"double heading" and pantographs

[hans-diesel]

On a lot of photos that Google translates as "double heading", I see that from the 1st locomotive both pantographs are on the wire and from the 2nd locomotive only the pantograph on the rear.

 

Why?

Is it really "double heading"? Meaning: both locomotives have a crew and provide power.

 

This is always when 2 locomotives from different classes are combined (e.g. an EF64 with an EF 65 or an EF65 with an EF200).

When 2 EF64's are combined, then I see that from both locomotives both pantographs are on the wire.

 

Thanks in advance, Hans

[kvp]

For AC operation, usually first locomotive front and rear locomotive back pantograph is enough. For DC operation, usually both pantographs on both units are used. There is no need for two crews as most japanese locomotives have multiple operation equipment. Some can even work with multiple units.

 

First locomotive both pantographs and second different type only one could mean the second is not pulling, just taking power for auxiliary equipment and HEP. This could happen when the two locomotives are not compatible and the head unit is doing most of the work. It could very well happen that both are pulling but one is happy with a single panto while the other needs both.

[hans-diesel]

Ok, thanks. All of which I also thought of. I hoped that someone could confirm or if I was wrong that someone could mention the real reason. Unfortunately we are still in doubt.

[hans-diesel]

About "double heading", thus it seems to be a Google Translation translation error.

[hans-diesel]

Having looked at a lot of photos and read their Google translated descriptions, I am only sure of cases of double power that involved two EF64 1000 locomotives, because both have both pantographs up. In all other cases (even those where a EF64 1000 is mixed with another class) the front pantograph of the 2nd locomotive is down.

 

I didn't look at AC locomotives because then a 2nd pantograph is not needed.

[hans-diesel]

Can somebody give examples of "double power"?

I am interested in DC locomotives.

And I know of DD51 examples (there is a nice Youtube movie that popped up more than once on this forum).

[railsquid]

Having looked at a lot of photos and read their Google translated descriptions, I am only sure of cases of double power that involved two EF64 1000 locomotives, because both have both pantographs up. In all other cases (even those where a EF64 1000 is mixed with another class) the front pantograph of the 2nd locomotive is down.

 

I didn't look at AC locomotives because then a 2nd pantograph is not needed.

 

if you post links to the pictures you were looking at, someone might be able to give more details and a better translation than Google can.

[westfalen]

I was thinking the same thing, it's an ambiguous enough definition without translation from Japanese thrown in.

 

A lot of photos, even by railfans, are captioned as double (or more) headers when one or more of the trailing locos are vehicles (dead in tow).  Which brings into the equation that terminology also can differ from country to country or even railway to railway.

[hans-diesel]

First, sorry for replying so late, I was ill the last days.

 

Yes, you are right, pictures will make things more clear. Here we go:

 

http://butsuma-tetsudou.cocolog-nifty.com/blog/2015/03/index.html

 

http://bosoview.sakura.ne.jp/loco/ef200/ef200.html

about EF200-3 and EF200-9

 

http://butsuma-tetsudou.cocolog-nifty.com/blog/2015/03/ef210ef510-3907.html

 

http://reirei500.blog.so-net.ne.jp/2012-06-12

 

http://kokumin.sakura.ne.jp/freight/ef66/2.html

 

I all cases two locomotives in front of the train, the first locomotives with both pantographs up and from the second locomotive only the rear pantograph.

 

I hope somebody can explain why.

 

Hans

[hans-diesel]

I also noticed lately that on the Wikipedia pages of the JRF EH200 there is mention of "replacing pairs of Class EF64s".

And on the page of the JRF EH500 "pairs of AC Class ED75s".

Ok, i already thought that these two classes run in tandem/double/whatever?

But, I don't find this kind of qoutes about other classes. So if it happens, probably not often. Or am I mistaken?

 

Hans

[kvp]

ED75-s and ED76-s were often used in fixed pairs. A married locomotive pair, like the EH500 is perfect for replacing them. There were famous banker locomotives that almost always ran in pairs, like the EF63-s of the Usui pass. For all other cases, the number and consist of locomotives are changing based on actual requirements. Many banking locomotives are added to the front and back of regular single locomotive trains, forming a two locomotive pair on the front, one in front and one in the back or other combinations. This means a train may travel with a single locomotive on one stretch of its route and with two on another. EF210-300-s are often seen helping other locomotives, either by pushing or pulling the train. In the 2nd case, the banker locomotive is actually on the front. As long as two locomotives could work together, they can be run together. It's even possible to see a more powerful (but possibly slower) locomotive taking over on a harder stretch from a weaker (but let's say faster or cheaper) one while towing it together with the train, so it could continue afterwards.

 

ps: the EF63-s actually ran in double tailing consists half the time:

http://en.wikipedia.org/wiki/JNR_Class_EF63