edbenton He already got it done. He called me tonight the results are in. TURNS OUT IT WAS A COMBINATION OF FACTORS. One was the water tanks like I suspected. Second was the truck design being a hollow Bolster it did not have the mass needed to stop hunting once it started. Last was the trackwork. What would happen according to his simulations 95% of the time is first the engines would hit a low spot and rock side to side getting the water sloshing in the tanks then once that was going the trucks would start to hunt keeping the first thing going and getting worse then throw in a curve and bang rear trucks on the ground. Was worse for them if coupled back to back like I suspected. The other 5% happened do to bad trackwork only given the RR's Finances at the time I could see that happening.
He already got it done. He called me tonight the results are in. TURNS OUT IT WAS A COMBINATION OF FACTORS. One was the water tanks like I suspected. Second was the truck design being a hollow Bolster it did not have the mass needed to stop hunting once it started. Last was the trackwork. What would happen according to his simulations 95% of the time is first the engines would hit a low spot and rock side to side getting the water sloshing in the tanks then once that was going the trucks would start to hunt keeping the first thing going and getting worse then throw in a curve and bang rear trucks on the ground. Was worse for them if coupled back to back like I suspected. The other 5% happened do to bad trackwork only given the RR's Finances at the time I could see that happening.
What was the peak L/V ratio?
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
Like the vertical and underbelly tanks on the SDP40F's, locomotive tenders had baffle plates in them to reduce the effects of water and fuel oil sloshing. This in turn reduced the aforementioned forces working upon the tenders.
The 40F's underbelly tanks had baffles in them from the facotry. It is unclear if the baffles installed in the vertical tanks came from the factory as well, or if the tanks were retrofitted.
His data showed that water levels between 75% down to 33% were the most dangerous on them. Fuller than that no real issuse lower and again not enough mass to cause a Problem. His data showed speeds were normal track speeds for the class of tracks and curves they would have been running on. AKA 79 MPH and 90 with ATS with approrite reductions for curves. Now with the tanks Everything I have pulled states they were never baffled WHY I never will know unless they were fearing low water levels shutting downt he heat in the winter. He ran the sims with both baffles and unbaffled and no change. Most derailments took place on his sims between 60-79 mph with the trucks hunting and almost a harmonic ocsilation of the bodies with the water tanks surging back and forth.
The belly tanks had baffles; the uppers were retro'd. What does the sim show on CWR on various railhead configurations (ground and unground) on curves better than 2 degree with a 200 to 400 foot runoff and 6 inch superelevation?
edbenton His data showed that water levels between 75% down to 33% were the most dangerous on them. Fuller than that no real issuse lower and again not enough mass to cause a Problem. His data showed speeds were normal track speeds for the class of tracks and curves they would have been running on. AKA 79 MPH and 90 with ATS with approrite reductions for curves. Now with the tanks Everything I have pulled states they were never baffled WHY I never will know unless they were fearing low water levels shutting downt he heat in the winter. He ran the sims with both baffles and unbaffled and no change. Most derailments took place on his sims between 60-79 mph with the trucks hunting and almost a harmonic ocsilation of the bodies with the water tanks surging back and forth.
So, how about some peak L/V values from the simulation?
Good Question. The L/V ratios ought to show something.......
And while we're at it, how can cousin get an accurate rendition of what is going on if he doesn't know the curve radii, superelevation and other such specific factors? And if he does, where is he getting such info? Generalized numbers on jointed rail as edbenton mentioned earlier would be valid only on the Santa Fe's ATS territory in New Mexico-Colorado-Kansas, where no derailments occurred. Most accidents occurred on CWR, didn't they? Except one where the track was proven to be out of gauge at an interlocking. There hasn't been mention of drawbar hp, braking effort, consists, railhead contour, track gauge, cross level and a host of other factors.........
I'm impressed. This busy computer programmer was able to write a complex program to simulate all the factors involved in less than 4 days while working his regular job? All the dimensions, factors, loads etc? That is impressive. Maybe he can come on and defend the numbers and explain the program so we can get a better grip on what it is intended to do and how it does it?
Give us the specific data, if possible. That would help us out.
I did ask him what he based the train weights on he told me historical consists which means 12-16 cars Approx weights of around 900-1200 tons weight. HE did figure in the Superelevation based on a commercial based program for engineers he did not say anything on the rail grinding or railhead contour. What he was going for was what I asked him were the main causes was it Track the Trucks or the Water tanks or some other factor and what were the fators in the design that COULD HAVE led to the derailments not a definative answer. People I asked my cousin that has no railfan interest at all in fact. He could have told me to SHOVE it he did this because he wanted to not because he had to now you are calling his data into QUESTION. WHAT DO YOU WANT HIS FIRST BORN CHILD TO MAKE YOU HAPPY.
No, but some understanding that a complex program such as that is extremely difficult to write in so little time, especially without a full understanding of the forces and variables which existed at that time.
Without allowing for draft and buff forces, such things as L/V ratios as mentioned earlier, and other complex mathematical computations, writing an accurate and reliable program such as described would be virtually impossible in the time frame allowed, unless a game platform were used as its base.
I would just like to know how he did it and what factors were used. I am sure others would be interested as well, since throwing out numbers as an explanation is nice, but without the basis for those numbers, the explanations tend to mean little or nothing. The explanation of the facotors that were and were not considerd would be helpful, and knowing whether another programs basis was used to make an add on program out of it would also be nice to know.
Computers weren't available in quantity and in the power needed to do the calculations back when the issues were occurring, so it would be beneficial for those of us on the board with computer programming experience, or with access to programmers to get the infor from your man, so we can compare notes......sort of like going to a doctor for a second opinion of a diagnosis. Nothing to get irritated about. We definitely appreciate his effort.
edbenton I did ask him what he based the train weights on he told me historical consists which means 12-16 cars Approx weights of around 900-1200 tons weight. HE did figure in the Superelevation based on a commercial based program for engineers he did not say anything on the rail grinding or railhead contour. What he was going for was what I asked him were the main causes was it Track the Trucks or the Water tanks or some other factor and what were the fators in the design that COULD HAVE led to the derailments not a definative answer. People I asked my cousin that has no railfan interest at all in fact. He could have told me to SHOVE it he did this because he wanted to not because he had to now you are calling his data into QUESTION. WHAT DO YOU WANT HIS FIRST BORN CHILD TO MAKE YOU HAPPY.
It's hard to call into question what hasn't been seen.
There is a market for the kind of simulation you describe. Your cousin should market it and publish and present at the ASME/IEEE/ASCE joint rail conference. (here is link to the conf for 2008 which was held the past April. http://www.asmeconferences.org/jrc08/ They haven't had the call for papers for 2009 yet.) His code is copyright protected - he could make a few bucks.
The numbers that are needed to predict the likelyhood of a derailment are the L/V ratio. That is the ratio of lateral force to vertical force of the wheels on the rail. Those are the numbers that need to be the output of the simulation. After having modeled all that other stuff, getting this as output would be trivial for him.
That's all I'm asking for. And, no, I don't want anbody's first born. I have two teens at home.
I will give him a call and see what he has for those measurements tonight and should have and answer for you.
One thing that strikes me about this theory is that if it is true there was no need to retire the SDP40F fleet. After all, the replacement F40PH units were all HEP (IINM) although I believe some older steam heated equipment was still operated using "steam tenders" mostly rebuilt from retired E units. So is it logical that converting the SDP40F fleet to HEP would have been a better response?
Was the seemingly hasty decision to dispose of these almost new locomotives a case of Bureaucratic overreaction (to appease congress)?
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
Probaly less overreaction and more a need to "play nice in the sandbox" and when your hosts tell you that your equipment is bad (remember, in their mind it couldn't possibly be their track) and threaten to restrict your operation or ban it altogether, the only option is to retire the fleet.
Conversion to HEP would have been a good choice, but at the time, blame was placed on the locomotives trucks, so no conversion would have appeased the complainers.
edbenton I will give him a call and see what he has for those measurements tonight and should have and answer for you.
I'm beginning to think this is a "trick" rather than a "treat".
carnej1 One thing that strikes me about this theory is that if it is true there was no need to retire the SDP40F fleet. After all, the replacement F40PH units were all HEP (IINM) although I believe some older steam heated equipment was still operated using "steam tenders" mostly rebuilt from retired E units. So is it logical that converting the SDP40F fleet to HEP would have been a better response? Was the seemingly hasty decision to dispose of these almost new locomotives a case of Bureaucratic overreaction (to appease congress)?
I don't think it was an overreaction. They had been limping along with speed restrictions on the SDP40Fs and had spent a small fortune testing to figure out what was wrong. If the testing had found something concrete, it likely that the locomotives could have been modified to improve the situation and make the long term use of the locomotives tenable.
There were just too many expensive derailments for the host RRs to ignore. The only clear path forward was to get rid of them.
A case of overreation was Conrail's 40 mph restriction on it's ex-EL SD45-2s and it's refusal to take HTC trucks on it's SD40-2s despite their success on other roads.
He has been busy recently he called me LAST NIGHT called his mother is SICK give him a break. The L/V Ratio when the trucks were hunting and the water tanks were sloshing was .82 so they were SCREWED according to him.
As a footnote I have read anything and everything on the SDP40F derailments and hopefully this will put alot of things to bed on them.
oltmannd edbenton I will give him a call and see what he has for those measurements tonight and should have and answer for you. I'm beginning to think this is a "trick" rather than a "treat".
Me too.
edbenton He has been busy recently he called me LAST NIGHT called his mother is SICK give him a break. The L/V Ratio when the trucks were hunting and the water tanks were sloshing was .82 so they were SCREWED according to him. As a footnote I have read anything and everything on the SDP40F derailments and hopefully this will put alot of things to bed on them.
.82 is not good, but not quite "screwed".
Sorry I didn't ask before, but also need to have the baseline "no water in tank" peak L/V ratio.
Is he interested in publishing?
edbenton As a footnote I have read anything and everything on the SDP40F derailments and hopefully this will put alot of things to bed on them.
What's the matter....don't want to play any more?
I take it the F40's solved 2 problems at once:1) No water tanks, due to the HEP2) Different trucks, no hollow bolster
3)Perhaps for passenger use, the GP40 was a better loco.
They certainly were durable.
Gave him a call last night caught him at home he had the program there he figured that you would want more. He asked what I needed and I told him. Baseline was with no water in ANY tanks L/v was .1 or less even with hunting at 90 mph so the water was the key.
edbenton Gave him a call last night caught him at home he had the program there he figured that you would want more. He asked what I needed and I told him. Baseline was with no water in ANY tanks L/v was .1 or less even with hunting at 90 mph so the water was the key.
That's not reasonable. Especially with truck hunting. There's something seriously amiss with the simulation.
Look I do not have the Simulation that he did in front of me getting him on the phone is hard. 3 he is very reliable in whathe does and I tend to take his results pretty well he was going off of his simulation which he programmed. He also stated if they are not happy with my results tell them to GET OFF THEIR DUFFS AND DO ALL THSI WORK NEXT TIUME THEMSELVES. I just found out that his mother has *** cancer is it is spread already and more than likely uncurable. My cousin went out of his way to help us try and figure out the reasons behind the one of the biggest failures in locomotive designs and you are still not happy. He told me flat out I am not running any more tests if they do not like this data Ed then they can shove it.
I'm not asking for any more work. It's just that we are back to square one with this. A simulations of the type you describe are very difficult to construct and get a reasonable match to observed data as it appears to be the case here. I don't think it's worth the effort to try to resimulate. After all, the locomotives are long gone. The sloshing theory is interesting to speculate about, but that's were it begins and ends, I'm afraid.
Sorry to hear about his mother.
Atill in all the simulaations the only differant variable was the water that was consistantly causing the units to derail. You can not put over 5 tons of water above the center of gravity p[er unit and then as it gets rocking not have an issue with it causing issues. Carrying 5 tons of weight 12 feet abover the rail head per the designs was STUPID baffled or unbaffled but remember the people that designed these engines were the ones that gave us the US TAX CODE need I say more. Instead of having EMD drop the 16 cylinder 645 into the FP45 design they came up with this design. Had they done that I think there may not have been any derailments at all. Either that or use the SD40-2 cowlit and put a steam gen in it also. There was a SDP40 they could have done it the right way if they wanted to. The Goverment chose NOT TO like about everything else.
Look, the best design engineers from private industry, the affected railroads and EMD all worked to solve this issue and what is done is done. I agree. Further work is fruitless.
I for one do not believe that a game programmer can outdo these professionals with any kind of simulation or results. I agree with Oltmannd that we are back to square one and nothing has been conclusively solved.
So for the issue, and for your cousin, probably, it has been a complete waste of time and energy.
Answers, whatever they may be, won't change anything. It is all water under the bridge.
Have your cousin submit his simulation as previously advised. We will look for it on the various web pages of the institutions mentioned. Thank him for us and good luck to him......
Railroads all over the world experience challenges with new locomotives. It is only a problem when a few original models are "all you're gonna get" instead of "prototypes."
It was interesting to read TRAINS NEWS WIRE Friday about transportation plans of the Presidential candidates. TRAINS does well at not getting political in their news items (Don Phillips does enough...), but obviously for Amtrak the choice is life or death.
Oh, well, maybe candidate Red would buy us new locomotives... and design them from the ground up... how about square wheels?
"Make no little plans; they have no magic to stir men's blood." Daniel Burnham
edbentonHe told me flat out I am not running any more tests if they do not like this data Ed then they can shove it.
Will do.
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