Alco prototype lengths:

PA: 65'-8"
PB: 63'-8"

Source: http://www.thedieselshop.us/AlcoPA.HTML#TechData

Consequently, as it is impossible to place an Athearn PB unit on top a Maerklin PA chassis (see: https://www.marklin-user...PA-1-models#post472622), the same should hold true for a Life-Like/Brawa PB shell.

I once had the same idea of creating a Santa Fe Alco PA-PB-PA lash-up. While the Athearn Alco PB running characteristics - when equipped with 11.5 mm diameter wheels by Mabar of Spain - would allow for this, I postponed the project due my inability to source Maerklin-compatible pin connectors to extent the "chords" (see pic) through a PB unit sandwiched between two PA units.

Please let me know if you manage to solve the wiring issue.

:o)

7-pole connectors: So I tried at home, but unfortunately no success. Neither of the many German-made cable connectors ordered is matching the one of the Alco.

Here the largest one in comparison with the Maerklin one (black cables): too big.

Here the smallest one in comparison with the Maerklin one (black cables): too small.

Yes, this frivolous thought crossed my mind, too. However, I would attack the female connector instead. The 49611 female connector is dangling at the end of cables, while the male connector is sitting "tight" on a 37611 board - see image.

@610: essentially, it would mean inserting a male/female connection into the existing cable, leaving the Märklin connectors where they are; the connection would be close to the 3761* end of the cable so the additional connectors would be within the shell of the 3761*, and 3761* could still be used alone.

Long ago I had bought an unpowered Proto 2000 PA-B with an A-B-A consist in mind, but when I did a preliminary test by attaching it to a 37610 fitted with a Kadee coupler and coupled a string of cars to it, one of the PA-B couplers broke during the test run. I still have to replace it by a matching Kadee coupler, but I must gather some courage to try and open the coupler box:



Jeroen

Regarding the matching of paint, here is some indirect evidence. I do not have the SP Alcos, so I cannot compare that livery. However, I find the Proto 2000 units in Rio Grande liveries tend to be a bit more orange than the Marklin units. Overall from a prototype perspective it is difficult as the yellows did become more orange as time went on. However, I think in the case of the Alcos Marklin is actually more correct to the prototype. I suspect that this sort of thing will be common, I doubt that any Proto 2000 unit will be a perfect match for Marklin.

Marklin 37612 and Proto 2000 PB unit (unpowered):



-Brandon

Here is a drawing I created. This is how I understand the possible solution (a solution where the the two A units can be used together again when you don´t want to operate them with the B unit). Please correct me if I´m wrong.

@jerdenberg: I´m shocked that one of the couplers of the PB broke!!! How many cars did you have attached during that test run?
So does that mean these Life Like PB´s come with cheap plastic couplers? The Kadee couplers are all metal, right? Do you think the breaking of the coupler would not have happened if a powered PA was behind it (that kind of "pushes" it a little bit?
@BrandonVA: Yes, colors of your Life Like RG PB looks a bit more intense/stronger than on the Märklin RG PA. What did you do with your Life Like PB in the end? Run it behind a single Märklin RG PA?
@jerdenberg again: I like your UP PA-1-PB-1-E6B trio! The color difference looks still acceptable I think!
I don´t know for the UP, but on the SP, A-B-B trios of a leading PA and two E7B´s were common between October 1953 and summer 1959. Here is a pic of the eastbound Sunset Limited in November 1954 with exactly such a combination:

Actually, such a combination would be a nice solution for me, because I could use the leading Märklin SP PA-1 and two Life Like SP E7´s. But because of 2 reasons, I won´t do that:
1. My 1950-1953 Sunset Limited is super heavy. It has a total weight of 4,2 kg and will become even a little bit heavier once I finished installing lights, interiors and passengers. My Märklin SP PA-1-PA-1 double unit is the ONLY loco that can pull it. A single PA-1 could not pull it. Both units are definetly needed to pull it. I also know that the Brawa E7A could not pull it because it´s much lighter than the Märklin PA, has only 3 powered axles, only one motor of course and fewer traction tires. So I can forget to have my Sunset Limited being pulled by a protoypically correct E7 A-B-B unit.
2. Having such a PA-E7B-E7B trio for my Sunset Limited (west of San Antonio) would be wrong as I model the Sunset Limited until April 1953 but not later. West of San Antonio PA´s did not show up before October 1953.

@everybody: Take a look and read through this, so you will understand my situation and problem. Let me know your thoughts!

My problem is basically that I want a SP diesel trio to pull my Sunset Limited west of San Antonio and my Golden State west of Tucumcari.
An E7 A-B-B trio would be perfect and correct, but because my Sunset Limited is too heavy, I cannot use such an option.
I could easily use that E7 A-B-B trio for my Golden State, but actually I don´t wanna spend money for a diesel trio to be used only for one train (Golden State). Especially not since for this train I already have correct steam power (until late 1953 steam locomotives in many cases pulled the Golden State and Sunset Limited).
So my drama is that my Sunset Limited is too heavy, but I want the same diesel trio for both trains west of Tucumcari/San Antonio.
So my only option so far is that PA-PB-PA solution with my Märklin PA´s and Life Like PB, although I know it would not be correct for this era.

Ambitious you are. I stick to an era and prototype which allows for shorter solutions.

ATSF Alco PA double-headers pulled the shortened "Grand Canyon" long-distance train between Chicago and Kansas City in 1967.

Already covered here:
https://www.marklin-user...-short-trains#post442213
https://www.marklin-user...-short-trains#post443139


http://santafe.gmbus.com

The San Diegan was a good contender, too:

@610, indeed, the PA has no problem with 104 cars, and I think that is not the limit … Of course, these are mainly 40' boxcars, reefers and stock cars, and slightly longer 3-bay hoppers.

Having the PA pull all of these cars required a trick. My layout (more of a tischbahn really, see simplified picture without switches) is a contorted double track oval along the walls of a ~4×4m (~13×13ft) room; I filled the inner track with cars in such a way that I could attach cars on the outer track over a switch, leaving about a car's length of inner track before the switch open for the PA to move before it would crash into the cars on the switch.



In the meantime, I have converted a Trix 22805 PA-PA combination, comparable to 37610/49610 (but with RP25 wheels and a very simple, silent, dcc decoder) for three-rail, and it runs fine on the layout. The only problem I encountered, for both 37610/49610 with a Kadee coupler and 22805 with its "native" knuckle coupler, was that they decoupled from the E6B while running; however, this decoupling of the E6B also happened with one of the Bachmann stock cars inserted between engine and E6B, but not when I added the PB between the stock car and the E6B. Further investigation is necessary here …

Jeroen

Wow, I´m astonished you managed to do that! I had this idea in my head for years, but not for my diesels but for my steamers. But I don´t have the skills and tools to do something like this. I but I would love some of my engines to have traction tires because it really would increase their pulling power a lot!

Sorry for going a bit off topic now but I really would like to explain you my problems now.

I have a Mehano SP 4-4-0 that was converted to AC and that pulls six Roundhouse 6 axle Palace cars. It can barely pull it on ground level, but already at the slightest grade, it stalls. I would love to operate this train on grades too, and I know it could do that with traction tires.


Then I have a Mehano C&O (AC model straight from the factory) that was modified into a RI 4-8-2. It´s supposed to pull 2 trains of mine: My 14 car Golden State and my 16 car Imperial.
My Golden State has 11 4 axle streamliner cars and 3 6 axle heavyweight cars. My RI 4-8-2 can pull it, but it´s operating at it´s limit. One car more and I´m sure it would not be able to pull it anymore. And it can pull my 14 car Golden State only on level ground. Here too I would love it to be able to pull that train on grades as well.
My Imperial has 12 6 axle heavyweight cars and 4 4 axle freight cars (1 express reefer & 3 express box cars). So 16 cars alltogether. This train my RI 4-8-2 cannot pull because it´s heavier than the Golden State. So for the Rock Island portion of my Imperial, I´m using a DL-107A-E7B-E6A trio which is prototypically correct. But of course, I would like my RI 4-8-2 to pull it too (same as the Golden State from Chicago to Kansas City and the diesels from Kansas City to Tucumcari).


Then I have a Mehano SP 2-10-2 with Bachmann tender that was converted to AC. It´s supposed to pull my 11 car El Costeño (from Tucson, Arizona to Guadalajara in Mexico) which is made up of 6 4 axle Roundhouse Harriman cars and 5 Rivarossi heavyweight cars. It can pull this train ok, but on grades it gets critical too. And I would love this 2-10-2 to pull my 33 car freight train (featuring 6 tin plate cars), but it cannot pull it. That´s bad because I don´t want to make it pull only a short 20 car freight train. I want it all or nothing. So I´m convinced that traction tires would help here too.


I also have a heavy brass Max Gray SP 4-10-2 which I´m currently upgrading with DCC and converting to AC in these days. My texan friend who bought and upgraded this engine for me did this great video of it showing it running on his beautiful layout. This engine can run through R3 curves which was the reason why I purchased it at all, because if it couldn´t, it would make no sense for me to buy it because I don´t have space for larger curves. It´s supposed to pull my 14 car Golden State and my 16 car Imperial (along with my MTH SP 4-8-4). I know it should not have problems with pulling these trains, as for example the MUCH lighter Mehano RI 4-8-2 can pull the Golden State too as described above. But this SP 4-10-2 I would also like to use for my 33 car freight train of course. And after watching the video of my friend, I was very negatively surprised to see how much it slowed down on his grade with only 12 plastic freight cars!!! I really want it to pull my 33 car freight train, and remember that my freight train also features 7 Märklin tin plate cars (also the Märklin gondolas and flat cars that I have for it are much heavier than those by US manufacturers). My friend told me that when the engine is going uphill at slow to medium speeds, it does not slow down. Only at high speeds (in the video shown at maximum speed) it slows down. So if it already slows down so much with only 12 cars, what would then happen with 33 cars??? That´s why I am convinced that traction tires would help very much here too! The 3 cylinder SP 4-10-2´s were such beasts; they would look ridiculous if I would only be able to have them pull 10 to 20 freight cars!


I know that some US model railroaders use Bullfrog Snot for traction-tire-less locomotives, but this is not an option for me, as it would be needed to be applied again and again with the time. Only traction tires are a solution for me!
But installing traction tires could be complicated too:
I could do it the easy way of course and install the traction tires on the last set of drivers on each of the mentioned steamers. But the point is that it makes much more sense to install the traction tires on the powered driver, which is never the rear driver but the center driver in case of 10 coupled steamers and the second driver in case of 8 coupled steamers. Because the directly powered center/second driver is more important than the indirectly (via the rods) powered rear driver. So to have the maximum advantage from the traction tires, it would be better to install them on the center/second drivers than on the rear driver.
Installing traction tires on the rear drivers would be an easier thing because taking off the rear drivers is much easier to do than taking off the center drivers or second drivers because all the rods and the gears. I would not dare to do that because I never did such a thing before and therefore would be afraid that I would not be able to install it back. But the rear drivers with their much easier access would not be a problem for me (on the 4-4-0 I would install the traction tires on the rear driver anyway).
But I also thought about another option: Maybe installing 4 traction tires on the 2 indirectly powered rear drivers (4th and 5th driver on 10 coupled and 3rd and 4th driver on 8 coupled steamers) would be equal to 2 traction tires on the directly powered center/second driver. What do you think would be the smartest solution here?

If you would tell me that you could cut in grooves into the running surfaces of the wheels of these steamers that I mentioned, I would send them to you if that would be possible. But I would send only the wheels if the option with 2 traction tires on the rear drivers or 4 traction tires on the rear drivers would be chosen. In case the option of traction tires on the center/second driver would be chosen, then I would send the whole locomotive as I don´t dare to uninstall the center/second driver and install it back.

@jerdenberg: Nice layout plan and smart solution to run such long trains!!! What do you think is the total weight of such a 104 car freight train??? Because if it surpasses 4,2 kg and your PA can pull such weight alone, then something must be wrong with my PA duo!

About the diesels:
The Brawa E7A has 1 motor, 3 powered axles and 4 traction tires.
The Märklin PA-1 A-A has 2 motors, 4 powered axles and 8 traction tires.
Also, one Märklin PA is heavier than one Brawa E7A.

Here is my explanation why I think that my PA´s are operating at their limit when pulling my 4,2 kg heavy 14 car brass Sunset Limited:
When I start the train, the motor sound of my PA´s starts a little bit before my PA´s start to move. Also when the train stops, the motor sound is still on for a little bit after my PA´s have already stopped. This is why I´m sure that they are operating at their limit, because they don´t react like this with any other train. I think it would have been better if Märklin built each PA with at least 3 powered axles instead of only 2, because I´m convinced that then my PA´s would not be operating at their limit when pulling my 14 car brass Sunset Limited. But anyway, I´m happy they do pull it at all, and these few moments where I hear the motor working before they move or after they stopped, is something I can live with.

What I´m trying to point out with this is that I see no chance in a single powered Brawa E7A to pull my 14 car brass Sunset Limited, although it has only 1 powered axle less than the Märklin PA-1 A-A.
By the way it´s also interesting to see what Brawa did with the DL-107. Their DL-107 also has 4 traction tires like their E7A, but it has 4 powered axles: The first axle of the front truck is powered and the 3 axles of the rear truck. I wonder why Brawa did not do that with their E7A too, because 1 more powered axled would of course increase it´s pulling power.
On the Rock Island portion, my Golden State and my Imperial will be pulled by my DL-107A-E7B-E6A (E6A shell on E7A chassis). That means with 7 powered axles and 8 traction tires, there will be enough pulling power for these trains. But my much heavier brass Sunset Limited is da different story.

The Soho brass cars of my Sunset Limited operate perfectly with their original wheels on my C-track and through my R3 curves. But in the beginning, when I hadn´t oiled them, the first 3 cars of the consist always tipped over in my curves (no classic derailing!) because the weight of the trailing 11 cars forced them to tip over. Only after extensively oiling all cars of my Sunset Limited, everything works out fine and the train rolls easier which makes it also a bit easier for my PA´s to pull it. Even if the Brawa E7A would be able to pull it by itself with its 3 powered axles and 4 traction tires, I would have a problem because of the 2 trailing E7B units because I know the heavy brass cars behind them would force them to tip over in the curves because they are too light. So powered E7B units would be THE solution. I´m very sure a Brawa E7A could pull my Sunset Limited if the 2 E7B´s were powered too. But unfortunately Brawa/Life Like doesn´t produce powered E7B units. Only Broadway Limited does that but this is not an option for me because first it would mean that I would need to convert these Broadway Limited E7B´s to AC and secondly I boycott Broadway Limited products anyway because they´re high-priced China shit. Also placing a Brawa/Life Like E7B shell on a powered Brawa E7A chassis will not work out because the A units are a little bit longer. So this is why I don´t see any chance of my Sunset Limited being pulled by a prototypically correct E7 A-B-B unit.

And last but not least: Unlike for most other US diesel fans, my most favorite all time diesels are the FM Eries! In my personal opinion they are the most beautiful ones. They´re my absolute favorites.
Proto has produced FM Erie A and B units. Both units are powered on all axles (no FM Erie dummies were produced).
That means having a SF FM Erie A-B-A unit, it would mean having a trio with 3 motors and 18 powered axles!!!
I always wanted to have that lone FM Erie A-B-A trio (90L-90A-90B) that SF had and that was produced by Proto.
I know that by converting them to AC, at least 2 powered axles would need to replaced by unpowered axles and the gears removed to make place for the sliding shoe. I thought to do that only on 1 of the 3 units and connect the units with connector cables, so that only 1 unit provides the current for all 3 and so that only 1 decoder and 1 sliding shoe is needed instead of 3 decoders and 3 sliding shoes. Do you think such a project would be realizable?

Thank you! When it comes to America, I model SP, SF and RI because these 3 are my favorite roads. I´m actually very happy and lucky that Märklin has produced the SF F7 and SP PA-1 and that Brawa has produced the RI DL-107, because after the FM Eries, these 3 are my favorite american diesels. I´m also happy that Mehno produced that 4-8-2 in AC which was easy to modify into a RI 4-8-2 and that MTH has produced the SP 4-8-4 in AC. So most of my favorite american locomotives I could get without having to convert them to AC (except the SP 4-4-0, SP 2-10-2 and SP 4-10-2). I also model mexican trains (NdeM and UdelS). I repainted a Märklin BN F7 into a NdeM F7 and a MTH NH FA-1 into an UdelS FA-1 (I´m very happy that MTH did AC versions of their FA-1´s!). My last american locomotive wishes are a SP AC-9 2-8-8-4 and a SF 3000 Class 2-10-10-2. If these engines would be produced as AC versions, then my american collection would be finally complete.

May I know who did it for you? And how much you paid for it IF you had to pay at all?
That tool is nice, but with this you still need a wheel holding fixture like this
And still I probably wouldn´t like to try this out as a total inexperienced beginner you know...too risky of messing it up! And also I would not want to spend 80 € for tools just for a few wheels.

Since this is a PA-1 thread let me present my "shorther brother" of the PA-1, the FA-1 here:
This is my MTH NH FA-1 that I used because it´s paint scheme made it an easy candidate for repainting into a mexican UdelS FA-1.

This is the finished result. I think I´m the only one who models such an UdelS locomotive, and of course the only one in AC too!

And here is my only source: It´s the only photo that I have ever seen so far of an UdelS FA-1 in this particular 1968-1972 paint scheme, and I repainted my FA-1 just by looking at this pic.