Electrification of rail services involves more than just running trains using electricity. Electrifying a rail system requires the upgrading of infrastructure and providing a means of getting the electricity to the trains – which may include new electrical substations, overhead power lines and new equipment.

To upgrade the existing GO system from conventional diesel to electric, a series of activities need to be undertaken:

• Conducting an extensive study to examine the implications and requirements of electrifying all of GO’s corridors that are both shared and owned by others (note – the Electrification Study is now underway to do this);
• Designing and building infrastructure to support electric trains (e.g., overhead wires, power substations, maintenance facilities, track insulations, signalling systems);
• Purchasing property for expansion of corridors;
• Manufacturing and purchasing new equipment;
• Opening more train storage areas, building new train maintenance and repair facilities;
• Retrofitting existing equipment and facilities, including Union Station, while continuing to operate GO service;
• Developing new operating and maintenance practices for the electrified system; and

Below is an example of an electrified rail corridor in another jurisdiction.

The process of moving to electrification is one which is complex and requires careful consideration. The current Electrification Study will examine the many requirements of an electrified system including a review of cost implications to GO Transit and its riders, where the power for electrification will come from and how system upgrades would need to be completed to support electrification. The Electrification Study is now underway and is expected to be completed by the end of 2010.

Diesel locomotives are self-sufficient units that combine a prime mover, traction motors, fuel tank, and operator controls to pull or push passenger cars over routes without additional infrastructure to supply power, except for fuel filling yards.

GO’s Current Fleet of Diesel Locomotives

GO Transit has used diesel engines throughout its history, with continuous upgrades to use the most up-to-date diesel fuel technology available.

GO currently uses diesel-electric locomotives in push-pull configuration with Bombardier bi-level passenger coach and cab cars. The majority of locomotives used now are F59PH units, built by Electro-Motive Diesel, Inc. between 1989 and 1990. They provide reliable service and achieve moderate performance with 8-to-10 cars to pull or push.

New Cleaner Diesel Locomotives on the Way

GO is currently taking delivery of 27 new MP40PH-3C locomotives, built by Motive Power Industries (MPI), to replace and supplement the F59PH fleet. The MP40 has increased power and is the only new-build passenger diesel locomotive model that meets current Tier 2 emission level regulations set by United States Environmental Protection Agency (EPA), and structural requirements by Federal Railroad Administration (FRA).

The modern diesel-electric locomotive has seen a number of incremental improvements. Horsepower has increased and substantial progress is being made in meeting increased environmental requirements while retaining a high level of reliability and maintainability. Current and next-generation diesel engines will be significantly cleaner in terms of air emissions than the older F59PH units now in service. It can be expected that these developments will continue, while maintaining technical compatibility with existing passenger coaches and operations.

GO’s MP40 new diesel locomotives use the best, cleanest diesel technology available, meeting all EPA Tier 2 Emission Standards.

Research and development is underway to reach a Tier 4 Standard by 2015. The Tier 4 Standard will reduce particulate matter by 70 per cent, and NOx by 76 per cent.

There are currently no air emission standards for diesel trains in Canada. GO Transit, with an understanding from Transport Canada, voluntarily follows the emission standards applied in the United States (EPA Tier 2 Emission Standards). All of the new MP40 locomotives meet this EPA Tier 2 Standard.

Diesel Use in North America

Today, the majority of North American commuter rail networks operate diesel engines.

Diesel Locomotive-hauled Coach (LHC) passenger trains are the standard technological approach for providing commuter service on non-electrified rail lines in North America. This approach has typically provided the lowest risk, lowest capital cost, quickest delivery and most flexible approach to commuter rail operators.

Many North American transit authorities use diesel technology, employing similar locomotives and cars as GO Transit. Some examples include: Florida’s Tri-Rail, Seattle’s Sounder, California’s Metrolink and Caltrain, Vancouver’s West Coast Express and Montreal’s AMT.

While diesel remains the predominant fuel source for North American commuter rail networks, electric trains are used in some areas for high traffic lines. In Europe and parts of Asia, electric trains are more common. Both diesel and electricity are common power sources for rail networks around the world.

Some Other Considerations with Diesel

Diesel locomotives are one of the heaviest motive power units and they generate relatively high wheel/rail forces. This leads to increased track and infrastructure maintenance costs, particularly as speeds increase.

Diesel locomotive performance parameters, such as power, acceleration and top speed, are relatively low when compared to electric propulsion. With GO’s typical configuration of one locomotive, train performance decreases with additional train length and weight, meaning that different train compositions potentially require different scheduled running times for the same service pattern. GO cannot easily increase system capacity by simply increasing train lengths. Longer trains may require a second locomotive, or, more practically, shorter trains may be offered more often.

The self-sufficient nature of a diesel LHC allows it to operate on any system track at any time. Diesel LHC trains may provide enhanced flexibility to work through unscheduled track and service issues.

Diesel locomotives can be combined with a variety of unpowered coach and cab cars. Changing passenger car type will not significantly change GO’s diesel LHC service.

GO’s existing push-pull fleet, in view of technology characteristics and its ability to meet Metrolinx’s goals to increase the capacity and performance of GO, will be assessed in the Electrification Study.

Electric locomotives do not carry an internal prime mover and instead rely on energy supplied by an off-car electrified traction power supply and distribution systems. For a given horsepower, an electric locomotive is considerably lighter than diesel locomotive. Further, it is possible to achieve much higher overall horsepower in a similarly sized electric locomotive than in diesel locomotive. The net effect is a benefit of higher overall train acceleration, speed and system capacity.

The strong but light electric locomotives have adhesion limitations. The locomotives are overpowered at low speeds and cannot realize the full benefit of their nominal horse-power ratings. The electric traction has it greatest benefit at the mid and high speeds, where it can help trains achieve the posted track speeds more quickly and maintain those speeds more consistently.

The locomotive could be designed to receive dc or ac power, either through an overhead contact system (OCS) and collected by a vehicle-borne pantograph or through a ground-level third rail system and collected by a suspension-mounted shoe. Dc systems can directly feed the collected power into the traction motor controllers. Ac systems require a large and heavy transformer and rectifier to change the input power into more usable power. Dc-powered rolling stock is typically lighter and simpler. Ac-powered rolling stock currently offers greater tractive efforts. Both types of electric locomotives will be studied.

Example of a High-Horsepower AC Electric Locomotive ALP-46:

Electric locomotives have the potential of regenerative braking, where the traction motors are used to convert braking energy back into electricity. This electricity can supply in-train loads, such as heating, ventilation and air conditioning (HVAC), lighting and low voltage power, or, can be fed back into the distribution system (OCS or third rail), for use by other trains on the system. Recently, there have been significant advances in energy storage devices (batteries, ultra capacitors, flywheels) to collect such regenerative power when it’s available, and to then feed it back into the system when it’s needed. Some storage devices are designed to fit on cars and locomotives while others are designed to be installed on the wayside, beside the tracks.

The market for electric locomotives in North America is very small in comparison to that for diesel locomotives. In contrast, the European market for electric locomotives is robust. Development of North American electric locomotive technologies is, therefore, slower and depends largely on the incorporation of European developments. Several high-speed, high-horsepower units of European origin, such as the ALP-46 manufactured by Bombardier, have proven records in North American service.

A dual-mode locomotive can operate in electric propulsion mode when in electrified territory, but extend service into non-electrified regions by switching to an onboard diesel engine. This type of unit combines the prime mover, alternator and fuel system of a diesel locomotive with the power collection and conditioning equipment of an electric locomotive. These systems feed a common traction control and propulsion system.

The dual-mode units typically have different power ratings in diesel and electric modes. Some models are relatively weak in electric mode while others are designed to be primarily a diesel-powered unit. In addition, since a dual-mode locomotive carries significant diesel and electric equipment, a compromise of volume and weight must be made. These units will always carry extra weight as compared to a single-mode unit.

Dual-mode locomotives allow operators to maintain the service continuity of a “one seat ride” while the system is incrementally and/or partially electrified. Three North American railroads – Amtrak, Long Island Rail Road and New York’s Metro-North Railroad – currently operate dual-mode locomotives in daily service that are diesel and electric (DC) capable. They are configured for third-rail power collection and cannot operate in electric mode under overhead AC power.  However, Bombardier is currently developing a dual-mode locomotive prototype for the North American market, under a joint procurement effort undertaken by New Jersey Transit and Montreal’s AMT, which will operate from diesel power or under overhead AC power supply systems. 

Dual-Mode Multiple Units

Currently, Bombardier also sells two models of single-level dual-mode multiple units (DMMUs) to Société Nationale des Chemins de fer Français (SNCF), the French national railroad. Similar to dual-mode locomotives described above, DMMUs can operate under overhead catenary power or from on-board diesel engines.

DMMUs have the same space and weight constraints as the dual‐mode and DMU/EMU locomotives. To fit the additional equipment into the DMMU car design, part of the traditional passenger volume is sacrificed for the propulsion equipment. As a result, consists are often configured as power car/trail car/trailer car/power car to balance propulsion performance with seating capacity. Although DMMUs offer significant benefits they carry a significant cost premium due to both their low manufacturing volume and the total amount of equipment that they must contain.

 

 

 

Diesel Multiple Units (DMUs) are self-propelled, passenger carrying vehicles that use one or more on-car diesel engines for power. They carry their complete propulsion system (i.e. multiple engines, fuel, exhaust treatment, and final drive equipment) making them heavier than Electric Multiple Units (EMUs) but reducing the need for off‐car infrastructure. Some DMUs use hydrodynamic or hydromechanic transmissions to directly drive the wheels while others, known as Diesel-Electric Multiple Units (DEMUs), use electric generators and traction motors similar to the diesel‐electric locomotives currently used by GO Transit. DMUs can be designed as either single-level or bi-level units. In North America, operating conditions have heavily favoured the use of single-level DMUs.

DMUs provide consistent, flexible performance as consists can be lengthened or shortened to meet ridership demand. By having multiple, distributed diesel engines, DMUs typically can have at least one engine fail without significantly affecting performance and service schedules. In addition, the combination of multiple engines and drive axles allow DMU consists to accelerate faster than diesel locomotive-hauled coaches (LHC). Further, due to the distributed tractive effort (force along the rail) and advances in train transmission design, DMUs are also effective options in low adhesion conditions and moderately steep grades.

DMUs are efficient in small consists, servicing a low‐density passenger base. They provide the option of extending or feeding current routes, providing off-peak service, or replacing locomotives in a high-service frequency operating scenario where shorter, more frequent DMUs replace longer, less frequent LHC trains. In Europe, some operators have also used DMUs to couple two small trainsets from lower density lines into a mid-sized consist at a feeder station.

DMUs are a practical, competitive alternative for running short consists approximately four to six units in length. When using longer consists, the benefits of DMUs are overshadowed by their high capital, operating, and maintenance costs. As an alternative, in some areas of the world DMUs pull a limited number of unpowered coach cars similar to their Diesel and Electric Locomotive-hauled Coach (LHC) counterparts. Although this configuration increases the overall seating capacity and lowers overall capital costs, performance decreases with each additional unpowered coach car added. Thus, when compared to operations that use traditional locomotive-hauled coaches (LHC), which benefit significantly from their ability to effectively pull up to 11 unpowered coaches, DMUs are typically not an economically viable option when running consists longer than six units.

Although widely used around the world in places like Europe and Asia, DMUs are infrequently used in Canada and the United States today. However, the concept of using DMUs has regained some visibility in North America with the reintroduction of United States Federal Railroad Administration (FRA)‐compliant DMU cars and recent interest by several districts in the United States to purchase these units for their operations.

EMUs are self-propelled electric vehicles that do not carry an internal prime mover but instead rely on energy provided by off-car electrification traction power supply and distribution systems. Like other electric locomotives, EMUs are supplied with off-vehicle power (either AC or DC) that is collected, conditioned, and used to power axle-mounted traction motors. EMUs are also equipped with regenerative braking an energy recovery mechanism that reduces vehicle speed while simultaneously converting some of its kinetic energy into usable energy.

EMUs are an efficient rolling stock technology for areas with high ridership and frequent service. They offer high acceleration rates and consistent performance across all trainset lengths as power is supplied to every axle in the train consist. In addition, as a result of traction motor torque being compatible with local axle loading, EMUs have superior grade-climbing abilities when compared to diesel or electric locomotive-hauled coach trainsets.

Studies have shown that EMUs are cost competitive with diesel locomotives and diesel multiple units (DMUs) over short to moderate route lengths with high ridership and high service frequency. Similar to DMUs, EMUs costs vary with consist length. However, EMU cost competitiveness is more strongly driven by service frequency and environment than by consist length. Modern EMUs also have enough power to pull a limited number of unpowered coach cars, similar to locomotive-hauled coach (LHC) services, thus increasing seating capacity while costing significantly less than EMUs to purchase, operate, maintain. However, consist performance will decrease with each additional unpowered coach car.

Given their performance characteristics, EMUs are commonly used across North America in urban environments where ridership and service frequency are higher. Although both DC and AC powered EMUs exist within North America, single level AC-powered EMU cars are more readily available and are commonly used across the continent. One example of this is Montreal's Agence Métropolitaine de Transport’s (AMT) MR90 built by Bombardier.

With less passenger capacity per vehicle than the existing GO bi-level coaches, EMU train lengths will need to increase in order to achieve equivalent seating capacity per train. Alternatively, work is currently underway by Caltrain in the San Francisco Bay Area to procure multi-level AC powered EMUs. Caltrain has worked for several years to secure a waiver allowing them to operate a proven, European designed, multi-level EMU in a mixed corridor that is non-FRA compliant.

The traditional diesel locomotive offers several opportunities for the integration of alternative fuels into operations without completely redesigning this long-standing technology.  Several government and transit agencies in both Canada and the United States are exploring the use of alternative fuels to meet environmental requirements.

Biodiesel

In Canada, Canadian Pacific and Natural Resources Canada tested four locomotives between Calgary and Edmonton for four months during the winter of 2009/2010. The locomotives ran on biodiesel blend and the program evaluated the effect of the fuel on the engines in cold weather. Similar tests have also been conducted by other operators across the United States. In stationary locomotive engine tests, the biodiesel blend B20, which is 20 percent biodiesel and 80 percent petro-diesel, reduced hydrocarbons and carbon monoxide emissions by 10 percent each; particulate emissions, by 15 percent; and sulfate emissions, by 20 percent. Despite the emission reduction benefits the use of biodiesels was found to have the following drawbacks:

• Biodiesel can have negative impacts on valves and gaskets in older engines.
• Biodiesel stores less energy per litre than petro-diesel, so on‐board storage capacities would need to be increased to compensate for more total fuel burned during a given locomotive trip cycle.
• Biodiesel is made from local, renewable, resources, but may not lower total carbon output, depending on harvesting and processing techniques.
• Biodiesel is typically blended with petro-diesel and this blend would need to change, potentially monthly, in cold climates such as Toronto.
• Biodiesel is typically blended with petro-diesel and this blend would need to change, potentially monthly, in cold climates such as Toronto.
• Engine manufacturers do not warrantee engines burning more than 5% to 20% biodiesel.

Natural Gas

Natural gas locomotives are usually diesel locomotives that have been converted to run on compressed or liquefied natural gas generators instead of diesel generators to generate the electricity that drives the motors of the train. Some CNG locomotives are able to fire their cylinders only when there is a demand for power, which, theoretically, gives them higher fuel efficiency than conventional diesel engines. Currently, CNG locomotives are operated by at least two railroads. The Napa Valley Wine Train in California, U.S.A. has successfully retrofitted a diesel locomotive to run on compressed natural gas before 2002. This converted locomotive was upgraded to utilize a computer controlled fuel injection system in May 2008, and is now the Napa Valley Wine Train's primary locomotive. Ferrocarril Central Andino in Peru has run a CNG Locomotive on a freight line since 2005.

The Burlington Northern, now Burlington Northern Santa Fe (BNSF), has also converted two locomotives to operate on LNG. The demonstration locomotives operated successfully on commercial coal service between Wyoming and Wisconsin from 1991 to 1996 when the program closed as BNSF could not justify the costs of LNG in long‐haul service. In the Los Angeles area, BNSF currently operates four LNG locomotives in regional and local service.

Although natural gas powered locomotives offer tangible benefits, they do present the following challenges:

• CNG cannot typically be stored on rail cars in sufficient volume to support one day’s operation.
• To travel longer distances, LNG operations require fuel tanks to be stored in an adjacent tank.
• CNG and LNG are combustible substances and present a significant danger during a collision.
• Mid-day refueling can be considered in order to travel longer distances, but this may delay locomotives and disrupt service schedules.
• Natural gas (CNG or LNG) reduces carbon monoxide (CO) and particulate matter (PM) but increases oxides of Nitrogen (NOx) as compared to diesel fuel.

Hydrogen

There are no known examples of locomotives being propelled by direct combustion of hydrogen. Hydrogen is not likely to be compatible with the traditional single large engine in a locomotive. Future studies may consider direct combustion in multiple small engines within a single locomotive. In addition, hydrogen poses the following challenges:

• Hydrogen is difficult to produce and store.
• Hydrogen presents a significant danger during a collision and may be a target for malicious acts.
• Direct combustion of hydrogen in an internal combustion engine is relatively inefficient.