blue streak 1 Gramp Here's derailment today near Tulsa. From the video, looks like bulkhead and coil cars were off track going into crossing? https://www.msn.com/en-us/weather/topstories/that-just-happened-train-derails-and-crashes-near-tulsa/vi-AA18lzsR?ocid=msedgdhp&pc=U531&cvid=edef6e5cc0e14fdab99b0641cb833515&ei=60 Was it the bulk head car rear truck jumped up at the grade crossing? Does that mean the bulk head car was off the rails? Are these press fits on same diameter each for axels and wheels or slightly tapered ? That difference would have indicated press Kns different during press oerations ? Would it be possible to make common freight wheel sets have a larger diameter inside solid collar that would prevent wheels to go less than inside gauge specs ? Also are the roller bearings fitted so the wheels cannot go gauge + ?
Gramp Here's derailment today near Tulsa. From the video, looks like bulkhead and coil cars were off track going into crossing? https://www.msn.com/en-us/weather/topstories/that-just-happened-train-derails-and-crashes-near-tulsa/vi-AA18lzsR?ocid=msedgdhp&pc=U531&cvid=edef6e5cc0e14fdab99b0641cb833515&ei=60
Here's derailment today near Tulsa. From the video, looks like bulkhead and coil cars were off track going into crossing?
https://www.msn.com/en-us/weather/topstories/that-just-happened-train-derails-and-crashes-near-tulsa/vi-AA18lzsR?ocid=msedgdhp&pc=U531&cvid=edef6e5cc0e14fdab99b0641cb833515&ei=60
First 5 minutes are about making wheels and wheelsets
Never too old to have a happy childhood!
bogie_engineer Wheels are mounted by simply pressing them on to the axle. There is a very specific surface finish, and interference range required along with a measure of bore and seat taper. The pressing operation requires a lubricant meeting AAR specs and the tonnage to apply is recorded on a chart during the pressing operation. The tonnage has to increase at a specified slope as the wheel is further engaging the axle. For locomotive wheels, the final tonnage has to be between 95 and 145 tons IIRC. The shop doing the work has to be inspected and approved by AAR showing they can meet all the requirements including the record keeping needed. Axle and wheels are serialized for traceability. EMD had a problem with wheels moving on the axles on the first batch of SDP40F's for Amtrak on the Santa Fe. After many cab rides, it was found a specific diamond crossing in the SW had bad alignment and the impact at the higher speeds that Amtrak ran was enough to move the wheels slightly. This resulted in increasing the tonnage required to the 95-145 range for the 10.25" bore loco wheels, prior, I believe, the minimum was about 75 tons. Whichever shop mounted these wheels will be under a lot of scrutiny, rightly so. Dave
Wheels are mounted by simply pressing them on to the axle. There is a very specific surface finish, and interference range required along with a measure of bore and seat taper. The pressing operation requires a lubricant meeting AAR specs and the tonnage to apply is recorded on a chart during the pressing operation. The tonnage has to increase at a specified slope as the wheel is further engaging the axle. For locomotive wheels, the final tonnage has to be between 95 and 145 tons IIRC. The shop doing the work has to be inspected and approved by AAR showing they can meet all the requirements including the record keeping needed. Axle and wheels are serialized for traceability.
EMD had a problem with wheels moving on the axles on the first batch of SDP40F's for Amtrak on the Santa Fe. After many cab rides, it was found a specific diamond crossing in the SW had bad alignment and the impact at the higher speeds that Amtrak ran was enough to move the wheels slightly. This resulted in increasing the tonnage required to the 95-145 range for the 10.25" bore loco wheels, prior, I believe, the minimum was about 75 tons.
Whichever shop mounted these wheels will be under a lot of scrutiny, rightly so.
Dave
This is it. 100%. The big question is how does an AAR certified wheel shop let this happen. This is really mature technology...
Cars go through many wheelsets in their life. Multiwear wheels will get re-turned a few times in thier life without dismounting the wheels - but new/rebuilt bearings will be applied at that time - from AAR certified bearing vendors.
Once the wheels are worn to the condeming limit, they are pressed off. The axle can be reused. It is inspected various ways, wheel seats are machined and new wheels pressed on.
The press tonnage is recorded for each wheel mounted.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
bogie_engineerEMD had a problem with wheels moving on the axles on the first batch of SDP40F's for Amtrak on the Santa Fe. After many cab rides, it was found a specific diamond crossing in the SW had bad alignment and the impact at the higher speeds that Amtrak ran was enough to move the wheels slightly.
Yikes! I'll bet whoever discovered that found it hard to beleive they were seeing what they were seeing! Also, probably lots and lots of furrowed eyebrows back at LaGrange...
Lateral forces high enough to start to unseat wheels, hmmm...
oltmannd Yikes! I'll bet whoever discovered that found it hard to beleive they were seeing what they were seeing! Also, probably lots and lots of furrowed eyebrows back at LaGrange... Lateral forces high enough to start to unseat wheels, hmmm...
This was definitely a big deal at the time in LaGrange and a lot of resources were expended to find the cause and fix the problem. The SDP40F's were notorious for rough lateral ride and a number of changes to the HT-C trucks were made to including opening up the lateral bolster to truck frame clearance to stops, softening the secondary rubber springs, and adding lateral dampers. But as far as I know, no derailments were attributed to the wheel moving issue. The prime people involved at EMD have all passed away in the last few years.
BaltACD blue streak 1 Gramp Here's derailment today near Tulsa. From the video, looks like bulkhead and coil cars were off track going into crossing? https://www.msn.com/en-us/weather/topstories/that-just-happened-train-derails-and-crashes-near-tulsa/vi-AA18lzsR?ocid=msedgdhp&pc=U531&cvid=edef6e5cc0e14fdab99b0641cb833515&ei=60 Was it the bulk head car rear truck jumped up at the grade crossing? Does that mean the bulk head car was off the rails? Are these press fits on same diameter each for axels and wheels or slightly tapered ? That difference would have indicated press Kns different during press oerations ? Would it be possible to make common freight wheel sets have a larger diameter inside solid collar that would prevent wheels to go less than inside gauge specs ? Also are the roller bearings fitted so the wheels cannot go gauge + ? First 5 minutes are about making wheels and wheelsets
Forged wheels. Figured these would be for what I'm assumed to be Passenger/HSR wheelsets. Most if not all freight wheels are still cast I believe.
bogie_engineer Wheels are mounted by simply pressing them on to the axle. There is a very specific surface finish, and interference range required along with a measure of bore and seat taper. The pressing operation requires a lubricant meeting AAR specs and the tonnage to apply is recorded on a chart during the pressing operation. <SNIP>
Wheels are mounted by simply pressing them on to the axle. There is a very specific surface finish, and interference range required along with a measure of bore and seat taper. The pressing operation requires a lubricant meeting AAR specs and the tonnage to apply is recorded on a chart during the pressing operation.
<SNIP>
Most interesting. I didn't know this. I would've assumed that they would've welded the wheels to the axles. That would sound more logical but I'm not sure what kind of issues would be created by welding them.
Fred M Cain Most interesting. I didn't know this. I would've assumed that they would've welded the wheels to the axles. That would sound more logical but I'm not sure what kind of issues would be created by welding them.
Welding would create a lot of problems first making removing the wheels to reuse the axle probably not economic. But more serious is that the axle is highly stressed at the junction with the wheel and welding brings in issues of stress concentration, weld quality, and effect on axle material strength from heating (heat-affected zone fatigue properties).
NYC-OhioPretty sure that those wheels are made in the Pittsburg area.
There's a couple of them scattered around Western Pennsylvania.
I grew up in Butler and saw the last days of Trinity running the old P-S plant. The last order for full cars built there were a batch of hoppers for Burlington Northern. Flatbed trucks would come down US-422 into town with enough wheelsets for two cars. Judging from the route they took, I think they were coming from a factory in Sharon.
bogie_engineer Fred M Cain Most interesting. I didn't know this. I would've assumed that they would've welded the wheels to the axles. That would sound more logical but I'm not sure what kind of issues would be created by welding them. Welding would create a lot of problems first making removing the wheels to reuse the axle probably not economic. But more serious is that the axle is highly stressed at the junction with the wheel and welding brings in issues of stress concentration, weld quality, and effect on axle material strength from heating (heat-affected zone fatigue properties). Dave
Not to mention the distortion of both the wheel and axle from the heat required in making the welds. Actions taken to limit the distortion would create stresses of their own.
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