Tractive effort, layout design, and a concern for the future

Like any other product, if I’m not happy with it, I won’t buy it. It’s not as if someone has a gun to my head, forcing me to purchase AZL UP Heritage locomotives.

I’m just glad we have the AZL folks.

Kez:
My point (well, part of it) is that, in N, the market seems insensitive to tractive effort. Thus, I interpret the higher average pulling power of Z locomotives as just coincidence. It was that way in N in the past! There were many bad-running locomotives, but there used to be few if any that ran well but were weak pullers. This created a problem for some modellers who'd designed their layouts around the better-running models that then existed (IE, Minitrix, Con-Cor/Kato).

zdave:
I don't care about modelling individual engines, cars or even whole trains. I care about modelling lines, locations, and times. Thus, I don't get the freedom to make separate decisions about buying each engine or car. My chosen prototype, whatever it is, dictates my buying. I don't need to consciously "resist" impulse-buying models that don't fit my layout's place and time because I have no interest in model trains except as actors to fill roles. This works the other way, too. I need to model everything that's there in the place and time. Thus, I cannot choose to not buy a model that fits in, because I'll have a role on the layout that needs to be filled.

So what I mean is... Say I start building a layout. Modelling my planned prototype relies on some locomotive that hasn't yet been released but is expected to be by the time I can finish the layout anyway. Now, what happens if it turns out that model is a weaker puller than any of the engines I tested and designed the layout around? Specifically, if it's not strong enough to pull my standard train length over the ruling grade I set based on what my test engines could pull?

Triplex
As for "What happens when someone starts making engines that DON'T live up to that standard?"  
Well that is a secret.

But for a 100 Billion dollar non refundable Cash payment, Paid in advance, I would be happy to look into my crystal ball and tell you what it shows me about the future.

Ok all i can tell you is that all of the AZL loco's that i own (except some of the Brass modes) have traction tires, and that i am happy with there pulling power.  Here is a link to a video showing how many cars I've had one pulling
 


or perhaps you would like this one with a 2 loco consist


I could have easily pulled more hoppers in both Videos but that was all the hoppers that i had at that point in time.

Will all Z scale Loco's pull as well as the ones in my video's?  I really doubt it, but in all honestly I have no idea.  I do not own a sample of every model nor have i tried to pull that many cars with all the other ones that i do own. 

The only way your going to know if a particular loco is going to meet your standards on your layout is to build the layout, buy the loco put it on your track and try it for yourself.   One loco may run perfect on one layout and run like crap or not at all on another,  Every detail of your trackwork, The quality of how well your track is laid, the radius of your curves, inclines, declines, turnouts & crossings, and their respective location of one to another will have a effect on the number of cars a particular loco can pull.  Tractive effort is just the tip of the iceberg. 

Sure it's a Gamble, but Like Zdave said "There are few guarantees in life and Z scale isn’t any different"

If your willing to put the time money and effort into Z scale the possibility's are endless,  If no one makes a loco that meets your standard,  Why not be that "someone starts making engines" yourself.    That way you can design it so the tractive effort meets your standards.  and if your "engines DON'T live up to that standard"  I'm sure you will learn the answer to your "What happens when" question rather quickly.

David

dazed:

The complaint against traction tires would be the same in every scale. AFAIK, the main complaint is that traction tires will inevitably wear out and modellers don't want to have to replace them. I've also come across someone complaining that running traction-tired engines increases the needed frequency of track cleaning.
(Regarding scale differences... I also recall someone telling me that Maerklin Z turnouts were live-frog, which would make a difference if that was the default in Z as opposed to N where plastic frogs are the default and any engine is obliged to be able to do reliable switching operations over dead frogs, but on investigation it appears Maerklin are dead-frog so I don't know what that person was talking about!)

tjdreams:

I'm not a model builder at heart. I'm an operator.
My modelling interest push for large layouts (that's a big part of what pushes me down in scale!) and large fleets. It wouldn't matter if I was the most skilled scratchbuilder in the world (which I'm not and never expect to be). That sort of person could build any ONE engine or car they wanted, but building the size of fleet necessary for the kind of operations I want would take them more than a lifetime.

barnegat (Actually, this is the most important part for everyone to read):

There are certain aspects of model railroading I care about and aspects I don't. There are types of "realism" that matter to me and those that don't.
IE, some modellers think sound-equipped models are "more realistic". Sound is outside the scope of my interests, and actively annoying. Some modellers consider railroad paperwork an important part of "operation-focused" modelling. That is likewise outside my scope. I care that what happens on the layout be realistic, not about those behind-the-scenes processes.
Likewise, the long-standing main selling point of command control, "Control your trains, not your tracks", is nonsense to me. The controls aren't a diegetic part of modelling; I don't care if my control inputs are in any way analogous to what a real railroad worker does. Controls are like puppet strings, and the only question is how well they do that job.
The sort of detail on most modern models, at least in larger scales, is ludicrous to me. Cab interiors? Underside detail? That's showpiece boasting. Plus, what's the point of having trains better-detailed than your scenery? It's the worst part of a scene that governs the overall effect. The "model" which I care about having every part be correct isn't a single engine or car, it's the layout.
The things that break my suspension of disbelief:
The presence of things (not just trains!) that I know shouldn't be there, but just as much so, the absence of things that I expect to be there. I care about statistical realism. What's common on the prototype should be common on the layout and what's rare should be rare. This is why product selection is critical: getting the overall mixture right is essential. IE, say that on the line you're modelling at the time you're modelling, around 1 in 5 engines coming through were U30Cs and C30-7s. Say that your layout has a fleet of 20 engines (which I consider rather small...) If every engine in your fleet is an accurate model of an engine the real railroad had but you don't have any 6-axle GEs among them, that will look glaringly wrong to me.
Non-prototypical constraints on the use of models. IE, I'm a manual uncoupling person because remote uncoupling ramps impose constraints on where you can uncouple. And you know those freight cars with built-in flashing EOTs that you can find in probably every scale? They've always hurt my brain because they don't have a place in my type of modelling. They seem only suited for show running, not operations. I need to be able to switch any cars in the yard together into a train in any order.

It's that last part that makes tractive effort such a concern. It relates to selective compression and how much one can tolerate. (I notice a lot of modellers tolerate a lot more than I do, but that's not the important thing here; that's a matter of degree, not nature.) To plan a layout, I have to think about train length and ruling grade. My process is... 1. What is a typical engine consist going to be? 2. How many cars do I need to not make that motive power look ridiculous? (I'm not likely to plan around an even longer train because of the opportunity costs -- I don't mean monetary, I'm talking constraints -- imposed on layout design by train length.) 3. What grade can those engines climb with that length of train? (I'm not likely to set a significantly lesser ruling grade because of, again, the opportunity costs on layout design imposed by grade limitations.) The critical thing is that step 3 requires testing with the WEAKEST engines I have. IE, I know that GP7/9s, F7/9s, RS-2/3s, FA-1/2s, etc. all have similar HP and TE in real life. Thus, a given number of RS-2s on my layout must be assigned the same length train as the same number of F7s. Doing otherwise would grind up my suspension of disbelief and launch it into orbit.

OK, this is no longer about Z scale, but...


I don't have a problem with such occasional repairs. I'm saying that the model market hasn't demanded that all engines pull up to some given standard, traction tires or not.
In N, there's a wild difference between what different models will pull even though traction tires are rare (on diesels; all steam seems to have them). In the 2000s, it was often said that newer models didn't generally pull quite as much as older models. This was blamed on lower-density frame alloys (change to lead-free?) and on frame cutouts for decoders including on analog models. It became notorious that newer Atlas diesels could pull half or less what Kato diesels of the same size could. I sometimes saw it said why. Most of the difference wasn't due to them being lighter, though they often were. It's slippery alloys in the wheels.


Well, they're still common enough that people reviewing locomotives tend to give them a failing grade if they can't reliably cross dead frogs at slow speed.


Notice exactly what I said:


I didn't say it didn't have other uses. That, in fact, is a nightmare for me. I'd love to be able to stay analog, as I hate programmable controls on every appliance, etc. that I have. I have ideas of what good UI is, and it's intrinsically impossible for programmable controls to meet them. The problem for model railroading is that I, as I just explained, accept no non-prototypical constraints on the use of my models. I have to be able to consist any engine with any other because that's what the real railroads can do.


That's why I can't yet plan on Z for my next layout. The statistics and usage of my roster are the place I won't tolerate any compromise.


There can be no exceptions to the rule that engines have to be able to pull a certain amount on a given layout. There is one subtlety: not all engines have to pull equally. IE, in real life, it takes two GP7 or F7 to match an SD40 in HP and TE, three to match an AC44CW. So I could elaborate on my previous example:
Say I'm modelling the late 1960s. In real life, the railroad might assign the same train 2 SD40/45s, 2 F45s, 2 U30Cs, 2 C630s, 4 F7/9s, 4 GP7/9s, 4 RS-2/3s, 4 FA-2s... or any wild combination thereof. (Thus the speed matching thing...) So on the model, the question is, which of those consists is the weakest? That in combination with the train length limits my grade.

Reason 1 why no exceptions: To model a place and time, I have to model the motive power assignments. I don't get the freedom to assign engines to the jobs the models are most capable of. IE, it doesn't matter if the best slow-speed runner I have happens to be my GP38, if the yard I'm modelling was regularly switched by an Alco S-2 at the time I'm modelling, I need an S-2 in my roster and I have to assign it to the yard job, and thus the S-2 specifically has to be able to pull a large enough cut of cars and do so through the yard switches at switching speeds.

Reason 2: In most cases, the ruling grade on a layout will be part of the mainline and every train running the length of the layout will have to climb it.



I know my interests require a large space! That's exactly why I was (silently) annoyed earlier in the thread when someone mentioned small scales being good for small spaces. Small scales are just as useful for getting more in medium and large spaces!
I happen to have a basement right now, cluttered with stuff but most of that could be moved over or out of the basement to free up much of it for a layout that would actually be able to comfortably handle long trains... but I'm not about to start such a layout, one of many reasons being that I expect to move soon. Fingers crossed for the next place...
Note I'm talking about N there. I know I couldn't fit anything of what I want in this basement in HO or larger, or probably in any basement. (Houses just aren't that big...) And I still couldn't do much in this space without double-decking, which is a big part of why planning around pulling power is so important

triplex

So You want to design your layout based on the Tractive Effort Standard of Z scale locomotives? Well I guess you are going to be Disappointed Because there is No such Standard in Z scale. Which pretty much explains "the... casual? lackadaisical? attitude many modellers take toward tractive effort" Why should we care about a standard that dose not exist and probably never will in Z scale.

Just like the real thing the tractive effort of each make and model of locomotive is going to vary according to its size, it's weight the number of drive axles, the motor and gearing. But more than just those things your track work is going to play a huge roll in what a given loco can pull. The percentage and length of grades, the radius of curves, the number of turnouts and crossings, and the respective location of each of these things in relationship to the others. Top that with how much the rolling resistance of each car changes as more cars are added to it, as it roles around a curved track, through a turnout, over a crossing or up a incline. The only way your going to calculate all these variables is to buy the loco's and cars you want, build a test layout and take the required measurements yourself.

Me well i would rather spend my time building my layout and running the trains than doing all that research and testing but if knowing the exact tractive effort for each of your loco and doing the research & calculations is what your into then by all means go for it and enjoy yourself.

David