The pulling power of steam

Since I have been in the process of rebuilding my layout, I've noticed some things about the locos and cars I had previously known and loved as dependable. Pulling power and truck type are completely thrown to the wind when you add inclines to the equation. My last N scale layout was built such that all lines were on the flat. There were two levels, three mainlines and a multitude of switches. Now I have expanded the size and added a 2% grade. At first I thought, "2% seems pretty good. Stay low with the grade and everything will run perfectly." I know some folks who run 4-6% grades. My question now is, "How does someone run on a 6% grade while pulling any more than one car?"

Mainly the thing that has thrown a wrench into the equation is steam. My previously tried and true steamers are completely inadequate for their tasks now. This has really made me question my layout all over again. Perhaps I am being too demanding of my steam locos, asking too much. Or, perhaps manufacturers need to take a step back in their designs. (or a step ahead)

My steam roster is this:
4 Spectrum consolidations
1 Kato Mike
1 MP Pacific
1 LL Mallet
1 Kato 2-6-4 tank
1 MA 4-6-2

The only steamers that pull their weight are the Spectrums. (granted I have not done the traction tire on the Mike yet) It is very disheartening. My Spectrums pull 20 freight cars easily up the 2%. This is something no other single engine can do on my layout now. None of the diesels pull more than 10 unaided. The steamers are worse than that. The MP Pacific, which previously pulled just 6 Arnold/Riv passenger cars, can now pull only 3 up the incline. (2 comfortably) The spectrums still pull the full 6 without slowing down. The Kato Mike can pull about 8 freight cars.

I also know that I need to apologize to someone on the Atlas forum, as I insisted that my LL mallet pulled 20 up a 2%. Unfortunately I forgot I had added a helper box to it. Alone it pulls 8 freight cars up.

What is up with steam? To me this is completely unacceptable. Why should we have to modify a loco or add a helper to it to pull more than 8 freight cars or 3 passenger cars up a 2% incline?

I can accept the fact that carrying capacity decreases 25% with each percentage point of grade. But when my previously loved MP Pacific struggles pulling 3 passenger cars, it's time to rethink what I'm doing. Or buying. It's not that I have to run long trains, but it would be nice to run consists of more than a couple cars. I really like the new design of my layout, but when things get this frustrating, maybe I should go back to flat.

Thanks for letting me rant.

Jacob

 

What's your curvature? Un-compensated curves also affect ability to pull. I remember reading somewhere that in N for each inch of radius of curvature under 15" you have effectively added the equivalent of another 1% grade.

Of course curvature as opposed to grade is not ameliorated by train length. Rarely will an entire train be on the rise of a grade. However the curve will effect the entire train length.

If you have 2% grades and tight curves combined you could effectively be pulling 5-6% grades.

 

Hi George. Actually the inclines are pretty much straight shots. I expected the carrying capacity to decrease, but down to 2-3 passenger cars or 8 freight cars seems a little extreme. (except for the Spectrums) The thing that was most disappointing was the MP Pacific. I really love that loco and got used to it pulling the line of CP passenger cars. I was thinking of picking up one of those Kato critters for it, just to give it a hand. I noticed on your website they have a new release of them coming out. Maybe it's time for a little Kato critter kitbashing. Alas.

Jacob

 

Fellow Sultan of Steam, you have found out about the unfortunate part of trying to model steam in N Scale. Many of the available steamers simply do not have the tractive effort necessary to pull a reasonable number of cars up a grade.

The Spectrum Consols are definitely the exception, rather than the rule, when it comes to tractive effort (although I am hoping that the newly released Mountain will be their equal). The Kato Mike, without the traction tire, is entirely hopeless; when the traction tire is added, it does improve, although it still is not anywhere near the Spectrum Consol.

While I have an MP Pacific, I have not yet had the opportunity to try it on a grade; only on the straight and level. There, its tractive effort seemed to be OK, but that may very well change on a grade (based on your findings, this would appear to be the case).

One of the better pullers, and in fact, in the same league as the Spectrum Consol, is the old ConCor-Kato J3a Hudson. I have one of these and it pulls very well, even on a grade (I have had a string of 20+ cars behind mine on a helix with a 2.25% grade that includes 12" radius curves; the entire train is on the grade for some time, and the Hudson pulled very well without any slippage whatsoever).

The one advantage that we do have in steam is that the tender on many steamers provides an excellent opportunity to use a Kato "critter" to improve the tractive effort (the Spectrum Doodlebug is also good for this). One downside on this, however, is that the critter (and the Doodlebug) only has two-axle trucks, and yet the locomotives that most require the help are those that have tenders with three-axle trucks (such as the Mallet).

It is possible, of course, to use the chassis/trucks from a A1A diesel to power such tenders, however, I have found that the wheel spacing on most A1A diesel trucks is much greater than on tender trucks, and in fact is great enough that the difference is noticeable. In addition, of course, the truck sides really need to be changed such that they actually look like tender trucks rather than diesel locomotive trucks.

I certainly think that there is an opportunity for some enterprising manufacturer to come out with a couple of different "powered" tenders that could be used with some of the steamers available on the market. This is especially true with the larger tenders (such as those on the Mallet), where if the chassis of the powered unit were made in a manner similar to a diesel chassis, a fair amount of weight could be incorporated into the tender (in addition to the motor), which would give the unit a considerable amount of tractive effort (similar to the LifeLike C-Liners and Erie-Builts perhaps?). Then you could have a Mallet that could actually pull 40 to 50 cars up a grade without any problem.

 

This an area where brass models have it over platsic. With a brass model you have lots of extra room for weight and larger motors which gives better pulling power.

For example: I bought a Hallmark ATSF 3751 that had a smooth roll but could not pull its own tender so I replaced the motor with the largest 5 pole I could stuff in the boiler and filled the rest of the space with putty weight. Now this model pulls 20 heavyweight cars with little effort.

Some plastic models have a little room for added weight but in most cases its not much if at all. Weight and motor torque is the key to better pulling power in a steam locomotive but in a plastic model its easier said than done.

 

While a two-per-cent grade on a model railroad may seem moderate, on a prototype, it is one nasty grade, particullarly a sustained two-per-cent grade.

As others have pointed out, you then add the disadvantage of the small size of the N scale and you get more problems. The introduction of grades shows why N scale locomotives need traction tyres. It is just a sad fact N scale modellers will have to suffer. The MP pacific is a case in point: No one can dispute that the metal boiler on that thing provides all sorts of weight; more than would give the requisite tractive effort to get up the side of a hill. Still, it will not get up a two-per-cent grade. Metal-to-metal (particullarly smooth metal-to-smooth-metal) has a nasty habit of slipping--low factor of adhesion, if you will. The traction tyre provides the requisite 'factor of adhesion'.

Once more, though, we must visit the prototypes. In areas where there were protracted climbs with one to one-and-one-half per-cent grades, there were one or two helpers on forty and fifty car trains. The prototypes even had formulae and rules for the number of helpers for the number of cars and tonnage. A fifty car train with a mikado and an A-B pair of diesel helpers does not seem unreasonalbe in the context of the practices of certain prototypes (such as those that dealt with protracted two-per-cent grades). A six to ten car passenger train with a pacific and a single diesel or a mikado as a helper does not seem out-of-line with prototype practice either, particullarly when you are getting into protracted two-per-cent grades. On most roads, there may have been a 'ruling grade' of two-per-cent, but even in the protracted climbs, the steady grades were one-per-cent or less. Even a half-per-cent grade put a strain on a locomotive.

I would not necessarily be unhappy with the performance of my locomotives-their performance seems to be close to that of the prototypes. What does rub is that you have to cut on and off the helpers after a rather short trip up the grade. The railroads tried to keep grades to a minimum-in steepness and number. There was a reason for this. It took extra power, extra labour, extra maintenance, more fuel and more water(where applicable)--in short it took more time thus IT COST MORE MONEY--to construct, maintain and use.

 

You have a number of limiting factors on this 2% grade that you are talking about. Are you sure that it is a real 2% grade? check all you measurements. I thought I had a 1.5 % grade on my layout, but the trains just wouldn't climb the hill right. Recheck my distances, and found I had built a 2.75% grade. Check that tape measure. Have you made sure the trackwork is in gauge? Get out the NMRA gauge and check EVERY inch of your track work.
You mention the passenger cars as being Arnold/Rivarossi(spelling?) passenger cars. Metal wheels and axles in plastic side frames? That type truck is not the most free-rolling. How about the freight cars? Micro-Trains trucks, and couplers? If they are the metal wheels and axles, rolling quality will be the same as your passenger car trucks. When you start dealing with grades, curves, reverse curves, etc. you want to have the most free rolling trucks that you can get. Have you made sure ALL your rolling stock's wheels are in gauge? Check everything with an NMRA gauge to make sure the wheels are in gauge on the axle. Just because it's a new car with new trucks don't mean the wheels are in gauge. Every so often I find a set of MTL wheels not quite in gauge. File 13 is where they go!
You mention layouts with 4-6 % grades, awful steep in my book. I will not be going much more than 1-1.5 % mainline grade on average with a section of 1.75 % grade just to make things interesting on the rebuilt INDIANA RAILWAY. And I plan on using helper engines on the 1.5 & 1.75 grades also. With DCC I'll have 2 Mikes upfront and a pusher in the rear. All engines will be independently controlled, by three seperate engineers, just as the protype did. I am planning on 20-30 car coal trains as being normal size.
There can be a whole bunch of other reasons why your engines don't pull well on grades. Check the railroad as a whole and get everything to work together.

 

Straw,

Do you have an address/website for Golfsmith? I'm ALWAYS adding weight to my locos. I model in HO, and I've been forging and casting lead to fit as much in as possible. I've added as much as 12 ounces to a diesel.

Mark in Utah

 

'Scuse me for showing my ignorance , but where can I find more info out about this "critter?" I've never heard of one before, but then again, I haven't been around this hobby all that long.

Thanks!

-- John

 

JS-

I can not swear to this, but I seem to recall that either or both of the two dealers who post here regularly, geep 35 and wig-wag, have mentioned having it (if I missed any other dealers, please do not get offended, I am simply not aware that you are here). Again, I can not swear to which one or either, but perhaps they can answer. If neither of them has it, I do know that M.B. woo woo woo in Baltimore has it. Look up some train store.com, or something like that and you will find them.

 

'Scuse me for showing my ignorance , but where can I find more info out about this "critter?" I've never heard of one before, but then again, I haven't been around this hobby all that long.

Thanks!

-- John </font>[/QUOTE]John,

Wig-Wag had them, although I believe they are temporarily sold out (it appears that there are more on the way however). You can take a look at them at Wig-Wag's site, here:

Wig-Wag Kato Critter

Paul (Colonel) there is one way to further improve the Kato Mike's pulling power, and that is to use one of the GHQ conversion kits. I believe the Western Pacific W3 conversion kit (coal or oil versions) is still available at some places. The cast pewter parts add a considerable amount of much needed weight, which greatly improves the traction. I currently have one of these kits to build myself (a friend of mine has already done one), and it works very well to improve the Kato Mike.

 

Brokemoto & Suttonredbird, thanks for the link!

-- John

 

Jacob--If you're still in the process of rebuilding, maybe you could have one route in your layout that completely avoids grades. That's the way mine is, or turned out. (I'm not a genius planner). My layout is essentially a big irregular dogbone, about 50' around. I always wanted to include one of those old Atlas viaducts and I did it with an inner, elevated "mountain" track that loops back under itself, going both over and under the viaduct, then rejoining the main track; I also ran a 2nd track around the main, making a double track. This is no "great layout," but the fact that the grades are "optional" is a big help, given the inconsistency we still have in N scale steam. The Spectrum 2-8-0 is great at handling the viaduct section, but passenger trains pulled by the good looking but weak MP pacific can still manage if they stick to the main line, The LL 2-8-8-2 can manage only a seven car train up the viaduct; and although the main line can accomodate a 25 car train, and the LL would look great pulling one, it can't. (When is LL going to make a traction tire?) And speaking of retrofits, get that traction tire on the Mikado asap and it'll be pretty much the equal of the Connie. With that upgrade, the Mikado is a truly great, fun performer. One more thing--a general question for all who might come across these words: have you had any experience yet running the new Spectrum 4-8-2? if so, what do you think of it? Thanks! ---Jim W.

 

Jay, actually I do have two level mains on the layout. The way it is designed is with two tiers. The lower tier has a connected double main which can run continually either with the grade or on the level depending on how it's switched. If it runs with the grade it goes as high as the second tier and can potentially connect with a level isolated main there. With the two completely isolated mains I can run seperate operations. So I can run the steamers level if I want, I just like to know they can make a climb if they need to.

I know I'm being a demanding nudge. I know there are certain "fixes" to the problems too. It's just that I figure if I've spent $100 on a loco, I shouldn't have to do major over-hauling to make it pull a couple cars up an incline.

As far as the Kato "critters"go, putting them in the tender might be a problem if the tender has some pick-ups there. Since I am not an electrical wizard I wouldn't want to try to splice a feed back to the loco from the "improved" tender. I was thinking more along the lines of converting them into a box car. This isn't going to help with the MP Pacific though, since it pulls passenger cars. Too long and too many axels. Although I could completely gut a crappy Bachmann loco and make it a tender drive and just use that as a helper. Or buy another pacific. Arrgghhh.

BTW they also have the Kato powered chassis at nscalesupply. I know George/wig-wag has the new releases listed as "coming" too, but you might want to check with him, as I know it's tough to keep everything current with a website. If they still aren't in, they will be soon.

Thanks guys for all the hints and comments. The level of knowledge here is greatly appreciated.

Jacob

 

Oh yeah, and I'm waiting for word on the Spectrum Mountain too. I may break down and buy one before the reviews come in, simply based on the performance of the Consolidations. I might pick one up tomorrow. If I do, I'll run it through its paces and post the results.

Jacob

 

Found another source of Tungsten: Buffalo Tungsten. They make it by the freight car load, and are willing to sell it for $20 per pound of powdered tungsten. They have several "grits" of powder, and can select the right grit if you plan on mixing it with resin.

Here's the contact:
jason@buffalotungsten.com

Mark in Utah