The LRC (a bilingual initialism: in English: Light, Rapid, Comfortable; in ) is a series of lightweight diesel-powered passenger trains that were used on short- to medium-distance inter-city service in the Canadian Provinces of Ontario and Quebec.
LRC was designed to run with locomotives, or power cars, at both ends and provide service on non-upgraded railway routes. To accomplish this, the LRC passenger cars feature active-tilt technology to reduce the forces on the passengers when a train travels at high speeds through curves. LRCs have reached speeds as high as on test runs.
On its only regular service route, on the Quebec City–Windsor Corridor, where concerns, signalling issues and conflicts with slower-moving freight trains limit this to or less. For service at these speeds, a single power car was used. Special signage allowed the LRC to run at higher speeds than normal traffic across a great portion of the Corridor when the tilt system was enabled.
The LRC locomotives and passenger cars are compatible with conventional equipment, and the same basic car forms the basis of the Acela in the U.S. The last LRC locomotive was removed from service on 12 December 2001. The passenger cars (with the tilt system disabled) are still in widespread use on Via Rail's Corridor service, but are being retired and replaced by Siemens Venture coaches. History
Problems with speed As a vehicle turns it generates centrifugal force, which is proportional to the square of the speed and inversely proportional to the radius. Even a small amount of force, acting across the length of the human body, creates a moment that can make moving about difficult. Centrifugal forces are not normally an issue in an automobile because the occupants are seated, nor in an aircraft where the fuselage is tilted so the centrifugal force passes through the line of the floor. It is primarily a problem in high-speed trains, where passengers and attendants often walk about while the train is moving. The force also pushes the entire train sideways, leading to wear of the outer rail. This was not an issue on early railways where the speed was low, but gained importance as line speeds increased and the radius of curvature became tighter.
One solution is to place speed restrictions on curved sections of track; another is to bank the railbed on the curve, with the outer rail higher than the inner rail so the net force passes straight through the floor of the coach. Banking the track is known as "cant" or superelevation. These measures were gradually adopted on the railways between 1835 and 1860. The use of track cant can only be applied where the speed of the train is fixed in advance. Slower, or stationary, traffic sharing the same line will experience forces pulling inwards, and, conversely, faster traffic will still experience forces pulling outwards. Long experience has shown that, to avoid discomfort on slower trains, track cant should not exceed 6°; and, for trains moving more quickly, cant deficiency should not exceed 4.5°.
Dedicated high-speed railway lines were being constructed in Japan in the 1960s. Japan had previously used a but decided to lay entirely new standard gauge lines for these services, the Shinkansen. The lines were designed for a running speed of , using gentle curves with minimum radii of , and entirely new signalling systems able to provide enough warning to stop a train at within . The Europeans were planning similar systems in several countries, while the UK, and Canada, could not justify such an expense given their passenger numbers.
Active tilt Another solution to this problem had been developed in the 1950s but not widely used: tilting trains. Tilting trains rock into the curve to tilt the passenger cars the same way that a superelevated track would tilt them inward. Tilting systems had been introduced in service by the Spanish Talgo, but this system was "passive" and took some time to respond to curves. Great improvement can be made by making the system "active", reading the forces on the cars with sensors and quickly rotating them to the proper angle using hydraulic rams. British Rail ran an extensive experimental program on active tilt systems in the 1960s that was highly influential, and followed these studies in the 1970s with a new tilting train design, the Advanced Passenger Train (APT). The technical design objectives for the APT included a maximum speed 50% higher than existing trains and curving speeds 40% higher, all while running on existing tracks within the limits of existing signals.
While tilting reduces the problem for the passengers, it does not change the forces on the rails. A train going around a bend at high speed rides up onto the rails, and if the flanges on the inside of the wheels contact the rails they cause considerable wear. Eliminating this effect is difficult, but it can be reduced by lowering the weight of the locomotive, or eliminating the locomotive and distributing the motive power throughout the train. APT took the former route, and the original APT-E used gas turbine power. Gas turbines have an excellent power-to-weight ratio, perhaps ten times that of a conventional diesel engine, with the downside that they use considerably more fuel at idle. This was not a concern when the APT was first being designed, but after the 1973 oil crisis they quickly changed the design to be electrically powered. This was even lighter than the turbine version, but requiring the lines to be electrified at great cost. As a result, only the West Coast Main Line from London to Glasgow used the electrically powered APT-Ps.First tilting train arrives early BBC News 5 January 2004
Turbo
The only route with passenger numbers and trip times suitable for high-speed service in Canada at the time was the Quebec City–Windsor Corridor, especially the portion between Toronto and Montreal that accounts for two-thirds of the passengers in the Corridor.Peter Warwick, "Via's bold Corridor plan", Trains, December 2009
The TurboTrain, or simply "Turbo" as CN preferred, was CN's first attempt to provide higher speeds along the Corridor. Designed in the early 1960s by United Aircraft Corp., the TurboTrain used a licensed version of Talgo's passive tilt system and a new turbine-powered locomotive. The CN trainsets were built in Canada by a consortium of Dofasco for the bogies and suspension system, Alcan for the car bodies, and Montreal Locomotive Works (MLW) for the engines and power systems. All three companies gained valuable experience with modern passenger train design as a result of the project.
The Turbo was far from perfect, however. Its articulated bogies meant that the train could only be uncoupled in the maintenance yards. If there was a problem with a single car the entire train had to be taken out of service, and the inability to easily change train length significantly reduced its flexibility. The design featured unique doors at either end to allow two trains to be coupled into one longer one, but in practice this proved too much trouble to be worth it. Moreover, while the turbine power was lightweight and proved very reliable, it was also very inefficient in fuel terms.
LRC A competitor to the Turbo had been brewing for some time at this point. As early as 1966 an engineer in Alcan had been formulating ideas for a new lightweight train and introduced the design to CN. The car body design was made mostly of aluminum for light weight, and built two inches lower than conventional sets to cut down wind resistance. The entire underside and running gear were also streamlined and tight-fitting from car to car to reduce the inter-car gap and the drag that causes. Active tilt in the cars would allow them to take advantage of higher speeds on existing lines, and an advanced suspension design would offer a smooth ride at all speeds.
The locomotive was based on the ALCO 16-251F prime mover rated at at 1050 rpm."LRC Locomotive - 1", Via Rail for-sale page This was the only suitable engine already being built at MLW; it was a relatively old design from the 1950s, and the LRC would prove to be one of its last uses in North America. To keep the train as a whole as streamlined as possible, the loco body was wrapped very tightly around the engine, at the same height as the cars. The resulting design was quite small even by modern standards, several feet shorter than the GE Genesis that replaced them in Via service, and thousands of pounds lighter. The light weight and low wind resistance would allow higher speeds while using less power, improving fuel efficiency.
Despite the older engine design, the LRC was a great advance in the state of the art over the Turbo in every way, offering a smoother ride at the same or faster speeds, with lower capital and operational costs, and the ability to easily change train lengths. In January 1967, the two companies approached Dofasco and MLW about the possibility of a new joint venture to develop the design. In December, the group presented their design to Transport Canada, and in January another presentation was made to the Department of International Trade and Commerce to gain funding. The Canadian government's Transportation Development Centre (TDC) outside of Montreal agreed to provide development funding for the technology under the Program for the Advancement of Industrial Technology (PAIT).
The effort found strong support within the government. The Canadian Transport Commission studied the problem of offering Corridor service and concluded that "the most profitable strategy to adopt involves maximizing the potential of existing railway facilities through the introduction of new vehicle technology.""Via's LRC Fleet", Via Rail
Designing the suspension The first consideration was whether or not a suitable tilting mechanism could be built into the bogies that would not require extra space or project into the car. Dofasco, a major steel manufacturer in Hamilton, won the majority of the bogie development contracts. They developed a system that consisted of two parts, a bogie and suspension on the bottom, and a separate tilting mechanism on top.
The suspension consisted of several parts. Between the axle and the bogie frame was a series of C-shaped steel leaf springs stacked inside each other for the basic suspension, with rubber sheets between the leaves providing some shock absorption. A second set of softer springs on top of the bogie provided finer ride quality. Four sets of shock absorbers completed the suspension.
The tilt controls were developed by SPAR Aerospace and Sperry Rand Canada. The car body rode on rollers fitted into two U-shaped arms at the front and back of each bogie. Hydraulic rams moved the car from side to side along these arms, tilting it up to 8.5 degrees.See diagram, , or image, This made the bottom of the coach slide sideways while it rotated, so that the axis of motion was in the middle of the car body, instead of the top (like the Turbo) or bottom (like most tilt systems). This reduced the feeling of motion on the passengers by keeping the rotation close to their center of gravity, and reduced loads to 0.5 g. Each bogie was equipped with an accelerometer and operated as a completely self-contained unit.
Prototypes and testing
With Dofasco's successful demonstration of a tilting system, additional contracts were offered to build a prototype train. The name LRC was carefully selected to define the project's goals bilingually: a lightweight train, operating at high speeds, and providing a more comfortable ride than existing trains. Alcan of Montreal won the contract for the aluminum passenger cars and the carbody of the locomotive, while MLW developed the new diesel–electric system.