• M/W

Don’t reface it, replace it

Written by Mischa Wanek-Libman, Editor, Railway Track & Structures; and Engineering Editor, Railway Age
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Complete track renewal work calls for large machines that offer custom solutions.

When railroads turn to large track renewal machines, they need equipment that offers versatility in both what can be accomplished and how it gets accomplished, for example, being able to work with various types of crossties. Yet, the machines still need the ability to customize their work, toward a solution unique to a given customer.

High-quality track

Harsco Rail’s TRT-909 track renewal system can replace both rails simultaneously, remove and replace crossties (concrete, pre-plated wood, or steel), pull and reclaim spikes, and distress the rails using induction heat, as well as remove and collect rail anchors.

Steve Byers, senior director of sales for Harsco Rail, says, “Development of the TRT was based on 25 years’ experience designing, manufacturing, and operating track renewal systems. Customer input was critical to the success of the project; not only did a Class I railroad steer the design process, it challenged us to do more, better, faster, and with added safety.”

The TRT-909 went into service in 2005. According to Byers, since then, more than 1,700 miles of track has been renewed.

“During this time, more than 30 improvements have been implemented to improve productivity, enhance safety, and reduce cost. One of the most important improvements was the Induction Rail Heater. With this system we can heat the rail to a neutral temperature without an open flame,” says Byers.

In addition to the Induction Rail Heater, Harsco points to the machine’s ability to apply and remove McKay rail fasteners, as well as other fastener types, and a spike puller capable of pulling eight spikes simultaneously as important innovations.

“The primary advantage of using the TRT-909 is the safety and efficiency derived from renewing rail, ties, and ballast in one automated pass. Material handling is an important element of any track renewal consideration, along with reduced labor, improvements in safety and track quality, and reduced future maintenance,” says Byers. “While each machine is tailored to a customer’s specification, we see opportunities on new machines to increase productivity, add automation, improve handling of excess ballast, and adapt to new ties and fastening systems.”

Machine versatility

Plasser American Corp. offers the SMD 80 series of machines for track renewal and track laying, as well as the WM 40/PK turnout renewal system.

Plasser American developed its turnout renewal system to handle what the company calls a large and unwieldy, yet sensitive track component. The company says utilizing a mechanized renewal and laying technique for turnouts enables fast and high-quality installation, without the need to worry about circumstances, such as a tight workspace.

According to Plasser, “The mechanized transport and installation of turnouts enables a wide variety of maneuvers of the complete turnouts or assembled turnout sections. The tasks of loading and unloading, lateral transport to the track, and also longitudinal transport on the track and in the work site are performed by the turnout relaying machine. This guarantees that the precise geometry of the pre-assembled turnout is retained until it is installed, because this initial quality of the turnout has a considerable influence on its service life.”

On the subject of track renewal, Plasser’s SMD 80 is capable of exchanging crossties and rail, as well as new track construction.

“Machines of the SMD 80 series represent the state of the art in a track relaying concept, which excels in terms of performance, flexibility and cost-efficiency. The machine set has been built according to the modular design system, which allows tailor-made solutions to be provided for each specific field of application,” says Plasser. The system’s modular components include a relaying machine with bogies and a crawler track, a power unit, and a self-propelled gantry crane to supply new crossties and take away old ones.

Crosstie variety accounted for

 The company says the SMD 80 series was developed with an awareness of short track possessions and designed its machines to take up and install a variety of crossties including wood, concrete, and steel. When machines are renewing track, it is possible to exchange the rails or to re-install the previously used rails.

Plasser points out the SMD system’s crawler track, which drives the machine forward during operation, guaranteeing high tractive power independent of the weather conditions. The machines of the SMD series can also be equipped with a regulating chain and transverse conveyor belts, which provide a smoothed out ballast bed. The regulating chain also allows the possibility to lower the new track compared to the old track geometry and of working near station platforms and on boxed-in ballast.

“A special advantage of the SMD technique is that the individual work units are placed in position concurrently at the start of the work site so that no ‘plough gap’ can occur,” says Plasser.

Plasser adds that when working on relaying track, the SMD 80 pushes the tie cars ahead of itself and when laying new track, the direction of work is reversed with the tie cars being pulled by the machine. The company notes the conversion between types of operation takes little time.

“SMD 80 stands for a track renewal and track laying technique [that offers] the greatest possible cost-efficiency [and] highest work output, even under difficult conditions. The flexible SMD system allows new functions to be integrated into the construction, expanding it even further,” says Plasser

Seven units, one system

For the WM 40/PK, “the high standards required for switch laying were taken into account in the development of the switch laying machines of the WM series,” Plasser says.

The SES (Switch & Panel Exchange System) WM 40 consists of seven units: one WRW carrier vehicle, two PA turnout lifting units, and four WTW turnout transport cars. The WRW carrier vehicle serves to transport turnout sections and track panels as well as one of the two turnout lifting units to the work site. This is designed with two 2-axle trucks or “bogies” (one axle

per truck is powered hydraulically), two auxiliary undercarriages, and two powered crawler tracks. The trucks are of a laterally displaceable design “to ensure exact track gauge when placed on the track and precise alignment for travel on track,” Plasser says.

Here’s how it works, as Plasser describes it: “The turnout sections or track panels are picked up and laid using both turnout lifting units (gantry units). The lifting stresses are distributed uniformly onto the turnout so that its geometry is not altered by sagging, twisting, or bending. Within the lifting units, the turnout sections can be displaced by 72 inches (1.830 mm) longitudinally and 80 inches (2.030 mm) laterally. If the turnout is longer than the lifting frame, extensions are placed at the front and the rear as supports to prevent any undesired bouncing or twisting of the turnout. One of the two turnout lifting units is fitted with self-propelled crawler tracks. Both lifting units can load themselves onto the turnout transport cars.

“The four WTW turnout transport cars are equipped with a hydraulic slewing loading bridge with which the turnout can be rotated so that the permissible loading gauge is not exceeded during transport. Two of the four WTW’s in this system are fitted with diesel-hydraulic self-propulsion that allows the vehicle itself as well as other vehicles in the system formation to be maneuvered in the work site area. Both the turnout lifting units and the turnout transport cars can be controlled by radio remote control, in each case by only one operator.”

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