# How much weight are you pulling?



## Skeeterweazel (Feb 11, 2014)

Hey guys. For those w/ a logging-type layout, or anything w/ a fair amount of grade, i was wondering how much weight you think you're pulling, weight of cars and "logs". Gonna use this info to test when i get my loco. As a W.A.G., i'd say around 10#, or twice the weight of loco?
Thx.
Marty


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## snowshoe (Jan 2, 2008)

I never actually measured the weight but I like to run shorter trains since Im using smaller engines. My usual is 3 log cars with real wood logs and caboose. That's with my Lumberjack.


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## work4fil (Jan 4, 2008)

From what I have seen in both literature and in one to one, size, length, etc. all depends on the situation. When we were cleaning up a setting we had logged, there may be only a few log loads going to the mill. If we had a breakdown, we may send a mix of full and empty cars or trucks, so the resources could be reallocated where needed.

A small mill may not require a lot of logs coming in for whatever reason. A larger mill would have a higher hunger for logs. So the size of train could vary greatly. I seen small four car strings to considerably longer going to the mills. Your needs can vary greatly, as long as you are happy.

So anything is plausible. 

Fil


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## chuck n (Jan 2, 2008)

A while back I measured the pulling power of some of my engines. I attached a fisherman's scale to the coupler and slowly increased the power to the engine until the wheels started to slip and then noted the weight on the scale. You can also hook the scale to a string of cars to see how much drag they have. This should first be done on a piece of level track. You can repeat the measurements on your grade and see the difference.





















You will note that the average for all the engines is a little under 1/3rd the weight of the engine, without traction tires and a little over 1/3rd the weight with traction tires. There was quite a range though.

I realize you are probably talking about live steam, but the tractive effort for them should be similar to electric locomotives.

I have also pulled the locomotive without power using the scale and noted the weight needed to pull the engine along the track. It wasn't much different that the value using power.

The weight of the cars is less important than the drag of the cars. As the grade increases the weight of the train becomes more of a factor.

Chuck


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## Skeeterweazel (Feb 11, 2014)

Chuck u are the man! I thought about doing something like that. Looks like some good info there. 

What is a traction tire?

For arguments sake, would you agree adding weight to a loco gives it more pulling power?

Would be good to know the weight of a car. Would the average car weigh about a pound, and a car w/ logs is may 2-3 pounds?

Thx again.


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## Totalwrecker (Feb 26, 2009)

Traction Tire: A rubber insert in a groove in the wheel surface of a drive wheel.
The rubber won't slip as easy...
I don't/won't have 'em.
I run short back woo...back desert trains, more wood 'n water than revenue...

John


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## BigRedOne (Dec 13, 2012)

Keep in mind that "drawbar pull" is very different than weight of the train being pulled. Your train can weigh a lot more than the drawbar pull of the locomotive, and still be well within the capacity of the locomotive. Grades and curves will both limit the train.

A traction tire is a thin rubber band in appearance, which fits in a grove on one or more of the locomotives wheels, to increase the friction between the wheel and the rail.


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## chuck n (Jan 2, 2008)

Some manufacturers of electric locomotives have one of the power wheels grooved and place a plastic band in the groove. That band has a little more grip on the rail.

I can only speak for electric locomotives. Adding weight will increase tractive effort. It will also put added stress on the motor and gear train. In my experience adding weight to an LGB Mogul caused excessive wear on the idler gear between the motor and the drive wheels. I was replacing the idler gear after I added weight. Removed the additional weight and no more replacements.

The friction in the journals is the most important factor. Lighted cars with wipers for power pickup add a lot of pulling resistance. Some cars are like pulling a brick along the track. Ball bearing wheels on your cars will significantly increase what your engine can pull. It is only on grades that weight of the cars starts to become a factor. The engine looses tractive effort and the drag of the cars increases.

I have an Aristo Mallet that easily pulls a train with 32 LGB iron ore cars, a battery car and a caboose. There are no BB wheels in the train. It doesn't even slow down on a 0.6% grade that slows down other engines with lesser loads.

Chuck


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## SD90WLMT (Feb 16, 2010)

Ya Chuck has the most complete list for traction output vs. loco weight..

Traction tires..rubber tires slipped onto an existing groove of a driver to increase traction..
Most do not like tires and remove them..
I'm just the opposite...!!
Yes..increasing loco weight can increase traction..based on many aspects however.
Increased wear of axles and or bearings...
Increased load on the motor..
Increased weight overall for loco structure..

You'll see my loco also listed above..full traction tires..nearly 20 pounds..
Lots of pulling power here...
The efficiency does not go up much when you look at the same loco that Chuck has..my 44% vs. His 41%... yet mine is pulling nearly twice the weight at the coupler..

You need not be so concerned with overall total car weight here...as Chuck pointed out, it has to do with rolling resistance..
This is where being able to measure the load and pulling capacity can best be matched..
But one can not run all day at the maximum values found by testing..
A balance in all things must be found..
I do this to optimize loads and pulling power..
Most should stay even more conservative in the car loading dept!!

Keep learning..have fun with it..I do !!!

Dirk


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## Skeeterweazel (Feb 11, 2014)

Thx. guys.
Chuck, i need you to build a layout w/ 3% grade. Hook your fish scale up between loco and say 4 log cars, and see what scale says. Get back to me asap.

HA!!!


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## chuck n (Jan 2, 2008)

I've got good news and bad news. The good news is that my layout at home has a section (short) with a 4% grade. The bad news is that I won't be home until late April.

You're on you own.

You can get a fisherman's scale for less than $20 at most hunting and fishing stores. In my case it was well worth the investment, as one of my other hobbies is fly fishing. You might even know a fisherman who has one. WE ALL LIKE TO BRAG ABOUT THE ONE THAT DIDN'T GET AWAY and we need the evidence.

Chuck


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## Skeeterweazel (Feb 11, 2014)

Dang it Chuck, you're holding up progress!

Once i get track and loco i can do some testing.

Thx.


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## chuck n (Jan 2, 2008)

Keep us up to date if you get some measurements. If you haven't gotten any data by the time I get back, I'll try to remember to make the measurements. Remind me in early May.

Chuck


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## Skeeterweazel (Feb 11, 2014)

Thx. Chuck.

Those w/ any info re: car weight and/or how much you pull on a grade please weigh in.
Thx.


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## SD90WLMT (Feb 16, 2010)

Ya mean like 2 1/4 - 3 pounds to pull 50 cars..
On 2.0% grade..
Never consider car weight.......

This is not helping Your logging runs at all..ha....
All my info is based on modern freight cars..and dismals...

He he...

Dirk


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## Skeeterweazel (Feb 11, 2014)

Dirk, anything helps. You think your numbers are real? 
Taking some WAGS, and making some assumptions, i'm guessing my little loco will have 1# of pull, after taking into account friction from cars. It takes .06# to pull a 2# car up a 3% grade. So at full power i can pull 16 cars. 1/2 of that is probably more than i'd ever pull. So i'm more confident that my 3% will work out.


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## SD90WLMT (Feb 16, 2010)

My numbers are based on actual testing results.....

I like to "play with My trains"...
....in ways that most don't.....

Dirk. ;-)


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## placitassteam (Jan 2, 2008)

My live steam Accucraft C16 is pretty much maxed out with three Acc coaches or four freight cars and a caboose when pulling a 3 1/2 % grade on a 5 foot radius curve. All have ball bearings.


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## Garratt (Sep 15, 2012)

It's the magical thinking thread, Good luck skeeterweasel, Thow shalt find out! 
The numbers, the numbers. Oh Gandalf, why do the numbers lie?


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## Totalwrecker (Feb 26, 2009)

Maybe after the cleaning lady scrubs your track and wheels and caps your stack with an oil catcher and smoke scrubber ...
Otherwise; Boss de plane de plane!

Your logger may be sure footed, but steam oil is a known consequence, us 'lectric folk usually doff the cap to the same of your ilk who can speak from the same sooty heart....

Be careful posing questions , only to scoff..... too many elephants.

Happy slippery slidey Rails,
John


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## Skeeterweazel (Feb 11, 2014)

Been running my LumberJack the last week or so. Having fun and learning. Picked up 3 plastic cars at the train show. Using bottle of water and brick as load. Haven't picked up a fisherman's scale yet. Weight of cars/load is 7.26#. Weight of loco is 5.4#. Plenty of oil on track. Out of corner going uphill loco spins a little in "cruise control" mode. Running manual it sits in corner until steam builds up to climb 3%. Pretty happy w/ the way things are going. Test track turn radii less than 5', real layout should be 5', so will be easier on loco. We'll see.


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## Kovacjr (Jan 2, 2008)

Chuck, I beg to differ on the drawbar for live steam. This is from the Drawbar competition when I brought my K28 down.


Jason Kovac Accucraft K-28 7lb 6.0oz 

As to what they can pull, I have pulled over 200lbs of Accucraft freight cars and another time pulled myself.





 




 

I see you got the Lumberjack parts from Regner that they shipped out. Looks like its all up and running.


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## chuck n (Jan 2, 2008)

Jason:

I think that you are mixing apples and oranges. 

We are talking about "Tractive Effort". Not the total weight of the train. "Tractive Effort" is number of pounds of drag an engine can pull at wheel slip. Up to a point, it has nothing to do with the weight of the train. If the train is too heavy the engine might not be able to overcome the inertia of getting it started rolling and just sit there spinning its wheels. That is why engineers try to have some slack in the couplers, so that they aren't starting all the cars at the same time.

My Accucraft electric K-28 weights 12 pounds and has a tractive effort of about 3.5 pounds. It will easily pull 10 brass Accucraft San Juan cars. I don't know how much they weigh, but it is significantly more than 3.5 pounds. However, the drag on these cars that the engine experiences on level track is significantly less than 3.5 pounds.

If you increase the grade and add curves, the drag of the cars may increase to the point where the wheels will slip.

Try coupling brick or two to the engine. I would imagine that it would not be able to pull it. The bricks weigh considerably less that the weight of your two examples. On level straight track it is all about friction, not weight.

Chuck


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## Kovacjr (Jan 2, 2008)

chuck n said:


> Jason:
> 
> I think that you are mixing apples and oranges.
> 
> ...


No I am comparing the same, Jason Kovac Accucraft K-28 7lb 6.0oz 

This measurement was recorded at Diamondhead at the drawbar pull on my live steam K28.


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## Chris Scott (Jan 2, 2008)

*MicroMark*
http://www.micromark.com/


*Digital Pull Meter*
http://www.micromark.com/digital-pull-meter,9577.html










Digital Pull Meter
Our Price: $23.65
Item #: 84708

Digital Meter Measures the Drawbar Pull That Your Locomotives Develop

Helps you maximize the performance of your locomotive fleet

Simply hook the wire to your locomotive's coupler, press the ON button, and turn up the power. Our digital meter displays the pulling force developed by your locomotive in ounces. Add weight to your loco and see how the pull increases. Pull a train with the meter to determine how many cars can be pulled per ounce, then assign your locomotives to pull a train just like a real railroad does. Capacity: 176 ounces. Readability: 0.1 ounce increments. Holds last reading. Includes automatic battery-saving shut-off (90-second), and instructions for use. For all scales of model trains. (Color may vary.)

View Instructions;
http://www.micromark.com/html_pages/instructions/84708i/84708-pull-gauge.pdf


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## chuck n (Jan 2, 2008)

Chris,

Similar to the rig I used the create the table in the earlier posts in this thread. The tractive effort averages about 33% of the weight of the locomotive. 

Chuck


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## Shay Gear Head (Jan 3, 2008)

That Micro Mark gauge will work but for all but the biggest steam locomotives.


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## SD90WLMT (Feb 16, 2010)

That micro mark gauge can measure..up to 11 pounds...

Dirk


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## chuck n (Jan 2, 2008)

Skeeter:

While rereading this thread, I discovered that I promised, last Winter, to measure the drag of my log cars on my grade, when I returned to Virginia. I put out 4 Accucraft long log cars on my 3.1% grade this afternoon. I took out my trusty fisherman's scale and attempted to measure the drag. Each car weighs 1lb 14 5/8 oz. Much to my surprise I couldn't deflect the scale. These are very free wheeling cars. I think the digital scale Chris talked about might detect some drag, but mine didn't flinch.

Chuck


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## SD90WLMT (Feb 16, 2010)

Hi Chuck...where you trying to measure all 4 cars at once??

Dirk


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## chuck n (Jan 2, 2008)

Dirk:

Yes, that is why I was surprised. They really roll easily. I don't think they have BB wheels.

Chuck


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## SD90WLMT (Feb 16, 2010)

Ok

How fine does your scale read...?

I'm ordering the Micro Mark version...

Dirk


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## chuck n (Jan 2, 2008)

Dirk:

My scale is marked only for 0.5 pound intervals. I have to interpolate between the marks.

Chuck

I got it for fish, not trains. I may have to get a digital one too.


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## SD90WLMT (Feb 16, 2010)

Understood Chuck...
In same boat!!! LOL
it's a 50 #er...I use just a small portion...
I can measure pulling 50 cars..
Not one car tho!!

Dirk


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## chuck n (Jan 2, 2008)

With what you are planning to pull, you might need a deep sea fisherman's scale, with a block and tackle!!

Chuck


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## Chris Scott (Jan 2, 2008)

chuck n said:


> Jason:
> 
> My Accucraft electric K-28 weights 12 pounds and has a tractive effort of about 3.5 pounds. It will easily pull 10 brass Accucraft San Juan cars. I don't know how much they weigh, but it is significantly more than 3.5 pounds. However, the drag on these cars that the engine experiences on level track is significantly less than 3.5 pounds.
> 
> Chuck


Chuck,
I think you might have meant 12 kilograms maybe ? - or actually 12.5 kg. Accucraft's K-28 Elec manual has total weight of 12.5 kg or 24.5 lbs. (loco and tender.)

Tractive Effort of an electric model locomotive is the power of the motor. Change the motor to a more or less powerful motor changes the locomotive's power ("Tractive Effort")


_*Tractive Effort;*_
Prototypically Tractive Effort is complex with lots of variables; weight on drivers, cylinder bore & stroke, size of drivers, etc. In live steam we have all or most of those variables albeit in scale version which means that given physics they all don’t scale linearly or at all. 

But we live steamers can still ponder the possibilities and have drawbar pull contests for fun, show, and tell – aka, bragging rights. As well as pull massively and ridiculously long trains with equally if not more massive and ridiculous amounts of fun and joy. ;-)

And, if you really want to drive yourself and everyone else completely nuts risking getting run out of anywhere tarred, feathered and on a rail bring up the subject of scale tractive effort. (I think still have a few feathers that I can't reach.)


*Scales, aka strain gauge;*
A Strain Gauge is for fish and luggage. Digital strain gauges for luggage available from Target, Walmart, BestBuy, REI, Amazon, etc. They sell cheap luggage scales that you could just as well use to weight fish. Specs; digital, xx.x , Eng/metric, hold, LED, beep, etc. 

Amazon; $5. >
http://www.amazon.com/travel-accessories-luggage-scales/b?ie=UTF8&node=2477391011

And this one; HK 50Kg/10g LCD Digital Hanging Luggage Weight Hook Scale; $5.50 displays in 4 selectable units: g, kg, lb, oz; LCD screen display with blue background light.
http://www.amazon.com/Digital-Hanging-Luggage-Weight-Scale/dp/B008327KZU/ref=sr_1_6?s=apparel&ie=UTF8&qid=1402017302&sr=1-6


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## chuck n (Jan 2, 2008)

Chris,

The weight of the tender is immaterial. It doesn't add any weight to the traction wheels. I weighed the engine on a bathroom scales in pounds. It is in the car now. I'm heading to an event in the morning. I'll try to reweigh it this weekend.

I realize that there is a lot that goes into a theoretical tractive effort. I tried to come up with a measurement that would work on my railroad with my engines and cars. I put the numbers out there as a ball park indication of what people might expect of their engines. 

If my 28 weighs more the wheel slip is still the same. Only the percentage of TE versus weight will change, to a smaller value.




Chuck


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## Dr Rivet (Jan 5, 2008)

Too bad Jason will not be here to nitpick the details of TE with Chuck this weekend. I planned to grease the track to make all testing completely irrelevant.

The weight of the load is not important... it is the bearings on the wheels and the resulting cumulative ROLLING RESISTANCE of the train. My 18 car Daylight weighs more than 200 pounds [MORE than Jason] but my Accucraft GS-4 will pull it up 0.6% grades.


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## Chris Scott (Jan 2, 2008)

chuck n said:


> Chris,
> 
> The weight of the tender is immaterial. It doesn't add any weight to the traction wheels. I weighed it on a bathroom scales in pounds. It is in the car now. I'm heading to an event in the morning. I'll try to reweigh it this weekend.
> 
> Chuck


I wasn't suggesting the weight of the tender had anything to do with traction. I thought it was a simple mistake and you would be gratified your loco weighted more given all traction talk about models involves weight; more weight the better. 

You'll have to work out with Accucraft your bathroom scale reading and their weight spec.

Maybe you for got to adjust the scale for weighting yourself versus weighting the locomotive?
     he he he...

I used to try and weight our dogs on our scale by weighting myself and then me with the dog. It worked ok at first with a puppy. It grew more awkward and less accurate as they approach 65-70 pounds.


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## Chris Scott (Jan 2, 2008)

Dr Rivet said:


> Too bad Jason will not be here to nitpick the details of TE with Chuck this weekend. I planned to grease the track to make all testing completely irrelevant.
> 
> The weight of the load is not important... it is the bearings on the wheels and the resulting cumulative ROLLING RESISTANCE of the train. My 18 car Daylight weighs more than 200 pounds [MORE than Jason] but my Accucraft GS-4 will pull it up 0.6% grades.


Isn't the rolling resistance a function of the weight? Less weight with bearings = less rolling resistance, and verse vice'a.; more weight with bearings = more rolling resistance, How's weight not important ?

PS: Will your GS-4 pull you up a 0.6% grade?


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## SD90WLMT (Feb 16, 2010)

So..you may change the motor to a more powerfull one...

It still will not pull any more cars..beyond what the loco could pull before..it may not overload the bigger motor as much..

Friction is friction..based on driver weight...

Go put a bigger motor in your toy..but do not add more weight..

Let us know..!!
Dirk


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## Skeeterweazel (Feb 11, 2014)

Guys, thx for the replies. Will try and track down a scale. Really curious about his stuff.


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## Chris Scott (Jan 2, 2008)

Chuck;

I thought you might be interested in this;

Tractive Effort
http://www.trainweb.org/girr/tips/tips4/tractive_effort_tests.html


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## chuck n (Jan 2, 2008)

Chris:

Thanks for the link.

Chuck

Note added, 6/7/2014, I just weighed the Accucraft K-28, without tender. The magic number is about 17 lbs not 12. Must have been a typo.


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