Smoke, sparks, fire & scary noises.

[Anonymous]

QUOTE: Originally posted by jruppert

QUOTE: Originally posted by adrianspeeder

I love the sound of a two stroke diesel, nothing like it. There is an old guy down the road with a big genset that is powered by an old Detroit Diesel. I am grinnin like a foamer when that thing roars.

Question: What are the differences in electrics for AC vs. DC dynamic brakes?

Adrianspeeder

Detroit Diesels, at least the older ones, have a bad reputation for being smoky, oily, overly complicated, and unreliable; but can be trouble free if well maintained. Personally, I like them, and when they're fully loaded they scream like a banshee!!

I once sat in the bilge between two 8V71's freshly overhauled out on a shakedown, one clockwise, the other counterclockwise. Each one was rated at 600 hp (marine engines can do it because of the cooling), with twin turbos, and double intercooling, they flat out screamed!!!

im glad this thread was resurfaced. wonderful stories and info!

and i just have to add this. god i hate detroits!! i work in the marine industry, and thank god all of our boats have CATs. all of our gens are non turbo detroits, and thats good enough for me. one boat we had for a time, mv. Gold Star, had detroit mains, ohhh couldnt stand it, LOUD, srceaming, and too under powered for her size.

[chad thomas]

Just digging up and old thread.[8D]

[gacuster]

Many thanks for the reply Randy, someone posted a picture of that locomotive earlier this year at its new home at a museum somewhere with a fresh coat of paint in Soo Line colors, so maybe its fire making days are over. Please keep the stories coming!

[Randy Stahl]

The big problem maker on the WC was the 703, we "stored" those GP-30s many times for the last time. with 703 we discovered that the inertial filter blower motor was unplugged, the locomotive air filters plugged up and the rich air fuel mixture caused a buildup of carbon in the turbo stack, this was our fire starter. The other problem with these engines was the radiator shutters were getting really balky, on cool or cold days the locomotives would never get up to operating temperature causing unburned fuel out the stack, hence the white smoke.
Randy

[gacuster]

Mr. Stahl,
What fascinating stories! I was wondering if you ever worked on a old Soo Line GP-30 that used to come to Manitowoc, I believe it was the 700 and was in the red & white paint with WC stenciled on the cab. I saw this unit leaving town once with thick white smoke pouring from the stack, I think it was paired with a GP-40. The next day in the paper there was a story about several grass fires this locomotive had started along the ROW near Valders. What was wrong with this engine to make it smoke like that?

[Anonymous]

Waaayyyy too funny Randy!

Norma

[Anonymous]

Another note on meggars. A GE field service engineer once wrote a trip report from Brazil that said that Brazilian electricians make the same noise as American electricians when they get across a meggar

[Randy Stahl]

Generally all railroads use the same pinouts. some exceptions are noted, however , one has to discover differences themselves.

[chad thomas]

Hey Randy,
I find the different uses of unassigned pins interesting. Could you give us a rundown of railroads using these pins and what for?

[Anonymous]

I want to thank everyone in this thread, especailly Mr Stahl... these stories are GREAT and the information is wonderful. Thank you!

[Randy Stahl]

This was know as field loop dynamic brake control. I have seen field loop on engines as new as SD-40s. Instead of using pin 24 as trainline potential, a seperate train line loop was used to control DB exitation.
Randy

[Anonymous]

QUOTE: Originally posted by Randy Stahl

This is a general pinout on EMD locomotives, some RRs have added trainline ground reset, slowspeed control,etc.
Pin#1 not normally used, some RRs are using this for slow speed control.
Pin#2 train line alarm, rings the bell in all the units.
Pin#3 governer D valve, for trainline shut down and engine rpm
Pin#4 control negative
Pin#5 emergency sanding
Pin#6 generator field
Pin#7 governer C valve, engine rpm
Pin#8 foreward, pin out pin 9 on the front pin 8 on the rear
Pin#9 reverse. pin out pin 8 on the front pin 9 on the rear
Pin#10 train line wheel slip light
Pin#11 not used,,
Pin#12 governer B valve
Pin # 13 control positive
Pin #14 not used
Pin#15 governer A valve
Pin#16 engine run relay
Pin#17 dynamic brake setup,( if equipped )
Pin#18 not used
Pin#19 not used
Pin#20 trainline brake warning light
Pin#21 dynamic brake setup controls rpm in dynamics
Pin#22 compressor syncronisation(if equipped)
Pin#23 trainline manuel sand
Pin#24 dynamic brake train line potential, 0-72 volt
Pin#25 MU headlights
Pin#26 some times used for mu ground relay reset
Pin#27 not used
most of these pins are allocated by the AAR but the ones that are not can and are used for many different things, for example the Santa Fe used the pin 19 as an extra control negative, the Milwaukee road used it for a positive to ring the locomotive bells, guess what happens when you MU them?
Randy

i got a question about this. . .

on the older first gen's ( gp9s come to mind ) above the round MU box. . is a square one. . whats this for? i was told somthing with the dynamics but? can you clear this up ?

[rvos1979]

QUOTE: Originally posted by Randy Stahl

With all the recent questions on alot of the locomotive tech, I thought I would revive and old thread.
Randy

Keep the answers and stories coming, Randy!

Speaking of sparks, it's always cool to clean the carbon out of locomotives at night!

The Other Randy

[Randy Stahl]

With all the recent questions on alot of the locomotive tech, I thought I would revive and old thread.
Randy

[Anonymous]

QUOTE: Originally posted by AlcoRS11Nut

QUOTE: Originally posted by Limitedclear

QUOTE: Originally posted by AlcoRS11Nut

Any Stories about ALCo's?

They smoke, they leak, they break, they get scrapped. The Alco story...

LC

Ouch....that hurts.[B)] [:D]But what about those ALCo's shortlines use......they can't break that much because if they did the small budget of the RR could they afford to fix them, or could they?

They can and they do. Not too many short lines using them anymore. A few...

Most Alcos and MLWs are pretty worn out these days...

LC

[Anonymous]

QUOTE: Originally posted by M.W. Hemphill

QUOTE: Originally posted by Limitedclear

QUOTE: Originally posted by AlcoRS11Nut

Any Stories about ALCo's?

They smoke, they leak, they break, they get scrapped. The Alco story...

LC

Uh, LC, popularity contests at railfan meets you must not plan to win, do you!

Mark-

It's that darn real world experience. It just kills the fun everytime. Ever had to change a radiator on an RS18u with only two guys and a big forklift?? Oh, yeah, it was leaking. And after we got it to the shop and got it back installed, we found out it didn't fit because the shop idiots recored it backwards. SO, we had to do it ALL OVER AGAIN...

Damn Alco JUNK...

LC

[AlcoRS11Nut]

QUOTE: Originally posted by Limitedclear

QUOTE: Originally posted by AlcoRS11Nut

Any Stories about ALCo's?

They smoke, they leak, they break, they get scrapped. The Alco story...

LC

Ouch....that hurts.[B)] [:D]But what about those ALCo's shortlines use......they can't break that much because if they did the small budget of the RR could they afford to fix them, or could they?

[Randy Stahl]

One lead goes to ground ( locomotive frame ) the other goes to the high voltage, like a bus bar , reverser etc.
Randy

[Anonymous]

So how would you connect a meggar to a circuit to detect a ground fault?

[Randy Stahl]

That is correct. My personal meggar is a yokogawa battery model, it can be found in many catalogs on the subject.
Randy

[ericsp]

If I remember correctly, megger is slang for megohmmeter. According to Electrical Motor Controls, 2nd Edition by Gray Rockis and Glen Mazur (American Technical Publishers, ISBN 0-8269-1675-9), a megohmmeter is "a device that detects insulation deterioration by measuring high resistance values under high test voltage conditions."

[adrianspeeder]

Oooooo, a meggar, i would like a picture please.

Adrianspeeder

[Anonymous]

Detroits will suck oil and keep stumbling even with the air intake blocked. I have seen them overspeed before, once in the tight confines of a bilge - pretty scary. It must be a two-stroke thing.

When I was going to school for diesel technology, in an injection class, I learned that the injectors are only putting out about five percent at high idle (maximum rpm,no load). This gives you a pretty good idea of how quickly an engine can possibly take off. It also gives you an idea of how important load testing is to really expose problems ( just because an engine is running at max rpm, is still at a fraction of load).

I think your average guy might be wondering what a meggar is. I know they are used for testing resistances of very high value. The ones that I have seen in the navy were very old and hand cranked.

[Randy Stahl]

Tools of the trade:
On the Milwaukee road we were not issued many tools. The little tool pouch that I had , contained an 8" cresent wrench, a needle nose pliers, a pair of Klien crimpers, 2 screw drivers, one Phillips and one slotted, and a pair of linemans pliers. The test equipment that we were isued consisted of a hand ful of alligator clips, a spool of wire, a lamp socket and a little light bulb, a lantern battery and a doorbell buzzer.
The Milwaukee preferred that when trouble shooting locomotives they be worked dead , I always preferred working live engines but I had to bend to avoid problems. Any problems in control circuits were worked with the doorbell buzzer. You could find most problems with broken wires and bad interlocks quickly and easily. If a low voltage ground was expected it was short work with a 72 volt light bulb connected to ground to locote the problem. The FM locomotives were almost always infested with grounds of one sort or another.
The locomotive shop had a piece of test equipment that was called "the bomber" . This tester had 3 settings: hipot, thump and burn. when a locomotive came in with a ground relay problem the first think you would do is use one of the shop meggars to find out the general condition of the electrical system, sometimes a meggar will find a hard ground with out going any further. If a meggar cannot tell you where the ground is then you move the locomotive into the shop and apply the bomber. The hipot setting works much like a powerful meggar, you still must isolate circuits and narrow down the problem to a specific part of area. The thumper setting sends a high voltage pulse throughout the high voltage system and the problem can usually be heard or seen. The burn setting will do exactly what is says it will do. You will find the problem , but most likely it now cannot be repaired.
The FMs were in bad shape by the time I got there. For many years the high voltage grounds have been repaired by sliding little bits of wood under the offending cabling, by the time I got there the cableing was raised a good 8 " off the generator room floor. They crap would pile up under the cabling and you would just raise it up a bit more to get it off the dirt.It was easy to tell the Milwaukee had little interest in running these engines much longer.
Randy

[Randy Stahl]

Fires & other mishaps is the topic of this thread, basically the stuff I remember after all these years, like feeling helpless standing up in the office watching a locomotive roll into the turntable pit after some idiot forgot to set a hand brake, or load boxing a locomotive for a customer while he's standing nearby and blowing up a turbo. you name it I've either seen it or done it. What really makes me jumpy though is getting zapped by my own test equipment. Using a meggar to test for grounds and charging up the AR10 capacitors, then touching the test leads and getting blasted with 1500 volts.
Randy

[jrw249]

Randy,
Did you ever see an engine blow , turbo shatter , flyweel or fan fly apart, etc------.
If so, must have been a horrible experience.

[Randy Stahl]

I have many RR stories that are difficult to relate, simply because cleaning up the language is a big job.
When I got my first REAL RR job with the Milwaukee, my coworkers had me terrified of the equipment. I was often sent out to assist the electricians with loadboxing locomotives, this was a scary job. Alot of the time engines were put on the loadbox to find the problems. One such occasion we were loadboxing a Fairbanks, the locomotive was reported smoking and throwing oil.... Typical for a Fairbanks but they wanted the problem solved. Alot of times we would put the FMs out side and put em in throttle 8 to blow the crap out of them. This FM was put on the loadbox and we proceeded to load her up. The cab was full of machinists and was pretty crowded, I was sitting on the floor behind the firemans seat. The FM was doing good in notch 8, all sorts of BIG chunks of carbon blowing out the stacks !! Not long into it the RPMs began increasing.. and increasing. The crowded cab began to empty out as Machinists jumped and ran off the loconmotive. The electrician I was working for pointed and told me to stay put. The engine was clearly running away, I was scared. My journeyman grabbed the CO2 fire extinguesher and calmly walked down the running boards, I couldn't hear him but i could see his mouth moving and not good words were coming out. He pointed the CO2 into the air filters and let it go, the engine RPM dropped off and the locomotive died. I asked him what that was all about , ( here's where you may insert bad words ) he said..."This fine machine is a little wore out and is started sucking lube oil out of the crankcase". Scared the @@@@ out of me !!!
Randy

[Anonymous]

Out of the freezer and into the cryogenic, stay warm.

That must have been soooo cool to get to actually operate a train when you were a kid. When I was a kid, I came running for every train and could not even imagine that.

[jeaton]

Randy

Just can't give up winters. Right? Good luck there and stay in touch.

Jay

[Randy Stahl]

I remember the first time I saw a "train". I grew up along the East Troy RR. I lived about 100' from the tracks. I remember the electric car , M-15 pulling cuts of cars back and forth between the SOO interchange and East Troy. Us kids mostly knew the train crews pretty well and they knew us and our familys. My grandparents on both sides had property along the RR so I had alot of contact with the little electric RR daily.
In 1972 a RR museum moved to town and free rides for the residents of East Troy was in order. This was my first train ride, North Shore line # 757. All of us kids payed close attention to any "new '" additions to the operations and were pretty exited when something different would show up on the RR. It was quite a few years before we got another train ride , 1976. Free rides !!! This time I was a little older (11) so I knew what was going on. I was disappointed to miss the NSL # 763 , so I had to settle for another ride on the 757. The conductor was a fellow named Don Liestikow, he told us that the cars were staffed by volunteers !!! I was intrigued, it seemed that I could join this group and "work " on the RR. The dues at the time were $10.00 I baled alot of hay that summer and scraped up 10 bucks.. They accepted my money I WAS IN !!!! Now I got free rides all the time!!!! I spent ALOT of time riding the plat forms of the North Shore cars, it never got old. I was allowed to run the cars and was not bad considering I was only 12 years old. The first train I operated was the NSL 411.
I met and became friends with alot of retired railroaders. This became my classroom and I chose my career because of the RR stories and tutalage given me by these fine people. I will always have fond memories of the Milwaukee Electric Ry & Light Co. equipment and the good ol North Shore cars. I chose to be a locomotive electrician at 12 years old because of them, and had all the basics down.
I recently accepted a job with the Montreal Maine and Atlantic RR as a manager of locomotive maintenence. I plan on being there by Oct 1st.
Randy

[Anonymous]

Come to think of it, it is a standard item. There's the ones that are in a vertical riser that turns 90 deg. to a horizontal plane with a circular cross section, and there's the ones that are low profile, a wide plate on top of the blower, with two large butterflys, much like a fireplace damper.

[broncoman]

[Often there is a flapper over the intake, held open by a quadrant. Flip the pawl and it shuts off air to the engine. I have seen engines continue to stumble after asphyxiating them, they will suck oil from blower seals, valve guides, anywhere! and keep running!

[Anonymous]

QUOTE: Originally posted by broncoman

QUOTE: Originally posted by jruppert

I used to work at company that made custom generator packages and sometimes when starting a unit for the first time, a feedback loop between the generator and the governor would cause violent surging in the engine's rpm, is this a problem in locomotives? When working on older Detroit Diesels and starting them for the first time after an overhaul before any adjustments have been made to the governor, they will "run away" and must be carefully kept from overspeeding, is this also a problem?

When I went through my apprenticeship, my journeyman always told me to keep a clipboard handy when working on non-DDEC detroits. They make a great kill switch.[:D] Of course this only works on 92s and smaller.

Randy,
How long is the normal apprenticeship for locomotive electricians? When you actually made journeyman, did a wave of terror sweep over you, your first day as a journeyman as you thought wow I am suppose to know all this now. Just curious.

I don't want to steal your question Randy, I just want to add a comment about Detroits.

Often there is a flapper over the intake, held open by a quadrant. Flip the pawl and it shuts off air to the engine. I have seen engines continue to stumble after asphyxiating them, they will suck oil from blower seals, valve guides, anywhere! and keep running!

[Randy Stahl]

Usually an aprenticeship lasts 4 years, I was never offred an apprenticeship so I spent a long time working as a helper. In time I was able to test up to a journeyman, the test was simply show that I know what I'm doing. I was hired at the BRC as a journeyman and never looked back. In retrospect the apprentices were treated alot worse than us helpers and we weren't treated real well !
Randy

[Anonymous]

QUOTE: Originally posted by Randy Stahl

QUOTE: Originally posted by jruppert

There is an override of low oil pressure shutdown for a number of seconds in the governor to allow for starting of the engine. This guy must have kept cranking the engine wondering why it wont start !!!!

When your leaning on the layshaft , you over ride any engine protection.
Randy

That sounds even more ham headed !!

[broncoman]

QUOTE: Originally posted by jruppert

I used to work at company that made custom generator packages and sometimes when starting a unit for the first time, a feedback loop between the generator and the governor would cause violent surging in the engine's rpm, is this a problem in locomotives? When working on older Detroit Diesels and starting them for the first time after an overhaul before any adjustments have been made to the governor, they will "run away" and must be carefully kept from overspeeding, is this also a problem?

When I went through my apprenticeship, my journeyman always told me to keep a clipboard handy when working on non-DDEC detroits. They make a great kill switch.[:D] Of course this only works on 92s and smaller.

Randy,
How long is the normal apprenticeship for locomotive electricians? When you actually made journeyman, did a wave of terror sweep over you, your first day as a journeyman as you thought wow I am suppose to know all this now. Just curious.

[mvlandsw]

QUOTE: Originally posted by jruppert

Randy, have you ever had problems with critters other than bats? I used to watch a N&W daily peddler come down a track that in the summertime was practicaly obscured by the tree canopy, and a wave of fleeing insects always preceeded the locomotive.

I frequently see bats chasing insects in the headlight beam at night. One time in a tunnel a bat came into the cab. I thought the brakeman was going to jump out.

[Randy Stahl]

QUOTE: Originally posted by jruppert

There is an override of low oil pressure shutdown for a number of seconds in the governor to allow for starting of the engine. This guy must have kept cranking the engine wondering why it wont start !!!!

When your leaning on the layshaft , you over ride any engine protection.
Randy

[Anonymous]

There is an override of low oil pressure shutdown for a number of seconds in the governor to allow for starting of the engine. This guy must have kept cranking the engine wondering why it wont start !!!!

[jeaton]

Randy,

You mean that isn't something you fix???

Jay

[Overmod]

What, no lube-oil warning or oil overtemp on a 567?

Oh, wait... lube level is a gauge next to the prime mover, and nobody read it, and the overtemp is a sensor that only works when there's enough hot oil to reach where it is...

Ouch.

[Randy Stahl]

" GET AN ELECTRICIAN "
That seems to be the magic fix all when some thing goes wrong on a locomotive. After all you can never be sure if the problem is caused by all those wires running everywhere.
This story I was reminded of the other day, seems one of the foremen went to start an SW1200, the locomotive started but failed to stay running.. At least thats the story that I got. I was approached by the foreman and went to look into the problem, as near as I could tell everything was working OK execpt the engine would not rotate, I even put a long bar into the flywheel holes and could not budge the prime mover at all. Thats right the engine had siezed up... a quick look in the crankcase ..... no lube oil !
Randy

[Anonymous]

Great stories and excellent info Randy! I work on hybrids which is probably the closest I'll ever come to loco technology but has some similarity -though on a smaller scale. I especially like your statement that voltage always returns to its source. That's always good to remember and to make sure you are not in its path.
Keep the stories and info comin'!

[Anonymous]

QUOTE: Originally posted by AlcoRS11Nut

Any Stories about ALCo's?

They smoke, they leak, they break, they get scrapped. The Alco story...

LC

[Randy Stahl]

The darkest days in my RR career are when a buddy gets hurt, or worse. The lead electrician on our RR is a fellow named Mike M. Mike is the kind of guy that makes you laugh even when things are going badly. It came as a shock to us when one day Mike left work in an ambulance. He was doing a job the he'd done many times, load testing an SD-45. Most locomotives are equipped with a self load feature that connects the main gen to the dynamic brake grids. Multi meters are then connected to a tect panel and the horse power is calculated from these readings. In tech terms the MG voltage is read on the voltage terminals and the current is read in millivolts from an 80 Mv shunt, so Mv times 80 = amps times volts divided by 700 = horsepower. Mike made the connections onj the test panel incorrectly, connecting pos. lead to MG volts and neg lead to loadtest shunt creating a dead short across the main gen. Mike was holding his meter in his hand when the short occured, we think he changed the meters setting to read milliamps, the meter turned into a fireball, burning him severely, the locomotive tripped the ground relay preventing a fatal electrocution.
You cannot let your guard down and you must think before doing, as if this weren't bad enough 2 weeks later another electrician did the same thing. At this point the company decided that they would provide 2 meters and the connections will be made before the engine is loaded. ALLWAYS THINK!!!!!!!!!!!!!!
Randy

[Randy Stahl]

Raccoons are terrible electricians: Leaving locomotives that are left stored for long periods are subject to animal infestation, mice, pigeons,bats, birds filling the dynamic brake hatch with nests,by far the most destructive are the raccoons. The scariest noises I ever heard came from the inside of the electrical cabinet, growling ,screeching and general carrying on . They rearrange the electrical cabinet to suit their own needs ,which means the locomotive wirring is done for.
Randy

[Anonymous]

Randy, have you ever had problems with critters other than bats? I used to watch a N&W daily peddler come down a track that in the summertime was practicaly obscured by the tree canopy, and a wave of fleeing insects always preceeded the locomotive.

[Randy Stahl]

FAST START. Thats what the little switch on the control stand says on a GP-30. What it did was a mystery. It didn't work , it hadn't worked for many years. When I came to the WC no one was really sure if it ever worked. I knew how it was supposed to work having dealt with GP-30 and GP-35s on other RRs so I went ahead and took the time to repair it when it came in for an annual inspection. It wasn't hard to fix, just a wire off a terminal board. I was satisfied I did a good job.
Our roundhouse tracks slope down hill into the turntable, it is necessary to put chains under the wheels to keep the locomotives from rolling out the door into the turntable pit.
When you want to remove the chains you must move the locomotive ahead. GP-30s are slow loading locomotives, they start in minimum field position on the load regulator so most guys slap the throttle to 8 to get the thing to move. I was standing a few bays away from the GP-30 I repaired,, working on another project, my co worker Donny B was prepairing to take the GP-30 outside, he started the engine(we air them up with house air before starting it) released the brakes and slapped her into throttle 8. She took off like a cannon shot, in the blink of an eye she was through the wall of the round house, dust and block were flying every where. The entire locomotive made it out to the parking lot . fortunatly no one had their car parked nearby. I told them I fixed the fast start and my boss was happy that some one knew how to fix it so I didn't get in trouble, It was fun to see the head scratching when the carmen came over to rerail it though.
Randy

[Anonymous]

I guess I'm posting just so this topic is on the front page. I think this is my favorite, the stories are cool, and the tech talk appeals to the gear head in me. Surely there are more poeple with cool stories to tell.

[Randy Stahl]

Injurys on the RR are taken very seriously, injured employees are reported to the FRA and alot of paperwork goes alon with an injury. some injurys are not very serious but If they result in lost time all injurys are treated equally. I pride myself as being a safe worker however I have had 2 reportable injurys in 20 years of railroading. One time I cut my finger on a slip ring cover on a GP-9, it became a reportable injury because I got 6 stiches, there was no lost time.
The other reportable injury is one I'll include in the scary noises part of this thread.
On a hot summer night a few years back I was confirming a grounded traction motor on an SD-45. This was a routine job on a routine night at work, this was about to change!!
I got down off the locomotive with my tool pouch slung over my shoulder. I felt a stinging in my right hand and when I looked down a LARGE bat had bitten me and was hanging from my hand (I about passed out) . A quick look around I noticed about 15 bats flying around the diesel shop. my co workers witnessed this and since we don't have tennis rackets laying around, everone grabbed long handled shovels and started swinging at these things, real dangerous, some one was going to get a shovel upside thier head. everyone calmed down in about 10 minutes and the shovels wen't away. I thought that was all there was to it. I put a bandaid on and went back to work. When first shift came in about 6:00am I was called in the bosses office and he insisted that I see a doctor. I had no choice. I scheduled an appointment and was able to get in about 8:00am I lived 4 blocks from the doctor so I walked. The doc got my attention when he told me I needed to get the rabies series. Now it became a reportable injury, as if the shots didn't hurt enough. I couldn't even walk back home
Randy

[Anonymous]

We were office testing a Servo 8808 Hot Box Detector, meaning, we would hook everything up and let it run a while before it was to be taken out to the field for installation. After everything was connected, my fellow technician was about to power it up, I snuck behind the rack - which stood about 6 feet tall - and lit up a cigar. Just when he hit the power switch, I blew this huge smoke cloud from behind it. The smoke came out of the front and all you could hear was "ki-ki---ki--ki--ki--ki !!!" he was trying to say "kill the power!" but, he couldn't get it out!

Another favorite is when someone is about to take a meter reading, and, you can see they're nervous (high voltage, but, it only hurts for a few seconds), just before they touch the test points, you clap your hands by using the finger tips against the other palm, which makes a nice high pitch sounding "pop". Usually makes them jump everytime.

[jrw249]

Randy,
With all your stories, you should write a book!!!!!!!

[Randy Stahl]

Winter time in Wisconsin can be very challenging for railroaders. The extreme cold,blowing snow make safety a high priority. Freezing temperatures are hard on the skin, getting your hands frozen to a grab iron is one of the many hazards. Wading through knee deep snow to throw a switch is commonplace. The fine dry powder that we sometimes get will ruin traction motors and generators. Pulling a locomotive into the warm roundhouse sometimes is self defeating because after an engine has been in 10 below cold, the nice warm roundhouse causes the locomotive to frost up, including the traction motors. If you are looking for a ground relay problem once the motors frost up and begin to get wet , all the motors will show grounded. You really only have a very short time to isolate a problem. Most work is done outside in the bitter cold.
One cold night, working 3rd shift we were running into all sorts of these problems, it started snowing at about 1:30am and was showing no signs of letting up, add to this the temp was about 0 deg with a 40 mph north wind. locomotives were falling down left and right, we were having difficulties just getting the snow off the running boards, throw in a dozen engines that won't load or that are getting ground relays and things were pretty much at a stand still. The yardmaster was on the phone continuosly , either he desperatly needed power , or one of the yard engines went belly up, requiring an electrician to go to the yard and look at their engines. We never gave up, but there was only so much we could do. Due to the weather many T&E employees were not able to make it to work so the train dispatcher was calling around the shops for qualified conductors, thats how desperate the situation in the blizzard of 95 had become.
After my 8 hour shift was over I breathed a sigh of relief, I walked out side the diesel house and took a look at the RR yard covered in 2 feet of snow, I got to admit it is pretty. It appeared to me that nothing was going to move today so tomorrow will be another busy day. I turned around just in time to see an approaching train, I coul'nt really make it out at first but as it got closer I could see double stacks ,ah train 119 out of Green Bay, the hottest train on the RR. It got closer and I was able to get a look at the power, holy cow!!!! The Green Bay yard must have been really hard up for power because on the head end of 119 were 4 high nose GP-7s with 4119 in the lead. It was quite a sight seeing these wonderfull old locomotives on the point of a stack train, in the middle of a blizzard. I had to see more of them so I called the chief dispatcher and asked if these engines were going through to Chicago and THEY WERE!!! We didn't have any thing else to give them. I got my clothes changed and headed out the door, into the car and struggled at 20 mph to Byron wi, about 10 miles out. Good thing they were changing crews or they would have beat me there for sure. After a short wait I could hear them whistling for the next crossing south.. Oh boy here they come, This will be a great picture, I should have plenty of time, I don't think those old engines can go much faster than 20 mph WRONG... They whipped around the curve and they were upon me , in a cloud of snow ,567 exhaust I was so impressed that I forgot to get that picture I assure you that my mouth was agape and my eyeballs big. They were easily doing 60 as they passed me. The train passed out of sight and I made the long trip home, the whole time saying to myself WOW!!!!
The blizzard wasn't letting up, when I got home my wife told me that the RR called. I called the RR back and related what I just saw, my boss wasn't impressed. He wanted me to return to work, many people on day shift called in, I was standing next to the window watching my wife leave for work. I saw her back out, get stuck, go ahead and plow into the side of my car. I told my boss what just happened and said the only way I can make it to work now is if they sent a train for me ha ha . About 3 minutes after I hung up the yard called to tell me a train was on it's way into town, he would stop and pick me up!!!
I figured what the hell!!! At least it'll take my mind off my smashed car. My wife made it to work and I set off to walk the 5 blocks to the RR tracks, damn was it cold, the snow was so deep cars were abandoned on the street. I got to the tracks as fast as I could , no train!! After 5 minutes I was ready to go home to bed, when the crossing lights came on. Around the curve comes a train, a very short train. The engineer stopped on the crossing and I got on, the engineer said I must be pretty important to stop Mr. BURKHARDTS BUISNESS TRAIN....
Randy

[Anonymous]

Hey guys,
Thanks for the great explainations. Very informative.

Anyway, enough of the tech questions for now. How about some more of your great stories Mr. Stahl.

[Randy Stahl]

Adrianspeeder is right positive to negetive =smoke, sparks,fire and scary noises.
The governer used most on locomotives is a PGR type governer, basicly they use a combination of 4 valves to control the rpm's. jruppert gave a very accurate summary of how the governer works and if you want to go deeper on EMD locomotives chapter 12 in the engine maintenence manual is devoted to governers, but I think jrupprt did a fine job on the governer mechanics, remember that we want 8-9 speeds from the governer the 4 valves are the speed servo's.
About pin #6 all this controls is the gen field contactors on each locomotive. The actual gen exitation on each locomotive is stand alone.
As for pin#16, you are correct, the ER relay in effect turns the governer and throttle response off.
Pins # 4, 13 are the control negative and positive, on trailing locomotives the control devices on all locomotives must be controlled from the lead locomotive, for example , the FOR (forward relay) has no power going to it as a trailing unit, unless you were to go back in each unit in the consist and throw all the reversor handles you could not change direction. this power comes from the lead unit and passes through the control breaker on the lead unit.
The MU brake warning light operates when the grid current for any reason is exessive, warns the engineer to back off on the dynamics, or look out the rear window and watch the fire. One interesting thing that happened to me shows the MU incompatability problem that some times pop up, on the IC they used pin 1 for emergency sand, some times this relay will get stuck and when it does and it is MUed with an engine equipped with slow speed control, the trailing engines will not load, that was a fun one to figure out.
As for ALCO stories yea I got a few, on the WC we inherited the GB&W fleet and ran them in reguler sevice in the dead of a wisconsin winter. I worked for the BRC and we had a fleet of ALCO's. I have an ALCO S-6 I am trying to sell to a good home.
My fondest memory of an ALCO is of the RS-20 -chopped & repowered RS-3 what a nice little engine, quick snappy throttle response, pull just about any thing, easy to get in and out of the cab and simple to work on. It had great all around visability was fairly quiet in the cab, fast brakes and good brakes, if it sounds like an engineers dream locomotive it was. I hope this is a good answer....
Randy

[AlcoRS11Nut]

Any Stories about ALCo's?

[AlcoRS11Nut]

QUOTE: Originally posted by Randy Stahl

I don't know if anyone else has this problem? I have a hard time staying awake on freight trains. Often times I ride trains to diagnose a mysterious problem, I'll take my trusty laptop, my tool pouch,food etc.sometimes I ride a train right after my usual shift. One time I got into trouble. On a train to Chicago I fell asleep, I was sleeping very soundly because I failed to notice the crew change. The WC crew delivered the train to the CSX, the CSX crew took over and I was happily sound asleep. When I woke up the train was just like I remembered it exept I didn't recognize the countryside. I was riding the 3rd unit in the consist. I waited for the train to stop for a meet and walked up to the cab. I must have scared the hell out of the crew, they weren't expecting someone coming in the back door. I didn't recognize the crew and I started getting that old sinking feeling. Turns out I was somewhere in eastern Indiana, I was in a panic. It was decided that I should get on the next westbound train and get back to Chicago. I arrived back at the BRC and had to wait several hours for the next WC train so I climbed into the cab of the WCs and took a nap...

Woops!

[Anonymous]

Randy can explain the governor valves, but to help you understand his answer I will chime in a few basic ideas about governors.

Your typical mechanical governor has other components, but basicaly, flywheights, a spring, and a balance bar. The flyweights are spinning when the engine is running, and their centrifugal force pushes a collar that moves the balance bar in a direction that moves the injectors to less fuel. On the other end is the spring, which moves the balance bar in the direction of more fuel. The balance bar has a break in it, where input from the shutdown lever enters.

Changing spring pressure changes how hard the flywheights have to pu***o decrease fuel, which they do with greater force as engine speed increases. At some point balance between spring force and flyweights are achieved. The shutdown lever "breaks" the balance bar so that the spring and the flyweights relax and the fuel rod moves to "no fuel" position. When the shutdown lever is in run position, the balance bar cannot move below idle position. This is a bare bones explanation of a mechanical governor.

There are diferent types of governor. A limiting speed or LS governor, gives direct control of engine speed, but only between a minimum and maximum rpm, this is typical of truck and automobile engines. It is possible to let the clutch out without touching the throttle, and the governor will pick up the load.

A constant speed or CS governor holds engine rpm to a single set rpm, and will vary fuel output to keep that rpm. This is typical of stationary engines.

A variable speed governor or you guessed it, VS governor, is like a CS governor, but the set point can be varied. This seems to be the type used in locomotives.

An LS/VS governor is typical in trucks with a large PTO, like a garbage truck. when you hear the engine go to a single higher rpm while the hydraulics are being used, the governor is in VS operation. Often in the cab there is an adjustment for VS rpm.

The type of governor in a locomotive engine is not mechanical but hydraulic, which is typical of larger engines because of the amount of force needed to move the fuel racks.

I have not been able to find a way to buy an engine manual directly from EMD or GE, but have seen used ones for sale on E-bay. But, if you go to your nearest Detroit Diesel dealer, buy the 71 series manual because the way it is set up, it is an excellent primer of everything you need to know about operation and maintenance of diesel engines. It has been written so that somebody with no prior knowledge can operate and maintain a diesel engine.

[Anonymous]

Inside all those electronic boxes is magic smoke. If you let the smoke out, they stop working!

[adrianspeeder]

Hmmm, pos to neg.... Fireworks?

Adrianspeeder

[Anonymous]

Interesting, It's a bit different than I thought. Most of these I understand, But I'm a little confused about how the governer valves work. Could you explain a little more about how this works ?

And pin #6 (gen. field) implies that the generator field is common throughout the consist. Is that right ? I find that suprising. I would think that each unit would be seperate. Or is this just a field controlling voltage for each unit ?

What is "pin #16 engine run relay" for ? Is this for emergency shut down of the consist?

What does "pin#20 trainline brake warning light" warn you of?

What are the controll neg/pos? Is this a referance for high and low of voltage dividers for controll voltages?

Oh, On the SF / MILW situation, I'm guessing the bell doesn't work. I would hope it's not the other way around and the bell is always on. I would imagine that would drive the crews crazy.

[Randy Stahl]

This is a general pinout on EMD locomotives, some RRs have added trainline ground reset, slowspeed control,etc.
Pin#1 not normally used, some RRs are using this for slow speed control.
Pin#2 train line alarm, rings the bell in all the units.
Pin#3 governer D valve, for trainline shut down and engine rpm
Pin#4 control negative
Pin#5 emergency sanding
Pin#6 generator field
Pin#7 governer C valve, engine rpm
Pin#8 foreward, pin out pin 9 on the front pin 8 on the rear
Pin#9 reverse. pin out pin 8 on the front pin 9 on the rear
Pin#10 train line wheel slip light
Pin#11 not used,,
Pin#12 governer B valve
Pin # 13 control positive
Pin #14 not used
Pin#15 governer A valve
Pin#16 engine run relay
Pin#17 dynamic brake setup,( if equipped )
Pin#18 not used
Pin#19 not used
Pin#20 trainline brake warning light
Pin#21 dynamic brake setup controls rpm in dynamics
Pin#22 compressor syncronisation(if equipped)
Pin#23 trainline manuel sand
Pin#24 dynamic brake train line potential, 0-72 volt
Pin#25 MU headlights
Pin#26 some times used for mu ground relay reset
Pin#27 not used
most of these pins are allocated by the AAR but the ones that are not can and are used for many different things, for example the Santa Fe used the pin 19 as an extra control negative, the Milwaukee road used it for a positive to ring the locomotive bells, guess what happens when you MU them?
Randy

[Anonymous]

Mr. Stahl,
The next question I have (on a list of many) is what are the pin assignments on the M.U. cable (not nessasarly the numbers, but what do they do) I.E. contact closure, voltage controll, ect.,,,

[Anonymous]

Oh, Randy, I actually have close to enough money for the S-1, and a good place to work on it with a pit and a drop table!

The only problem is these funds were previously allotted for a mortgage downpayment at some future date. I checked with the comptroller (wife) if we could make a budgetary revision and her answer was beyond the decorum of this page. Sorry!

[Anonymous]

I should also add that the design of the AR-10 having two sides with the bridge in between IS very efficient, because it deals equally with any type of fault - a ground, an open, or a short.

You were saying not all locomotives have ground fault protection in the dynamic braking, I think that's what promted the questions.

[Randy Stahl]

Yea, a voltage regulator { easier to say} lol, and you are correct about the D14 and the AR10
Randy

[Anonymous]

I recently spent the weekend reading the manual for an FP-40, and while it was an awfull lot of information to soak up in one sitting, I do remember the bridge rectifier, because of the "baseball diamond" in the scematic, which rings the bell in my head, "ding - bridge circut!". If the the potentials are equal on either side, there is no current through the circut; current flows to the side with the higher potential when a difference exists.

I also remember that the D-14 mates directly to the AR-10, and the auxilliary generator has an external reference voltage generator that controls aux. gen. exitation by changing duty cycle of a constant voltage signal.

[Anonymous]

Yes it is.
thanks

[Randy Stahl]

First let me say that the questions so far have been very good, I would hire any of you in a heartbeat as my apprentice.
First lets establi***he sources of the electric currents in a locomotive , remembering that electricity always returns to it's source
1. Batterys, provide power to start the locomotive about 64 volts d.c.
2.Auxillary gen/exiter. A self exiting direct current generator that provides 72 volt d.c. for battery charging, exiting the D-14, all control power, lighting and cab equipment
3. D14 alternator. exited by the aux gen, makes power proportional to engine rpm. at idle approx 65 v.a.c. throttle 8 approx 270 v.a.c. provides power for cooling fans, inertial blower, traction motor blowers{if equipped} and AR10 traction alternator exitation.
4. AR10 traction alternator, exited by the D14 via SCR, provides high potential for traction motors.
With all these different electric potentials it is important to keep them isolated from each other therefor all locomotive wireing is 2 wire, nothing is grounded like in the automotive industry.
Lets look at the AR10. AR10 is actually 2 alternators in one, a left side and a right side. They connect at a common bus on the positive and neg bus. so the 2 sides of the AR10 are connected in parellel.
Each side has a neutral connected at the center of the Y windings, this connection is the basis of the ground relay detection circuit.
A traction motor will run until the insulation in the motor breaks down, at that time any leakage of current will find a path back to that connection we talked about,this can be very destructive, so what the clever engineers did is look a very sensitive relay, connected one side of this relay directly to ground and the other side to the AR10 neutrals, so that when voltage/current get too high this relay operates and stops the locomotive from loading. One other thing, remember I said that the AR10 is really 2 machines connected in parelell, if one side of the machine is making more power it will trip the ground relay. Because the diodes and fuses that rectify the traction power some times blow an imbalence can occur so the clever engineers placed a bridge rectifier BETWEEN the 2 neutrals with that ground relay coil sitting right in the middle.
I hope this is a good answer guys
Randy

[UPTRAIN]

Yes Randy, please do so [:D].

[Anonymous]

Mr. Stahl,
Could you please explain to me what the ground relay is all about?

[UPTRAIN]

Randy, tell us some more!!!

[Anonymous]

QUOTE: Originally posted by jruppert

Detroits are almost universally in fire truck engines.

since the mid eighties, Detroit has gone four stroke. I think they still make the two-stroke but I'm not sure.

It seems all of the engine manufacturers are coming to the same conclusions; four stroke, crossflow heads, electronic unit injectors, single overhead cam, smaller turbos...

EPA emissions regs...

LC

[Anonymous]

Detroits are almost universally in fire truck engines.

since the mid eighties, Detroit has gone four stroke. I think they still make the two-stroke but I'm not sure.

It seems all of the engine manufacturers are coming to the same conclusions; four stroke, crossflow heads, electronic unit injectors, single overhead cam, smaller turbos...

[tree68]

Part of the sound of a fire truck going by (along with the wind-up siren and the airhorns) is that Detroit...

[Randy Stahl]

I would have enjoyed those detroits, I can't resist listening to a 20 cyl emd in an sd45.They still impress me to no end!!!!!

[Anonymous]

QUOTE: Originally posted by adrianspeeder

I love the sound of a two stroke diesel, nothing like it. There is an old guy down the road with a big genset that is powered by an old Detroit Diesel. I am grinnin like a foamer when that thing roars.

Question: What are the differences in electrics for AC vs. DC dynamic brakes?

Adrianspeeder

Detroit Diesels, at least the older ones, have a bad reputation for being smoky, oily, overly complicated, and unreliable; but can be trouble free if well maintained. Personally, I like them, and when they're fully loaded they scream like a banshee!!

I once sat in the bilge between two 8V71's freshly overhauled out on a shakedown, one clockwise, the other counterclockwise. Each one was rated at 600 hp (marine engines can do it because of the cooling), with twin turbos, and double intercooling, they flat out screamed!!!

[Anonymous]

I should have been more courageous. I figured something along those lines but because I couldn't give an exact answer, I refrained from answering. I have asked you so many questions, I don't want you to think that I was ignoring yours.

I am guessing that the axel broke on the side opposite the pinion, or there would be damage to the motor? Or would it make a diference?

[Randy Stahl]

A while back I began telling about a GP-40 ,I'll continue the tale: I was sure this was going to be a gravy run, when I saw the ONE wheel off the track I knew that it was goint to be a long day. The thing that made sense to me was the somehow the gauge of the wheelset had changed, shrunk. I confirmed this by crawling under the engine and as soon as I seen the traction motor support caps I knew what I would find ,,A broken axle.
Seems the lubricating wick had fallen out and so much heat built up, enough in fact to shatter the axle in side of the support cap.
The crew was gone, dead on hours, The only people around were the two of us from the roundhouse, 2 carmen to put things back on the track, and one train master. of course the whole RR was tied up and many trains were going to die on time . Needless to say the pressure was on. first thing we had to do was get rid of the freight train that was attached to us, A following train cut away from their train and pulled our train south. The GP -40 we discovered would not stay on the track going north so of course we had to limp it south 15 miles. had we been able to go north it would have been only about 3 miles. The only thing to do with this locomotive was to get it to a spot accessable to a crane and change the truck out, so since my engineer card was still good I was selected to run these engines south to a quarry at the brake neck speed of 4 mph. A few hours later we spotted the locomotive ,set a hand brake and set off for home.
As we were driving home it occured to me that this could have been a major disaster, driving through the small towns our RR ran through knowing that if circumstances had been different , the sleeping people would have been awakened by the sound of a derailing freight train.
Randy

[Mookie]

Nance - bet you are like me, you are learning - even if by osmosis!

Mookie

[Granny74]

Bob has enjoyed hearing this thread and appreciates both the questions and the good answers you give. As Bob is legally blind, I read the forum postings to him. Now I don't understand all of this, but he does! Thanks for the info.
Bob and Nance from AZ

[Randy Stahl]

First I'll try to answer the questions about locomotive governers, you are right on the money to say that there is a single rpm the governer maintains for each throttle setting.
There is a hard wire connection between the locomotive controller and the governer, in fact there are 5 wires running almost directly to the gov. Inside the gov are 5 speed solinoids, A valve , B valve, C valve , D valve the corresponding wires are 15T ,12T, 7T, 3T. All wires with a "T" are trainlined, that is they also go to the M>U> heads. The RPMs are controlled by combinations of these valves being energized. In parelell with the circuits to the gov is the throttle response panel or TH module, this module gives the exitation system it's notch reference and sets KW/ trottle notch. The last valve inside the gov is the over riding solinoid , this solinoid over rides the gov pilot valve, the gov uses the pilot valve to control the load regulator, if the engine looses rpm because of too heavy of an electrical load the gov will reduce exitation ... just to maintain the set rpm.
A 567 or a 645 roots blown engine is what you are referring to , they are not super charged or turbo charged, simply blown
Adrian speeder, We don't have AC engines on our RR. I have a BASIC understanding of these engines but do not consider myself qualified to explain these complex machines,,,sorry
Randy

[adrianspeeder]

I love the sound of a two stroke diesel, nothing like it. There is an old guy down the road with a big genset that is powered by an old Detroit Diesel. I am grinnin like a foamer when that thing roars.

Question: What are the differences in electrics for AC vs. DC dynamic brakes?

Adrianspeeder

[Anonymous]

I guess stationary generators are set up a little different because they don't have operator input. I am under the impression that the engineer's throtle does not directly affect engine RPM, but loads the alternator, then the governor acts acordingly.

Is there a single RPM that the governor will hold when operating under load, and vary fuel setting to maintain that RPM?

One other question, I noticed a 567 has scroll type blowers for intake air. It is a common misconception on Detroit Diesels that they are super-charged because they have a blower. The blower on a Detroit typically turns a little bit less than twice crankshaft speed to produce a few inches of water pressure for exhaust scavenging. A Detroit Diesel is not considered supercharged until it has a turbo. Is the same true for the 567?

[Randy Stahl]

If you are familier with Detroit engines you have a leg up because EMD engines are very similar. Good thing the idle speed on EMDs is only about 300 rmp other wise overspeeding the engine might be a problem. Woodward governers are set before they are installed, we have very few problems with them. As far as a feed back loop causing rpm problems: at idle there is no power to the governer in fact the locomotive will idle fine with the gov unplugged, this is normal idle. EMD engines have an overspeed trip device that trips at about 1000 rpm.
The biggest problem starting a freshly overhauled EMD is getting it up and running for the first time, With the poorly seated rings and valves the prime mover needs a little help making fire. This gets a little scary, most guys use 2 cans of ether, one in each airbox, if the ether ignites in the airbox and the covers are on tight the fire will blow back into the air filters, I've seen doors blow open, covers fly off,enought to send the whole shop running.
If a locomotive prime mover is hunting: there are a variety of reasons, if it hunts in idle there may be air trapped in the gov. a bleeder screw is provided to burp the gov. there is also a compensating needle valve to extract air and even out rpm.
The most common form of hunting is throttle 7-8 hunting, this is most commonly a problem with the exitation system causing an overload of the prime mover, which is trying to compensate by moving the load regulator, the load regulator moves kinda slowly so instead of immediate load correction the load reg and the exitation sys just don't get it together
I hope this answers your question!!
Randy

[Anonymous]

I used to work at company that made custom generator packages and sometimes when starting a unit for the first time, a feedback loop between the generator and the governor would cause violent surging in the engine's rpm, is this a problem in locomotives? When working on older Detroit Diesels and starting them for the first time after an overhaul before any adjustments have been made to the governor, they will "run away" and must be carefully kept from overspeeding, is this also a problem?

[UPTRAIN]

Good stories, keep it up!!! [:D]

[Anonymous]

Mr. Stahl,
Thanks for your explainations !!! I have ben a train enthusiast all my life, and an electronics technician (communications) most of that too. I have never come across someone that can explain things to me like you. I have more questions for you, but right now I don't have the time to post them. It's great that you have the attitude that you do about teaching others. I have thew same attitude about sharing what I know, But in todays world most people try to monopolize information to be the "smarter" one. Thats a sign af a weak mind to me.
Anyway thanks again and when I get a chance I'll try to pick your mind again. [;)]

[Randy Stahl]

All good questions: The grids are actually in pairs with a pair of traction motors usually motors; 2&5, 1&4, 3&6. the traction motors cutouts also work with this combination. Or it would also be accurate to say that there is one grid per traction motor, on the scematic it shows the pairing, an example in a gp 40 only has 4 grids, 4 motors. I think your right about the max dynamics at around 25- 30 mph the extended range has another peak at around 10-15 mph.
The cooling fans are 2 wires connected across a portion of two of the grids 2 fans on an sd , 1 grid on a gp. they operate off of voltage drop across a grid so the higher the grid voltage is , the faster the fan will run. The grids on an older emd look like BIG electric heaters, there is no heatsink because the grids are air cooled, on newer emd's the grids are arranged in a circle beneath the big cooling fan but the wireing is the same. the grids on an sd40 weigh 200 lbs each the sd60 is 900 lbs for the whole assy.
I was an instructor in this area for a while, I enjoy teaching my trade to others. Not at all like the journeymen that I worked for , I havn't been called a worthless little maggot for many years, I vowed that I would never be like they were. Keep the questions coming guys!!!
randy

[Anonymous]

Hey Mr. Stahl, thanks for taking the time to answer my questions. you have provided me with some great info. The picture is getting clearer.
Now lets see if I got it.
The main generator provides the field for all TMs
each grid handles 2 TMs (SDs) output
extended range cuts down the resistance of the grid (load)

This is one of those things where each answer brings up more questions. I hope you can put up with me[:D]

Say your going down hill in DB notch 8 gaining speed, about what speed do you hit the 700 limit, both in normal and extended range? my guess would be 25MPH normal & 12MPH extended.

If you have a grid failure on one set of TMs, do the other 2 sets kick out or will you continue to have 2/3 dynamics operating.

how are they paired up ? 112 233 , 123 123 ,

What do the actual resistors physicaly look like? Is the heat sync itself actually the resistance element, or is it resistors with seperate heat syncs.? If so what kind of resistors and how big are they.

Also is the cooling fan speed fixed, or does it vary with the amount of heat to disipate?

One more thing. How many "grids" are there? so far it seems at least 6 seperate ones are needed.

Thanks

[Randy Stahl]

Good questions!!!
First , the circuit is pretty simple ALL six traction motor fields are connected in series with the main gen. the traction motor armatures are connected in pairs.. 2 armatures 2 grids.. 3 sets, all their own little circuits ( on an SD ) Extended range dynamic brakes are very simple, all that is done is shorting out sections of each brake grid. Use ohms law to figure the values. under 10 mph you will not approach the 700 amp grid limit, you can though if you short out a part of that grid.
It is more correct to say that the rate control cap discharges faster , the higher the grid amps go. Very good questions!!!
Randy

[Anonymous]

Yes it does, thank you.
Am I correct in assuming that the discharge rate starts to increase faster and faster as speed increases ? If so is it linear or exponential increase.
Also Iv'e seen DB force graphs that indicate that some transition ocours in dynamics, but have not seen any mention of this. Is this something that happens on extended range dynamics? Is it about different methods from different manufacturers?
Also are dynamics series or parallel?
thanks.

[Randy Stahl]

One other thing worth mentioning is the fact that not all locomotives have ground relay protection in dynamics. The conventional ground relay circuit is only in the gen power circuit with no connection to the grids, remember that electricity ALWAYS returns to it's source, in the case of dynamic brakes the current source is the traction motor armatures. The only ground protection is on the tractionmotor fields and with only 975 amps and around 50 volts on the fields chances are slim of tripping the GR. there is a way to protect the grids and newer locomotives are protected.
Randy

[Randy Stahl]

Dynamic brake grids are rated at 700 amps, you are absolutly correct. The resistance of each grid is .86 ohms. All of the regulation is done by main gen exitation, maximum traction motor field current is 975 amps, of course traction motor armature current is also 700 amps. A you increase traction motor field amps there is a proportional increase of traction motor armature current You understand that at hi speeds it does not take long before the 700 amp grid current is reached, perhaps at 50 mph it only requires 150 traction motor FIELD amps, you will not get maximum braking effort until you can achieve the 975 field amps. simply put you must cut stronger lines of flux inside of each traction motor. The dynamic brake regulator senses the grid current and when 700 grid amps is approached the DBR discharges the rate control capacitor lowering the amount of main gen exitation.
I hope this effectively answers your questions. Keep them coming.
Randy

[Anonymous]

Mr. Stahl,
You have a knack for explaining tech issues, perhaps you could explain something for me.
I understand that the dynamic brake is limited to 700 amps (is it 700 at the grid or each traction motor? not shure) and that as speed picks up braking power increases untill that 700 limit is hit and from that point on the braking is less effective as speed increases. I would like to know how this is acomplished. I mean the regulating the current. Is it done by varying the excitation in the generator(traction motor) or is it modulated with some sort of time division. Please explain.

[Anonymous]

I can't call the GP40 story, But I find your thread very interesting.

[Randy Stahl]

Thanks JCHNHTFD, I didn't think too many people were reading my little thread. Any guesses on the GP-40 story??
Randy

[jchnhtfd]

Only one wheel not on the track? How very odd...

Seriously -- all I do is fly a desk these days, and it's so durned great to read these tales and get reminded that there is a real world out there with real people and real things in it! Keep it up!

[Randy Stahl]

The ho
ttest train on the RR was for many years the pig train 218 that ran from Green Bay to Chicago. One night the round house got a call from a very concerned dispatcher .
It seems the lead GP-40 had caught fire, the fire was under the locomotive and was put out in good order but soon caught fire again. The night foreman was going to send a couple of mechanics to look at this engine assuming they would only have to cut a pinion. I overheard this conversation and reminded the foreman that pinions don't usually catch fire, so I wormed my way into a gravy road trip , on overtime even!
When we arrived at the locomotive the fire dept. was just wrapping up and we were able to inspect the locomotive , the one thing I thought was strange was that ONE wheel on the locomotive was not on the track .
Let me know what YOU think is wrong with this GP-40
Randy

[Randy Stahl]

One of the nicest things we didi on the Wisconsin Central was modernizing our fleet of SD-45's to microprocesser traction control. The first few engines we did woked great. We needed to see just how these locomotives improved perfomance so we arranged to take three rebuilt engines on a heavy train up Byron hill. A bunch of us from the shops rode along to monitor TM temp, motor current, axle speeds etc. Leaving Fond du lac we were impressed, the train was accelerating smartly as the hogger made a run for t he hill. The engines were on their knees as the 1.5 % grade started in earnest but these SD-45's made an impressive show as they dug in and pulled at 7 mph. Over the hill we started picking up a little speed when at 22 MPH the engines made transition, ALL of the engines made transition at exactly the same time, We were impressed by the accuracy of the micro but the train went into emergency as the train parted our enthusiasm evaporated. A software change was in order to make transition speeds more or less random.
Randy

[Anonymous]

QUOTE: Originally posted by Randy Stahl

I don't know if anyone else has this problem? I have a hard time staying awake on freight trains. Often times I ride trains to diagnose a mysterious problem, I'll take my trusty laptop, my tool pouch,food etc.sometimes I ride a train right after my usual shift. One time I got into trouble. On a train to Chicago I fell asleep, I was sleeping very soundly because I failed to notice the crew change. The WC crew delivered the train to the CSX, the CSX crew took over and I was happily sound asleep. When I woke up the train was just like I remembered it exept I didn't recognize the countryside. I was riding the 3rd unit in the consist. I waited for the train to stop for a meet and walked up to the cab. I must have scared the hell out of the crew, they weren't expecting someone coming in the back door. I didn't recognize the crew and I started getting that old sinking feeling. Turns out I was somewhere in eastern Indiana, I was in a panic. It was decided that I should get on the next westbound train and get back to Chicago. I arrived back at the BRC and had to wait several hours for the next WC train so I climbed into the cab of the WCs and took a nap...

I think everyone has this problem to a greater or lesser extent. Of course, I have never fallen asleep in a cab...

I have found that since becoming an engineer and having to keep running the train at all times it is much easier to stay awake and focussed than it was as a trainman.

LC

[Randy Stahl]

SD-24 smoke: I think we had the last SD-24s in regular service. These were very challenging locomotives to troubleshoot . they had many , many , steps of transition. I believe they started in series, four steps of field shunting , to series parellel, four steps of field shunting, to full parellel, four steps of field shunting. I think I remember this engine having 30 high voltage contactors. The timing of the entire transition was controlled by relays and resistors, recalibrating itself after each step of transition. Toss in about 100 control rectifiers to prevent feedbacks and you have alot of stuff that can go wrong. The arrangement of the electrical cabinets was almost whimsical, I used to joke that the locomotive must have been designed at the tavern on tavern napkins, this was not an easy locomotive to get at the switch gear, especially in the rear electrical cabinet.
I was often assigned to work on these engines and developed a healthy fear of them. We used a motor gen set to set the transition and many times I got knocked on my rear by 600 volts. With so much stuff in the transition circuits it seemed like everything you would touch was live
Randy

[Randy Stahl]

I don't know if anyone else has this problem? I have a hard time staying awake on freight trains. Often times I ride trains to diagnose a mysterious problem, I'll take my trusty laptop, my tool pouch,food etc.sometimes I ride a train right after my usual shift. One time I got into trouble. On a train to Chicago I fell asleep, I was sleeping very soundly because I failed to notice the crew change. The WC crew delivered the train to the CSX, the CSX crew took over and I was happily sound asleep. When I woke up the train was just like I remembered it exept I didn't recognize the countryside. I was riding the 3rd unit in the consist. I waited for the train to stop for a meet and walked up to the cab. I must have scared the hell out of the crew, they weren't expecting someone coming in the back door. I didn't recognize the crew and I started getting that old sinking feeling. Turns out I was somewhere in eastern Indiana, I was in a panic. It was decided that I should get on the next westbound train and get back to Chicago. I arrived back at the BRC and had to wait several hours for the next WC train so I climbed into the cab of the WCs and took a nap...

[Anonymous]

QUOTE: Originally posted by Randy Stahl

I work with some very rough and tumble guys. alot of the machinists are over 250 lbs 6'1" you know the type, beer drinking loud and tough. I found out just HOW tough one night. I was selected to repair a dynamic brake hatch on an SD-45, the cabling was badly burnt and we were out of the correct cable. the best we could do was try to strip some cabling out of a scrap engine ( I think the 8993) I asked for and receive a helper in the form of Donny A, a big tough RR man from the GBW. We crawled up into the hood of this locomotive hulk and proceeded to unbolt cableing. I was briefly startled by a group of pigeons sitting directly on the cables I was taking. Since it was pitch black out the birds didn't want to fly away so I figure I'd just move them to a different perch. I grabbed one and said "here Donny, put this stupid bird over on your side , I jumped a foot when Donny let out a blood curdling screech, I thought he was hurt. Igot out from inside of this hulk and pressed Donny to find out what the problem was, he said he didn't like pigeons and he proved it , squeeling like a little girl . Of course he wanted to make sure that we kept this to the two of us.
Randy

[:D]

He's probably seen that Alfred Hichcock movie one too many times.[:0]

[Randy Stahl]

I work with some very rough and tumble guys. alot of the machinists are over 250 lbs 6'1" you know the type, beer drinking loud and tough. I found out just HOW tough one night. I was selected to repair a dynamic brake hatch on an SD-45, the cabling was badly burnt and we were out of the correct cable. the best we could do was try to strip some cabling out of a scrap engine ( I think the 8993) I asked for and receive a helper in the form of Donny A, a big tough RR man from the GBW. We crawled up into the hood of this locomotive hulk and proceeded to unbolt cableing. I was briefly startled by a group of pigeons sitting directly on the cables I was taking. Since it was pitch black out the birds didn't want to fly away so I figure I'd just move them to a different perch. I grabbed one and said "here Donny, put this stupid bird over on your side , I jumped a foot when Donny let out a blood curdling screech, I thought he was hurt. Igot out from inside of this hulk and pressed Donny to find out what the problem was, he said he didn't like pigeons and he proved it , squeeling like a little girl . Of course he wanted to make sure that we kept this to the two of us.
Randy

[Anonymous]

Great Stories, very amusing! [:D]

[Randy Stahl]

Part of my job is to test locomotives after major work is performed, such as turbo changes etc. We usually loadbox engines that come out of the shop to make sure everything is working, cooling fans etc. It's also important to make sure the engine is making the correct horsepower. On one such evening I was sent out to loadbox an SD-45 that just had it's turbo changed. I started the engine and went into the cab to allow the locomotive to warm up. I sat down in the firemans seat and glanced out the rear window and noticed smoke coming from the area near the turbo, thinking that there was an exhaust leak I went ahead and walked around to see what was going on. The aux gen drive was glowing red and smoking, I ran aroung the other side, and pulled the layshaft back to shut the thing down. No sooner did the engine stop rotating that a loud bank followed by a dandy orange fireball lit up the night . A coworker walking past the engine took off running as the top covers blew open. After I stopped shaking I realized that the locomotive had a limited crankcase explosion. We let the locomotive sit for the required 2 hours following the explosion and upon investigation found that the installer failed to provide lateral play in the aux gen causing over heated bearings and an oil fire inside the prime mover.
Randy

[Anonymous]

this is cool hee hee, once i saw cn 304 at washago with a red fuel tank, i thought thats not normal, then when he went through the greasers at the end of a home switch, the tank fell off and sent fir everywhere. that was so hot that day. hee hee

[M636C]

I had a scare while checking a newly built English Electric locomotive in the Rocklea plant near Brisbane. Thermometers were located at crucial points in the cooling circuit and I had been tasked to walk around and note the readings at ten minute intervals. The locomotive was connected to a load box, a big (variable) resistor capable of taking more than the 2025 HP from the 12CSVT engine which was running for the first time since installation. I opened the hood door nearest the radiator, read the thermometer, and closed the door. There was a loud bang followed by a hissing noise and it got very hot very quickly. The radiator header tank just behind the engine had a drain plug on my side, or to be more correct had no drain plug. When the tank was painted, the threaded hole had been taped over to keep paint off the threads. It had been taped very well, enough to hold a full tank of water, at least until the steam pressure built up as the temperature increased. The correct plug was put in, the tank refilled and the test continued but I read all the temperatures with my head well clear of the hood for the rest of the test.

Peter

[mvlandsw]

I had the blue fire effect from the dynamics on B&O GP30 6900 one night. I had stuffed the train orders in the space between the radio and the top of the control stand. Some of them slipped partially out and unfolded down over the brake warning light blocking it from view. This was before the brake current was automatically limited to a safe level and I apparently exceeded it.. I was coming south down hill on the BR&P slowing down approaching the Echo train order station when the night lit up brighter than day. There were power lines along the tracks and I thought we had derailed and knocked them down. When I looked back along the unit blue fire and sparks were coming out of every opening and crack in the hood. Later when I looked at the brake grids only a small part had melted but it sure made an impressive sight.

[Randy Stahl]

6582 is an SD-45 . A few years ago it was having problems with ground relays . I was assigned to look at this engine so at 5:00am I made my way out to the service tracks. I was having a little trouble getting going at that early hour, I decided on a little shortcut, I placed the locomotive into self load and started notching out, I was expecting the ground relay to trip but I did not expect what happened next. The sky and the surrounding area were lighted by a blinding flash, followed by a report like a cannon. in the chaos the ground tripped and the engine returned to idle, I knew what happened and that old sinking feeling came over me. I dreaded looking out the rear window for fear of what I would see. Sure enough the top of the locomotive was on fire, and what a fire, it looked more like a blast furnace, the flames were at least 25' high. I grabbed the fire extinguisher and jumped onto the roof. After emptying several I began to dawn on me that I was wasting my time. My coworkers started feeling sorry for me and came with a couple more fire extinguishers
and the comedy began. I was firing my extinguisher down from the top and a couple of other guys were shooting up from the bottom. I could'nt figure out why I was getting the powder back in my face. The foreman called the fire dept. and they were afraid of electrocution I had to assure them that it would be fine to put water on it , the only way to get the fire out is to cool off the grid hatch.
I was very disappointed with myself , the reason the grids blew out was because the DB fans were not running and I failed to check this before I loaded heavy, all I would have done was take a piece of paper , hold it up to the grids and see that the paper is sucked into the grids. The 6582 was badly damaged, the hot molten metal from the grids melted holes in the carbody in many places, the dynamic brake cabling was destroyed , all six grids were gone and the freshly painted locomotive needed repainting.
Of course there was an investigation and it was found that a wire fell off a #4 traction motor cut out coil, this wire was the neg for the rear load test contactor.
By the way that trick for getting fireworks in dynamics is a gimmic I use for chasing unwanted people out of the cab, you don't have to move the isolation switch though, all you have to do is slam the dyn selector to off, the "B" contactor will open with a loud bang and a bright flash, thats normal... after all it's only 975 amps and about 50 volts
Randy

[adrianspeeder]

Sweet, I love electrical stories, don't get to hear many. Going into electrical engineering is what i always wanted to do. It started when i was plugging an alarm clock into an extension cord and somehow it zapped and threw me across the room. I wanted to know exactly what happened and that took me to where i am now.

Adrianspeeder

[Anonymous]

You are joking, right?

[Anonymous]

Hey LC, take an old EMD -2 , put it in dynamic #8, open up the electrical cab door, then take the start / Isolate - run switch and turn it to start and watch the fire fly. Don't worry thats how you check the dynamics.[(-D][:-^]

[Anonymous]

I can't say from an electricians standpoint but only from my own as an Engineer. One night I was running an older GE and a couple other 6-axles off the hill. We only had about 40 cars and I had about 10 pound of air holding the train well as we rolled onto the flat. I wanted to cool things down so I released the air and set the throttle to idle and began counting down to switch to dynamics for a short speed restriction ahead. As I set the dynamics and brought them up to the fifth position (I can never bring myself to call them notches, that is a throttle only to me), a bright BLUE flash lit the night and my conductor (who had assumed the backseat, feet up attitude) almost jumped out of his seat. I asked him if it was close dry lightning as it was a humid late summer day . He looked and me and was about to speak when I set the dynamic up a bit. ZAP! There was that flash again. He was pointing out the back window at the resistor grid and said in a shaky voice, "It's lighning alright, came right out of the dynamics! Five forks of it too!". Needless to say we didn't use the dynamics for the balance of the trip And they were on my report to the Mechanical folks. My Conductor, loves to tell that story to this day, how "forked lighning" was coming out of the unit as we blazed down the hill. That's my only really good electrical story...

LC

[Anonymous]

Interesting stories. Please share more.Being a electronics technician myself I find your stories particularly interesting.

[locomutt]

QUOTE: Originally posted by Randy Stahl

With all the sophisticated test equipment available these days it's easy to forget that the best trouble shooting tools are still the eyes,ears and nose.
On one particular evening I was asked to look at a GP-35 that was having some loading problems, I could smell something was wrong as soon as I stepped into the cab, burnt semi-conductors..I stuck my nose into the electrical cabinet to smell my way to the problem. I found a little red rectifier hanging by it's wires , it seemed that the smell was indeed coming from this device. It was a hot night and I was sweating alot so when I moved closer to sniff the rectifier a bead of sweat rooled down my nose and made contact with the positive side of the rectifier, since I was holding on to the negative with my hand I completed a current path through my nose. Got two black eyes!
Randy

OUCH!
And you have to love those rectifiers. Slightly off topic,but I have a couple of scars on two fingers where I touched a power supply I was working on here at the house,and got bit.[:p]

[Randy Stahl]

With all the sophisticated test equipment available these days it's easy to forget that the best trouble shooting tools are still the eyes,ears and nose.
On one particular evening I was asked to look at a GP-35 that was having some loading problems, I could smell something was wrong as soon as I stepped into the cab, burnt semi-conductors..I stuck my nose into the electrical cabinet to smell my way to the problem. I found a little red rectifier hanging by it's wires , it seemed that the smell was indeed coming from this device. It was a hot night and I was sweating alot so when I moved closer to sniff the rectifier a bead of sweat rooled down my nose and made contact with the positive side of the rectifier, since I was holding on to the negative with my hand I completed a current path through my nose. Got two black eyes!
Randy

[Anonymous]

awesome stories...more more more!

[Randy Stahl]

I just got my BA-6 from the RR retirement board, as of june I now have 240 months on the railroad. Today I feel old. I thought I'd share some of my memories of the last 20 years.
It's been a rough week, this week I have been working on problem locomotives. the ones that fail with the same cause over and over. The W.C. 6593 caught fire Sunday while I was testing it (at least the problem presented itself) it wasn't a major repair and as far as I know the engine is running fine today. Well goota go to work....
Randy

[TrainFreak409]

Man, they got you good. Who knew railroad technicians could pull of such a wonderful prank? How did that make you feel?

[8]TrainFreak409[8]

PS. I wish I had some interesting stories to tell