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Post by sd40dash2 on Nov 13, 2019 3:34:42 GMT -8
Youtube recommended this review of the latest Athearn SD39-2. I had never seen a video by "FishplateFilms" before and thought this was well done. Looks like the person behind the channel is from Australia and has numerous other modelling and railfan videos as well. Perhaps this will be of interest to someone here:
"The last time I bought an Athearn loco was over 30 years ago, and while I love their freight cars , I have been hesitant to get a new locomotive from them after reading about early Genesis motor problems , and still remembering the high current draw "Blue box" motors! But I have been impressed with photos of the new "RTR" line of SD39 & 40 _2 engines , and , it is easy to replace the motor with a Kato HM5 motor to improve the performance , so I took the plunge and gave one a go! Being fitted with Soundtraxx Econami sound was a bonus as the new Tsunami 2 decoders are a step up from the series 1 and now have motor control equal to ESU. Out of the box , the model ran as good as any Kato or Atlas I have , and I don't think I will be replacing the motor any time soon...so much so , I have 3 of these units now and they all run super smooth and sound great! These units have a few surprises, so take a look and see what is under the hood.
Gregg :-)"
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Post by sd80mac on Nov 13, 2019 6:33:42 GMT -8
Curiously enough, EMD never built an SD39-2, at least for North American use.
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Post by edwardsutorik on Nov 13, 2019 7:31:36 GMT -8
But BNSF did. BNSF 1883 is an SD39-2, according to the railroad.
Ed
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Post by cemr5396 on Nov 13, 2019 8:13:18 GMT -8
I was wondering why what appeared to be an SD40-2 to my eyes was being referred to as 'SD39-2'. So what's the deal with those? Are they de-rated or something?
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Post by csxt8400 on Nov 13, 2019 8:17:26 GMT -8
Yeah, they were derated at least on the blue card..
2999 HP lol.
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Post by edwardsutorik on Nov 13, 2019 8:25:29 GMT -8
I was wondering why what appeared to be an SD40-2 to my eyes was being referred to as 'SD39-2'. So what's the deal with those? Are they de-rated or something? The book I'm looking at, the 2011 BNSF revue, says they kept their horsepower. That they were "re-named" to show that they were in "yard and terminal service" in 2008. FWIW. It says they were brought back to SD40-2's in 2010. Anyway, this is hardly the latest news on them, I guess. Maybe they've got a new name. The Diesel Shop roster, which claims to be current, is calling them 40-2's. Ed |
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Post by fr8kar on Nov 13, 2019 8:28:20 GMT -8
I've had this locomotive in my consist for at least the past two weeks. I love those old Santa Fe SD40-2s in yard service. It's hard to find their limit.
As far as the model is concerned I'm not a big fan of that sound decoder. Something was weird about the way it notched up. It almost sounded like the idle sound was pitch-shifted higher.
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Post by fr8kar on Nov 13, 2019 20:55:53 GMT -8
For the record, BNSF 1883 has "SD39-2" stenciled on the sill and "SD40-2" on the FRA blue card. I have seen several locomotives derated for yard service (sometimes just by 1 HP), but this locomotive is rated for 3000 HP, also per the blue card.
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Post by sd40dash2 on Nov 14, 2019 4:29:55 GMT -8
Interesting prototype comments here. Why go to the trouble of derating an SD40-2 to use it in yard service? Why not just use it as desired?
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Post by kpack on Nov 14, 2019 13:41:10 GMT -8
BNSF did the same thing with some of the GP50's. They derated them to 2500 HP and labeled them as GP-25's.
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Post by Donnell Wells on Nov 14, 2019 15:17:34 GMT -8
I'm intrigued to know more about the improvements to the BB motor in the video.
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Post by 690 on Nov 14, 2019 18:05:17 GMT -8
Interesting prototype comments here. Why go to the trouble of derating an SD40-2 to use it in yard service? Why not just use it as desired? My guess would be to help prevent wear on the engine and other parts when you’re not getting the full 3000 HP out of them. CSX has put pins in the clutches of turbos on GP40-2s to prevent the turbocharger from engaging, which effectively limits them to 2000ish HP, but if they want to “uprate” it back to 3000 HP all they need to do is pull the pin out. Same thing with their B40s that they downrated to 2000 HP (B20-8s), albeit on those it was a software restriction. I don’t know what practical difference there would be with rating a SD40-2 at 2999 HP vs 3000, but obviously they have some reason for it. |
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Post by cemr5396 on Nov 14, 2019 18:48:50 GMT -8
I don’t know what practical difference there would be with rating a SD40-2 at 2999 HP vs 3000, but obviously they have some reason for it. Practically, 1HP is nothing. I know a guy who used to work in a RR diesel shop, and he told me once if you took a bunch of SD40-2s and compared the number of horsepower that they are actually producing (not the 'spec' number), you would probably find a couple things; First, they probably aren't cranking out 3000HP any more, and second, the variation between units could be significant. Whether that means 10, 25, 50 or 100 HP I don't know. I would bet that the '2999HP' SD40-2s aren't de-rated at all, but rating them as having 1 less HP has some sort of benefit to the RR. Whether it means they don't have to inspect the unit as often as a 'road' unit, or somthing else, there's gotta be a reason and it's probably paperwork or maintenance related. |
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Post by 690 on Nov 15, 2019 2:20:08 GMT -8
I don’t know what practical difference there would be with rating a SD40-2 at 2999 HP vs 3000, but obviously they have some reason for it. Practically, 1HP is nothing. I know a guy who used to work in a RR diesel shop, and he told me once if you took a bunch of SD40-2s and compared the number of horsepower that they are actually producing (not the 'spec' number), you would probably find a couple things; First, they probably aren't cranking out 3000HP any more, and second, the variation between units could be significant. Whether that means 10, 25, 50 or 100 HP I don't know. I would bet that the '2999HP' SD40-2s aren't de-rated at all, but rating them as having 1 less HP has some sort of benefit to the RR. Whether it means they don't have to inspect the unit as often as a 'road' unit, or somthing else, there's gotta be a reason and it's probably paperwork or maintenance related. Yes, I’m aware of that. We used to have a SD40-2 that put out well over 3000 HP (and eventually it blew the crankshaft because of it, but that’s neither here nor there). The spec number, especially on older engines, is just a ballpark of what the engine would produce for horsepower (usually it was slightly higher in reality), and just changing fuel rack settings is enough to make a difference. What I meant for difference is much of what you said, where saying the engine was rated at 2999 vs 3000 is just a paper change to allow them to get away with something that they couldn’t otherwise if it was still listed at 3000. |
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MrMRL
New Member
Just workin' on the RR, moving your Amazon, UPS, FedEx, USPS packages.
Posts: 23
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Post by MrMRL on Nov 15, 2019 5:04:33 GMT -8
(For example...)
In the State of California, the BNSF Railway “de-rates” the listed HP of select diesel locomotives in order to slide under the radar of EPA air quality requirements and local emissions standards for older Tier-0 and Tier-0+ units (locomotives built between 1973 and 2001). So, locomotives with a horsepower rated “<3000hp” can be considered exempt of many of the state and federal regulations. This typically applies to SD40-2s, GP50s, GP60/Ms, etc used in Yard or Local service around the state. In short, they’re kinda-sorta just gaming or BSing the system. Plain and simple. I work on and around many of these units 5 days a week...
But back to topic, thanks for the review video link. Because of the video, I just ordered one of the Athearn BNSF1883 models from M.B. Klein.
~ Mr. MRL
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Post by canrailfan on Nov 15, 2019 5:10:43 GMT -8
De-rating units from 3000 to 2999 HP could also mean that computer programs used by many railroads to assign motive power would no longer assign these units to mainline service. The simple drop of 1 HP could keep these units in a pool for local or yard service only.
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Post by cp6027 on Nov 15, 2019 8:39:22 GMT -8
Interesting prototype comments here. Why go to the trouble of derating an SD40-2 to use it in yard service? Why not just use it as desired? My guess would be to help prevent wear on the engine and other parts when you’re not getting the full 3000 HP out of them. CSX has put pins in the clutches of turbos on GP40-2s to prevent the turbocharger from engaging, which effectively limits them to 2000ish HP, but if they want to “uprate” it back to 3000 HP all they need to do is pull the pin out. Same thing with their B40s that they downrated to 2000 HP (B20-8s), albeit on those it was a software restriction. I don’t know what practical difference there would be with rating a SD40-2 at 2999 HP vs 3000, but obviously they have some reason for it. Exactly. Typically, locomotives can only use their full horsepower to create tractive effort (force to pull the train) at speeds above 12-15 mph. At lower speeds, the tractive effort performance of the locomotive is typically limited by the weight of the locomotive on powered axles and the coefficient of adhesion between wheel and rail. An SD40-2 in yard duty that spends most of its time operating in the 10-15 mph range may never need to produce more than 2,000 hp. So better to derate it to operate more efficiently in that lower horsepower range than to have the full 3,000 hp capability and constantly operate it inefficiently in the lower end of its power range. |
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Post by railfans on Nov 16, 2019 7:45:09 GMT -8
I'm intrigued to know more about the improvements to the BB motor in the video. I recently purchased one of their newish SD38’s. To be honest I don’t think they’ve changed anything with the motor on these. I think the improved performance has everything to do with the motor control on the decoder being able to better compensate for the motor. Of course the only way to really test that theory is to get a DCC ready model and see how that runs. But like Greg in the video, I was amazed how well this new RTR model runs when I got it. Jamie |
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Post by edwardsutorik on Nov 16, 2019 9:25:44 GMT -8
I'm working on my new Athearn SD39 (BNSF 6208).
I changed CV 128 from 215 to 60 (sound level) (WAY too loud)
I changed CV 3 and 4 from 0 to 80 (momentum) (runs nicer with momentum--more authentic, too)
That's all, so far. It starts a little fast in speed step 1. And it looks like the top speed is faster than "usual". So, when I get to it, I might bring the speed curve down-or sumpin'.
I see no need to change the motor. Runs fine, as is.
Decoder: Econami (I think)
Throttle: NCE
The loco's a bit light (13 3/8 oz). I added 2 oz of lead in the fuel tank. Might add a bit in the body, partly for weight, partly because the loco has a bit of that "speaker inside a plastic box" sound. So, if I see what looks to be a way to dampen that, I'll give it a try. Turning the sound down helped a LOT.
Ed
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Post by stevewoodward on Nov 18, 2019 15:19:59 GMT -8
I'm working on my new Athearn SD39 (BNSF 6208). I changed CV 128 from 215 to 60 (sound level) (WAY too loud) I changed CV 3 and 4 from 0 to 80 (momentum) (runs nicer with momentum--more authentic, too) That's all, so far. It starts a little fast in speed step 1. And it looks like the top speed is faster than "usual". So, when I get to it, I might bring the speed curve down-or sumpin'. I see no need to change the motor. Runs fine, as is. Decoder: Econami (I think) Throttle: NCE The loco's a bit light (13 3/8 oz). I added 2 oz of lead in the fuel tank. Might add a bit in the body, partly for weight, partly because the loco has a bit of that "speaker inside a plastic box" sound. So, if I see what looks to be a way to dampen that, I'll give it a try. Turning the sound down helped a LOT. Ed Hi Ed, Thanks for the report. Can you let me know how the slow speed performance is? I'd like to get one but my other recent RTR purchase, an SD38, had some pretty severe cogging issues at slow speed. |
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Post by edwardsutorik on Nov 18, 2019 15:40:28 GMT -8
Steve,
As is, the loco has no cogging at all. It runs totally smoothly. On speed step 1, it goes 1.4 MPH.
I mentioned that I think it starts a little fast. And the top speed is fast, too. So I thought I'd just lower CV 2,5,6. Nope. Not on this decoder. So I'm gonna have to muck around with speed curves, or somethin'. Definitely doable, I think. But it's been a couple of years since I worked in that area.
What I'm getting to is that, while your request fits nicely with what I want to do, it might be awhile. That said, the loco gives every indication that it will stay a good runner.
I do wonder why you're having problems. Maybe your decoder is "older" than mine. MIght be a drive problem, too. If you're in the mood, you could disconnect the decoder, and run straight DC. Cogging = fix the drive. No cogging = replace the decoder. Or re-program, if you "messed" with it.
Ed
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Post by stevewoodward on Nov 23, 2019 5:42:17 GMT -8
Steve, As is, the loco has no cogging at all. It runs totally smoothly. On speed step 1, it goes 1.4 MPH. I mentioned that I think it starts a little fast. And the top speed is fast, too. So I thought I'd just lower CV 2,5,6. Nope. Not on this decoder. So I'm gonna have to muck around with speed curves, or somethin'. Definitely doable, I think. But it's been a couple of years since I worked in that area. What I'm getting to is that, while your request fits nicely with what I want to do, it might be awhile. That said, the loco gives every indication that it will stay a good runner. I do wonder why you're having problems. Maybe your decoder is "older" than mine. MIght be a drive problem, too. If you're in the mood, you could disconnect the decoder, and run straight DC. Cogging = fix the drive. No cogging = replace the decoder. Or re-program, if you "messed" with it. Ed Thanks Ed. Yes, I will likely try it on DC and take it from there. On speed step 1 it practically stops between cogs. Steve |
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