locomotive design in North America with AC traction (F69PH)– one inverter per two axles

• 1991 - EMD built the first heavy haul locomotives in North America with AC traction (SD60MAC)– one inverter per three axles


SD60MAC - 1st heavy haul AC prototype

• The SD60MAC added a new page to the book of locomotive technology history

• Previously, dispatchable adhesion was typically less than 30%

• With the SD60MAC, dispatchable adhesion was raised to 35% and higher

• The SD60MAC demonstrated unprecedented adhesion levels of 45% for starting trains

• This set the stage for Unit reduction on Heavy Haul Trains


1st North American Order for AC Technology Freight Locomotives(Burlington Northern orders 350 SD70MACs)

1930 1940 19601950 19801970 1990 20001993



Productivity Improvement

3 SD70MAC locomotives replaced 5 SD40-2 DC locomotives in heavy haul service


SD70MAC - 1st Series of AC Production

• Today, over 900 SD70MAC locomotives are in service

• This is a highly successful Systems Integration of – AC traction– Advanced computer systems– High traction bogie design

• SD70MAC’s reputation has been established for high locomotive reliability

• SD70MAC locomotives are typically dispatched at 35 to 38% adhesion


EMD AC Traction in India and Australia

• Examples of modern EMD AC traction technology in other regions of the world– India:

21 mt axle load, broad gage, 4000 HP– Australia:

Narrow and Standard gage, 3000 and 4300HP20mt to 32mt axle load

– Mexico and Venezuela : 32mt axle load, standard gage 4300 HP

• All locomotive designs have demonstrated very high adhesion– 35 - 40% dispatchable adhesion– 43 - 50% starting adhesion


Queensland Rail, Australia

GT42C-AC Locomotive3000 thp, Cape gage (1067mm), 20 tonne axle load


SD70ACe/LCIIn operation on BHP in Australia

• 4300 Traction Horsepower.


Why is the Adhesion so High?

• Speed-torque characteristic of AC motor promotes higher utilization of adhesion

• High speed computer and sophisticated wheel creep control have been developed

• Diesel engine with fast response is needed to optimize adhesion

• Where radial steering bogies are used, transverse wheel slippage in curves is virtually eliminated


Wheel Creep Control

• 1970s - EMD was the first locomotive builder to establish and use the wheel creep control concept

• 1980s-1990s - EMD optimized use of adhesion-creep concept on modern AC and DC traction systems

Wheel-RailAdhesion Wheel Slip Systems operate

at lower adhesion levels

EMD’s Creep ControlSystem operates at peak

of Adhesion-Creepcurve

Wheel Creep


Tractive Effort-Wheel Creep Curves

Typical 3-Axle Truck Tractive Effort – Wheel Creep Curve Characteristics AC Motor Truck Control AC Motor Axle Control DC Motor Axle Tractive Effort Axle #3 Axle #2 Axle #1 Wheel Creep – Per Cent

AC traction motor loading is dependent upon the friction-creep load line for a given axle.

AC traction motors load at a higher tractive effort than DC traction motors based on their torque-speed characteristic and individual axle friction – wheel creep curve.


Inverter InverterInverterInverter

Bogie Control Axle Control

Connected in parallel within a truck and controlled by a common high power traction inverter (truck control),

Individually connected to a low power traction inverter (axle control).

On a high adhesion AC Traction Locomotive, the AC traction motors are either:

AC Systems Design- AC Traction Motor Loading


SD70ACe Inverter Truck Control

EMD Systems Design Approach To Inverter Truck Control:

• Maximize System Reliability with Lower Parts Count• Automatic Load Sharing between Traction Motors within a Truck • Wheel Diameters wear together and maximize tread life• Radial Truck Design provides higher Tractive Effort and Power

in curves• Fast Wheel Slip Control System with Rapid Inverter Torque

Control • Quick 2-Cycle Engine Load Control Response• Proven High Voltage, High Tractive Effort, and High Power

Inverter • Design with minimal EMI concerns


Inverter InverterInverterInverter

Wheel Mismatch In ServiceBogie Control Axle Control

WheelMismatch

WheelMismatch

Mileage Mileage

Wheel DiametersAlways Converge

Wheel DiametersDiverge Unless Bogie Control is Emulated

Wheel Diameter Wear Mismatch


SD70ACe/LCI OverviewTraction System Reliability

• Inverter– Utilizes proven IGBT inverter

technology. Phase Modules are air cooled.

– Inverter control system is integrated into EM2000 locomotive computer.

Eliminates two additional computer systems (more than 25 cards in each).Improves reliability and diagnostic capability.


AC Inverter Phase Module Maintenance

• Projected life expectancy of the Inverter Phase Modules- Greater than 15 years

• Maintenance - No preventive replacement- Replace only when failure occurs

• AC Inverters are Repairable


• Performance Advantages of AC Traction

– Higher wheel-rail adhesion 40% advantage

– Higher tractive effort20 to 40% advantage on starting TE Greater than 40% advantage on Continuous TE

– Improved mission reliability Traction Motors

– Lower traction motor maintenance

– Train Handling AdvantagesFlat Top Low Speed Dynamic BrakeRoll Back and Opposite Direction BrakingNo issues for Dead in Consist Towing

Creating Value For The Railways


AC Traction Motor Reliability and Maintenance Less Time in Shop Compared to DC Motor

• Less Maintenance

– No Brushes to Change

– No Commutator to Inspect

• Fewer Failures than DC

– No Stall Burns

– No armature ground relays,

– No flashovers

AC Traction Motors have Less Maintenance and Fewer Failures


AC Motor Overhaul

• Overhaul Interval

– At overhaul, AC motors generally

require only stator and rotor

bearing attention


AC vs. DC Locomotive Market -Historical Deliveries in USA & Canada 1993 to 2005

• When AC Traction was introduced, there was a rapid traction technology conversion for heavy haul freight

• However, DC traction has comprised 40 to 50% of the new locomotive market

0%

20%

40%

60%

80%

100%

90 93 96 99 02 05

Traction Technology Conversion

AC Traction

DC Traction


Largest Single International Order for Locomotives(EW&S orders 250 Class 66 diesel-electric locomotives)

1930 1940 19601950 19801970 1990 20001996



Largest Single Locomotive Order in History – 1000 SD70Ms

1930 1940 19601950 19801970 1990 20001999



AC62%

DC38%

AC and DC Locomotive Deliveries

• Recent EMD Delivery Experience is approximately a 60/40 Spilt of AC to DC in the Marketplace

US and Canadian Rail MarketAC vs. DC deliveries Since 2005


Comparison of Key Buying Factors

Key Buying Factors AdvantageAC Traction

▲▲▲

Traction (kW) = =TE at Moderate to High Speed = =Purchase Cost ▲Ease of Maintenance/ Skill Set / Training ▲

TE Starting and at Minimum Continuous Speed

DC Traction

Train Handling

Adhesion


What Factors drive The DC or AC Purchase Decision?

Service Heavy HaulHigh Speed

RequiredPerformance

Life Cycle Cost

Analysis

Business Plan Growth

Fleet Planning &Logistics

Railway Procurement Decision Model

Maintenance Planning

Capital Cost and ROI

Duty Cycle and Asset Utilization

?

Training&

Facilities

Financing


When is DC Traction Preferred?DC Traction is the preferred lower cost solution for:

– Moderate to higher train speeds– Passenger service – light tonnage General Freight service– Inter-modal freight service

Different solutions for different needs


Perspectives From the North American Rail Market

Canadian National feel the added tractive effort benefits of AC can not be fully utilized on their system to justify the premium for AC locomotives over DC. Canadian National continue to purchase 100% DC Locomotives.

Canadian Pacific - 100% of CP's purchases since 1998 have been AC. They believe AC traction provides much greater reliability and provides unit reduction as they cross challenging grades in the Rocky Mountains.



BNSF continues to purchase both AC and DC as they have operations and fleet sizes that can separately utilize the advantages of each. AC for the Powder River basin heavy haul coal operations and DC for their higher speed intermodal operations. BNSF are able to keep their fleets focused on specific operations.

UP has standardized on a building block philosophy utilizing units that can run reliably in any corridor of service. The 4300-4400 hp block with AC technology has become that standard. UP has only purchased AC freight locomotives since 2005. The SD70ACe is utilized primarily in high speed intermodal service. UP Mechanical Dept believes the added cost of AC is more than offset by the lower maintenance costs, longer component life to overhaul, and higher reliabilityof the AC system for a standardized fleet.



CSX has been purchasing AC locomotives exclusively since 2006. They have concluded that AC Traction is a more universal locomotive for them. Premium for AC is justified based on the perfromanceand life cycle cost.

NS has historically purchased only DC locomotives. They have recently purchased some AC locomotives but report that the purchase was driven by special incentives rather than a desire to switch to AC locomotives. They also maintain the perspective that they can maintain their DC fleet to a higher standard at a cheaper cost than their competition.


EMD AC Traction Summary

• Since 1993, EMD has delivered over 1500 AC traction locomotives

• The market shifted from DC to AC for most heavy haul operations in North America

• EMD is building AC traction locomotives for international railways predominantly for Heavy Haul applications

• Many railroads continue to purchase DC traction for non-heavy haul General and Intermodal freight operations

• Current EMD Market Split is approximately 60% AC and 40% DC


AC vs. DC Traction Conclusions• EMD has successfully introduced both AC and DC

locomotives designs with higher horsepower diesel engines, advanced computer technology, and high traction bogies

• AC traction has generally been the choice for heavy haul freight where the number of locomotives can be reduced

• DC traction is generally the choice where unit reduction cannot be achieved e.g. General Freight Operations and for medium to high speed operation.

• The weighting on the many decision variables used lead to different procurement conclusions for different customers.


Question Time

merits of ac vs dc locomotives

Business

emd market

developing ac traction

emd significant milestones

asia north america

north america em

emd historical perspective

merits of ac vs dc locomotives

south america africa