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603 looks nice sandwiched between the P42s. I wonder how many "unschooled" CZ passengers will think their train has three working engines...

Cool catch, Fan Railer.
 
WhoozOn1st said:
603 looks nice sandwiched between the P42s. I wonder how many "unschooled" CZ passengers will think their train has three working engines...
Cool catch, Fan Railer.
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Just a heads, that's not my video. I'm based in the east coast by the NEC. I usually mention it when I repost stuff I find, but I'm not sure why it slipped me this time.
 
jis said:
The single ACS64 has started test runs on the NEC. It is running south from Wilmington. It's acceleration performance with 8 Amfleets is turning out to be considerably superior to that of even Acelas. Reportedly from 0 to 125mph in 3/4 th mile!
Click to expand...
I am surprised why this is a surprise. Surely the specs were calculated precisely. How can a locmotive perform significantly better than anticipated? It would suggest that somebody messed up on their calculations, which is a bit worrying as they could equally mess up in the opposite direction.
 
cirdan said:
jis said:
The single ACS64 has started test runs on the NEC. It is running south from Wilmington. It's acceleration performance with 8 Amfleets is turning out to be considerably superior to that of even Acelas. Reportedly from 0 to 125mph in 3/4 th mile!
Click to expand...
I am surprised why this is a surprise. Surely the specs were calculated precisely. How can a locmotive perform significantly better than anticipated? It would suggest that somebody messed up on their calculations, which is a bit worrying as they could equally mess up in the opposite direction.
Click to expand...
the specs are the minimum. It's possible to build something that exceeds the specs. Nobody messed up on anything.
 
Same source reports a similar opportunity to catch the locomotive tonight (8/16) running up to newark and turning back afterwords.
 
cirdan said:
jis said:
The single ACS64 has started test runs on the NEC. It is running south from Wilmington. It's acceleration performance with 8 Amfleets is turning out to be considerably superior to that of even Acelas. Reportedly from 0 to 125mph in 3/4 th mile!
Click to expand...
I am surprised why this is a surprise. Surely the specs were calculated precisely. How can a locmotive perform significantly better than anticipated? It would suggest that somebody messed up on their calculations, which is a bit worrying as they could equally mess up in the opposite direction.
Click to expand...
So exceeding specification is messing up? Interesting where we have descended! New aircraft routine exceed specifications. Exceeding specifications in general is a good thing, not a bad thing, and it does not indicate that it necessarily happened just by chance.
 
Now that I'm at work, let me elaborate a little further - I (help) write performance specs for a Navy weapons system for a living.

You don't write a spec that says "The ACS-64 shall haul xxx,xxx lbs at a top speed of 125 MPH and an acceleration of yy m/s2" for this exact reason.

The spec would correctly be written "The ACS-64 shall haul xxx,xxx lbs at a top speed of at least 125 MPH and an acceleration of yy m/s2 or greater given that the following conditions are met: a) level track; b) environmental conditions as specified in section x.y.z; c) power inputs as specified in section a.b.c, d) etc, etc, etc".

Now obviously, after the plans were drawn up, and before construction started, it's highly likely that there was some performance modeling done to ensure that the design would meet the minimum specs. If the actual performance varies greatly than the predicted performance, that suggests that your performance model was pretty crappy and there was a risk that things wouldn't have turned out this rosy. But that's an issue for the M&S folks, not us requirements folks. :D
 
Ryan said:
cirdan said:
jis said:
The single ACS64 has started test runs on the NEC. It is running south from Wilmington. It's acceleration performance with 8 Amfleets is turning out to be considerably superior to that of even Acelas. Reportedly from 0 to 125mph in 3/4 th mile!
Click to expand...
I am surprised why this is a surprise. Surely the specs were calculated precisely. How can a locmotive perform significantly better than anticipated? It would suggest that somebody messed up on their calculations, which is a bit worrying as they could equally mess up in the opposite direction.
Click to expand...
the specs are the minimum. It's possible to build something that exceeds the specs. Nobody messed up on anything.
Click to expand...
I've worked in engineering myself (although not directly with trains, although I did work in train testing for a while) and usually you take the specs and work backwards from that, so you look at the the load cycles and the drag and limiting factors and on the basis of that determine how powerful the various componnets need to be. You don't take a more powerful part just for fun because that's a cost factor and hence you don't suddenly see your equipemnt perform considerably better than expected. In my experience, whenever something performs differently than expected, be it better or worse, then somebody made a mistake in their calculations or was working from a false assumption or somebody ordered a wrong part. Well engineered stuff works pretty much exactly as the calculations predicted. Its not military enginering or aviation where you have lots of safety margin everywhere because you can't fully predict the use case. Electro-mechanics is a well understood discipline and simulations and tests correlate with a surprising level of accuracy. This is one reason why they've stopped building prototype locomotives as they used to in the days of steam trains. Take it from somebody who's been in the trenches of the development lab and done it many times.
 
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But we do not know what internal design specs Siemens used. We only know the spec in RFP. It is entirely possible that Siemens had a drive pack off the shelf that met and exceeded the RFP specs and they chose to simply use it instead of designing a new one that exactly meets the spec.
 
jis said:
But we do not know what internal design specs Siemens used. We only know the spec in RFP. It is entirely possible that Siemens had a drive pack off the shelf that met and exceeded the RFP specs and they chose to simply use it instead of designing a new one that exactly meets the spec.
Click to expand...
Exactly, we have to also consider that the design is based off of an existing locomotive design from Europe. Siemens wasn't designing a completely new locomotive, they were re-purposing a design to fit in to the RFP specifications. Naturally you'll have some parts you can just take off the shelf. When selecting those parts you'll always want to chose the one the exceeds specifications rather than the other way around.
 
cirdan said:
Ryan said:
cirdan said:
jis said:
The single ACS64 has started test runs on the NEC. It is running south from Wilmington. It's acceleration performance with 8 Amfleets is turning out to be considerably superior to that of even Acelas. Reportedly from 0 to 125mph in 3/4 th mile!
Click to expand...
I am surprised why this is a surprise. Surely the specs were calculated precisely. How can a locmotive perform significantly better than anticipated? It would suggest that somebody messed up on their calculations, which is a bit worrying as they could equally mess up in the opposite direction.
Click to expand...
the specs are the minimum. It's possible to build something that exceeds the specs. Nobody messed up on anything.
Click to expand...
I've worked in engineering myself (although not directly with trains, although I did work in train testing for a while) and usually you take the specs and work backwards from that, so you look at the the load cycles and the drag and limiting factors and on the basis of that determine how powerful the various componnets need to be. You don't take a more powerful part just for fun because that's a cost factor and hence you don't suddenly see your equipemnt perform considerably better than expected. In my experience, whenever something performs differently than expected, be it better or worse, then somebody made a mistake in their calculations or was working from a false assumption or somebody ordered a wrong part. Well engineered stuff works pretty much exactly as the calculations predicted. Its not military enginering or aviation where you have lots of safety margin everywhere because you can't fully predict the use case. Electro-mechanics is a well understood discipline and simulations and tests correlate with a surprising level of accuracy. This is one reason why they've stopped building prototype locomotives as they used to in the days of steam trains. Take it from somebody who's been in the trenches of the development lab and done it many times.
Click to expand...
See my later post. You're confusing requirements with performance models.
 
Off topic slightly but if these are truly performing better than the specs that's a great think as long as they meet the specs relating to maintenance and safety. I would hate for these locos to be the HHP-8 part II. But if everything works out as planned and then some I think it gives Siemens a huge advantage in getting the contract for the Acela II whenever that is awarded given Amtrak's less than stellar relationship with Bombardier. Plus I personally would love to see Velaros running 200mph plus on the future NEC high speed right of way.....he a man can dream!
 
jis said:
But we do not know what internal design specs Siemens used. We only know the spec in RFP. It is entirely possible that Siemens had a drive pack off the shelf that met and exceeded the RFP specs and they chose to simply use it instead of designing a new one that exactly meets the spec.
Click to expand...
Okay, in that case we may have been talking at cross purposes, as my understanding was that Siemens was surprised at the performance. If they knowingly over-engineered the locomotive for whatever raeson, that is something different entirely.
 
Last edited by a moderator:
cirdan said:
jis said:
But we do not know what internal design specs Siemens used. We only know the spec in RFP. It is entirely possible that Siemens had a drive pack off the shelf that met and exceeded the RFP specs and they chose to simply use it instead of designing a new one that exactly meets the spec.
Click to expand...
Okay, in that case we may have been talking at cross purposes, as my understanding was that Siemens was surprised at the performance. If they knowingly over-engineered the locomotive for whatever raeson, that is something different entirely.
Click to expand...
Yep. I very much doubt that Siemens was surprised. Amtrak was pleasantly surprised. As an aside, it is also entirely possible that Siemens may indeed be consciously over performing in order to get into the pole position for the inevitable Acela II order too.
 
cirdan said:
jis said:
But we do not know what internal design specs Siemens used. We only know the spec in RFP. It is entirely possible that Siemens had a drive pack off the shelf that met and exceeded the RFP specs and they chose to simply use it instead of designing a new one that exactly meets the spec.
Click to expand...
Okay, in that case we may have been talking at cross purposes, as my understanding was that Siemens was surprised at the performance. If they knowingly over-engineered the locomotive for whatever raeson, that is something different entirely.
Click to expand...
Actually we do know a bit of that. The ACS is basically the Americanized version of their existing Eurosprinter & Vectron platforms.

peter
 
True. But the Vectron platform can be scaled for many different performance requirements os speed, power and tractive effort. We don't know for sure what exact configuration of the Vectron Platform was used by Siemens in fulfilling this RFP.
 
Is the 0 to 125 in 3/4 mile a firm number from Amtrak or scuttlebutt? If true, that would be just shy of 3mph/sec, an acceleration that even modern transit cars struggle to meet.
 
PRR 60 said:
Is the 0 to 125 in 3/4 mile a firm number from Amtrak or scuttlebutt? If true, that would be just shy of 3mph/sec, an acceleration that even modern transit cars struggle to meet.
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That was the scuttlebutt, but you know how scuttlebutts go. I am trying to get some more reliable verification, but have not been able to get in touch with the reliable contacts due to more pressing issues on both sides.
 

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