does anybody know what this is?
- gws
Hi George,
It is one of the early German 3 phase experiments.
The following is from “Haut - The pictorial history of electric locomotives”
The engine was built by Siemens between 1899 and 1903 and ran on the Zossen-Marienfeld test line, the line was 8km long (5 miles), power was 10kV @ 25/50Hz 3 phase. The engine (BoBo) had 4 motors @ 250hp each, weighed 52 metric tons; reached a top speed of 64kph (40mph). The line voltage was transformed onboard down to 750V; speed control was with the star/delta arrangement.
Haven’t found the write up on the Net, yet, when I do I’ll post the link.
The Haut book is another of the “harder to get” items.
PS I found a write-up in the German WIKI which has some different info on that test line
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Siemens and AEG formed a study group in 1899 for “highspeed electrical railways”.
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The Marienfeld - Zossen line (33k; 20+miles) was part of the Royal Prussian Military Railway
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Apart from the engine in the picture they also tested railcars. AEG’s railcar set a speed record of 210.2kmh (130mph) on Oct 27th 1903.
http://de.wikipedia.org/wiki/Militär–Eisenbahn_Marienfelde–Zossen–Jüterbog
Even with HJ’s description, I have to say that is indeed an odd prototype!
Tom,
It certainly was, OTOH most of the early electrics looked a bit “odd”. 
What is interesting is the 3 phase motors, it took many more years before that came back and then only because the semi-conductor technology could handle the speed regulation. Not to mention “chopping, slicing and dicing” 
1 phase AC into 3 phase AC.
“You’ve come a long way, baby!”
BTW there were a few industrial applications i.e. speed regulation of standard 3 phase AC motors on machine tools, that were the forerunners of the railway stuff. Developed by (at least in Switzerland) the mfgs who were big in the RR propulsion field. 1 phase AC@50Hz to DC to 3 phase AC @ 0-100Hz.
I got this photo via an email. The sender wanted to know what it was. I got the 3 phase part right…
more photos at his site, http://www.historicphotos.ca/
- gws
Very interesting!!! Thanks for the link.
Interesting Photo.
How would one switch tracks?
I remember seeing motor/alternator sets to generate three phases from two back in the late 1970s. These were for our power hungry mainframe computers with inefficient TTL logic. DC power supplies designed with 3 phase AC inputs naturally had much less output ‘ripple’ than a normal single or two phase supply.
The old mainframes also had 100’s of front panel indicator lights that each corresponded to a register bit or an address bit somewhere in the computer. Test programmers would cause the lights (bits) to chase themselves around the front panel and form other interesting patterns.
(Simple pleasures for sim… uhh, let’s just say it was fun to watch.)
Sincerely,
Joe Satnik
Looks like it would have required a lot of tunnel clearance !
Gary Buchanan said:As most things that you don't see anymore.... not all schemes are practical.
Looks like it would have required a lot of tunnel clearance !
- gws
Gentlemen,
That was an experimental line used by the AEG, Siemens & Halske study group to see what could be done with 3 phase. I’m reasonably certain that getting there and getting back required
a) steam powered helpers
b) dismantling of the “pantos”
PS BTW the Swiss line Burgdorf - Thun was also using 3 phase, however they used only two contact wires arranged in a horizontal manner. Same system on the Jungfrau Railway and the Simplon electrification, those are railways with LOTS of tunnels!
at that time, motor and motor control technology wasn’t too far along. A synchronous motor was well understood, rugged and relatively small but it had two serious problems for locomotive applications
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it ran at only one speed
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it required 3 phase power
It must have been interesting to get the thing up to speed because synchronous motors do not slip gracefully.
Neither of these “features” would stop experimenters from trying it just to learn something.
- gws