TECH FOCUS – MECHANICAL Today, there are pockets of adoption, but it hasn’t gone wholesale. RAILWAY AGE: What if active draft became the standard? It seems to me that, all things considered, it would be cost-effective. If there’s a good case to be made that the industry abolish prior specifications and go to active draft only, make it the standard. Would there be any issues in terms of retrofitting draft gear pockets in existing cars? MONACO: Not really. We’ve been able to get creative with the guts of the hydraulic unit, and I’m sure other suppliers have as well. A 10-inch travel unit in its pocket can be 9/1. A 15-inch travel unit can be a 14/1 or a even a 13/2. In Adam Klopp’s test data, you can see that 13/2 isn’t really that much worse than the 15-inch when it comes to impact performance. So you’re not giving up very much. We’ve accomplished that by putting elastomeric pads inside the cushioning unit on the front side of the piston and the inside of the front head. A couple of donuts in there to do all the work. Looking again at the Task Force research results, there is a dramatic difference between hydraulic cushioning devices and draft gears. That’s all pretty well understood. Again, the cushioning unit values are really very close to what’s happening with the draft gears, if you look at the magnitude of the values. What you’re sacrificing in train action forces is minimal compared to the damage that can occur in a higher-speed impact in coupling events.
In the event it would receive a draft shock in the train, it would have some degree of cushioning in that short amount of travel. But that didn’t go anywhere, either. There are expired supplier patents on this internal stuff. We sold a few, but the railroads weren’t sure if it was going to cost more, and there was constant churning over the specifications, M921E for autoracks and M921F for standard railcars. RAILWAY AGE: You left the industry for a few years and returned in 2005. Had any progress been made? MONACO: It finally turned into a research initiative, but started really slow. 42 Railway Age // February 2024
The railroads said, “Well, we’ll try one.” Our committee said, “No, you can’t just put one in there and expect that car to get slammed and say it’s performing better.” You have to equip the entire train. You need to avoid that buildup of velocities when you don’t have any attenuation in the draft direction, especially if you’re going down a grade and you have slack run-in, a buildup, and then you start going up a grade and those connections come out and you have high draft shocks that result in fatigue damage to the coupling system and even broken knuckles and train separations. In any case, testing occurred with only one unit. And sure enough, it didn’t do a whole lot. It helped a little bit.
RAILWAY AGE: What has the advent of longer trains with PSR, these 10,000-foot and 15,000-foot trains, done? And what about dynamic braking, where the locomotives, not the air brakes on the cars, are providing much of the braking force? It has been suggested that dynamic braking, while it has its benefits, especially when applied with distributed power, doesn’t do much to mitigate in-train forces. It could actually make them worse. There will be higher incidents of in-train draft and buff events. MONACO: I tend to agree with that. Obviously, the in-train dynamic forces are going to be higher. One thing is certain: Railroaders are going to have differing opinions. Bottom line: As long the industry’s stakeholders work together, safe, productive and profitable railroading will be the result. railwayage.com