125 MPH Certification Testing (Passenger Equipment)

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Hal said:
Many of them start shaking and vibrating badly at 90 MPH. Have to reduce speed from 110 MPH. Don't know if it is poor maintanence or the design. Will be interesting to see how they do at 125 MPH.
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Has to be maintenance, because they were designed to be good for 125 and are still tested and certified for 110. Probably bad maintenance of the suspension system, which IIRC is pretty complex.
 
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neroden said:
Hal said:
Many of them start shaking and vibrating badly at 90 MPH. Have to reduce speed from 110 MPH. Don't know if it is poor maintanence or the design. Will be interesting to see how they do at 125 MPH.
Click to expand...
Has to be maintenance, because they were designed to be good for 125 and are still tested and certified for 110. Probably bad maintenance of the suspension system, which IIRC is pretty complex.
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I suspect it is maintenance. Years ago when Metroliner Amfleets ran at 125 MPH and Northeast Amfleets ran at 110, every now and then they substituted a Northeast Amfleet if there was an equipment shortage. Those cars would ride rough and vibrate because the suspension had not been tuned.

Sent from my iPad using Tapatalk
 
neroden said:
Thirdrail7 said:
Actually, it is a joint test between NJT and Amtrak to get the ALP-45s and Viewliner 1s ready for 125mph. They ran them together to save time, manpower, track space and it also allowed the FRA to kill two birds with one stone. This consist will continue to roam both ends of the corridor for the next week or so.
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Awesome. I've been wondering when they'd recertify the Viewliner Is for 125 mph. (We knew they were planning to do so before the Heritage cars went away, and we know the Viewliner Is were supposed to be good for 125 with no mods.)

Thanks for the info.
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I don't know how much of a modification this incurs but they changed the wheel profile from an industry standard to better match operating on the corridor, which brings me to the post below:

Hal said:
neroden said:
Hal said:
Many of them start shaking and vibrating badly at 90 MPH. Have to reduce speed from 110 MPH. Don't know if it is poor maintanence or the design. Will be interesting to see how they do at 125 MPH.
Click to expand...
Has to be maintenance, because they were designed to be good for 125 and are still tested and certified for 110. Probably bad maintenance of the suspension system, which IIRC is pretty complex.
Click to expand...
I suspect it is maintenance. Years ago when Metroliner Amfleets ran at 125 MPH and Northeast Amfleets ran at 110, every now and then they substituted a Northeast Amfleet if there was an equipment shortage. Those cars would ride rough and vibrate because the suspension had not been tuned.

Sent from my iPad using Tapatalk
Click to expand...

The intricate details are a bit over my had but I under the basics of the issues. It is no so much as a maintenance issue. It is a wheel profile issue. The wheel profile of the eastern long distance fleet isn't really matched for operation of the NEC. They are matched to operate over CSX, NS and other slow routes. As such, there will always be that extra bit of lateral motion on the viewliners and AM2s.

Another point that is exacerbated when long distance trains operate over the NEC is a maintenance condition known as tread worn hollow. As you can see, there are established limits identifying if the wheel is condemnable( will/will not turn or total replacement.) If is within limits, chances are the will not be replaced, particularly since the majority of the trip will be at slower speed.
 
Thirdrail7 said:
The intricate details are a bit over my had but I under the basics of the issues. It is no so much as a maintenance issue. It is a wheel profile issue. The wheel profile of the eastern long distance fleet isn't really matched for operation of the NEC. They are matched to operate over CSX, NS and other slow routes. As such, there will always be that extra bit of lateral motion on the viewliners and AM2s.

Another point that is exacerbated when long distance trains operate over the NEC is a maintenance condition known as tread worn hollow. As you can see, there are established limits identifying if the wheel is condemnable( will/will not turn or total replacement.) If is within limits, chances are the will not be replaced, particularly since the majority of the trip will be at slower speed.
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That explanation makes sense. I now recall a car inspector forman explaining something like the above to me.
 
The lateral sway doesn't bother me at all, and I expect it to be bigger on faster track; that's just what trains do, right? Relatively small variances in wheel profile shouldn't cause what *I* think of as "rough ride", as long as the wheels are still basically conical. (But of course if the tread is worn hollow, they aren't...)

Hal was referring to "vibration", which I think of as high-frequency, and which should be mostly dampened by the air suspension. And "rough ride", which I associate with up-and-down motion, which should also be somewhat dampened by the air suspension....

I can see, however, how tread-worn-hollow would cause large amounts of all three types of "rough ride", up-and-down, left-to-right, and high frequency vibration, as well as off-center ride, and well beyond the ability of the air suspension to compensate. :-( Hopefully Amtrak will be willing to condemn wheels when they have tread worn hollow enough to destabilize the ride, even though it does mean more frequent replacement and therefore more cost.
 
How were the results of the ALP-45DP high speed test?
 
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Palmetto said:
jis said:
CSXfoamer1997 said:
Also, about the test, was it in electric mode or diesel mode?
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In case one happens to have read the Wiki page on the ALP45DP one would already know the answer to this question, since an ALP45DP is not capable of operating above 100mph in diesel mode.
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Only 100 MPH? On the NEC, that's like doing 55 MPH in the left-hand lane on I-95 in Melbourne! :D
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It is even like trying to do 55mph in the right hand lane on I-95 in Melbourne. :D
 
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Amtrak172 said:
How were the results of the ALP-45DP high speed test?
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I would presume that it went well and the DP is now certified for 125 on the corridor. However, since none of NJT's passenger stock is certified for 125, it's sort of a moot point until there's more cert runs.
 
Did anyone happen to catch ALP the retest in Maryland this week?6 Perhaps there are pictures on Facebook somewhere.
 
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Thirdrail7 said:
Did anyone happen to catch ALP the retest in Maryland this week?6 Perhaps there are pictures on Facebook somewhere.
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The Pitz man got a few shots of it at Wilmington... standard Comet equipment with a 45 on one end and a 46A on the other.
 
With Amtrak now upping the speeds of all of its NEC trains to a MAS of 125mph, what does that do to PV owners? While I can see some PVs being able to do 125, I'm not so sure about the heavyweight units.
 
Already from NYP-BOS they are only allowed on 65/66. They could probably continue on the eastern long distance south of New York. But the real answer is it looks interesting. I'll have to ask Kevin when I see him soon
 
Seaboard92 said:
Already from NYP-BOS they are only allowed on 65/66. They could probably continue on the eastern long distance south of New York. But the real answer is it looks interesting. I'll have to ask Kevin when I see him soon
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The PV community should be up in arms over this. I'd think I would bebe pretty comfortable in Hickory Creek going 125 or any non-heavyweight PV car. That being said, some PV's might not have the structural integrity for the higher speeds. Some of the newer ones maybe if they've had serious framework done.
 
Northeastern292 said:
With Amtrak now upping the speeds of all of its NEC trains to a MAS of 125mph, what does that do to PV owners? While I can see some PVs being able to do 125, I'm not so sure about the heavyweight units.
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Amtrak is probably years away from upping the speeds on the long distance trains to 125mph. Even when they are able, you will likely see private cars remaining on the Long Distance trains. They carry private cars on train 42 quite often and they run it as a 110mph train.

Remember, LD trains are receive/discharge only on the NEC, so there is always time in the schedule.
 
The standards to have a PV on Amtrak are vastly higher then the standards Amtrak has for their own cars. Right now the PV community has been quiet about that.
 
Thirdrail7 said:
Northeastern292 said:
With Amtrak now upping the speeds of all of its NEC trains to a MAS of 125mph, what does that do to PV owners? While I can see some PVs being able to do 125, I'm not so sure about the heavyweight units.
Click to expand...
Amtrak is probably years away from upping the speeds on the long distance trains to 125mph. Even when they are able, you will likely see private cars remaining on the Long Distance trains. They carry private cars on train 42 quite often and they run it as a 110mph train.

Remember, LD trains are receive/discharge only on the NEC, so there is always time in the schedule.
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Are there any plans at all to make any schedule changes for LD trains on the NEC when all the Viewliner 1s have been certified for 125mph and LD trains have no Heritage equipment in them?
 
When you realize that assuming there are 150 miles of track in NEC South with the potential of 125mph operation, operating a train at 125 instead of 110 over that saves all of ten minutes or so. For LD trains that is not critical enough to bother with higher level maintenance of wheels necessary to do so comfortably. That is why I very much doubt that there will be any significant time table change for them on the NEC. It will all just get eaten up in padding.
 
North bound that might be the case, but southbound surely timetabling a train to run slow for padding is just going to hold up platforms at stations whilst the LD trains sits & waits to for the padding time to expire? Time which could be used to allow a NEC train to catch up time if delayed or increase capacity on the route?
 

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