Heavyweight RPO options

[randgust]

When I step back an era that I'm unfamiliar with I learn a lot, and get surprised.

I've done a full heavyweight consist to go with my two ATSF brass steamers, nothing prototype-specific but not completely inaccurate either.

I've wanted to add an RPO, finally found an Undec MT RPO in less-than perfect condition for a low price.

Studying this car and testing it have resulted in a bunch of observations.    First, this thing hates curves.    I have four MT 85' heavyweights with the medium-profile flanges, they work fine around my 11" reverse loop, body mounts and all.    Not this car.   It binds up in two places, the trucks bind against the mail door stirrups, and the lead axles of the 6-wheel trucks grind into the coupler box.  I thought I'd have no problem with a 'shorty' car and this one is the worst of the bunch.    It jams right up.   

Now that I'm looking at ATSF prototypes, while the Pullman bodies were at least similar,  ATSF didn't seem to use six-wheel trucks under any of its cars, which is half my problem anyway.  https://www.psrm.org/trains/passenger/atsf-74/     Really looks like I want a long-wheelbase, 4-axle Pullman design, and move the bolster well back.  Yeah, that's a chore.

That side-sill beam so typical of ATSF was done nicely by the M&R car sides version that is now apparently no longer made.  If I'm wrong, tell me, but it looks like that stopped around 2012.    So I'm resigned to using/modifying the MT one, and if that means moving bolsters and changing trucks and doing 'stuff' I'm OK with that.   Doesn't have to be perfect, but I can't leave it the way it is anyway.   May as well tweak it closer.

I'm still puzzled though, about the use of 6-wheel trucks under this model, and wondering if that's even typical for a 60' car.   Doesn't appear right for ATSF at least.

[sd45elect2000]

Yes, The Milwaukee had 6 axle RPO's. So did many other railroads that ran heavyweight cars on 100lb rail or less. Remember , its still a heavyweight car, I'm guessing the the 60ft RPO still weighed in excess of 90 tons. Lots of axle load for a railroad running 90 lb rail.

[thomasjmdavis]

OK, I can help a little bit with info, not so much with the practicalities of the MT car, other than a few guesses and notes.  Hope this helps.  Sorry if I launch into "lecture mode."

On the MTL car.  Based on what is loosely called a "USRA" RPO.  The basic design pre-dates USRA, and the best guess I have seen is that the car is based on a CB&Q car (EDIT: car is New Haven prototype, see bbussey comment below) of around 1913 or 1914 (IIRC).  In any case, cars of the same basic design (or at least door location and window arrangement) were in use on many railroads.  The offset location of the bolster on 60' and 70' MTL head end cars is toward the ends of the car, whereas on the longer sleepers and coaches, the bolster is offset toward the center of the car.  I assume (not being involved with the design) that the car is made this way so that the coupler lines up better when the shorter cars are coupled to a longer car.  The window arrangement of the Atlas car is closer (6 windows together) but I am not a fan of those shortie cars generally- weight is in the roof (top heavy), the roof is attached and therefore not replace-able, the wheels....ggggrrrrr....let's just say they are not appropriate to a $36 car....or a $10 car,...at least the ones that came on mine. And they've attached the wide stirrup under the mail door to the trucks, rather than to the sides, so it does turn more sharply, but looks silly.

The 3 most obvious differences between the MTL car and ATSF car are the trucks and the side sill (which you note) and the window arrangement.  All ATSF heavyweight RPOs had 6 windows together towards one door, not the 4+2 and 3+3 arrangement of the MTL. 

Now.... perhaps a helpful bit.  From the plans in the Head End Cars book by Ellington, the ATSF trucks (they are a unique design- were made at one time by Pecos River, but very hard to find) have a 9' wheelbase.  The bolsters are spaced 43' 3.25" apart.  This places the truck far enough from the end that it looks like it would clear the stirrups and coupler pocket, but I couldn't say for sure without actually doing the work.

On the ATSF sill....there is some good news....assuming the M&R sides on mine are correct (and Roberto is very precise), the sides of the Santa Fe car are just about the same as the MT in height, which is to say, the sill is an "add on" with no cutting required.  A piece of plastruct channel or similar could be glued in place under the edge of the side.  This also hides a few "sins".  In my case, when I moved the bolster, I cheated and did not manufacture a new bolster (which would be hidden by the sill) and instead just drilled a bolster hole and used a nylon washer as a spacer to get the proper height.

On the M&R sides.... the last I heard from Roberto, he had retired from his "day job" (which for the past several years has apparently been a day, night, 24/7 type job).  And was planning to do some new runs of sides.  However, I think that meant finding a new etcher, and THEN Covid intervened- and has disrupted things in Italy just as it has here.  So, while I am hopeful (based on last communication) that we may see M&R sides again at some time in the future (and I "need" 5 more baggage cars and maybe 1 more RPO, myself), at present no guarantees.

The 6 wheel trucks are prototypically correct, although I think that some cars of that design (or similar cars) used 4 wheel.  Certainly, there are numerous examples of 4 wheel trucks under heavyweight RPOs.  It also appears to me that in some cases, the prototypical trucks were moved a bit toward the center of the car, and there is some overhang at the ends.

[CBQ Fan]

The MT ATSF mail train RPO’s have 4 wheel trucks to my surprise.  The RPO from the individual release has 6 wheel trucks.

[Mark5]

The MT ATSF mail train RPO’s have 4 wheel trucks to my surprise.  The RPO from the individual release has 6 wheel trucks.

My guess is that reason being that they did not have a four wheel truck until the single window coach came out.

[thomasjmdavis]

The MT ATSF mail train RPO’s have 4 wheel trucks to my surprise.  The RPO from the individual release has 6 wheel trucks.

Looking at the side view of the artwork, vs the old production here in front of me, I think they must have moved the bolster toward center to accommodate the 4 wheel trucks.  The artwork shows the bolster under the door frame (on the side closest to the end) which is just where the bolster is (relative to the door) on the ATSF drawings. 

@Shipsure - did your brilliant engineering staff (not being sarcastic, really mean it this time) move the bolster on the recent run of RPOs for the Fast Mail to correctly center the 4 wheel trucks?  Extra points if the new truck centers work out to 43' 3.15 scale inches.

[CBQ Fan]

My guess is that reason being that they did not have a four wheel truck until the single window coach came out.

Makes perfect sense to me.

[jargonlet]

@randgust I have a pecos river rpo that needs work if you're interested.

[Cajonpassfan]

@randgust I have a pecos river rpo that needs work if you're interested.

Frankly, the PRB car is the only way to go for the ATSF prototype, if reasonably priced. It’s such an signature car. PRB has two versions, with and without clerestory windows afaik. Both accurate. A warning though: the original PRB trucks look good, but suck in terms of rolling “qualities”... Fortunately, I only needed one. The KATO lightweights off the Super set are right on, too.
Otto K.

[bbussey]

The MTL RPO is based on a New Haven prototype built by Laconia Car Company (New Hampshire) in 1913 and 1914.

What radius are you trying to run the MTL car on?  I’ve never had a problem running the model.

[randgust]

I'm a 70's guy so stepping back into the heavyweight age is new territory - and the train I've assembled just gives my brass stuff something to pull for display.  So I got the MT car on a whim.   Probably wouldn't have gone this far except for the curve and derailment issues.    11" curves in three places on hidden track, and off she goes.   Nothing else does in the heavyweight train.   The used car had been completely dissassembled into pieces and I highly suspect that whoever had it before ran into the same problem and just gave up on it and sold it.   It was pretty obvious it had been assembled and then torn back apart, thrown back in the box.

After doing some digging I'm seeing the MT 'mail train' ATSF version with 4-wheel trucks and a bit baffled as that would require a whole different body casting and relocating the bolsters closer to the center, as the floor is cast into to sides.   I'm impressed but can't believe MT went to that length and then apparently has not sold that modified carbody with 4-wheel trucks separately, at least that I can find it.   

I dug around in my parts box and found a set of Pullman-Standard heavyweight 4-wheel trucks with a long wheelbase, studied the situation, and I think I'll just relocate or fabricate a new bolster and then maybe add on the side sill beams.  I'm not in this heavy enough to want to make a really accurate train model, but it always irks me to not have a train with a good representation of head end cars.   And my uncle was an RPO clerk on PRR.    And, with my layout, weight and rolling quality is definitely an issue here, I've lightened several other cars in the train.    If it weren't for the inability to manage the 11" curves I don't think I'd have messed with it at all except for lettering it.

For any RPO fans, the operating car up on the Osceola & St. Croix is just extraordinary - fully restored RPO in operating condition.   I rode in it a couple years ago and it was just so amazing as the restoration is so good.   It looked just like this:
http://www.davidpride.com/USA/Minnesota/Osceola_11_047.htm
Rocking up the CN line in the RPO compartment watching the mail bags gently swinging, and being in the door when they did a mailbag demo pickup, yeah, way cool.   

[thomasjmdavis]

The Fast Mail RPO is the first RPO they have produced with 4 wheel trucks- so until a few weeks ago, it was not on the market.  The tooling is modular (for instance, they produce the car with blank sides for artwork for various "memorial" cars- not sure what they call them, but you know what I mean), so I think changing out the floor means a new tooling piece, but NOT like producing a new car shell (if they were going to produce a new car shell, I imagine they would have gone ahead and made a different, preferably Santa Fe, style of RPO). 

The MTL RPO is based on a New Haven prototype built by Laconia Car Company (New Hampshire) in 1913 and 1914.

Thanks Brian.  I was going with speculation I read at the time that it was based on CB&Q drawings from one of the magazines that had been published a few years before the car was released.  But I will take your word for it and am guessing you sent them the NH drawings and/or consulted on details. 

@randgust
On the tracking, I've never had an issue with mine either, but the tightest curves I've run on are 15" m/l.  My first thought is that the issue may have to do with what it is coupled to- are either the tender (or the car in front if not running RPO first) or the car behind equipped with truck mounted couplers?  Any cars farther back in the consist with wheel issues (something potentially dragging or binding in the curves)?  Also, with the offset bolsters, the MTL cars do run with some odd overhangs- and the tighter the curve, the more overhang- are there any potential obstructions in the hidden track sections?

[randgust]

I took a piece of sectional track that's soldered up so that I can see and feel the car issues when it's flipped upside down, and the interference is at three different locations:

1)  Lead axle, interior wheel face rubbing on coupler box
2)  Lead axle, journal movement restricted due to end stirrup
3)  Middle springs, binding on side door stirrups.

The stirrups are easily removed as they are a separate part, but the issue with the truck position binding the lead axle into the coupler box is problematic by design.   The trucks are way outboard of a typical mounting, as well as the bolster off-center.   The four-axle trucks will very much alleviate that one.   Not sure on the stirrups, but there may be some etchings in my collection that will help and they can mount further off the car side than the casting can.

The other MT heavyweights work just fine, and I even body-mounted all my Rivarossi's to match and get a decent set of steps in there.    My Hallmark northern makes it as modified, and my 20-car train of 85' piggyback flats including body mounts, so yeah, it's very much this car.  The only other car I've ever 'outlawed' (and that was due to stringlining) was the Atlas piggyback with the short coupler shanks.

I'll just get this hacked up and MT will release the four-axle variant as an alternate car, but somebody has to do it.

[brokemoto]

When you deal with body mounts, six axle and things such as stirrups and steps, you do not wonder why RR, Lima and C-C had none of the above and truck mounts back when nine and three quarters was  considered "normal" and eleven "broad".

The portion of the pike where the prototypes run has mainline curves of at least thirteen and three quarter inches, so, none of this is a problem there.  On the non-historic, though, the parade track has eleven inch curves.  When the switcher was pushing or pulling the passenger train to or from the station, the MT full RPO would clear those curves with minor difficulty if coupled to a car with truck mounts.  If it were coupled to a body mount, it derailed.  It never had a major problem with a locomotive body mount; steam or diesel.  The largest diesel that I ever used for this purpose was an RS-2.  The largest steam was a ten-wheeler.  The "minor" difficulty was that there must have been some binding, as I did have to give more throttle.  I never saw any climbing, but there was some resistance.

The Atlas full RPO has six wheel truck mounts.  If there is any binding/resistance, I do not see it.  I can couple it to a body mount and it will not derail on those curves.

I did have a problem similar to Original Poster's with the MT baggage/Mail.  I really wanted to use that car, as a baggage/mail would be more appropriate for a short line, even one that depends heavily on mail trafffic.  That car is longer than the full RPO.  It constantly derailed on the parade track curves.  At one point, I did try several four wheel trucks.  The best results came from those on the MDC express cars.  You can remove the coupler box from the MT cars, which allowed for accommodation of the truck mount.  Still, even the MDC trucks were not satisfactory, for several reasons, most of them appearance.  Eventually, I had to bow to practicality and use the full RPOs plus add either a combine or baggage car to the consist.  I simply re-lettered the baggage/mail for a CNJ car.

[CBQ Fan]

The Fast Mail RPO is the first RPO they have produced with 4 wheel trucks- so until a few weeks ago, it was not on the market.  The tooling is modular (for instance, they produce the car with blank sides for artwork for various "memorial" cars- not sure what they call them, but you know what I mean), so I think changing out the floor means a new tooling piece, but NOT like producing a new car shell (if they were going to produce a new car shell, I imagine they would have gone ahead and made a different, preferably Santa Fe, style of RPO). 
Thanks Brian.  I was going with speculation I read at the time that it was based on CB&Q drawings from one of the magazines that had been published a few years before the car was released.  But I will take your word for it and am guessing you sent them the NH drawings and/or consulted on details. 

@randgust
On the tracking, I've never had an issue with mine either, but the tightest curves I've run on are 15" m/l.  My first thought is that the issue may have to do with what it is coupled to- are either the tender (or the car in front if not running RPO first) or the car behind equipped with truck mounted couplers?  Any cars farther back in the consist with wheel issues (something potentially dragging or binding in the curves)?  Also, with the offset bolsters, the MTL cars do run with some odd overhangs- and the tighter the curve, the more overhang- are there any potential obstructions in the hidden track sections?

The RPO/baggage car is a CB&Q prototype.