Date: 2024-07-17 Page is: DBtxt003.php txt00021262
Transport
Rail ... Diesel Locomotives
Video ... In depth look at the DDA40X #6922 Worlds largest diesel locomotive
Original article: https://www.youtube.com/watch?v=ERNezIjd-GE
Burgess COMMENTARY
Peter Burgess
752,294 views
Nov 5, 2019
Traveling Tom
40.4K subscribers
Enjoy this in depth look at the DDA40X. This locomotive is a engineering marvel, and I ended up going back to North Platte 5 more times for additional filming. In the end I had several hundred scenes which took a long time to edit. But I think it turned out pretty good and it's a rare look at nearly every aspect of the DDA40X.
These locomotives were built by the Electro Motive Division of General motors from 1969-1971. There was 47 locomotives produced. Eleven locomotives have survived and are in museums. One locomotive is operational (Union Pacific #6936 currently in overhaul), and another locomotive is used for spare parts. The DDA40X weighs 545,000 lb (247,000 kg), is 98 ft 5 in (30.00 m) long, and can produce 113,940 lbs of tractive effort. It has two 654E3 16 cylinder diesel engines, built by General Motors that produce 3,300 horsepower each.
These locomotives were some of the most successful, most loved, and most reliable locomotives Union Pacific ever owned. Union Pacific used these locomotives non stop racking up millions of miles over the years. In just 10 short years these locomotives were totally worn out from years of hard use.
sitnorthplatte.com/director...
This locomotive is open to the public during the Summer months including the cab. Check this website for information for hours of the Cody Railroad Park in North Platte, Nebraska https://vi
More information can be found here about the history of this locomotive https://en.wikipedia.org/wiki/EMD_DDA40X
For a video on the removal of a engine power pack https://www.youtube.com/watch?v=LmiUo...
Many thanks to the kind people at the Cody Railroad Park who allowed me to film this locomotive. Any questions about this locomotive leave them in the comments and I will try to answer them.
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Hi Tom, The box in the nose at timestamp 25:31 is the 'EL Type' cab signal box.
Note: EL does not mean the Erie Lackawanna. Originally US&S developed 'EH' cab signal equipment for Steam Locomotives (before my time). The system was upgraded to 'EL' cab signals for diesel locomotives.
Just looking in the box I see all of the Glass relays, Master Relay, Amplifier and Decoders have been removed. Union Switch & Signal was a division of Westinghouse Air Brake (WABCO)
Yes, I'm a locomotive electrician and still work on 'EL' with 'LSL' cab signal equipment.
Also wanted to say a PCS causes a Penalty brake application, not an emergency brake application.
In a Penalty Brake Application the brake pipe is reduced to approx. 64 psi.
An Emergency Brake Application is a quick release of the brake pipe dropping the brake pipe pressure to zero. When you don't acknowledge the alerter, you receive a Penalty Brake Application and have to move the automatic brake handle into the suppression position (the bump between full service and Handle off) for 10 seconds to recover.
The device at timestamp 1:03:52 is actually called the Aux Gen. The companion Alternator is on the back end of the Main Alternator / Generator.
As you touched on, the Aux Gen supplies 74 VDC for lighting, battery charging and supplies the field for the Companion Alternator. The Companion Alternator supplies the 240 VAC to run the different blowers and rad fans, plus supplies the field for the Main Alternator / Generator. Yes EMD calls it a Generator because the rectifiers are part of the package and you have a DC output on the Bus bars, but the machine itself is actually an Alternator.
FYI the front two slip rings are for the Companion Alternator and the rear two slip rings are for the Main Alternator / Generator.
At the shop where I work, we have a barring over machine that uses a hydraulic cylinder that fits into the holes in the flywheel to turn the engine over for inspections.
It's funny you add oil at the ice cream box, we usually just add oil in the upper deck or remove one of the crankcase covers if the locomotive is shut down.
Looking at the traction motor at timestamp 1:17:50 The two cables closest to you are the field cables 'F' & 'FF', the two cables on the other side are the armature cables 'A' & 'AA'. The cover beside the armature cables is removable and allows you to renew the commutator brushes.
How dynamic braking works, all the fields for all the traction motors are connected in series to the Main Alternator / Generator. The Armatures for each motor is connected to the dynamic brake grid in the dynamic brake blister, this is the function of the MB (Motor Braking) switch gear. As you increase the handle position the Main Alternator / Generator supplies more field voltage / current which increases the output from the Armatures of each traction motor. The Dynamic grids are a set resistance, you're varying the output by varying the voltage of the traction motors fields.
This is why you cannot use Dynamic braking if you cutout one or more traction motors. This locomotive also looks like it has extended range dynamic braking. As the locomotive slows, dynamic braking becomes less effective because the traction motors are producing less current at the lower speeds. The extended range contractors begin removing grids from the circuit which keeps the current high on the remaining grids allowing dynamic braking to remain effective at lower speeds.
I was on this locomotive when it passed through our shop on it's way back to the museum. From what I was able to see, this locomotive is basically two GP40-2's under one carbody.
One thing that you mentioned that surprises me, UP never changes the oil unless there is a problem. The railroad I work for actually changes the oil on a regular maintenance cycle. You did an excellent job with the video and gave everyone a very nice behind the scenes look at a very unique locomotive. Thanks for sharing the video,
Cheers, Rich.
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Fred Howland Fred Howland 1 year ago Just thinking of the thousands of smart people who must’ve worked so many hours to design such an impressive piece of engineering is humbling.
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One thing that you mentioned that surprises me, UP never changes the oil unless there is a problem. The railroad I work for actually changes the oil on a regular maintenance cycle. You did an excellent job with the video and gave everyone a very nice behind the scenes look at a very unique locomotive. Thanks for sharing the video,