2695 Walkaround

[@trainfixer1981]

21:34 BWR (Brake Warning Relay) The ye ole locomotives I look after have a FTR (Forward Transition Relay) which sits on a generator positive busbar, mind you we only have one step to put those FS resistors across the TM fields, so your stuff may differ? Always enjoy your videos, I send the younger guys straight here to be schooled!

[@CDROM-lq9iz]

I knew someone would know these better than me. I honestly never would have thought to look at the generator busses. That said, our other GP35s have three different sets of field shunting resistors, and a correspondingly high number of transition steps, all controlled by the electronic control system. I appreciate you watching and commenting! And I've heard similar remarks from guys I work with.

[@LeviSheets-s5j]

I have an idea won’t you let Northflok southern have it or get an railroad museum bye it and rebuilt it so it can run😊

[@heavy-iron]

So weird for me seeing something between the old 9s and the new(er) 40s. It's like seeing a hybrid between those two generations. The older units did not have modular systems like transition control modules or IDAC wheel slip control modules. All of it was done discretely using relays, resistors, diodes, magnetic transductors and sometimes limit switches in the load regulator (in the case of the 7s and the early 9s I believe.) As someone else stated, FTR and RTR relays are used instead to signal the rest of the transition relay logic when to increment or decrement. (Forward transition relay and reverse transition relay.) I'm used to seeing parallel power contactors, series power contactors and two FSR field shunt resistor contactors. As for the old vs new load regulators, my understanding is the only major difference between them in essence boils down to power rating. Newer units with solid state field control modules can get away with a very small rheostat (like the one pictured in this video I think) whereas the older units contained a commutator and carbon brushes which fed down to a large resistor grid beneath them. (Missing from this unit.) Didn't see anything that resembled a field control module in this video either so I'm just as confused. My understanding is that SCR field controls didn't come into use until EMD retired the use of DC generators and started employing alternators with the 38s and 40s. Old style load regulator seen here: /watch?v=_4TciuR3m2U As for the sheer, absurd number of capacitors and resistors packed into this panel, my first guess would be that a lot of it is for controlling the 15 stages of transition you mentioned. Nowhere near that many in an old 9 with only 4 stages of transition! And it's not like any of it is controlling SCRs or anything fancy like that. SCRs don't work on DC!

[@CDROM-lq9iz]

It's odd to me too lol. Everything we have is either a Dash-2 or newer, or has been upgraded to Dash-3 controls. Seeing one that predates the Dash-2 stuff but doesn't have the microprocessors is outside my wheelhouse. We do have one random GP9R running around that's a hermaphrodite because it does have a few Dash-2 modules, but still doesn't have Dash-2 switchgear or anything like that. It's a treat to deal with if it ever breaks. I definitely am not near as familiar with the older stuff as you are. I was given an SD45 electrical manual during my apprenticeship, which has some of the modular components, although they still aren't the same as the Dash-2 modules. Also, I'm curious, do the transition control relays just operate based off of the main gen voltage alone or is there some kind of current transducer somewhere? Also also, our GP35s have Series contactors, parallel contactors, and three field shunting contactors. I actually went and found the transition state list; S-FF (Series, Full Field), S-FS1 (Series, Field Shunt 1), S-FS2, S-FS3, S-FS4, S-FS5, S-FS6, S-FS7, P-FF (Parallel, Full Field), P-FS1, P-FS2. So, it's only 11 steps, but still alot. Ok, so there must be some kind of Battery Field Driver hidden somewhere, I just couldn't find it. That is still an older style LR, (the LRs on most of our Dash-2s don't look like that) but without digging out the book I couldn't tell you the names. I would assume that the BFD works with the LR similar to how the SB module on a Dash-2 works with the LR. (i.e. it sees a signal from the throttle control and a signal from the LR, if the throttle signal is higher, it turns on the Battery Field, if the LR signal is higher, it turns off the Battery Field. I honestly don't know if there's a rate control in there (might be what some of those capacitors and resistors are for) or if there's some kind of feedback from the main. For sure, and now that I got myself thinking about it, there probably is a good chunk of those resistors that are for DB and Throttle control circuits.

[@jeffstrains]

I haven’t seen this locomotive in about 10 years or so.

[@CDROM-lq9iz]

@@jeffstrains I already forget the date I saw on the air parts but it's somewhere between 5 and 10 I'm pretty sure.

[@jeffstrains]

@@CDROM-lq9iz do you where 6981 went? I haven’t seen that locomotive in years either.

[@CDROM-lq9iz]

​@@jeffstrainsfor as long as I've been working there, the 6981 has been in storage. I have no idea why it's stored or what's broken, but it's been sitting outside the shop for a while.

[@joshthetrainfan]

Wait, why is 2695 getting cut up? Looks pretty good to me.

[@CDROM-lq9iz]

@@joshthetrainfan I'm not really involved in the decisions for this kind of stuff but a couple factors that I think went into the decision are 1) it's not a Dash-3, and all our other GP35s are Dash-3s, so we don't really carry parts for it anymore. 2) It was already a problem child before being put in storage. It was infamous for randomly failing to load and without the Dash-3 controls, it makes troubleshooting more difficult. 3) The ALCO trucks underneath it are all but impossible to find parts for anymore and it's a heck of a process to convert them to ride on Bloomberg trucks. To be completely honest, if I had like $500,000 laying around for whatever, I would be half tempted to buy the darn thing, gut it, and see if I could "convert" it into a GP38-2 or something like that. I like a challenge and like to think I'm pretty good with the Dash-2 stuff.

[@joshthetrainfan]

@@CDROM-lq9iz Yeah that makes sense..

[@CDROM-lq9iz]

@@joshthetrainfan Yeah, I'm sure there's plenty of guys at the shop who will breathe a huge sigh of relief when it gets cut up.

[@joshthetrainfan]

@@CDROM-lq9iz I’d say so

[@CDROM-lq9iz]

@@joshthetrainfan Yeah

[@LeviSheets-s5j]

I have an idea won’t you let Northflok southern have it or get an railroad museum bye it and rebuilt it so it can run😊

[@CDROM-lq9iz]

@@LeviSheets-s5j I'm not sure if they'd sell it to a museum or not to be honest. If I had the money laying around, and the tools and space to do it, it be willing to rebuild it into a GP38-2 or 39-2. I'd accept the challenge to rewire and rebuild everything lol. Even if it was for a museum that bought it.