ED42 assisting train - want know a bit more about this

[worldrailboy]

decided it was best to start a new thread in the right place [away from N scale] to ask this

I presume the power substations must had been spaced close together on the Usui Pass due to the heavy power draw from just these four units alone on top of the train itself?

and not to nitpick but how did they decide to operate with one front and three rear located units all the times? or was it just something that struck from the start just like that

small question, I presume the express train itself was more or less dead in tow traction-wise since I can't imagine any non-rack traction being of much assistance over the pass in question?

lastly I could imagine these units being individually coupled together didn't always appear in the same makeup all the times inbetween servicing or being stabled? I noticed two particular photos where it was ED 42 2 heading the four units sitting at station while the other photo showed ED 42 3 heading the express uphill

[Nick_Burman]

Have you seen this:

<a href="http://www.youtube.com/v/2b27E1I2BaY" target="_blank">http://www.youtube.com/v/2b27E1I2BaY</a>

http://www.youtube.com/watch?NR=1&feature=endscreen&v=WYyQnDkQqvQ

The Usui Pass section was supplied from a single substation situated at the foot of the grade, plus boosters fitted along the section. The locos were fed 600V DC through a third rail but used pantographs on the yards. The third rail ensured much better power delivery than catenary, despite the dangers and complications. Usui Pass was the only railway application of third-rail power collection in Japan and the only part of the Tokyo-Nagano line which was electrified at the time, everything else being steam/diesel operated.

When these two films were done the writing was on the wall for the ED42s. On the film you can already see the (1500V) catenary and second track which would replace the rack rail section with an adhesion-only helper district (on the same 6.6% grade). Freight was routed away (to the Chuo and Koumi lines) and only passenger trains used the new helper district. Since the line was then electrified all the way from Tokyo to Nagano all service was then done with MU trains. On the Usui Pass section these picked EF63 helpers but there was no joyriding - contrary to what happed during rack days the MU sets had to pitch in and motor their way up the mountain together with their helpers.

I guess the ED42s operated like that out of experience. The diesel MU trains could have helped their way up the mountain by motoring but I think this would have damaged their transmissions. And ordinary passenger/freight equipment could not help as you can see in the films. As for locomotive formations, these must have varied on a daily basis as individual locos were rotaded for servicing and maintenance.

Cheers NB

[worldrailboy]

thanks a lot nick

I could imagine why DMU's wouldn't assist since I don't think that diesel-hydraulic transmission ever works well with imbalanced train powers unlike diesel-electric traction

as for adhesion-only, isn't that like what the Hakone Tozan Series 1000 did? 8% grade without rack even although I guess its a short EMU

as for no joyriding, that wouldn't be quite new to me. I know that during the electrification zenith in usa there were some mountain routes where the run-through diesels still pretty much helped as much as they could with the trains
http://www.trainweb.org/milwaukee/EPortalJoe.jpg
thats an example just in case anyone wanted one

[marknewton]

I guess the ED42s operated like that out of experience. The diesel MU trains could have helped their way up the mountain by motoring but I think this would have damaged their transmissions.

I reckon the ED42s were marshalled that way for good reason. The crew of the leading unit would have control of the train/automatic brake, and by having the other three locos on the rear doing the bulk of the pushing, they could keep the slack bunched-up, and minimise the risk of damaging the couplers or dividing the train.

I'd also be inclined to think that the DMUs would be under power when climbing the grade. But that's based on my own experience with our DMUs, which may not have the same design of torque-converter and final drive as the JNR stock. They'd happily trundle up and down 1 in 20 grades all day.

Cheers,

Mark.

[Nick_Burman]

I guess the ED42s operated like that out of experience. The diesel MU trains could have helped their way up the mountain by motoring but I think this would have damaged their transmissions.

I reckon the ED42s were marshalled that way for good reason. The crew of the leading unit would have control of the train/automatic brake, and by having the other three locos on the rear doing the bulk of the pushing, they could keep the slack bunched-up, and minimise the risk of damaging the couplers or dividing the train.

I'd also be inclined to think that the DMUs would be under power when climbing the grade. But that's based on my own experience with our DMUs, which may not have the same design of torque-converter and final drive as the JNR stock. They'd happily trundle up and down 1 in 20 grades all day.

Cheers,

Mark.

Yes, indeed. However they could have marshalled the locos in other fashions, like spread across the train or two on front/two on the back. I guess that the Japanese fathomed the idea of putting 3 on ther back and one on front out of experience gathered during steam and early electric days. There is another Youtube vid which shows the EC40s (the early AEG/Esslingen electric locos which started electric traction on the Usui route) operating the line sometime in the 1930's, by then they already ran using the 3 at the back method.

The Usui Pass route was a tad steeper than 1 in 20...it also depends on the speed ratio of the transmissions, with gearing for high-speed ops I would not be surprised if the KiHas seen on the film were somewhat allergic to motoring up very steep grades...


Cheers NB

[worldrailboy]

bit different subject but looking at this talk about the ED42 as a specific use locomotive that was eventually suppressed of its duty had me thinking about something else from north america on a similar theme

Norfolk & Western used some heavy mallets to move tons of coal over the mountains, but even with that there was one section which was a steep tunnel that was giving them trouble so it was electrified to relieve the smoke problem. now the thing is that when this particular section was relaid on a gentler grade, the whole electrification ceased having any purpose anymore