Yesterday I spent some time

Yesterday I spent some time assuring that I had ALL WHEEL pick-up on my Bachmann 4-8-4, and that it was well lubricated, and the wheels were all clean. It was running very good, BUT it still could not pull that many cars up the considerable grades on my stone viaduct. I even added some external lead weights to the body of this steamer,..that helped, but I knew I could likely never get enough weight into that engine to make a really big difference.

Today I thought what if I added one of my Proto 2K engines into the consist. Its a 1K model of the DL109,..lots of weight, lots of pulling power. I put it behind the steamer. (BTW the B-unit there is unpowered)

With both the steam and the diesel pulling it seemed like I could just keep adding cars, and it would pull them. I began to think of how I might disguise that diesel engine into some sort of 'powered freight car' to make it appear as though the steam engine was doing all the work . OR, how about adding power to the tender as a pusher?

I figured there must be some discussions of that on this forum, so I did a quick search.

Tender Drive for Steam

This was the  very last posting added to this conversation, 
https://forum.mrhmag.com/post/tender-drive-for-steam-thinking-out-loud-12190154

Most of the previous postings had dealt with adding power to the tender in lieu of having a power source in the main boiler. I'm wondering about having power in BOTH the main body and the tender.  And making that tender HEAVY like the diesel example above so it could substitute for it??

Should be

It should be easy enough to power a passenger car with a Diesel mechanism. You could use a cheaper decoder and speed match the two units. Same could be done with a period box car and a B-B switcher unit. you might be able to get everything into a 40' but a 50' will be easier.

Bob

Prior art...

Dear Brian,

As posted previously here on MRH...
(Rich Weyland's N-scale N&W Y6b with 2x Atlas Alco RSC-2 "powered tender" super-power)
 

The NGers, esp those in the HOn30 "Maine 2'er" world
(Hayden and Frary, et al) have long been putting 4-axle diesels under boxcar bodies to allow the illusion that the 0-4-4 Forneys could haul like their prototypes,

http://www.hon30.org/recipes-for-powered-boxcar-and-forney-truck/

and HOn30 loggers have been doing similar things with N scale LL SW1200 mechs under "powered water tanks" to form "looks like a dbl-headed Class A Climax consist, actually 4x diesel mechs" consists capable of hauling loaded disconnect log trains stretching over 4 actual feet, with a trailing load exceeding 1/2 kilo, on 9" radii curves and 4% grades...

(A "powered water tank" car, based on an N scale tankcar body and an N scale LL SW1200 switcher mech,
powering a Price 16-wheeler geared loco)

Happy Modelling,
Aim to Improve,
Prof Klyzlr

Curious …

What is the grade, the curve radius, and how many cars before the Northern starts slipping?  While I loathe the things, does the locomotive have traction tyres?

Have you been inside it?  Is there weight throughout the boiler?  Is the weight balanced?  Putting something round underneath the frame and determining where the center of gravity is, is an important step.

Mike,...I have not done any

Mike,...I have not done any intensive look at what might be done to any individual steam engine I have. I just know that I have a number of large steam engines, and its my understanding from lots of previous discussions, across more than a few forums, that in general this is a real problem. For instance I have a number of those VERY NICE Proto Heritage steamers that I understand have these same pulling/traction problems.

Over here I was doing some cursory running of a couple of my Allegheny and Mountain locos. You will see some photos of my grades (close to 4%), and you will see where I taped some 'wheel balance weights' onto the tops of the boilers,..
https://forum.mrhmag.com/post/locomotive-steam-diesel-pulling-capability-tests-12219492
I did that same thing to the 4-8-4 the other day, and it only marginally improved things. And that Bachmann 4-8-4 does not have traction tires. Nor do a number of my other steamers. Then you run into the problem of finding drivers for your engines that will match the engine and accept traction tires.

Those are a few of the problems I would be interested in circumventing by finding a 'disguised pusher'. Wonder if it could be generic enough to have application in our individual tenders as well as a 'generic tender/freight car',....perhaps an aux water tender for those various steamers??

The truth is that model steam

The truth is that model steam engines will never pull like a model diesel will.  First off the weight of the steam engine is not any greater and usually a lot less then the diesel and they cant be as they are not any larger.  In the prototype this is the exact opposite.  The steam engine weighs more as the boiler is solid steel and filled with water vs the diesel having a lot of air gaps.  And a lot of the weight of the model steam engine is either hanging over the drivers or held up by non powered wheels.

Then you have diesels with 8 or 12 driving wheels and you have steam engines with typically 8.  Only the largest have 12 or 16.  And as noted above getting the same weight on the drivers is much harder.  As the weight has to be balanced so that all ythe drivers get about the same amount of you actually can make things worse.  
 

On top of this is that often it is a matter or perception vs reality.  I know a guy that insists his steam cant pull well enough and his diesels pull better.  But I proved him wrong on his own layout.  I ran a maxed out steam train around.  Then swapped it for a single diesel and it slipped on the grade.  His reply was that he ran tripple headed diesels…. Now how one engine with 8 drivers was supposed to perform as well as three engines with a total of 36 powered wheels I will never understand…. But that is what he thought.  So his steam sits in the yard and he runs diesels.    
 

-Doug M

tractive effort depends on weight

the tractive effort, even on a model, depends on the weight on the drivers and is typically ~20%.   the number of drivers is irrelevant.

lead can easily be melted and shaped to fit into space in the loco.  small lead shot can be put in bags and added.   tungsten is 1.7x heavier than lead.  tungsten powder in bags can be fitted as well as held together with blue.    also try to keep it centered (balanced) over the drivers

Motorized Bogies/Trucks

Could I have a very heavy, 4 axle (better weight per wheel), disguised slug that could end up pushing my steam engines?

Could they make use of some of these Motor bogies/trucks
https://forum.mrhmag.com/post/044t-switcher-identify-small-steam-engine-12213177

one sample,..

more here,..
https://forum.mrhmag.com/post/044t-switcher-identify-small-steam-engine-12213177

One slug might end up being utilized to push a whole variety of my steam engines. That could be a worthwhile investment.

Auxillary Water Tenders

I'm liking this idea more and more. I already have one of these tenders for my Rivarossi Allegheny (yes I know the prototype Alleghenys never needed these).

I also have 1 or 2 of the stock N&W ones.

some other observations,....
Auxiliary Tenders for Steam Locomotives

The simplest solution …

Might be to set your layout in the transition era and just double head with diesel road switchers behind the steamers!  Some prototypes did it.

The idea of putting slug drives in tenders and consisting them would definitely work - just a lot of effort and cost.  Diesel trucks under them could probably be disguised with glued on steam tender truck side frames if you care about the look of the trucks under the tenders. 

Some model steamers pull better than others.  Even with steel tyres, I accidentally hooked my Rapido Royal Hudson on two three heavy Athearn GP7s and dragged them down the track.  No slippage. 

Personally, i’d just limit. Y train length to what works, per loco, (a tonnage rating, just like the prototype) and forget about it.  Longer trains require helpers. 

The Contrarian Solution

I can only build small layouts...my current is 14x2-1/2. No grades. Pulling power is not a issue. 

are the wheels spinning?

if so, a different drive system or motor won't make a difference.

try taping some lead on top of the loco to see if there's a difference

Is it actually a problem?

It's obvious that there are de facto limits to how much they'll pull. I'm not contesting that. But to what degree is the situation causing actual problems on the layout?

Most of us are fairly limited in terms of layout size, and this puts some fairly strict limits on train lengths. How long are your passing sidings? Yard tracks? As an example, passing sidings on my layout are limited to about 20 cars long plus power. (I'm using 40' cars, since that's pretty typical for the steam era.) My impression is that a 20 car train is on the long side for most home layouts.

My experience is that most steam locos can pull 20 freight cars up most grades, or at least come pretty close. This excludes the smallest power (in my case, an 0-6-0, a 4-6-0 and a 2-6-0), but likely the smallest power wouldn't be asked to pull such large trains.

Few of my steam locos can pull 40+ cars up a 3% (uncompensated) grade, but a 50-car train will be in two towns - and thus two passing sidings - at the same time.

"We keep adding as much

"We keep adding as much weight as possible,,,,, "

But Do we? How many enter CRAZY MODE when adding weight? Most decent plastic shelled steamers now have metal frames that fill the boiler but the zanac they use isn't the densest metal out there. So how far are you willing to go to replace it with something as heavy as, er, lead? You could machine out large sections, very carefully after examining what parts are critical for alignment of the spinning bits, and replace them with lead. High tech would be looking at 3d printing in something suitably heavy. You also carefully take a mold and cast a replacement. (Hey! It worked for steam engine frames.)

 Another step on the crazy-train is to use the plastic shell to make a really big lost wax casting of the shell. You loose the old shell in making one, but they were doing this in N scale with Rivarossi shells back a bit. Do wonder how big lost wax can go.

 Or you could just double head those Bachmann's (The KISS method.)

Double Headed Engines

I will be using my Mountains (4-8-2) in a dbl head fashion, but I am not excited about dbl heading those 4-8-4 Northerns.

I'll get a count of the number of cars I am now pulling with my engine singles and combos tomorrow,.... or the next day,...got to get prepared for mini-open house this weekend.

Express Boxcar

Some rummaging around in my cargo trailer turned up a slick looking freight car, labeled an express box car,...Walthers #932-6042

It's obliviously a modern day concept, but my question is did anything like this concept exist in the older days,..in the steam days??

What sort of era was this car ?,..

there were head-end cars in the steam era

Your car looks to me like something from the 1960s or later, but there were definitely express cars in earlier eras. One notable source of them was the large fleet of Pullman Troop Sleepers of which there were something like 2400 were built in 1943-44. Of course they had wartime duties, but after the troops came home in 1945-46, they were sold to various railroads and converted into various other things. Notably many became express box cars or baggage cars and were seen on many passenger trains for the rest of the steam era. Express cars were LCL and were more or less the equivalent of FedEx of the early 20th century.

Earlier than that, on some trains and in some areas, milk cars were pretty common head end cars. Practices varied (apparently widely) but these often were found on commuter trains and 2nd class passenger trains. You wouldn't see them on the 20th Century Limited or the Super Chief, but many other trains might have carried them on some part of their schedule.

What's the reluctance to double-head Northerns? Granted that configuration wasn't especially common, but it wasn't unheard of. What was not unusual was putting a Mountain helper on the front of a Northern, if the trains got too heavy. Normally the lighter engine took the lead position. On C&O in my era, it was normal practice to assign a 4-8-4 over the Mountain Sub as long as the train was 12 cars or less. If the train was longer/heavier than that, a 4-8-2 helper was typically assigned, although during the war years the trains often got so heavy that two 4-8-4s were sometimes given the task, or a dual-service 2-8-4 would be the helper. Eventually the wartime traffic got so heavy that they adopted the practice of running multiple sections, each limited to 12 cars and a single 4-8-4, 4-8-2 or 2-8-4.

In earlier eras, or on other roads, double headed 4-6-2's (particularly on PRR) or a 4-6-2 helper in front of a 4-8-2 were often seen.

Belt Driven Trucks

What if we take a look at some O-scale ideas?

https://forum.mrhmag.com/post/whats-on-your-workbench-december-2018-edtion-12211536

The problem is dominated by weight & grade

The number of drive wheels do matter, but to a lesser extent to grade & weight.  A 4% grade is a very severe grade.  Add some curvature to the climb & it quickly is equivalent to a 5+% grade.  The actual resistance is complicated by the actual local grade.  

The expectations should be based on the weight comparison, steam engine boiler compared to the diesel.  For a 2.5% grade, I consistently measure 3 additional cars per five ounces of weight.  In round numbers, that derivative is 3 times larger at zero grade and 1/2 as large at 4% grade.

Basically that says at high grades you likely can not add enough weight to appreciably increase your train length.  
 

The additional of drive units are the more practical solution.  How you do this, as was indicated earlier, is dependent on how long your trains can be.  Rob talks about pulling 100 car trains.  Depending the make up of cars that train is 50-55 feet long.  Not many layouts can handle that.  
 

A more likely length is 15 cars.  This is 7-12 feet.  To run that at a reasonable speed on a 4% grade you likely will need 4-5 units.  That many engines will look odd.  As Prof K referred to, making powered cars allows the train appearance to be more realistic.  
 

This is the conflict of severe layout grades on realistic train operation.

My viaduct grade issues are a

My viaduct grade issues are a result of my desire to permit double stack container cars to get into the central peninsula zone, requiring them to get under this bridge and this arch structures.
 

Both of those required heights were fortunately near each other, over in that corner where the tracks were going thru the back wall into the helix area. So I needed to get to that height using one ramp on the length of the layout, and the other one across the width of the layout, ...15 x 11 shed interior.

 
 

My original thoughts were how can this be that bad?,...after all there are numerous old small layouts that had a figure 8 arrangement with a bridging crossover. Of course these small layouts were not anticipating running longer trains.

I'm pretty happy with my track plan, so now I just need to explore different options on making my trains negotiate it,...and I quite a few steam engines I would like to make usable,...and some of them without being dbl-headed.

I love those Heritage articulated steamers by Proto, but I would really like to see them able to pull at least 20 cars by themselves. I believe there are quite a number of other modelers that would like to see the same,...without having to resort to all the weight adding, etc to get there. What if they could simply buy a 'disguised pusher' that could be utilized along with any number of their other steamers??


*****Might be an interesting project for one of those manufacturers to pursue,..in lieu of those constant repetition of existing models??

Grade is irrelevant to the

Grade is irrelevant to the OP.  The OP commented on steam engines not performing as well as diesels.  So the curves and grade are presumably the same and will effect them both.  Weight per wheel and number of wheels is where the difference comes in.  
More weight on a wheel means more traction.  But relatively this is a minor increase.  Double the weight per driver will not typically increase the traction by double.  But you double the number of wheels and you DO double the traction.

Like i said while I believe that steam (especially the modern plastic) tends to pull worse one on one then diesels do I still think that we are seeing the issue in that most the time we run two diesels in part because for moderate size steam engines they are about as long as two first or second generation diesels.

-Doug M

one possibility

Is Bullfrog Snot. I've never used it, but there apparently are plenty who have. It basically allows you to paint a traction tire on a wheel. It is not conductive, so you definitely want to put it on a driver on the side that the tender picks up the current. The name is a bit cringeworthy, but a google will turn up a fair number of satisfied users, and they are in enough different forums that it would seem to be unlikely that they're all faked.

Bullfrog Snot

One other well known member on this forum (who in the past has pulled some long train), did make a comment about how much trash it picked up. He didn't care for that aspect.