Hello Railfans!
While reading another thread (bad electrical pickup on a Bachmann tender) I came across a procedure Ive known about, but dont do. Adding weight to a steam loco tender to enhance its electrical contact to the rails.
When i have this electrical problem I come at it from an electrical path problem view (fix the path) and that works. Im quite sure adding weight to the tender would work too, i just dont do that.
My questions are following, aside from it gaining better electrical performance, how does this added weight affect the pulling power of the model?
I sometimes use extraordinarily weighted cars (test cars not layout cars) to simulate the weight of a long train when breaking in or servicing locos. My loco fleet is unaltered, loco or tender, concerning added weight. I would add weight over the drivers to increase TE when a layout of size becomes available.
However, Im curious. When i use the loaded cars, i see how the model works under the load. Adding weight to your tenders would seem to decrease your pulling ability because the model now weighs more as a stand alone unit (no train). Thats more work on the motor than in its stock oem form and theres no train behind it yet.
Have any of you noticed this? Has this posed problems? Also consider, some of you may use correctly weighted cars too. Now thats more weight in tender, plus weighted cars. That HAS to drop the 'tonnage ratings' on your locos. Does it?
I know wre talking small weight amounts here, but it all does add up, and you can measure it on a volt and amp meters.
(I also forsee heat problems too... anyone?)
Thanks for the info!
PMR
I weight my tenders, but I also run short trains, 12 car maximum. I also have no grades.
Any reduction in pulling power does not effect me, but it makes sense that there would be some loss.
-Kevin
Living the dream.
I add weight to all my tenders but for a different reason. Most stock tenders are so light they wobble and I don’t like wobble on my tenders. I add about 4 to 6 ounces to my tenders but then again I add 8 to 10 ounces to my locomotives too.A typical Rivarossi Cab Forward has about 2.8 ounces of drawbar out of the box. My weighted Cab Forwards have 5.8 ounces of drawbar or more. You can’t add weight to a Rivarossi using the original Rivarossi motor, it will overload and the heat from the motor will melt the plastic boiler or cab. I remotor all my locomotives with can motors.The added weight to the boiler does increase the wheel contact to the rails but stopping the wobble was my primary reason. Good all wheel power pickup trucks work with out added weight. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Mel's got a point here. Let me elaborate a little more. Steam loco models tend to be front heavy, if you consider a standard tender behind. This was especially so with brass locos. More modern cast, mass-production steam should have tender weighted about right, if designed well. YMMV there.
I was a bit of a skeptic on this matter for the same reasons already mentioned. Life can be more complicated than theory. The extra mass and non-linear application of power in a typical steam model tends to horse the tender around, affecting contact. I suspect this is in part behind the "wobble" he discusses wanting to dampen.
An old timer first suggested trying it to me. It worked well to my surprise. I understand the sentiment to "fix all the contacts" but adding weight is much more convenient in many situations. Assessing a model to buy? You'll not get a chance to go over the electrical paths and improve them, but you may be able toadd an external weight on your test run. If it improves contact, you know that some tinkering after purchase should fix it right up, an appropriate time to consider such a major cleaning or mods.
Made me a believer. Don't use weight as a crutch, but you can find it helpful in many situations where it is a useful fix keeping in mind its limitations.
Mike Lehman
Urbana, IL
If you are concerned with the loss of pulling power in a properly weighted, pivoted, and 'side-bearinged' wobble-free tender, you could always adapt something like Stanton drives, put them on a control-only decoder for DCC and consist them with the locomotive, or do a little electronic 'matching' if on DC. Or otherwise motor some or all the axles for additional pull...
I run long steam powered trains, have done extensive pulling power testing, and I weight all my tenders.
Adding between two and four ounces effects pulling power in the obvious way, it reduces it by one car.
Why is adding weight necessary and good?
Most steam locos have longer rigid lengths than their tenders, creating lots of side pull at the drawbar in curves. So like Mike said, tenders get horsed or bullied around.
Add to that fact the wires between the locos and tenders in recent decades which offer resistance to movement and can have lifting effects on tenders, and the need for extra weight is clear.
The extra weight is not just about electrical contact, it is about smooth, solid tracking which has the side benefit of more reliable electrical contact.
Given the dynamics of the coupling between the loco and tenders, most tenders are too light out of the box.
Sheldon
I add weight to all of my tenders, but I also add weight to all of my locomotives.As Sheldon mentions, extra weight in the tender is basically equal to one freight car.
I don't normally run long trains, as I have lots of grades (the major ones long and at about 2.8%) and lots of curves (reasonably wide-ish on the mainline at 34" radii or more). If the train is long or exceptionally heavy, I simply add more locomotives...perhaps doubleheading the front end, and, if necessary, adding a pusher (or two).As far as I'm aware, pretty-well all decent-quality steam locomotives offered nowadays have all-wheel pick-up, and my for my older ones, both brass and cast metal, it's not difficult to add it to them, too. In most cases, I also add all-wheel pick-up to the tenders. I also run all of my tenders with "live" coal loads.
Wayne
After re-reading the original post several more times, I have few more comments.
Like Mel, I have added additional weight to a number of locos to improve their pulling power with no ill effects. I do not have any old locos like Mel's Rivarossi models.
My steam loco fleet consists of models from Bachmann/Spectrum, Proto, BLI, more recent Rivarossi, Mantua, some older brass and even IHC.
In addtion to additional weight to various locos and most tenders, many are kit bashed in various ways including a good number of tender swaps.
In fact, most of my steam locos are Bachmann/Spectrum and even more of my tenders are Bachmann/Spectrum.
While I have conducted lots of tests on the pulling power of locos and the rolling resistance of rolling stock, I have never bothered with measuring motor currents.
I have never overheated or damaged a motor with addtional weight or in use pulling trains. I run DC and my max voltage is just under 14 volts.
I know what my locos will pull and when that is exceeded, like Wayne, I simply add another loco. Most of my trains are double headed.
I have been known to redesign a drawbar or two to improve operation.
These kit bashed Bachmann locos have a draw bar that connects ahead of the attachment of the trailing truck to better deal with the offset forces of the long firebox and cab of thse locos.
Most of the time weight is the answer because the problem is bad tracking, not pooly designed pickups.
As most of you know I have a lot of Rivarossi articulated locomotives with oil tenders, the tender truck detail is very nice but for power pickup they’re very close to worthless.
I replaced all my Rivarossi tender Buckeye trucks with metal trucks, the Precision Scale trucks (32346) are very good at power pickup but constantly derail, I don’t recommend them. The Bowser Buckeye (35107) trucks look and work great.
I add 4 ounces to the oil tenders that stop the wobbles and most likely really helps with power pickup.It’s been awhile but I think the Rivarossi tenders wobbled before any of the Mel mods.This is a Mel kitbash Cab Forward to a Southern Pacific AC-9 with 10 ounces of added weight increasing the drawbar to a bit over 6 ounces, with dual Canon EN22 motors.
By using #8 birdshot it is easy to spread out the weight for proper weight distribution over the drivers. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
ATLANTIC CENTRALThese kit bashed Bachmann locos have a draw bar that connects ahead of the attachment of the trailing truck to better deal with the offset forces of the long firebox and cab of thse locos.
This is interesting because it's precisely the logic behind the American Arch articulated four-wheel trailing-truck design on the early Woodard Berkshires. And it leads to the perhaps 'arch' question: do you experience any difficulties backing these locomotives against a substantial load? This was a great problem for the Berkshires, as the truck would try to 'cock' sideways at the articulation points, and the steering at the abbreviated pivot point just at the rear of the driver wheelbase was much worse, with that l-o-o-o-ng polar moment of inertia out there behind, than what could be achieved in a Delta design at the extreme rear outside corners of the long firebox-and-cab overhang. (In practice I suspect your Delta trailer would have rear frame extensions on either side of the booster engine, and have progressive external rocker location devices right under the rear of the cab, radial to the swing, that would engage teeth on those extensions...)
OvermodKevin, this would be interesting to show, both in an 'annotated' side view (showing the line of the new drawbar and its 'pivot axis' both in the locomotive and at the tender) and in detail shots of the actual components.
I think you meant this for Sheldon.
OvermodThis is interesting because it's precisely the logic behind the American Arch articulated four-wheel trailing-truck design on the early Woodard Berkshires.
None of my operating steam locomotives, except my Bachmann 2-8-8-4, have four wheel trailing trucks. The Bachmann EM-1 2-8-8-4 uses an amazing mount for the rear truck, and that locomotive can back through a 22 inch radius S-Curve with no problem.
OvermodDo you experience any difficulties backing these locomotives against a substantial load?
My maximum train length is 12 cars, so no, I do not ever reverse against a substantial load.
Sheldon can probably answer all this better than I can.
Overmod ATLANTIC CENTRAL These kit bashed Bachmann locos have a draw bar that connects ahead of the attachment of the trailing truck to better deal with the offset forces of the long firebox and cab of thse locos. Kevin, this would be interesting to show, both in an 'annotated' side view (showing the line of the new drawbar and its 'pivot axis' both in the locomotive and at the tender) and in detail shots of the actual components. Note that as the drawbar moves from side to side, the trailing truck also 'hinges' under it so there is no fouling even on sharp curves. This is interesting because it's precisely the logic behind the American Arch articulated four-wheel trailing-truck design on the early Woodard Berkshires. And it leads to the perhaps 'arch' question: do you experience any difficulties backing these locomotives against a substantial load? This was a great problem for the Berkshires, as the truck would try to 'cock' sideways at the articulation points, and the steering at the abbreviated pivot point just at the rear of the driver wheelbase was much worse, with that l-o-o-o-ng polar moment of inertia out there behind, than what could be achieved in a Delta design at the extreme rear outside corners of the long firebox-and-cab overhang. (In practice I suspect your Delta trailer would have rear frame extensions on either side of the booster engine, and have progressive external rocker location devices right under the rear of the cab, radial to the swing, that would engage teeth on those extensions...)
ATLANTIC CENTRAL These kit bashed Bachmann locos have a draw bar that connects ahead of the attachment of the trailing truck to better deal with the offset forces of the long firebox and cab of thse locos.
Kevin, this would be interesting to show, both in an 'annotated' side view (showing the line of the new drawbar and its 'pivot axis' both in the locomotive and at the tender) and in detail shots of the actual components. Note that as the drawbar moves from side to side, the trailing truck also 'hinges' under it so there is no fouling even on sharp curves.
I will take some pictures and answer the questions in a bit.
Very interesting replys - thank you! Ok, lets review for a bit....
*Added weight in tenders increases electrical perfomance.
*Added weight in tenders decreases 'tender wobblys'.
*Added weight in tenders drops tonnage rating by 1-2 cars.
The first one i think we can all agree on as its an obvious one to understand. Its been a long time fix.
The second i can also agree with. Though i have to admit, i find it suprising that so many of you have "wobbly tender syndrome". I run mostly Riva's in steam, IHC and a few old Mantua's. None of which seem to have this problem. They track fine and therfore hardly ever wobble.
Sheldon raised a very good, unmentioned point - the wiring! And todays DCC models have alot more than their older ADC counterparts. I have run into this problem but it was easily fixed by relaxing and repossitioning the wires (both ADC or DCC). I didnt have to add weight. Good point though, as the wiring sometimes will 'float the tender'!
Ive also never had a problem with drawbar swing. Matter of fact i usually pull mine closer for a more accurate look. So im not seeing any drawbar problems, luckily. Even on tight radii. Wiring can also hamper the swing - see above paragraph.
That leaves door number three above. And the reason i posted, mostly. It has been said the added weight only decreases tonnage by 1 car. maybe 2.
Given that i was reading 8 ounces for a tender alone i was thinking this would translate into about 5 to 10 cars lost in tonnage. Not one or even two maybe as stated.
Theres the amazement into this lil forray. In this, and the post this was based on, some of you add weight right out of the box just to be adding weight. And it seems like an atrocious amount too! 8 ounce tenders?? (on a side note, is this deterimental to turnout points? they are soft rail and easily bent under alot of weight.)
So you see, by the time one reads that you've added 8o to the back, another 8o or so over the drivers, im thinking.... this thing wont even move itself! Much less pull a train. Youll need a helper just to get out of the engine house. My dinner doesnt weight that much!
Thanks for the info folks. Without electrical or wobbly problems, i cant see an advantage of adding weight to my tenders. Over the drivers - you know it! Though should it need be done, im very glad to know a 1-2 car disadvantage is the only penalty. Not 5 - 10 as i imagined and the adding weight process is tried and true.
Under the rules to which ill be operating, dblheading is ok, but not a common practice. The line is mostly flat. The rumor has it the PM ran short, fast trains. To me though, short is atleast 40 cars and fast tops out at about 60smph. Loosing 1 - 2 is ok. But 5 - 10 like I originally thought??? Oh Mon Dieu!
A modern 2-8-4 doesnt look just quite right pulling only 10 cars zipping down the main. Now, to go a little ....
Hey Mel! What did you do with all those Riva Buckeyes? Are we allowed to do any horsetrading here?
Thanks again for the inputs guys - very interesting indeed!
Green Lights Folks!
Douglas
PM Railfan Hello Railfans! Very interesting replys - thank you! Ok, lets review for a bit.... *Added weight in tenders increases electrical perfomance. *Added weight in tenders decreases 'tender wobblys'. *Added weight in tenders drops tonnage rating by 1-2 cars. The first one i think we can all agree on as its an obvious one to understand. Its been a long time fix. The second i can also agree with. Though i have to admit, i find it suprising that so many of you have "wobbly tender syndrome". I run mostly Riva's in steam, IHC and a few old Mantua's. None of which seem to have this problem. They track fine and therfore hardly ever wobble. Sheldon raised a very good, unmentioned point - the wiring! And todays DCC models have alot more than their older ADC counterparts. I have run into this problem but it was easily fixed by relaxing and repossitioning the wires (both ADC or DCC). I didnt have to add weight. Good point though, as the wiring sometimes will 'float the tender'! Ive also never had a problem with drawbar swing. Matter of fact i usually pull mine closer for a more accurate look. So im not seeing any drawbar problems, luckily. Even on tight radii. Wiring can also hamper the swing - see above paragraph. That leaves door number three above. And the reason i posted, mostly. It has been said the added weight only decreases tonnage by 1 car. maybe 2. Given that i was reading 8 ounces for a tender alone i was thinking this would translate into about 5 to 10 cars lost in tonnage. Not one or even two maybe as stated. Theres the amazement into this lil forray. In this, and the post this was based on, some of you add weight right out of the box just to be adding weight. And it seems like an atrocious amount too! 8 ounce tenders?? (on a side note, is this deterimental to turnout points? they are soft rail and easily bent under alot of weight.) So you see, by the time one reads that you've added 8o to the back, another 8o or so over the drivers, im thinking.... this thing wont even move itself! Much less pull a train. Youll need a helper just to get out of the engine house. My dinner doesnt weight that much! Thanks for the info folks. Without electrical or wobbly problems, i cant see an advantage of adding weight to my tenders. Over the drivers - you know it! Though should it need be done, im very glad to know a 1-2 car disadvantage is the only penalty. Not 5 - 10 as i imagined and the adding weight process is tried and true. Under the rules to which ill be operating, dblheading is ok, but not a common practice. The line is mostly flat. The rumor has it the PM ran short, fast trains. To me though, short is atleast 40 cars and fast tops out at about 60smph. Loosing 1 - 2 is ok. But 5 - 10 like I originally thought??? Oh Mon Dieu! A modern 2-8-4 doesnt look just quite right pulling only 10 cars zipping down the main. Now, to go a little .... Hey Mel! What did you do with all those Riva Buckeyes? Are we allowed to do any horsetrading here? Thanks again for the inputs guys - very interesting indeed! Green Lights Folks! Douglas
I have questions for you and a comment or two.
How much do your cars weigh? Mine are at or just slightly below NMRA RP, so the average passenger car is 6 or 7 ounces.
What kind of turnouts are you using, and why would an 8 ounce tender effect them differently than the 20 ounce loco pulling that tender, or the 7 ounce passenger cars in might be pulling?
Yes, sometimes the wires can successfully just be re-arranged - sometimes they don't stay re-arranged....
Sometimes the loco design is less than perfect regarding the wires.
Look closely at the drawbar on this Spectrum Heavy Mountain, hopefully you can see my modification, a "dip" in the drawbar to better clear the wires.
I don't think you really understood what I was saying about drawbars. It is not about swing, it is about the offset pulling angle, like a long passenger car (the loco) coupled to a 34' hopper (the tender), adding side stress that increases as radius gets sharper.
Not a big issue for me, my minimum radius is 36", but it can be a factor on sharper curves. My typical freight train is 35 to 50 cars, my new track plan will be appearing in my layout design thread soon.
I don't just arbitrarily add weight, but I have learned what works and what does not.
With the particular models on my roster, I have never had any wobbly tenders, before or after adding weight, but I remember back in the day how light and wobbly many Rivarossi tender were.
And lets remember where the tender is in a long train, at the head of the line where the whole weight of the rest of the train is pulling sideways on its rear coupler ina curve.
My next post to answer Overmod may offer more insight.
Overmod ATLANTIC CENTRAL These kit bashed Bachmann locos have a draw bar that connects ahead of the attachment of the trailing truck to better deal with the offset forces of the long firebox and cab of thse locos. Sheldon, this would be interesting to show, both in an 'annotated' side view (showing the line of the new drawbar and its 'pivot axis' both in the locomotive and at the tender) and in detail shots of the actual components. Note that as the drawbar moves from side to side, the trailing truck also 'hinges' under it so there is no fouling even on sharp curves. This is interesting because it's precisely the logic behind the American Arch articulated four-wheel trailing-truck design on the early Woodard Berkshires. And it leads to the perhaps 'arch' question: do you experience any difficulties backing these locomotives against a substantial load? This was a great problem for the Berkshires, as the truck would try to 'cock' sideways at the articulation points, and the steering at the abbreviated pivot point just at the rear of the driver wheelbase was much worse, with that l-o-o-o-ng polar moment of inertia out there behind, than what could be achieved in a Delta design at the extreme rear outside corners of the long firebox-and-cab overhang. (In practice I suspect your Delta trailer would have rear frame extensions on either side of the booster engine, and have progressive external rocker location devices right under the rear of the cab, radial to the swing, that would engage teeth on those extensions...)
Sheldon, this would be interesting to show, both in an 'annotated' side view (showing the line of the new drawbar and its 'pivot axis' both in the locomotive and at the tender) and in detail shots of the actual components. Note that as the drawbar moves from side to side, the trailing truck also 'hinges' under it so there is no fouling even on sharp curves.
Here are some photos of the drawbar setup on my freelanced Mikes, built from Bachmann Bershires.
My limited computer graphic skills and my lack of patience for same does not allow me to annotate these photos as you suggest, but hopefully the photos will make it clear enough.
The drawbar is attached where the original 4 wheel trailing truck was attacted with a floating link. As you can see the new Delta truck is attached to the drawbar, just behind its attachment to the loco.
As built by Bachmann as a 2-8-4, the tender was connected by drawbar connection at the back of the frame/ashpan behind the trailing truck, which would swing out rather far on moderate radius curves.
My system keeps the drawbar near the track centerline all the time, reducing side stress on the tender.
The loco weight has been increased to 19.5 ounces from the original 13.5 ounces.
The tender weight has been increased from the original 5 ounces to 7 ounces.
The loco will pull 35 of my 4.3 ounce piggyback flats on level track:
The loco will back up that nearly 10 lb train thru curves and turnouts without any difficulty. The weight of the tender, the direct line of the "push", aided by some positioning and steering effect of the trailing truck, results in smooth operation in both directions. No string lining going forward, no buckling in reverse.
And yes, the white plastic bar on the bottom of this model simulates the Delta truck frame extension and rocker locators that would be on the prototype.
PM Railfan Hey Mel! What did you do with all those Riva Buckeyes? Are we allowed to do any horsetrading here? Thanks again for the inputs guys - very interesting indeed! Green Lights Folks! Douglas
Check your PM Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
ATLANTIC CENTRALAs built by Bachmann as a 2-8-4, the tender was connected by drawbar connection at the back of the frame/ashpan behind the trailing truck, which would swing out rather far on moderate radius curves. My system keeps the drawbar near the track centerline all the time, reducing side stress on the tender.
With the documented issues about trying to back up that arrangement (which apparently was more difficult than with your system) Lima went to a Delta-style trailer... and encountered difficulties. There is a specific relationship between pivot, wheelbase, and axle spacing that produces a two-axle trailing truck that acts as a proper Bissel in curve following, and the axle spacing needed for weight-bearing effectiveness was NOT the geometric spacing needed; in fact with the rear axle used for a booster (and hence needing to be reasonably tangent to curves at all points it was running) the lateral required for the forward axle was substantial. Timken addressed this with a weird expedient: the journal boxes of the forward trailing-truck axle are free to shift laterally to some extent, and their load is carried by a pair of hardened-steel rollers on hardened surfaces below and above so the axle 'floats' laterally in the frame while remaining fully weight-bearing. This might be thought of as an extremely-long-frame two-wheel Delta truck, with the long tongue being carried by 'helper' wheels. This in turn was replaced in the AMC designs with a more conventional (by then) style of two-axle trailer... with the consequences at, say, a Franklin radial buffer that are as you stated regarding side thrust and potential stringline forces.
I believe Ed can provide us, as he usually does, with pictures of both the American Arch and the 'intermediate' floating-lateral arrangement.
Sheldon)
What type curves/switches do i run? Right now im on essentially 2 test tracks. One loop for continuous (break in) running, and one switching module (for testing short S curves, electrical contact over frogs/points, coupler swing/trip pin drag etc etc).
While the layout I intend to build will feature 32" or broader curves and #8 or higher switches, right now i use 24" on the loop, and #4s on the module. If I can get anything running on these tight constraints - im figuring they will have no problem on the future layout.
And when that layout is built, my collection will be built (kits), broke in, and ready to go. Mostly this post was to get a good idea on what you, those that have already moved further ahead in this weight thing, are doing. Again, i am rather suprised at 'all the weight being thrown around'. - pun intended. From the other post i mentioned at the top of this thread.
Concerning switch rails and points: I might have questioned an 8oz tender and not the 20oz loco pulling it or the heavy passenger, never the less, the question at all was how does this affect anyones switches/infrastructure per se?
I have noticed personally with Atlas (of all manufacturers!) alot of differences in their track (becuase of different contractors they use to make it). Same piece matched to same piece. One switch can handle the load while another, the point rails bend or twist under most loads (yes, i removed it from use).
Remember, my rolling stock isnt weighted (more on this below). But im experienced enough to know to look for these things. Someone rather new to hobby that just adds weight to a tender to fix an electrical problem... now all the sudden might get track problems. I remembered the problems ive seen with this and it got me to thinking about it. As in - how much is too much? Wheres the bar now?
Drawbar swing) I am totally following what your saying about the drawbar. My comment was meant as a topic highlight only as in, even though i shorten my drawbars, im not seeing any problems here since im testing on tight radii. I was pointing at body shells rubbing, wires pinching, etc. Not so much the dynamics of your point of discussion.
Do i use weighted cars? Ya know, I have pondered the NMRA weight thing for decades. I can think of as many reasons to add weight as i can to not add weight(again why i posted this thread, i wanted to see if yall know something i dont that may help solve it one day for me).
Ive been around long enough to know there are so many variables to consider other than just the 'adding weight' decision alone. Many operational problems other than simple things like rails bending. But i am enticed by the NMRA idea.
The layout ie: multi level flat, no grades (pretty common). But between those levels you need either a helix, or a very long hidden grade. And you know, YOU KNOW that the Mikado you had moving those 37 NMRA weighted cars across your shelves just hit the grade of its life with that helix and came to a complete slipping STOP!
Bring in the helpers! Now what railfan wouldnt want to spend an hour or so pushing a heavy freight up a grade, right? But truth be known, if i wanted to do that.... Id model the C&O, not the relatively flat PM. -ok no weights.
Another truth be known is some of my cars do wobble. Tenders, no, but cars yes. So in the last paragraph you wouldnt want to weight your cars just to make your operations a lil easier (climbing grades). But out on the visible shelf when you get that ole girl pulling back up to scale speed and you dont want the wobblies.... what ya gonna do? - ok add weights.
See the delima? One that ALL of us Railfans endure in the MANY facets of this hobby. The weight thing is one of mine, so i posted.
There has to be a happy medium. I want to hear what others had done on this. Weighting the driving wheels is a no brainer - still deciding on all the axles behind those. And an 8oz tender definately begs the question... are you kidding me? And you say it works huh..... I find that dog gone interesting - tell me more!
Thanks for the inputs folks!
OK, physics does not scale down, we know this.
And, everyone's layout goals are different. I model a freelanced line that interchanges with the C&O, B&O, and WESTERN MARYLAND. And I am not building a multi deck layout with a long helix. But I do have grades, not a flat table....
My grades are 2% and less. Most of my grades only change elevation 2" and then have a level stretch.
In real life, whatever a Mikado might pull would be cut in half by a 2% grade.
Two of my Mikados will pull those 37 cars up a 2% grade, even on a curve, since all my curves are 36" radius and larger. All my 35-40 car freight trains are double headed, or have much bigger power than Mikados.
I don't obsess over every car being spot on the NMRA RP, and I often err slightly below the formula. But cars that are too light are a string line risk when you are pulling 35-50 car trains. My experiance says long trains need cars with similar weights and slighly heavier is better than slightly lighter.
I do use a special freight truck on most equipment - Kadee sprung metal trucks with Intermountain code 110 metal wheels.
Reasons:
Testing revealed this combination to be exceptionally free rolling. More free rollling than any other equalized or rigid truck I could find.
I will not use semi scale wheels or couplers.
Maybe, just maybe, My Mikados (and my other modified locos) pull more, and pull more up hill, because of low rolling resistance?
Your rolling stock is not weighted? Well do you take out the factory weights? I find most cars are close to the NMRA RP out of the box, and by the time I add metal trucks they are even closer.
I know this, when this new generation of locos started showing up, diecast frames with plastic boilers, plastic tenders with metal floors, wires between loco and tender, I started having trouble with tenders derailing (especially in reverse) and poor pickup.
But adding two ounces to a 5 or 6 ounce tender solved the problems when fussing with the wires and other solutions did not.
And I run my locos pretty close coupled as well. My little mod to the Bachmann Heavy Mountain shortens the drawbar 3/16" and I still run them in the closest hole.
Because I do so many tender swaps, I make lots of custom drawbars, some fancy like the Mikes, some basic.
I built a multi deck layout once ...... never do that again.
I have never had any trouble with switch points that I could say was a result of equipment weight. I have used mostly Atlas or hand built track for the last 40 years.
My big tenders, like those on a PM 2-8-4 weigh 7-8 ounces. A Bachmann 2-8-0 tender, more like 6 ounces, they started out at 4.
So the weight I add is equal to 1/2 to 1/3 of a freight car, depending on your standards for freight cars. The effect on pulling capacity is almost unmeasurable, but lets call it one car.
A prototype example of steam locos and grades. In the 40's manifest freight trains of 5,000 tons on the B&O would leave Baltimore headed west with two Mikados on the point. The ruling grade from Baltimore to Brunswick is about 1%.
At Brunswick the two Mikados would be replaced with two 2-8-8-0's for the next leg of the trip west, with a ruling grade of 2.2%
So two Mikados pulling 35-40 cars on 2% grades on a Model layout is actually pretty realistic.
One more thought, I would be curious to know what brands and types of locos and rolling stock you are running?
ATLANTIC CENTRAL One more thought, I would be curious to know what brands and types of locos and rolling stock you are running? Sheldon
Ive been collecting for so long it runs the gamit Sheldon. A to Z both for loco and car. With a few exceptions. No brass.
Steam loco types would be 0-4-0 to 2-10-2. I have no articulateds, yet. Diesel would be pre-war, 1st and 2nd gen. Nothing past that.
All my rolling stock has its original weight. I dont remove any - loco or car. Since i prefer 2nd gen diesel era and older the cars i have generally fit this era. Again, with a few... collectable exceptions.
An interesting update. I have not purchased any yet, but the new (last couple of years) Bachmann USRA Pacific and Mikado, as well as the new streamlined PRR K4, all show additional weights in the tenders on their respective parts diagrams.....
I am considering the purchase of several Mikados and Pacifics, if I get them, it will be intersting to weight the tenders and inspect the inside.