• Tier 4 Evolution Series prototype unveiled

  • Discussion of General Electric locomotive technology. Current official information can be found here: www.getransportation.com.
Discussion of General Electric locomotive technology. Current official information can be found here: www.getransportation.com.

Moderators: MEC407, AMTK84

  by MEC407
ES44AC Tier 4 demo units are now testing on Union Pacific. Photo by Matthew Griffin:

http://www.railpictures.net/viewphoto.php?id=484178" onclick="window.open(this.href);return false;
  by MEC407
No. GE has chosen to use non-urea methods to meet Tier 4.
  by MEC407
Another nice photo by Matthew Griffin:

http://www.railpictures.net/viewphoto.php?id=485567" onclick="window.open(this.href);return false;
  by GEVO
Due to emission credits the class 1 railroads have accumulated, EMD and GE will be able to continue to build tier 3 diesel engines until about mid year 2015. So about a 6 month delay for tier 4. That said, the freight locos built from there on out until at least 2017 will only be from GE. Apparently EMD does not have any freight offering that meets the tier 4 standard. Not sure what has happened to their project but that is what we have been told for months.

EMD does have a tier 4 compliant diesel passenger loco but it uses a Cat C-175-20 4 stroke engine. The Cat diesel requires SCR after-treatment, something which the class 1's do not want to deal with.
  by MEC407
From Bloomberg:
Bloomberg wrote:As rain pelted the windows at General Electric Co. (GE) offices in Chicago, executives debated whether to build a low-emission locomotive. The deliberations went on for two days, and to keep the mood upbeat anyone with a negative comment had to toss cash into a jar on the table.

Though predictions were for anemic demand, the team voted to press ahead and spend $200 million to develop the engine. The decision in April 2013 turned out to be pivotal, not only for GE. Caterpillar Inc. (CAT) took industry forecasters at their word and may not have a model meeting the U.S. pollution standards that kick in Jan. 1 until 2017. GE’s will be ready next year.
. . .
The wager secures GE’s spot for at least a few years as the world’s largest locomotive maker, and sets Caterpillar back in its goal of grabbing enough market share to be a closer No. 2.
Read the rest of the article at: http://www.bloomberg.com/news/2014-09-2 ... tives.html" onclick="window.open(this.href);return false;
  by MEC407
Photo by Bob Hanggie:

http://www.railpictures.net/viewphoto.php?id=506995" onclick="window.open(this.href);return false;

Photos by Matthew Griffin:

http://www.railpictures.net/viewphoto.php?id=506957" onclick="window.open(this.href);return false;

http://www.railpictures.net/viewphoto.php?id=506958" onclick="window.open(this.href);return false;
  by Allen Hazen
Well, now we know why Conrail painted a giant logo (wheels on rails, a.k.a. can opener) on the sides of its units: this paint job is boring without some sort of decorative element!

(Thanks for posting the links to the photos!)
  by MEC407
Video by Jim Gray:

https://www.youtube.com/watch?v=TaiUvCSg8RQ" onclick="window.open(this.href);return false;
  by Allen Hazen
Just looked at the Jim Gray video. At the end, U-tube gave a choice of related videos: one was a GE promo on L250 and V250 marine engines: lots of shots of tugboats (etc)with loud music. Also a bit of a view of the engines. (L250 is GE's name for the eight-cylinder (and maybe 6-cylinder) inline versions and the 12 cylinder and 16 cylinder V versions of the GEVO engine when they are marketing it for non-locomotive applications). The 12-V250 is NOT quite the same as the GEVO-12 used in locomotives: it seems to have two turbochargers, and the turbochargers are at the end with the flywheel for connecting the generator rather than at the far end.

(And-- given that CP has made a big purchase of off-brand 2000 hp locomotives with two-stroke engines-- when is some big railroad going to decide to be serious enough about GP-38 replacement to make it worth GE's while to build the "ES22" with a straight-6 GEVO?)
  by MEC407
GE has a web page outlining many of the changes and improvements they've made with the new Tier 4 locomotives:

http://www.getransportation.com/locomot ... technology" onclick="window.open(this.href);return false;
  by Allen Hazen
General rule of technological development: things get heavier!
From the GE web-page that MEC407 links to (describing changes to engine block):
"A larger casting (+8”) and increased weight (+7,000 pounds) allows for larger bearings and crank with increased overall cylinder pressure capability for better reliability and performance."

Since the total weight of a GEVO-12 engine is in the neighborhood of 50,000 pounds, this is a big increase.

It sounds as if there have been some pretty fundamental changes in the engine. "Two stage" supercharging, to allow for higher compression ratios. At least sometimes enough more "oomph" in a cylinder power stroke to motivate a change in the crank-shaft to allow larger bearing area (8 inches total, so the big end of each rod gets about two thirds of an inch wider).
So both the thermodynamic and the mechanical aspects of the design have been changed in a major way.

(Thanks for the link!)
  by MEC407
Photo by John Sesonske:

http://www.railpictures.net/viewphoto.php?id=529937" onclick="window.open(this.href);return false;

What caught my eye is that the exhaust stack seems to be pushed to one side, rather than centered. That's... different. It also looks smaller, but that might just be the perspective...?
  by Allen Hazen
About that Tier4 exhaust stack (MEC407, previous post)…
http://www.railpictures.net/viewphoto.p ... 235&nseq=3" onclick="window.open(this.href);return false;
is another photo. Foreshortened, hard to make out, but… it looks as if there is an exhaust opening at about the position (fore and aft position, that is) of the one in the photo MEC407 linked to, but it is (i) wider and (ii) centred. I think there are slats in the opening, with those in the right side of the opening slanted up and to the right and those in the left side slanted up and to the left (so that, on both sides, they would tend to direct exhaust away from the locomotive centre line). Because the photo MEC407 was taken from the right side of the locomotive, we see into the openings between the slats in the right half of the exhaust opening (so the right half looks like a dark rectangle), but see the sides of the slats in the left half (so it looks like hood-top sheet metal).