It's pretty neat when they're at almost the same RPM, you get that pulsating hum which is due to a "beat frequency" as the frequencies are nearly the same.

@@BenjaminEsposti yeah i love that pulsating sound but it will only live in my memories now days bcs i cant find any register of a SD40 doing this in particular

I absolutely love the sound

Is mine too. Miss the flared radiators.

The EMD 645E3's & 710G3A's or 710G3B's are the best sounding two stroke prime motors. It's just that the GP40-2's & SD40-2's have proved and retained for soo many years now how reliable and versatile these units are. I can't say the same for alot of modern EMD units,espiecally in terms of tractive effort and dynamic braking. I will personally add that I miss the MP15DC's/AC's and the 645E's which will always be my favorite road switchers.

Sebastian Roll you know she loves you when she goes full throttle

Planetesimal Planetoid A machine can love you back. just like a car, it does its job well if taken care of.

Well, I wouldn't say that though. A well-maintained machine will run like a clockwork, and that's how it shows you it's love.

a machine DOES love you back lol

@@S7VolTagE *you know she loves you when she honks while going past you or the driver is telling you to duck off, whichever is true xD

Yeah I can imagine, Love listening to it with headphones, Will probably never get the chance to hear or see one for real. Live in Ireland, Real diesel locomotive are almost gone, Used to see them as a school kid , always stopped to listen.

andyvdb6, There are still thousands like this one in operation here in the USA. There were about 3000 SD40-2's ever produced, but there are also other's like the SD70 types that have a very similar sound - in fact, they're even more powerful and have a larger cylinder displacement.

It is amazing. I live where this video was taken

@@andyvdb6 I live not too far from the east coast US Mainline so I see these things from time to time but I do have to drive about 20 minutes to see them

@@legostar55 kzfaq.info/get/bejne/fq9mobhyq7yVY4k.html This is about all we have left in Ireland These two are 40 years old and still looking good. made by EMD I believe

About every diesel locomotive i've heard sounds the same. Idle, low RPM: Roots blower (two stroke Diesel engines need constant boost to keep cycling). High RPM: Roots blower disengages, large turbocharger (often not coming w/ wastegate, there's no need to in such large turbos, so they start building up boost only at fairly high RPM) starts spinning. If four stroke, there's still a battery of turbos of increasing size (sequential turbocharging), so, again, loud whine at all RPM ranges.

+TeraVolt Two stroke EMD units sound nothing like a 4 stroke diesel. EMD's came one of three ways: Naturally Aspirated Supercharged Turbocharged Turbo EMD units utilize a clutch to spin the turbo impeller at lower RPM. At higher RPM, the clutch disengages, and the impeller free-wheels. GE and Alco units do not utilize a turbo clutch, so there is a little bit of turbo-lag in older units, which is why they smoked under certain conditions.

I agree Raja!

@Scott E But nowadays the 70ACe T4s utilize the 1010J engine, which is four stroke! 😁

Saw some OnionPacific locomotives today while waiting at a rail crossing (long, long consist, moving just above a fast walk) and those thundering things did not sound like this at all. They had a most definite thunderous noise, as well as a little *soot* for a moment upon acceleration.

Strange enough, I happen to be a professional guitarist, but I'm truly fascinated with the EMD sound. They never cease to amaze me. I wish I could hear more of that EMD sound, as apposed to what's out there now. I live not too far from railroad tracks. Keep those classic videos coming, chief!

You're right! I don't like those 'all horn and no engine sound' type of videos.

It sort of is! A turbine is injecting air into the diesel engine, producing the jet noise.

railjames I think you will find that the clicking sound was the water dumps on the air reservoirs.

Thank you gravelydon, I think you are correct.

gravelydon Could that be for climate reasons? More moist for example. Here in Europe (the Netherlands) i have never heard this. Even not on American made locomotives like the class 66 which is actualy a SD70 or SD80 as far as i know. Only shorter (20 metres) and 12 cilinders (EMD 12-710G3B) instead of 20 (EMD 20-710G3B), but with the same EMD 710 series 2 stroke diesel engine. I notiched on vids that all American loco's do this clicking but no one here in Europe. I wonder about this difference.

jpsholland I have had both railroaders and railfans tell me it is too keep moisture out of the air brake lines. I do think you are right as to climate reasons, as it seems to be on railroads that operate in cold climates.

jpsholland An example is that CSXT runs from the warm humid areas of Florida up to wintery Canada. In winter time, water will freeze in the brake pipes. That can result in a dangerous situation. Even just in Florida we can have upper 80°s in the south to below freezing in the northern parts of the state at the same time. When an air compressor compresses the air it raises its temperature but the moisture level goes up as moisture does not compress. When the compressed air cools, the moisture condenses out of the air. The air tanks then fill up slowly with water. You can have high humidity even in colder temps. At the bottom of the reservoirs are drains. They can be operated a number of ways. Old way was a manual valve. Not the best but the cheapest way but relies on the crews to drain them regularly. Another way is to use bucket valves. When the water gets above a certain point and air pressure drops thru use below a certain point, the valve opens and dumps the water in the line or tank. Then closes till the next cycle. Yet another way is that when an air compressor kicks out at the pressure setting, the air operates an air operated dump valve. Closes after a preset drop. And in more modern systems, the dump valves are electrically operated along with the compressor clutches. How effective are the automatic systems, better than nothing but if there is a large enough air draw, you still can get water in the brake pipes. Like when a string of cars are pumped off after setting at a remote location. And when pressures in the cars drop for an application, the moisture will also condense out. 100 scfm of air at 80°F & 75% humidity compressed to 100 PSI and cooled back to 80° will dump over 5 gallons of water in an 8 hour day.

Martincho Chevy Thanks. Glad you enjoyed!

Very true, As a kid I loved having to wait at a railroad crossing waiting for the diesel locomotive to pass, adoring the engine sound, Unfortunately where I live they are not often seen these days. kzfaq.info/get/bejne/fq9mobhyq7yVY4k.html

Lisa, great EMD sound. Glad you enjoyed.

In Chicago, Metra uses EMD F40PH with HEP. It’s nice to listen to the engine spooling up when they enable HEP, but then you will hear the loud engine noise the rest of the ride as it runs constantly at notch 8.

I heard notch 8 is the fastest notch in the emds and the GE's

GTA V gamer He was referring to the amount of throttle that these particular units were hopped up to in this video, not their max which is indeed 8. I heard it hit notch 6 around the :30 mark, and I think this is as high as it went in this video. Aside: The turbos on these units just absolutely sing a killer song.