How many coal cars can your SD70MAC's pull?

[darth9x9]

Hey AggroJones,

Yes, they can certainly pull. I am quite impressed with the Atlas units. I should have bought stock in Atlas before I purchased all the ones I did. [;)]

[kiss]

It has been my experience that some 3 axle truck's on SD class
Diesels tend to have the center set of wheels set lower than the front and rear wheels which greatly reduces the tractive effort from 6 wheel contact with the rail to only 2. This also causes the engine to derail. Putting a slight bend in the forward and rear of the side frame greatly inproves the pulling ablity of these engines.

[AggroJones]

Those Atlas units are pretty powerful, huh?

[darth9x9]

At the shows that my club attends, I usually try to run a 110+ coal drag on the Sunday of the show. We model in HO scale. The cars are all properly weighted, Kadee couplers, and metal wheels. At the last show, I ran 128 coal cars using 5 Atlas GP38s and GP40s. There was a slight grade as the floor in the Cow Palace is not the most level of places. I usually run 5 or so engines just because it looks better.

One show about a year ago, I was approached by a major metal wheel manufacturer (name withheld to avoid being flamed). He asked me whose metal wheels I had on my coal cars. I told him a mixture of Intermountain and Atlas. He told me that if I used his metal wheel sets, I would only need 3 engines instead of the 5 that I had pulling the 112 coal cars. I said to him, "let me show you something." So I pulled the head end of the coal drag around to where we were standing and I removed 3 of the 5 engines - leaving only 2 Atlas GP38s. I cranked up the throttle and the two units pulled the train without a slip. The only thing he could say was, "Have a nice day."

[Anonymous]

Ok try this,has any one tryied this on a model layout......what about two locomotives on the point with a very LONG train on a slite grade with a powered DPU on the rear! has anyone tried this yet?????????BNSFfan.

[fiatfan]

Here's the link to the NMRA page for car weighting:

http://www.nmra.org/standards/rp-20_1.html

Tom

[Allen Jenkins]

I'm waiting................................no, the locomotives have no weight requirements. The heavies used to be the Athearn SD45 with the SDP40 chassis, ('cause they wern't but 14 SDP40's built), weighted down with the loco-carbody weights.........Or, like Barney Conger, a Bowser E-3 w/the Pitman DC motor, weighted to the nines, which held the hoss in Atlanta, awhile. He had both the ACL Champion, and the SAL Orange Blossom Special, Styled by Dave Muller, (dec.) Southern Scale Models, Acworth, Georgia. Ya'll are scarin' me! The NMRA carweight specs are in ya'lls paperwork, and I'm listening, cause I got words for you, the train sim community is luggin'. acj.

[Anonymous]

You know I was asking myself this question (not about SD70MACs but about any loco) just a few days ago and was going to post about it and forgot to post it.

The question about how much a car should weigh is a very good question. Is there a formula to use to determine how many cars a certain engine CAN pull? Or it is simply a trial and error deal? Yes, I do know that grades do make a difference but how do grades figure into the formula if there is a formula? Since I have HO, and many forum member also model HO, does the formula change for other scales?

Good question and some good comments so far on this one. [:)]

Keep up the good work guys and gals. [8D]

[Anonymous]

well all i do to weigh my cars is add 2 1/2" hex nuts above each axle on the inside of the car. also metal wheels add weight to.

[Allen Jenkins]

Come on now guys, lets get our wits together and standardize our car weights, I've already run non-standard weight cars, to find their is no compairing or rating engines, if everyone uses different weights on the same cars. I used to weight cars, 'just can't remember the formula!

[Anonymous]

I'd say it depends on the locos. I'd suggest that a A-B-B-A set (all super powered) of the Athearn Blue Box F7s would probably haul more than four of their Dash 9s. This would be due to the higher weight and axle loadings (hence more traction). I've had a powered A-B set on some hefty intermodal trains where a pair of Dash 9s have obviously been working hard, but the Fs cruised away with no problems. I also have a Bachmann Dash 8 that has far more haulage ability than the Athearn Dash 9 though it's not noticably heavier.

If you're aiming for maximum haulage abilities (mainly for crowdpleasing at club exhibitions, as few people are lucky enough to have a layout of their own of that size - I certainly don't!), I'd suggest filling every available space in the locos with lead ballast (I massively improved an Athearn PA by doing this, it'll pull anything now) and fitting metal wheels to all stock (these decrease rolling resistance noticably - fitted a few Athearn cars with Proto metal wheels and they are now noticably more free-rolling). You'll also need a power unit (transformer/controller) with plenty of amperage to cope with the loadings, as most starter units won't cope with four locos being worked hard!

[Anonymous]

Alleni dont know, one of the members is an NMRA member and he has all that stuff, but try there web site?

[Anonymous]

at this years train show i seen a big boy pull 102 emty coal cars on a flat layout, seemed like it would never end......... not stuggleing either

[Allen Jenkins]

This would be a good time to remind me how much a car is supposed to weigh, according to NMRA specs.

[Anonymous]

it all depends on what percentage of grades you will go up...at our club an Kato 6 axle can pull 20 accurail grain cars with NMRA standard added weight up a 2.1% grade now we havent maxed themout so i figure 22 maxed but on a flat i would say 55 is more believable. so do the math 3x55=165 on a flat...thats more than prototypical, but if you can only pull 20 up a 2% grade to get 100 coal cars up that you would need 5 or 6 engines to do that...and thats more prototypical.

[Anonymous]

This is a Question Im asking any modeler out there.
How many cars eather coal cars,freight cars,or etc,can be pulled by 1or 2 or 3 or whet ever locomotives on a model layout?
Because the reason Im asking is, In the October 2003 MR it states that the kato EMD SD70MAC can pull somewhere between 55 to 60 cars with only one unit.
If 55 to 60 cars can be pulled with one, than how many can 2 or 3 and so on can these locomotives pull the longest train on a layout?
Id sure like to here from any modeler out there.
I swear I saw a model video many years ago, this coal train must of been 100 cars long,at least! but I could've been wrong too.
Well that's it for now,BNSFfan.[:)]