I was looking over the specs for MRC's new Brilliance sound decoders and balked when I came to this statement, "synchronized diesel engine sounds with eight notches"... That means the engine sound only changes every 16 steps!? Looks like a reluctance on the part of MRC to truly live up to their promise that these decoders are brilliant! Any thoughts?
OK - since I can't do that, can you tell me - do you hear a gradual change in engine noise, or does it jump higher with each notch and remain at that level until the engineer moves the throttle to the next notch? Remember, I'm asking this sincerely, I'm not trying to be a wiseguy...
| OK - since I can't do that, can you tell me - do you hear a gradual change | in engine noise, or does it jump higher with each notch and remain at that | level until the engineer moves the throttle to the next notch?
Distinct "jump." Remember the diesel is powering a generator that is doing the real work. The notch setting the engineer is using is related to the amps of current necessary to do the work. Amtrak's F40's would be at run 8 in the station because of the current needed by the passenger cars.
Are you sure that a F40 would be running at run 8 in the station? Since the locomotive needs to keep a "small amount" of pulling power to the train in order to keep the cars stretch during any braking. Air brakes act on the rear car first and then moves forward. The engineer will have to keep relieving the engine brakes to allow the stretching action to take place. Another thought regarding "8 notches" is that this is only referred to the road locomotives. Switchers have no notches, just free wheeling on the throttle. Of course this is all based on when I worked for the Santa Fe and Southern Pacific on the west coast over the "loop".
| > amps of current necessary to do the work. Amtrak's F40's would be at run 8 | > in the station because of the current needed by the passenger cars.
| Are you sure that a F40 would be running at run 8 in the station?
It had to do with the HEP - head end power - which fed off the prime mover. Locomotives that supplied the HEP had to turn fairly consistent RPM's. And, yes, they are very loud at the station. I've never heard one in an enclosed station, but in the outdoor stations you can't hear yourself think. Whereas freight trains are all but silent on the other track.
OK - if that is the case, I suppose a change in sound every 16 steps is according to prototype. Would that also be the case with steam engines? I ask because MRC has similar wording for their Brilliance Steam Decoder - "8 steam chuffs", I believe...
I watched a crew run a train and I assume they needed a speed that was somewhere between two notches because the engineer was toggling the locomotives between the two notches. Sounded interesting as the engines would rev up then slow down but the train maintained a constant (slow) speed.
I'd be interested to know if the 'notched' decoders have the lag often found on the real thing. Ie) Locomotives notch up but the train does not immediately speed up. Alternately, the engineer may back off a couple notces and the train keeps on going at the previous speed.
No it doesn't. once the train is stopped the throttle goes to the idle stop. Most likely it was already there before the train stopped. The engine brakes are kept bailed off such that the braking is all done by the cars, inertia keeps the weight of the engines pulling against the coupler of the first car
Nope, its' around the other way. The air valve that is relieving pressure on the train line is in the locomotive, not on the rear car, thus the initial pressure drop occurrs at the point of release, and propagates to the opposite end of the line, such that the brakes on the rear car are the last to release and the last to apply.
This is somewhat applicable to handling a freight train, but doesn't apply much to a passenger train, especially the short trains that are the norm these days. There is very little slack in a consist of six or seven passenger cars; so little, in fact, that it is not noticeable.
I have spent thousands of hours in switchers, from S-2s to SW1500s. I've operated Alcos, Baldwins, EMDs and Fairbanks-Morse, and I've never seen one with a notchless throttle. Maybe you saw dynamic brake controllers that were notchless, but not a throttle.
The best guess for the FP40 and its attendant high RPM at rest, is that the engine is kept running in notch 5 to provide Head End Power for the train. Speed control is by changes in excitation to the MG, while engine speed remains constant. At notch 7 the engine speed either goes to max, or is linked to the throttle setting. While I have never operated an FP40, I have operated locomotives that were configured to work in that way.
Not at all, no problem. I realise that if one can't get close to the real thing often, one's notion of what's realistic tends to get hazy.
It jumps: At every notch/run change, the engines rev up and noise level increases. Takes a second or two. vrum-vrum-vrum ---> vruuuum ---> VRUUUM ---> VurAH-AH-AHM! (That's EMD 567s as near as I can phoneticise them.) There's also generator whine and turbocharge howl that increase at every notch. Who says diseasles are boring????
Plan your next vacation to take you near a busy main-line yard. It will be worth it. If there's a shopping mall nearby, you can let the rest of the goof off in air-conditioned comfort while enjoy your addiction in peace. :-)
Back in the late 50s days, before sound-abatement efforts, a triplet of F7s accelerating the CN's Super Continental westbound from the old Edmonton station nearly deafened me. I was standing under the 105th St overpass (now long gone) one track over from him, and the engineer notched them up just as the engines approached me. Wow! Couldn't hear myself yell! There's an old record around of a similar notching up of a trio of FTs, IIRC: played at _realistic_ levels it will shake your house, assuming you've got the amp and speaker power to do it right.
The Huron Central (operating subsidiary of Genesee Wyoming, formed to lease the CPR line between Sault Ste Marie and Sudbury) runs about 150 yards from our house, down the street and across the highway. Usually has three units, and they rumble real nice as they go by. He usually notches up eastbound about the time he gets level with our street. There's a slight grade, and he's dragging 50 or so loads, mostly steel and pulpwood. Nice.
steam chuffs", I believe..< Not sure what they would mean by this for a steam engine. Steam would not have any steps but a steady increase related to speed. Probably ad writers who have no idea what they are talking about.
Then, the sound does change incrementally as "the engines rev up and the noise level increases. Takes a second or two". I don't see how that could cause an absolute "jump" from one notch to the next, as if the sound became completely different at each new setting???
Well, my attempt at writing down how it sounds represents four runs, not the transition from one run to the next. The --> is the transition, and it really does take only a second or so for the engine to rev up from one run to the next. If I could've figured a way of doing it, I would've written eight versions of vrum instead of four. :-) BTW, I've heard an engine rev through four notches while standing in the yard, took about 2 seconds.
From my trackside observations, when an engine is running in run 6, say, it will sound pretty much the the same regardless of how fast the train is actually moving. That is, a drag freight in run 6 may be moving at 25mph, while a fast freight may be moving at 40. Run 6 produces a certain amount of power, and that translates into different speeds with different loads behind the drawbar. In fact, when the train starts, first the engine revs up, and then the train begins to move. But I don't know how tricky it would be to get that effect with a decoder.
Without actually hearing the sound in your decoder, I can't say how realistic it is. But if it's based on actual sound recordings, I'd trust the mfr, for the actual sounds at different run/notches, anyhow.
In any case, there should be eight steps, and it looks like the shift from one level to another will just happen faster electronically than mechanically.
That's just it - this is MRC we're talking about, and I really don't trust them...
Well, I still have my doubts, especially when it comes to steam, which has no notches, and yet the Brilliance steam decoders are said to have "8 steam chuffs", which, IMHO, is like saying it also has 8 notches, and that only makes sense if you consider that MRC has always been behind the curve when it came to supporting DCC's "speed steps".