Been wanting to post this for a while!! From Dad. Massive, 28 unit BNSF power move! As stated, locomotives 1,2 and 28 were running. The remaining 25 are DIC.
Wow! That's a lot of heavy metal on the move. And in some passes, it looks like they're really haulin'! Fantastic video, Keith.
Looks like the exhaust stacks are covered on most of the units that weren't running. Is that typical for a power balancing move, or is it likely that those locos were headed for long term storage - or just coming out of storage?
According to video description, this is the D-SagBar, a power move from Saginaw, TX, to Barstow, CA. Returning to service. Line up included: 27 ES44DC and 1 Dash 9.
Good to see units being put back in service. I've spent a few days in the last month railfanning NS's main in South Carolina and tonnage is definitely on the upswing there too.
I'll bet the global microchip shortage's impact on automobile manufacturing is denting carloadings in that business sector.
Unless otherwise restricted, light power can operate at passenger train speeds. Of course traction motor speed restrictions will prevail. But they can operate at 70mph+. There may have only been 3 units on line in power, but I bet the crew wished there were a few more in dynamic braking only. Even tho these locos have shock absorbers, they can and will bounce around. Consider this, when the journal boxes are pressed fwd of aft, depending on buff or draw forces, it will act as a bit of a buffer too. So when in minimal throttle setting some locos may kind of pogo bounce. Light power moves can be a challenge to keep on speed in undulating territory, they are heavy, short and speed differentials can be significant. It has always amazed me how easily a locomotive will move, I mean when you take into account 200+ tons, the bull and pinion gears X6, that need to turn basically 800hp electric motors also X6, and they will roll as easily as a boxcar, that has always impressed me, how well "engineered" they are.
I had one of those light power moves a few weeks ago, but it was 10 units and they were moved as a consist, not like the DSAGBAR where one or two on the head end are online along with a DP. I was only allowed to use one unit for power, but I put a second on for dynamics only since it wouldn't stop well at all. Like Tom says these consists are allowed to move passenger speed, but the fly in the ointment is we aren't allowed to use throttle over 40mph anymore except on certain trains, so I never really got up to speed except on one hill that didn't have a slow order anywhere nearby. It was exhilarating to move that fast since freight speeds are quite a bit slower in the area, and especially when you can't use the throttle. We were also very popular with the paparazzi that day. I got followed almost the entire journey from Fort Worth to Oklahoma City by several photographers.
Had some time last Saturday to check out the NS main between Greenville, SC and Spartanburg, SC for the first time. Found some good spots that I want to return to and came away with some shots like these at Taylors.
I'm not sure what the theoretical limit is, but I've seen a guy at our club do ten or more. It's worth noting however, that he did it using the app on his tablet and not on a regular handheld DCC throttle.
About 12 years ago I MU'd 10 locomotives with my Digitrax Zephyr with about 100 cars just to see if I could do it. The lead locomotive followed behind the caboose by about 3 cars. The locomotives were distributed within the train. It was tricky to control and prone to stringlining.
Here's a poor picture of all 17 (at the time) of my Arnold Rapido GPs on the track at right on my Treble-O-Lectric layout. They all ran fine together and my MRC 9500 handled them without blinking: Doug
Thanks, Dan, and sorry about the post not relevant to the thread subject but it is in the sub-thread of how many prototype locos might be the limit in transport and it kind of getting shifted to models. Now, back to the real thing! Doug
The most I've ever seen ALL under power lashed together were 8 MU'd together. More than that, you'd need either DPU's or manned helpers. Hopefully the 1:1 engineers can give some input as well.
This is one of those questions that has no good single answer. The number of locomotives strung together in a single consist can vary widely according to territory, RR and many other modes of instruction. The max here is 9 unless special permission is granted, and then only 36 compensated axles of power can be on-line on the head end. Sometimes you can have problems with that many units getting a good air test done, As it takes a long time for the air signals to propagate thru all the valves and hoses, when your actuating (bailing) setting and releasing the automatic brakes and so on. Now if a big chunk of units are OOS (out of service) on a power move, many of these units are DIC, and the air will be boxcared, meaning the brakes will set and release just like a boxcar. Even though the brakes set and release, they are still 200+- tons per operative break. So, like Ryan said they typically dont brake, or stop very well. Of course DP operations changes all this a bunch. DP can give me a headache.
A coal train passes Tower 17 in Rosenberg on the BNSF tracks back in 2004 just after UP retired it. We were preparing it to move to the museum.