In 1973 I worked for Con Edison NYC in Substation Maintenance. I had the opportunity to visit the Staten Island Transit System sub station. It looked like a regular small substation. But inside the switch house. There was a door that lead to some metal steps. When you went down those steps. It opened up to a huge underground area. There were three huge dynamos set deep in the ground and spinning furiously. With a row of giant amp meters along one wall. There were steps and catwalks across the diameter of the dynamos. So you could look down into them from above. I was very impressed as I stood looking down into the giant spinning top of the dynamo. Then my boss said, "Wait for it..." In about 30 seconds the dynamos let out a howling scream that mad you cover your ears. At the same time all of the amp meters swept slowly to the right of their limits. It stayed that way for about 30 seconds or so. Then slowly went back to "normal". The boss turns to me and said, "That was a train going by." I will never forget that experience.
Phillip Moore Absolutely incredible experience. Your one of the lucky few who saw raw power in action. Reminds me of the hoover dam alternators. It would be great seeing some construction pictures.
I'm a System Operator for a western utility. We have a car 'shredder' in our system and I can always tell when a car is going through it because the load on a 160 MW bank that feeds it starts swinging pretty wildly.
@@fardreaming meaning the arm on the power drop gauge moves pretty far and wildly around the gauge. Some people might use "swing" to dramaticize a bit. Great stories though
@@garyh4458 I dated a girl in the 1990s who actually believed that. Well, I shouldn't say, 'believed'. She'd just never really thought about it. All she knew was all the really old pictures she saw in books and stuff, and the old 'videos' on TV were in black and white.
@@xaenon Haha. That's funny, but I can understand. Whenever I see colorized version of really old film the first thing that pops to my head is that it is a shame that those people didn't get to see themselves that way. But, of course, they did, but not in film.
For those who need more background: “A rotary converter is a type of electrical machine which acts as a mechanical rectifier, inverter or frequency converter. “Rotary converters were used to convert alternating current (AC) to direct current (DC), or DC to AC power, before the advent of chemical or solid state power rectification and inverting. They were commonly used to provide DC power for commercial, industrial and railway electrification from an AC power source.”
As a yacht rigger I worked for a real Connecticut Yankee who built every tool, rig, jig, and machine geegaw if none was available to suit his needs. In the course of our work, one day we came upon a 14" Rockwell table saw which was free for the taking if we could move it from a machine shop basement 14 feet down. Being riggers, no prob and basically free. But it doesn't end there, boss wants it in his. Again easy move, but here's the rub... the utility said no go on the 240 line. So he ran a 3 phase motor by spinning it with a 120 then taking the 240 off the 3rd pole.(?) I know that might be oversimplified and or technically incorrect, but I would use it on occassion and that is the configuration I know I saw. But of all the trades I'm jack of, the one I regret lacking is electrical, and believing electricity is not a hobby and a little bit of knowledge means there is a whole lot of ignorance remaining... so besides replacing a plug or switch I never dikked with it. And at 60 and in failing health my mind can't take the strain of learning something else. Although I get the basics here
@@tommypetraglia4688 Most home circuits for dryers, ovens, water heaters, etc. do that. They take two 120V breakers and use those as hot and neutral 240V. That’s not three phase, though. More than likely, he rewired the motor for 240V.
So this had AC Motor taking the 3 phase AC as input... and spinning a mechanically linked Generator to produce DC... ?? Love the control panel. Manual Control seemed to require knowledge for the order of operations.
@@Wildstar40 We still use coal in major proportion to produce energy. It's old and pollute much, but it's reliable. If we could fix problems with pollution and minimize environment destruction of mining we could still use coal. However, what's past is past, and at last for E.U. the coal shouldn't be here as from 2050.
This is the exact same procedure they used for connecting power plants to the grid. Someone had to manualy tweak the steam turbine or water turbine to get the massive generator spinning in sync with the grid before throwing the switch.(But there ware obviusly systems in place that prevented you from doing so if it was way off mark)
Sounds like putting a sychronous hydroelectric generator on line by hand. First close the gates on the turbine, then fill the water inlet pipe, then connect the generator field coils. There are three lights connected to the generator output and the power line. Then open the turbine gates and bring the generator near synchronus speed. The lights will turn on and off in a pattern as the generatpr output frenquency approaches the line frequency. When all the lights go out there is no difference in frequency between generator and line. Then close the output switch. The generator is then locked onto the main line. Then gradually open the turbine gate and watch the killowatts go out and the money roll in.
And if you miss your moment slamming in the switch, hear the huge bang as the circuit breakers trip. Wait for your racing heart to calm down, reset them and try again... :-)
01:09 did I see a spark there? Meaning that there is a voltage potential on those metal switches? And he is touching them almost? Yup... like the good ‘ol days
Well... busses would be worthless without current flowing. You don't move electrons without a potential difference so... thats kinda how a switch works when you close it.
General Superintendent Robert Lobinstien, (Loby) was an Icon In the New York City Transit. Mr. Lobinstien was so instrumental I. Preserving the Rotary Converters at Substation #13 on 53st for a history in Manhattan. I was privileged to work with Loby for many years in the Power Department and he was one of the best people I ever met.
That's pretty awesome. I literally work next to that switching station on 53rd. Ironically the reason I was looking at this video. I'm not sure this video is at the spot im thinking of. I'm on 53rd between 6-7th Ave.
Back in the 1960's the Chicago Transit Authority ran rotary converters to rectify 30 Hz . Commonwealth Edison had to provide the 30 Hz power from 60 Hz and used 42,500 horsepower synchronous motor-generator couples for this purpose. They weren't self starting so there was a 1500 horsepower motor used to bring them up to speed for each one. I believe they turned at 600 rpm and the coupling shaft was about a foot in diameter. I was impressed.
@@johnluck8916 From Google: the efficiency is about 60 to 75 percent, which is about twice that of primary generators. They had some very old steam powered 30 Hz generators at other power stations, but they were run from low pressure boilers, and were rather inefficient. I'm sure all are now gone by now, and the Transit Authority rectifies 60 Hz by more modern means.
My dad worked in one of these substations on 38th St in Brooklyn. As a kid in the 70's, I got to visit a few times. They had six of those rotary converters (I believe made by Westinghouse) which looked identical to the one in this video. In addition to these converters, they had huge transformers and two control panels (one for AC and one for DC) for each one. To the best of my memory, Con Ed sent them 11,000 volts AC and the transformers knocked it down to around 400 volts. The rotary converters then converted this to 600 volts DC which went to the third rail to power the the trains. My dad and the other workers took these machines On and Offline in addition to constant maintenance which was mostly brush changes, commutator cleaning and lubrication. As a kid, I was fascinated by all of it. I'll always remember this as well as the insane volume of the sound especially when multiple converters were running at the same time.
So this is Loby. Fantastic work to all of you. Thank you for preserving this control house and the rotary as a working setup, I hope this tradition continues into the future. I'd love to see the machine run some time. We are restoring a 6 story tall waterworks steam engine that shares common castings with the large family of Alternator Corliss engines that once ran in the 74th street power house and no doubt fed this very rotary station. We have just finished putting our 1914 250 volt DC motor and switch board back on line to demonstrate to visitors in exactly the same way as this.
Actually, this substation was fed from the 59th st IRT Powerhouse, not 74th st. The two plants were similar in the way they worked. Would love to see some clips of the Allis Chalmers reciprocating steam engines.
I serve as a docent at the Mt. Wilson Observatory which is a little newer than this substation, first telescope being built in 1905. DC electric motors of similar vintage are used throughout the historic observatory where Edwin Hubble discovered the expansion of the universe. We have several panels with exposed knife switches, though only at 110VDC. They now have safety covers in front, but the 110VDC still powers all the motors used to drive the telescopes, and associated equipment from that era. Modern rectifier banks from SoCal Edison now replace rotary converters which in turn replaced the 1500 cubic inch two cylinder Fairbanks Morse generator still in the powerhouse, and still in running order. That 1912 generator powered everything on the mountain in its day, but did so by charging a large bank of batteries at night. Its vibrations and noise, even from 1/8th of a mile away, were considered too much for the extreme sensitivity of the 100 inch telescope optics. That telescope was still the world's largest when I was six years old in 1948.
He didn't once explain any of the terms he used. Unless his audience is full of EE's like me, or at least electricians, all those technical terms will just wash over the tourists like the buzzing of bees. I understood what is going on, because I've studied the history of electrical distribution equipment and electrical trains. But his depth of knowledge doesn't make him a good teacher at all.
@Kandela Brown from what I gathered, the DC voltage on the train track (3rd rail) is fed backwards into the system in order to bring the system up to speed so that the AC side of the system is synchronized to the grid. Then the system is connected to the grid with the converter voltage slightly higher than the bus voltage so that current is pushed into the system and the converter becomes a load on the grid and supplies power to the train. I'm a mechanical engineer, not an electrical, so I could be wrong.
I remember going into the substation on New Lots Ave in Brooklyn, as a kid. The guys who ran it had a long stick with an abrasive block on the end that they used to polish the slip rings? commutator? The machinery was mounted in a pit a little below street level and a good portion of the floor of the station was an open mesh steel grid over the pit. It looked like a fun job to work there!
Beauty ! Good job IEEE . Thanks Mr. Superintendent for your knowledge and opportunity to share the startup procedure. Also few people know that Rot. Conv can be reversed and used and motor or start from whichever rail. Thanks for giving visibility with technical rigor.
They used to use smaller units to provide high voltage dc for radio sets in airplanes and ships. They are known as “Dynamotors” and were invented by Nikola Tesla. The a/c and d/c windings are on a common armature with a commutator on one end and slip rings on the other. That is mechanical means of rectifying a/c current or vice versa. I have one in the back of my truck that turns 12v d/c into 500w of 60 hertz 120v a/c. Modern inverters are more efficient and economical. I like the old mechanical things. The dynamotor was invented in the 1880s. Nikola Tesla still holds the record for the highest mechanically generated frequency at 144khz. In 1916 he sued Gueglimo Marconi for patent infringement and won.
The quality of these motors is amazing. I Manage a chip mill and we use a 2160 volt synchronous motor on our chipper that was built in the 1930s and originally used in a steel foundry. The motor controls have been modernized and computerized and we start it by simply pushing a button. The motor itself is all original aside from the carbon brushes and brush springs that are replaced with regular maintenance.
Would love to have met this man. Incredible how overbuilt these rotaries were. They were being used until 1999 when ConEd said no to providing 25 Hz AC.
Tiny bit of historical context. The electrical grid in at least most of the eastern half of North America, was 25 HZ Ac until somewhere in the late 1950's. It was a massive project to, in many circumstances, install 60 HZ AC of all sorts of electrical gear into the grid and leave unpowered. That was just the grid. Also going on at the same time was the conversion of every type of building and other use of 25 HZ AC electricity to 60 HZ AC. Pretty much all the new gear had to remain unpowered until the day of change over. In the case of this piece of kit, I can only assume some bean counter thought it would cost to much. Slight aside. I worked for the local school board (Toronto) for along time. One school I was in a number of times, there was a motor I noticed with more data plates than usual. One day I stopped and took a look and realised this motor had been converted from 25 HZ to 60 HZ. The old plates had been over punched with XXX's but were still readable. The other neat thing about this motor is it still has oiling cups and there is a oil can beside it. Apparently a few drops every couple of weeks. By the way this motor is for a washroom exhaust fan so it runs everyday for at least 12 hours.
@@foamer443 If you mean the entire power grid, then I call BS on that. A lot of consumer appliances would not have functioned properly at 25 HZ. If you mean a separate grid that only powered industrial machinery and the like, then OK.
@@pauldzim Yes it was, just do some research. 25 Cycle electricity was common, many household appliances had 25 Cycle transformers in them, I own many these transformers.
@@MrCarlsonsLab So they built special versions of electric clocks, phonographs, TVs etc for the entire eastern half of the US?? That's hard to believe, if you're talking the late 1950's. Maybe earlier, sure. Edit: The Wikipedia article is a little unclear on the dates, but a chart there says that in 1946, southern Ontario, Canada was still using 25 Hz. That chart doesn't say anything about the US.
@@MrCarlsonsLab Not in the mid Atlantic part of the east coast. We were firmly 60 hz in 1952 (as far back as I recall). In 1966 in Niagara Falls they had 25 hz at Sir Adam Beck in Canada and 60 hz at Robert Moses right across the river in Lewiston NY. Some big factories didn't want to replace huge 25 hz motors so they kept running them using converters. Some pump motors were as big as a box truck, I wouldn't want to replace them either.
The Orange Empire Railway Museum in Perris California had a rotary converter to supply 600 volts DC to run the street cars (trolley cars) around the museum ground. It was a lot quieter than the diesel generator they used before that. Great machinery.
It sounded to me like this is no longer in use providing power to the subway, but is still functional and can be run for demonstrations. Preserved for historical interest. This would be considered too unsafe and too labor-intensive for actual use in present day. I would imagine it could be modified to automate the control system and safety covers or safer switches installed, if they were still using it now they would have done so, but clearly haven't.
There is supposedly a huge hall full of these under Grand Central and during WW2 the US Army had armed guards in there 24/7/365 at all entry points from the surface/upper levels.
Hard to imagine that even with the still newness of electric itself, they could figure out how to design and build all these machines that did such obscure things to it! I used to work in the 200 block of E 21st st NYC around 1980 and remember a nearby subway powerhouse that in the summer had the doors but grill doors in place open due to the heat and you could see and hear some large 1904 era machines running inside!
These were relatively crude mechanical implementations of mathematical concepts of electromagnetism that had reached a high degree of refinement about forty years previously. Whether 40 years is a short time or a long time depends, I suppose, on what else was taking place at the time. Industrialization and shipbuilding were already taking place on a massive scale, and such effort could in principle be directed toward electrical infrastructure just as well as toward any other technology. But steam was still the thing. It was a visionary leap - and perhaps a real gamble - to commit resources to such a complex undertaking as we see in this video. What an interesting time for our species!
Sometimes I look at old technology having more imagination, and engineering technology than newer products. Like the torque converter used in Power Glides, or those smart toster ovens from the 1940's. They could problem solve with the technology of the day, and do so without computer chips.
I am not sure I got it either, but I think this machine converted direct current (DC) to alternating current (AC) for the subway. The weight of it served as a buffer to smoothen out the spikes in the electricity when the trains started and stopped accelerated, a mechanical battery. If I am wrong, please correct me!
@@torstenpersson5629 It first uses the DC from the third rail to get spinning, then switches over and converts the incoming AC supply to DC and pushes back onto the third rail. Insanely clever and far simpler than a high power synchronous AC motor starting system of the day.
I been inside and seen that same type of generator as a kid about 40 years ago inside the substation on Nostrand Avenue between President and Union Streets in Brooklyn. I believe it powers the 2 and 5 down to Flatbush Junction. They used to keep the front door open but after Sept 11 it's been tight as a drum...
*I worked in a factory that made tar paper using large rollers. The entire system was run by a DC power generator that was spun by a large AC motor at about 100 horsepower. The DC motors were controlled by large rheostats with heavy copper windings. It was like Dr. Frankenstein's Laboratory with the noise and some arcing. I liked working there.*
i have pictures of the very same station that was on 213th street and whiteplains rd. in the bronx..... its all the same... feels good to see it working.... i got pictures of it abandoned. right before they take it out to build a low income building witch we all know will be gentrified in another 10 to 15 years... anyone wanna see my pics let me know this power house was much bigger than that one.....
"Westinghouse". Note how you see Tesla nowhere. The absolute genius behind everything this man is operating and well, quite literally the entire planets electrical systems. 3 Phase Alternating Current. 12-1/2,25,50,60 even 440 Cycles per second (Hz). Love it!
Very nice video. Enjoyable and informative to watch. Power initially for the NYC subway was provided at 25hz (cycles) AC that had to be converted to direct current. These rotary converters were all over the city in substations. I recall seeing these structures, containing up to about six of these interesting machines. 25 hz AC is no longer used, today 60hz AC is converted to direct current using mercury vapor or solid state rectifiers. These rotary converters were gradually phased out. nycsubway.org has an excellent description of the workings of the subway.
@@klam77 Well, the NYC subway is bad, but running on DC is not the reason it’s bad. As for the motors: obviously they were DC motors. Modern cars use inverters and can use induction motors even though they are powered from a DC rail. Whether they are used in any particular DC 3rd rail system mostly depends on history and politics, not engineering, though.
Ah, motor-generators. I remember them from US Navy nuclear power training. Submarines used them to convert AC from the steam powered turbines to DC to charge the batteries, and DC from the batteries to AC for emergency power in case of a SCRAM.
I just made a comment about the same thing. If you remember they were designed to start from the AC side of the motor generator but they could only do it twice. It was done once to test them. After that you only had one more shot at starting them from the AC side. The sub that I was stationed on had to do an AC side start because of a casualty situation that we were in. The nuke EM Master Chief, that had over twenty years in, said that he had never seen or heard of it being done on a boat. What had happened was that we were doing a reactor SCRAM drill. Of course we were running on the battery while the reactor was SCRAMed. In the middle of the drill the bus bar (with no spare bus bar on board) from the battery vaporized (that is not an exaggeration) and we lost all of our power. There was just enough residual steam in the system to get the SSTGs to turn over to supply just enough AC power to start up the two AC-DC motor-generators. That allowed us to get the reactor back up and running. If they hadn't started up we would have been dead in the water until the electricians could jury rig a connection from the battery to the boat, which they eventually did. And that is how we got a four day liberty call in Barbados while waiting on spare parts to be flown in.
@@BernardGreenberg Thanks for the clarification. My sub quals were done over 40 years ago. I remember them being referred to as motor-generators. But I was a Missile Tech, not a nuke EM, so I wasn’t knowledgeable about the inner workings of them.
BC Hydro had a mercury vapour rectifier set up on the end of their transmission line out to Vancouver Island. en.wikipedia.org/wiki/HVDC_Vancouver_Island
we've still got some rotaries running in germany as ac/ac frequency converters to bring down the normal 50hz grid frequency down to 16,7hz, which is the frequency our electric trains run on :)
@@davetheelasticgoose4838- So how does that low frequency work for powering trains? I'm confused. In aircraft they move everything to 400 hz as it equates to lighter motors although I don't know how.
Good to see this beautiful machinery preserved in operational state! Did I understand correctly, that you use one phase ("the 3rd rail") from the public 3-phase network to run the DC-generator as a motor in order to spin up the system and sync it to the frequency of the grid? This reminds me of the navy where we had to synchronize diesel driven synchronous generators to the network of the vessel. The speed of the generator hat to be adjusted to about 60.5 Hz, i.e. about 0.5 Hz above the network frequency and we used lamps indicating the voltage difference between generator and network. You had to slam in the breaker just at the moment when the indicator lamp went dark. Otherwise there was a danger that the entire ship lost power. (Which happened once during my service - not to me fortunately.) And at the harbour there was a huge engine room full of rotary converters converting 3-phase50 Hz (European standard) to 3-phase 60 Hz to provide power to the ships in the harbour. Thanks for the great video Harald
No, they drive it on the 3rd rail just for display - that's the "live" rail that powers the subway trains with DC (which sits beside the two ordinary rails where the trains roll). So they run the machine in "reverse" so to speak, the DC generator working as a motor during this demonstration and I assume the AC motor is disconnected from the grid as the machine has been replaced by static converters.
The third rail in the subway is the 600 volt rail running along the outside if the tracks in the tunnels that runs the trains' motors. The thing is only covered with a thin piece of wood over it, and they welded those rails live as I remember by covering it with a sheet of rubber to protect the guy welding, scary as heck!
Harold, normally yes. Back in 1904, you had to get the rotary unit up to speed before before switching over to AC to power. There were two ways to do this. Use third rail DC power from another converter in the substation that was already running, or if the substation had to startup from nothing, as in a power failure, use one of the motor driven generators. Either way, DC had to be used to bring the unit up to speed.
I read somewhere that there were issues getting several Rotary converters in sync and also the polarity of the rotary converter could not be predicted. What do you think?
Stumbled across this. (What? In RU-vid?) I know about rotary converters; I ran one just as an experiment that converted 12VDC to 120VAC in my friend's car to be able to run a short wave receiver at a hamfest around 1963. (The noise from the brushes was beyond OK.) Yet, I am not sure what this yumongous rotary was converting. As a side note, my grandmother's apartment, 54 W. 74th St, NYC, had DC service at least until she moved out around 1970. Her refrigerator was of the....dang, can't remember the correct name....type that used heat to cool. The heat for some of these could be electrical, or propane, or kerosene back in the old day. Adsorption! Got it. Also found in campers.
All refrigeration uses heat to cool.well i guess not all but most. I believe what you're talking about used ammonia as the refrigerant and a heat source to boil it and then chemically react with hydrogen to cool. In theory, your head does the same thing, except the heat source is the compressor and theresno chemical reaction, just a phase change from pressure differential. Still... you gotta heat the coolant to get your heat rejection and expansion at the valve. Pretty neat no matter which way is used. And "modern" camper fridge that don't use electricity are exactly the same as old so you're right there. Maybe a bit more efficient in terms of weight, material, and heat dissipation.
This is incredibly informative and educative. I sort of assume that, somewhere in today's world, something very similar still does go on, even with all the semiconductor based devices.
Adjusting the field while its connected to the 25hz supply to adjust its speed? Huh? Power factor sure but not speed. Unless he meant the field winding on the DC motor, but that isn't going to sync it with the line. Going to need 3 light bulbs or a syncroscope for that...
25Hz power generation originated at Niagara Falls because the first turbines installed were designed to spin at 250 rpm and that was set before alternating current was chosen as the current of choice. The first installed Westinghouse generators were 12 pole, which when spun at 250 rpm , generated 25 cycle power. That frequency was ideal for large commutator-type motors and rotary converters such as the one seen here. 25Hz was still being generated by Ontario Power Generation (SAB1, generators G1 and G2) at Niagara up until 2009, supplying steel mills and other industries that required it for their aging machinery.
So are those big bus bars and knife switches energized to 600V? Totally exposed? Even by 1904 standards that seems pretty unsafe. Also, it sounds like it uses the 600VDC from the third rail to get up to speed, then synchronizes with the mains power and switches over - so how did the third-rail system start up from unenergized? Was there an alternative method for starting it from mains power? Was this station not capable of that but others were, so they'd start up those, energize the system, then bring other stations online?
Then it would probably freak you out that in American homes sometimes the electricity would be transmitted by two parallel but naked copper wires that ran from ceramic cap (insulator) to ceramic cap. These wires were only about 6" apart and in certain parts of the house, not where the residents normally occupy, those two naked live wires would be fully exposed.
@@bigk4755 Yikes! Bare is scary alright. My house (built in the 1800's still has vestiges of the "knob and tube" wiring - individual wires, but at least they were insulated!)
Ah Back In A time when everything was build heavy-duty en barely brakes Just Like 1950s inline 6 engines the whole car can Rust away before the engine dies
Don't forget the inline 8 cylinder engines, i.e., straight eights. I've driven several cars with straight eight engines, Packards and Pontiacs, and ridden in Buicks with straight eight engines. Many cars had them available, including Hudson, Studebaker, Pierce Arrow, LaSalle, Oldsmobile, Chrysler, DeSoto, Duesenberg, Hupmobile, Mercedes, and others. That's 13, but there were a few others.
Oh God spoken like a true layman who's never designed/engineered a newer piece of equipment. Stuck in the fairyland "good ol days" mentality. Those 1950's inline 6's you so naively glorify.....what was the MPG on them? How much pollution did it inject into your lungs and give you cancer? What was the per-liter hp/torque outputs?
Cool! The "Letterman theater" is actually a CBS theater that was used for various things (the major networks have studios all over the city) until it became the home of _The Ed Sullivan Show_ and was renamed from "CBS Studio 50" to the Ed Sullivan Theater. Other shows used the facility, and in the '80s it was still used for TV. When Letterman moved to CBS, CBS bought the property outright (it had been leased before then) and configured it for Letterman. The Letterman show was still there when the facility was converted for HDTV, one of many changes. It's not clear when all the steel stuff mentioned in the video was added, but it's been a working TV studio since 1948, so obviously there has been suitable EMC for television at least since then. I was always curious what was in that building behind the theater, finally I know!
Shame how *Metro Media Square* in Los Angeles, where "All In The Family", "Good Times", "One Day At a Time", etc. was raised to make way for another worthless LAUSD school to pump out more illiterates.
That is awesome to see it in operation. I hope the gentleman that is explaining the operation to us has this information written down somewhere on how to operate it. The day when no one is left around that has the knowledge to operate it will become scrap😪
They are exposed yes but normally on those big old blade-switch panels they are set up so there is no ground-route with the neutral (in AC) or negative 0V (in DC) referenced to Earth/Ground. In this way they are not hazardous unless you touch two. I know sometimes where there was a reference to ground they'd have a thick rubber matt on the floor to electrically isolate the person operating the blades.
i saw a drawing of the first crane that my former employer built back in 1900 ish. no cabin just 3-4 levers and some pedals, sitting next to a exposed 2m diameter flywheel rotating 10cm away. no cage no cover of anykind.
From Wikipedia: A rotary converter is a type of electrical machine which acts as a mechanical rectifier, inverter or frequency converter. Rotary converters were used to convert alternating current (AC) to direct current (DC), or DC to AC power, before the advent of chemical or solid state power rectification and inverting. They were commonly used to provide DC power for commercial, industrial and railway electrification from an AC power source.
And hydro-electric generators; they vary the amount of water flowing through them until the Synchroscope (my favourite instrument!) shows exact synchronisation then *bam* in goes the circuit breaker!
