The austrailian trains mate

[shadesman89]

G'day mate has anybody heard of the es44dcis they use in the Australian down under. They are used for iron ores and are huge to accommodate their huge cooling since they work in the desert if anyone has more info or picks please post them here

[Ericmopar]

I posted some videos from You Tube. That guy has a lot more at his You Tube channel.
I've always thought the extra cooling was overkill. Our engines are already designed to cross our deserts at very similar temps.

viewtopic.php?f=41&t=10828&p=125052&hilit=Tourists+down+under#p125052

[GSkid]

Well wiki appears to have the only info on it I can find. Says....

Rio Tinto Group has ordered 51 ES44DCi locomotives for operation on their privately owned rail line, operated by Pilbara Iron. The ES44DCi uses the AC6000CW's longer frame to allow space for a heavy duty cooling system to cope with the hot desert environment that the locomotives operate in. Units 8100-8118 were delivered in a predominantly grey paint scheme, while units 8119-8150 feature additional red lettering and striping.

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


Why they went with DC instead of AC traction, especially for heavy ore hauling.... is beyond me.

[shadesman89]

I evern heard They own some es44acs that wetre pulled right of production and still had their BNSF livery any of you maates know how they move the locos to Australia

[buzz456]

Google Trans Pacific Projects.

[Ericmopar]

Why they went with DC instead of AC traction, especially for heavy ore hauling.... is beyond me.

It's not that straight forward.
If I can find the video I'll post it, but suffice to say, that AC traction costs much more to purchase and maintain.
The thing that a railroad operations officer stated when asked why they were switching back to DC on new locos, was that the AC locos only show an improvement during very low speed, heavy load operation, that is not practical in the real world. The AC locos can grind down to impractical speeds under loads that would be nearly impossible to start on a grade anyway. The computers also derate the power under such loads.
It turned out to be part of the reason so many SD40 and other older generation engines are being rebuilt. Some talented engine crews did some math, and found out that older engines quite often delivered more real world traction and H.P.... They did the math, tons vs speed and the numbers with these new wonder engines weren't always adding up.
Also: If the Pilbara region iron ore trains venture downgrade when loaded, and upgrade when unloaded, then the argument for AC traction is even poorer.

[GSkid]

Well I'd like to know who is buying DC cuz all the orders I keep reading about always involve AC for freight. AC's biggest expense item are the inverters. But prices have come down for AC thanks to the major increase in orders that occurred in the last 15 years. Volume brings prices down.

EMD used to have both the DC traction SD70M-2 and the AC traction SD70ACe on it's home page. Now the only SD70ACe remains. The only DC freight loco I found there is the British Class 66.

So you could be right that some may have started ordering DCs. But every news article I read referring to purchases by class I & II railroads keep mentioning AC models.

[Ericmopar]

Biggest expense for AC I think, is the Inverters. Those are usually combined with the necessary VFD, to control traction motor speed.

[GSkid]

Biggest expense for AC I think, is the Inverters. Those are usually combined with the necessary VFD, to control traction motor speed.

Yeah I corrected my post to inverter. All this DC talk had me brain fart (and a lack of sleep) and say rectifier....which is fine....for AC generator to DC traction. Says the guy who took a electronics course from a tech school for the fun of it. Hardly used that skill cuz most electronics today are almost cheaper to replace than repair. Hence why most mom and pop shops have closed in the last 15 years.

I only see DC thriving in passenger locos and older freight locos. It's been awhile since I've seen new DC freight locos ordered.

[Ericmopar]

It's strange.
I was doing some reading, and as far as I could tell, they make AC with an alternator, then rectify it to DC, then put it back through the Inverter/VFDs and turn it back into variable frequency AC.
I remember some of this from industrial electronics. VFDs Bad... Hold current in large capcators that shock Eric bad... Eric arm hurt days... Eric's boss say sorry, should have warned me first time work on VFD's... Boss no tell Eric to bleed Caps first...