GE Tier 4 GEVO vs GE Dash 9-44CW

[kenben]

So these to engines look really simular. What is the difference between them?

 

THX

[peahrens]

kenben

So these to engines look really simular. What is the difference between them?

 

THX

 

I would have to digest these Wiki items as I don't know off the top of my head:

https://en.wikipedia.org/wiki/List_of_GE_locomotives

https://en.wikipedia.org/wiki/GE_Dash_9_Series

https://en.wikipedia.org/wiki/GE_Dash_9-44CW

https://en.wikipedia.org/wiki/GE_Evolution_Series

I have the Kato 9-44CWs and they are among my favorite locos.

 

[Wolf359]

The GE Dash 9-44CW has a moderately sized radiator, and the roofline dips between it and the dynamic brakes. The exhaust stack is also quite distinctive. https://commons.wikimedia.org/wiki/Category:GE_C44-9W_locomotives_of_the_Union_Pacific_Railroad#/media/File:UP_9728_GE_C44-9W.jpg   The GE ET44AC Tier 4 GEVO has a very large radiator, much bigger than on the Dash 9-44. It also has a bit of a hump around the exhaust stack. https://commons.wikimedia.org/wiki/Category:GE_Evolution_Series_locomotives#/media/File:BNSF_1991.jpg

[Metro Red Line]

The Tier 4 GEVO (ET44) is essentially the 21st Century version of the 1990s-era Dash-9. It has the same basic design roots (the cabs are nearly identical), which evolved graduating to the AC4400 (the AC version of the Dash-9, which introduced more computer-based controls (including DPU capabilities) and fuel efficiency), and from then on was the ES44, which had more computer-based control, fuel efficiency and adhered to Tier 2 of the EPA's emissions standards. The ET44 is an even more advanced version of the ES44, with more state-of-the-art computer control, fuel/tractive efficiency and most importantly, adhered to Tier 4 of the EPA's emissions standards (hence the Tier 4 name). You can tell an ET44 from the older models simply by looking at the rear radiator housing, which is angled like the roof of a house and much larger than its predecessors (the large radiator is necessary to minimize diesel exhaust to comply with its Tier 4 rating). It's also the longest GE freight locomotive in terms of body size. 

Note all of the above locomotives maintained the same horespower of more or less 4,400 HP; while GE also tried to develop a 6,000 HP locomotive (the AC6000), it was ultimately not worth the effort for many reasons, and most of the AC6000s were built at an interim rating of 4300/4400 HP anyway. Ultimately, 4,400 HP became a golden number in terms of pulling power and fuel consumption/emissions.