I remember growing up and hearing the train go by. There were two distinct sounds, the click of the rail joints and the heavy thump of a flat wheel.
Today, we rarely hear either. The widespread use of welded rail has virtually eliminated the regular click of the rail joints. The other, the heavy thump of wheels with big flat spots, is another sound seldom heard.
There is no doubt that slid flat wheels are not good for the underlining rail. As railcars got heavier and faster, the slid flat inspection criteria in Rule 41. Handling Line Responsibility – Condemnable At Any Time of 2 inches or more in length (41.1.a) or Two or more adjoin-ing spots each 1 ½ inches or over in length (41.1.b.) was too generous and damaging. The advent of wheel detectors that measure excessive loads from wheel impacts provided much improved means of protection against rail damage from defective wheels
This is good news for railroads to help lower their rail maintenance costs and help make the tracks safer. But there is an-other indirect benefit to rail-roads from the wheel detectors. Slid flat wheels were “Handling Line” responsibility. Meaning, if a railcar was on a railroad and found to have slid flat wheels, it was that railroad’s responsibility and cost to re-place the wheelset. This has always been a point of contention with railroads. Their argument was that they may have not caused the problem, but were stuck with the result. It was like a game of “Musical Chairs”, when the music, or a railcar in this case, stops; they get the bill
High KIP wheels, on the other hand, are owner’s responsibility. The rules allow various threshold that could alert a car owner and give them the opportunity to capture a car with higher kips before reaching the condemning limit. Although that sounds great on paper, in reality it only works for fleets that operate in a con-trolled cycle; like unit coal trains. As anyone that operates a lease fleet, the biggest challenge is to both capture cars and then route them to repair shops. In generally by the time it hits the shop, the wheels in question are either gotten worse and have been replaced or the defect had been smoothed out.
Wheel replacement costs typically are 25% – 35% of fleet maintenance expenses. Of the wheel costs, the biggest percentage of wheel replacement costs can be tied directly back to high KIP wheel re-placements when all related costs are included (removal of mate wheel, axle, roller bearings, jacking, etc.). In addition, the old formula of charging for the net change of service metal, as measured by rim thickness adjusted for flange wear has been replaced by a straight wheelset replacement charge. This has also driven the wheel costs much higher.
The problem, as I see it, is the lack of auditability when wheels are tagged as high kips.
We have a suitcase full of gauges for high flange, thin flange, thin rim, tread worn hollow, shelled, built-up and the list goes on. But nothing for a high kip wheel. When a wheel detector tags a wheel as meet-ing the high kips criteria (90,000 lbs or greater, Rule 41.A.1.r.(1)), there is no physical means of verifying the condition.
I’ve heard stories of a high impact wheel detector located on a curve that routinely tags high kip wheels when no other detector tags the wheels. I’ve also seen single locations that replace more high kip wheels other Class I’s replace on their entire system. Maybe we should thank them for being extra diligent????
So, is there a solution? Unfortunately, there isn’t any movement to eliminate the high kip wheel rule. And I agree, it shouldn’t be replaced because it is helping to eliminate dam-age to the rail from defective wheels. At the same time, the replacement rate is reaching epidemic proportions.
There is a lot of debate on what is driving the defects that result in the high kip replacements. Is it the heat input from tread braking on the newer cars at have higher axle loads and seeing faster train speeds? Is it as predicted in the 90’s when the decision was made not to increase the wheel size from 36” to a more optimal 38” when we upgrade the cars from 263,000 to 286,000 GRL? Is it other factors such as train handling? Dragging cars with brakes applied? Failing to re-lease handbrakes? Other?
I don’t have the magic solution, but I do have a couple of suggestions:
- The industry needs to develop an objective method to physically validate a high impact/high kip condition.
- Focus on finding and eliminating the root causes which may include wheel diameter, alternative braking methods, development of automatic handbrake re-lease, develop new wheel designs or materials or other causes.
- Place more accountability for wheel damage on the handling line when caused by operating issues such as failing to release hand brake, poor train handling, dragging car before brakes are released, etc. – hard to prove; but are real causes.
These suggestions are not something that could easily be accomplished. It will take the cooperation of the stakeholders, railroads, car owners, wheel suppliers and the rules committees to make this a priority. Right now, it is a huge cost driver to the car owners with no solution in sight. So, if high kips are truly a problem for the railroad’s track structure; let’s get to the root cause instead of throwing money at expensive band aids.
What’s A KIP?
There are a couple of definitions of a “kip”. One definition is “a gymnastic exercise performed start-ing from a position with the legs over the upper body and moving to an erect position by arching the back and swing the legs out and down while forcing the chest up-right. I can’t even figure that out much less try it.
For our use, the term Kip is engineering slang for 1,000 pounds-force. So, a 90 Kip wheel is a wheel that is generating 90,000 lbs. of force when measured by a wheel impact detector.