Friday, September 29, 2017

ONT, BAYL turn to portable CNC wheel truing

Written by 
  • Print
  • Email

Ontario Northland Railway (ONT), Canada, and Bay Line Railroad (BAYL), Panama City, Fla., have adopted CNC (Computer Numerical Control) portable wheel truing machines for maintaining and repairing locomotive wheelsets. The machines are from Delta Manufacturing, Escanaba, Mich., a supplier of portable, under-floor and above-floor wheel truing systems.

CNC Machining is a process used in the manufacturing sector that involves the use of computers to control machine tools. Tools that can be controlled in this manner include lathes, mills, routers and grinders. While high-speed CNC-controlled machine tools have been used for decades in manufacturing, railroads have only recently begun to transition from manually controlled devices to portable CNC machining.

“Wheel-related service disruptions can easily cost $10,000 or more per incident, including downtime,” according to Delta. “This includes time waiting for repairs, the cost of shipping wheelsets or moving entire locomotives to reconditioning facilities, outsourcing wheel profiling to mobile contractors, lost revenue from canceled train departures, and even Federal Railroad Administration (FRA) fines.”

Delta CompositeDelta says availability of CNC-controlled portable wheel lathes “is dramatically expediting wheel profiling and reducing costs by enabling safe, precise, on-site locomotive wheel truing, whether in the field or at the shop. Unlike outdated portable lathes that require operators to work at the wheel in a labor intensive, manual process, these easy-to-use lathes are controlled using a handheld pendant at a safe distance from the machine.”

CNC technology “has revolutionized the precision metal parts manufacturing industry,” Delta notes. “Multi-axis, coordinate-based profiling eliminates the potential for human error to cut a virtually perfect wheel and flange every time. Because such equipment costs a fraction of in-floor wheel systems, it is affordable to even short lines, and can pay for itself in less than one year by reducing repair costs and service downtime.”

The FRA requires locomotive wheels to be inspected every 90 days for defects such as flat or shelled spots, thermal cracks, and thin or high flanges. Wheels must also be incompliance with specific AAR (Association of American Railroads) wheel measurement profiles. Noncompliance with FRA can result in enforcement actions and penalties.

“Previously, if we had a locomotive wheel defect in our Cochrane terminal, we shipped the locomotive to our larger North Bay facility, which took it out of service for up to five days,” says ONT Manager of Training and Continuous Improvement Chris Wilson. For us, that could mean not being able to run a train, which is a huge loss of revenue.”

According to Wilson, ONT considered purchasing an in-track wheel truing machine for Cochrane, to service its fleet of 24 locomotives. The $2 million price was prohibitively expensive for the smaller facility. Delta’s CNC wheel lathe provided a viable alternative.

“Since such equipment is portable, it can quickly be brought to a disabled locomotive to re-profile wheels onsite,” Delta says. “Our Wheel Hog, for example, can be utilized at the remote site, with the locomotive raised on mechanically locking jacks, so the wheels can be quickly and precisely re-trued. This approach can dramatically reduce the cost of service downtime and eliminate the expense of moving a locomotive or shipping wheelsets to a reconditioning facility.”

BAYL, a subsidiary of Genesee & Wyoming, operates 23 locomotives on 108 miles of track from Panama City north, has also switched to a CNC portable lathe.

“Without our portable Delta Manufacturing CNC lathe, we’d have to move a locomotive, or spend about $10,000 to buy a wheel and bring in a crane to install it,” says David Nunnery, Mechanical Manager. “Instead, we can bring a portable wheel lathe right to the locomotive and cut the wheel onsite.” The equipment is utilized in the shop and in the field, as needed.

According to Nunnery, BAYL previously paid a contractor about $3,000 per wheelset trued in the field as required. “Now we’re paying about $400 to have our own employees cut a wheelset with the portable CNC lathe,” he says. “We save about $70,000 a year with it. For remote repairs, mid-and long-line operations could save considerably more.”

“With the old hand-cranked wheel lathes, you worked up close to the wheel,” says ONT’s Wilson. “With our portable CNC machine, however, you stand back at a safe distance, control the operation with a handheld pendant, and watch the machine do the work. We’ve had no injuries with it during the two years we’ve been using it.”

According to Wilson, ONT chose the CNC portable wheel lathe because it “is very safe, precise, and fully automatic” and “provides the same wheel profile every time and is not so dependent on the skill of the operator. Once the machine is set up, it cuts the wheel to the correct AAR profile. Because the lathe is computer controlled, it is “much more accurate than the old hand cranked lathes. After you determine the x and y axis during setup, there’s no more wheel profile measuring required. It’s monitored automatically and keeps a running total of how much material you’ve removed from the wheel.”

Delta says its CNC unit can true a single wheelset in four to six hours, depending on wheel condition, “a relatively short time to recondition an entire four- or six-axle locomotive.”

“If we have a wheel defect, we can put the locomotive back in service in about 24 hours using our portable CNC wheel lathe,” says Wilson. “The lathe paid for itself in the first six months, just in reduced downtime.” He adds that the CNC lathe “allows us to eliminate wheel defects that can increase [wheel impact loads] and also lead to electric traction motor failures. This approach can significantly reduce maintenance costs. Since we’ve had the CNC wheel machine, we’ve experienced an 80% reduction in traction motor failures on the locomotives in that terminal. We’ve saved at least $300,000 in about two years.”

Wilson estimates that, when factoring-in the ability to keep locomotives in service longer with less downtime for repairs, another $100,000 in maintenance cost savings per year is possible.

“You will never go back to a hand-cranked lathe once you try a portable CNC unit,” says BAYL’s Nunnery. “Whether you set it on a rail, on a flat surface, or over a pit with adapters, it is easy to use. You can teach a new operator to use it in one or two wheel cuts, and virtually eliminate issues related to operator error and service downtime.”

Get the latest rail news

Rail news and analysis from Railway Age, IRJ and RT&S by email