Extending weld life

Service providers ramp up their efforts to enhance the welding process and improve the life of each weld.

{besps}July15_welding{/besps} {besps_c}0|1welding.jpg| Holland says its aim is to develop flash-butt welding technology that provides high-quality and cost-effective solutions.{/besps_c} {besps_c}0|2welding.jpg| A Chemetron boom truck lowering a welding unit down.{/besps_c}

Service providers ramp up their efforts to enhance the welding process and improve the life of each weld.

Rail welding service providers are focused on expansion, be it in their portfolio of services offered or in the geographic area served. They all note that they are stepping up research and development in order to improve, enhance and even automate the welding process by bettering the equipment and software utilized.

Mobile welding

Chemetron Railway Products, a division of Progress Rail Services, says it continues to expand its fleet of mobile welding units.

“To meet the increasing demand for mobile flash-butt welding, we are increasing the size of our fleet with additional in-track units that can be used for rail installation or portable welding applications,” said Scot Campbell, national sales manager – trackwork. “We are also adding rubber tired units with extended reach cranes. These units will have a 30-foot reach, ideal for welding turnouts or other long reach applications. Like our CAT track-hoe units, these can travel on the road and rail.”

Additionally, to support the Canadian market, Progress Rail says it is dedicating mobile welding trucks and personnel based in Canada. Campbell notes that on the fixed plant side of the business, the company’s welding facilities have many new features including automated spot and end polishing, enhanced control and power systems that provide consistently high quality welds.

“Chemetron works closely with our customers and rail suppliers to extend the life of our welds. At our new Russell, Ky., facility, state-of-the-art control supervises every aspect of the welding process, ensuring repeatability of the operation. The fully-automated material handling includes a new rail end preparation system that polishes the rail head, rail base and the rail butt with no human interaction, resulting in a consistent and repeatable electrical contact while welding,” said Campbell. “Chemetron continues to refine the uniformity and reduce the size of the Heat Affected Zone. The improved uniformity and reduction in size will extend the life of our welds.”

Complete service line

Holland LP acquired the BankHead Group based in Atlanta this past March and the company notes it is excited about this addition as it allows Holland to offer a complete line of welding services. These services include: Fixed plants, porta plants, in-track flash butt, thermite and electric welding for frog repair. Russell Gehl, vice president – maintenance of way sales at Holland, says this expansion helps to complement Holland’s turnkey welding division, as well. He notes that this division is now able to make all the welds in a turnout including those that were previously unable to be made with the long reach flash-butt truck.

“This year’s focus in new construction flash-butt (FB) welding has been directed toward turnouts and welding [insulated joints] into track,” said Gehl. “Other customers have been focusing on distressing work, which focuses on correcting and setting neutral rail temperature (NRT). We have set things in motion to help monitor NRT when we are setting it through the FB welding process.”

Gehl says weld quality is always a concern for Holland’s customers, who are interested in studying weld life by evaluating new welds, as well as those with extensive tonnage. Gehl notes that monitoring weld life span in various types of environments, such as different grinding and maintenance practices, allows the railroads to create predictive models to determine future maintenance programs surrounding welds.

“Holland is spending more money in R&D than ever before to help improve weld quality, processes and advance future products,” said Gehl.

He continued to say that one of the year’s initiatives is updating Holland’s entire welding fleet with a new state-of-the-art welding control system.

“This control system monitors rail movement faster than ever before. The system is capable of monitoring the weld process at 8,000 times per second. The new system also offers improved shear drag monitoring, slip detection and correction and enhanced automated quality control procedures. The control system also offers the ability to transfer data via cellular card and allow remote access for monitoring and trouble shooting. Some of the newest systems offer GPS tracking of weld locations. The new control system will help improve the weld quality and the weld monitoring process,” said Gehl.

In addition to software improvements, the company is also embarking on developing a new lighter weight mobile welder.

“This lighter weight design allows us to transport the welder head and puller all within the truck and remain Department of Transportation compliant,” said Gehl. “This may not seem like much, but it allows Holland to be considerably more flexible when jumping from defect to defect in a repair welding gang. The first prototype is working on a Class 1 and shows every sign of being a success.”

Engine-driven welders

In the latter portion of 2014 and early in 2015, Lincoln Electric Company moved forward in establishing upgrades to engine driven equipment and developed new products with railroads that increase productivity and enhance quality says Brian Meade, manager of Lincoln’s global railroad program.

He notes the company’s new Air Vantage 600 SD engine-driven welders contain less wiring and fewer connections than previous designs and the printed circuit boards are environmentally shielded using Lincoln Electric’s engineered encapsulation and protective frame trays. The 64-horsepower Deutz diesel engine reduces particulate matter and nitrous oxide emissions by 90 percent and increases fuel efficiency. Meade explains that the machine is capable of locking out weld limits to keep welders from going outside of the recommended welding procedures and has been designed for better reliability in colder weather.

“About 40 percent of our equipment is subjected to extreme cold,” said Meade. “Improving the cold weather starts early in the mornings is a big step for us and it helps the welding crews.”
Another product Lincoln has developed to improve the preheating of Thermite welds is a newly-designed propane torch heating head.

“The welding managers are really happy with the even and consistent way the rail ends are heated with this product,” Meade said. “Any way we can help reduce the number of weld defects is a big help to the railroads, especially when one railroad can make thousands of welds per year. Lincoln Electric is looking forward to making more improvements for the railroads in the coming months.”

Thermite welding

Orgo-Thermit, Inc., is marking the 120th anniversary of Professor Hans Goldschmidt, founder of what would become the worldwide Goldschmidt-Thermit Group, receiving imperial patent #96317 for the “process to manufacture metals and alloys.”

Dave Randolph, president of Orgo-Thermit, said, “This patent laid the foundation for the development of the Thermit® welding process, thus becoming the world leaders in Thermit® welding technology and manufacturing processes.”

Randolph continued that the company is expanding and diversifying its product line and points to a magnetic safety fence, manufactured by Rail Safety Systems, which Orgo-Thermit showcased at the 2014 American Railway Engineering and Maintenance-of-Way Association (AREMA) Annual Conference and Exposition.

According to Randolph, the fence does not require digging out ballast or the use of shovels and can be assembled in a few steps. The magnetic stanchions attach to the web of the rail and are connected by tubes three meters (9.8 feet) long. The safety fencing is designed with a quick locking mechanism at each end of the tube, which allows for an unlimited number of sections to be assembled. Orgo-Thermit will again have the fencing on display at Railway Interchange being held in Minneapolis, Minn., this October.

Pertaining to its existing product line, the company has made enhancements to its degradable crucible system. This system, like Orgo-Thermit’s metallurgical welding powers and refractory molds, is manufactured in the United States. Randolph says the company’s self-sufficient manufacturing process reduces product lead times.

“Though our degradable crucible system has been in use for many years and well received by all our customers, we just recently converted all the welding crews of a major Class 1 railroad to the degradable crucible system in lieu of the multi-use crucible system,” said Randolph. “The degradable crucible system is fitted with lifting handles, a first in the industry, making it ergonomically-friendly for the welders that handle the crucibles every day. Another added advantage is in the design of the crucible cap that entraps hot metal sparks or reaction debris from leaving the crucible, thus making it both safer and greatly eliminates the possibility of fires starting in the vicinity of the weld.”

Randolph also notes that Orgo-Thermit’s Research and Development Department has made great strides in the development of a locally-manufactured wireless ignition system that initiates the chemical reaction remotely. The wireless ignition system is in the final stages of testing and approving the system in house. He says to further enhance the company’s product offering, it offers two-piece and three-piece refractory mold configurations, suitable for all the major rail profiles.

In addition to in-house initiatives, the company is working with Transportation Technology Center, Inc. (TTCI), on weld process improvements, such as Orgo-Thermit’s Head Alloyed Plug.
Randolph explains, “Orgo-Thermit Inc., in conjunction with TTCI researchers, recently completed a [Facility for Accelerated Service Testing] track testing program, under 315,000 lbs. cars, where 10 Head Alloyed Welds were installed at the heavy tonnage loop (HTL) for heavy-axle-load testing.

“These test welds were installed on the high rail of a five-degree curve in February 2011. During this test trial, the welds did not receive preventative grinding or lubrication.

“Seven test welds with an initial running surface hardness of around 380 [Brinell Hardness Number (BHN)] were made between 390 BHN and 390 BHN High Strength (HS) rails, two welds were made between 340 BHN to 340 BHN Intermediate Strength (IS) rails and one weld was made between 390 BHN and 340 BHN rails.

“The seven welds were installed per Orgo-Thermit Inc. welding instructions and the additional three welds were installed to investigate the impact of the unintended application of the alloyed plug on weld service performance.

“These tests have shown that the welds in the High Strength rails exhibited a wear rate approximately 50 percent less of that observed in standard hardness thermite welds. The two welds in Intermediate Strength rail increased in vertical height due to the decreased wear of the weld metal but as a result of increased wear of the surrounding softer rails.

“The weld joining the two rail grades, HS to IS, neither wore nor dipped compared to the rails and saw very little wear/batter relative to the adjacent rails. The unintended application of the alloyed plug did not affect the weld service performance,” said Randolph.

Robot welding

Plasser American Corporation, points to its many years of experience in the production and operation of rail bound, hi-rail and container flash-butt welding machines and mentions that new welding standards have resulted in an increase in welding requirements.

“Conventional welding heads used up to now are mostly based on a Russian patent and do not or only partly meet these new requirements,” stated Plasser. “More stringent requirements, combined with Plasser’s knowledge gained over the years, resulted in the development of our own automatic welding robot.”

The company points to the new weld head’s working parameters of up to 10 inches stroke with 168 tons of force, which allow closure welds to be made without the use of additional rail pullers.

Plasser says welds made by its APT 1500 R welding robot, which is available on rail bound, hi-rail truck or container platforms, utilize a fully automatic process. The company says the full automatic welding process reduces the possibility of human errors to almost zero, thus, ensuring consistent welding quality under the most difficult conditions. The welding head automatically aligns the height and running surface, as well as crowns the rail. The automatic centering device measures rail alignment via distance transducers located in the weld head. The measurements are saved for quality assurance reasons, stated Plasser.

Another special feature the company points to on the weld head is its utilization of alternating current with a medium frequency of 1,000Hz, allowing the use of very small transformers in the weld head. The head runs on direct current, which Plasser says has a positive effect on the weld quality.

The built-in welding shear places a load only in the direction of compression utilizing separate hydraulic cylinders. A non-contacting temperature measuring system allows for the precise cooling of high alloy rails with the help of a post heating process. The hydraulic system allows for very fast movements of the weld head, even for closure welds under full load (low consumption weld). The design of the clamping jaws eliminates the need to grind off company markings on the rail web, thus reducing preparation time stated Plasser.

Plasser says operator errors can be ruled out with the automatic robot welding process, which results in high reliability and documented welds of consistent high quality.

Aluminothermic welding

Oliver Dolder, executive vice president, managing director of Railtech Boutet, says the company continues to focus its efforts on commercializing a trio of new products: The QP Hybrid Welding System, Head Wash Repair (HWR) welding and the Startwel® Ignition System. Dolder notes the three products were created to meet customers’ requests in improving the overall aluminothermic welding process.

“The QP Hybrid molds use a compressible lining in order to get a perfect fit on the rail. This allows the welders to make a great quality weld by drastically reducing the chances of any flashing to occur during the welding process, which in turn, significantly increases the life of the weld,” said Dolder.

He says Railtech Boutet customers are using the HWR weld in the repair of transverse defects, corner gauge defects and minor shelling. The company calls the HWR a great “preventative maintenance weld,” giving its customers an opportunity to repair a small defect before it grows and leads to a break in the rail.

“We are currently working on finalizing the procedures to repair defective flash-butt welds with this process which is something our customers have been asking for,” said Dolder.

The company says its Startwel® Ignition System provides more accurate and consistent tap time and allows the welder to ignite the weld charge to initiate the pour process for the Railtech Aluminothermic Weld System, replacing the traditional “sparkler” igniter design. Startwel is classified as non-hazardous for transport, which means there are no shipping restrictions and it can be shipped overnight should an emergency arise.

“Following up on our customer’s requests, we have started to grow and improve our training, technical support and field assistance programs,” said Dolder. ” We understand that today’s welders needs to be comfortable with our product in order to be productive and our customers depend on us to provide this type of assistance when needed.”