San Juan evolution and Protocraft couplers uncoupling due to length and weight. Limits?

Fellow railroaders...

 

We need "Safety shelf" couplers. If a working model made in metal were available as in the Prototype, this problem of "popping apart" would be impossible 98% of the time if at all. The safety shelves won't allow the knuckles to override each other. I'm not saying this is a "cure all," but it would be a VERY positive start.

 

I don't have track down yet, so I can't answer my question about whether the Protocraft couplers will work on long cars exceeding 60' and on what radius track. The action is fantastic on the new Ready to run models!

 

I've addressed this Shelf coupler issue here & on other sites, but for modelers 1975 onward these couplers are a "must." Watch modern freight trains & see how many couplers without safety shelves are on that train. If a working model were made,it would help stop the problem mentioned here.

On long trains 15 cars in length, how wide of a curve is needed to keep the cars from stringlining? I've got 13 4750 cu ft cvd grain hoppers coupled together and am wondering about this. In HO I pulled 12 cars around a 19" curve with no problem, so I'm thinking pulling a 13-15 car train in O scale around no less than 50" curves  should be a problem but I'm only "guesstimating" here.

 

Thank you for all inputs here.

 

Al Hummel 

 

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EDITED BY THE WEBMASTER...

to fix some formatting problems and eliminate some extraneous text that was at the bottom of this post.

Not for those folks modeling prior to 1960, or especially the 1930s thru mid 1950s "steam era"!

Or earlier yet......  There are some link & pin era modelers out there.

They would not solve the problem described in the original post anyway. The couplers are pulling apart not compressing together and riding up over each other.

 

I have heard that the SJ couplers can pull apart under a load. I guess you need to watch how many diecast cars you put in a train.

Thanks for that additional information. I didn't think that "shelf couplers" would have solved such a problem anyway, so I'm glad that you brought that up.

Do you have a O scale locomotive that will LIFT 100 lbs?

That brass Hi Sierra/Clouser version pulls apart?  Mine has a positive locking feature, and it looks like the brass has to fail first.

 

I, and probably most of us, are unfamiliar with the problem, not having the space or inclination for 40- car freight trains.  My max is 15, and even then it spans half of my loop.

       
       


I have a 24 car brass mail train- each car exceeds 5 lbs. most are 6.5-7 lbs. 3 Key PA's do pull it fine. And yes the drawbar is over 100 lbs.

This train is around 65 lbs on the coupler.

       
       


I am referring to the new couplers. Not the Clouser traction couplers

What radius track are you using where the passenger train is running? NICE!!

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On Tuesday, February 3, 2015 2:02 PM, O Gauge Railroading On Line Forum <alerts@hoop.la> wrote:


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| Subject: San Juan evolution and Protocraft couplers uncoupling due to length and weight. Limits? Reply By: Erik C Lindgren In: Train Forums / 2-Rail SCALE | |



This train is around 65 lbs on the coupler.   This post contains 1 photo. View This Reply
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Allan, where is all this extra text coming from (highlighted in red) every time you post? You absolutely MUST fix this or I'll have to suspend you again. I cannot keep cleaning up the mess you leave every time you post!

I want to make a draw bar pull test car to assist in an experiment in testing these Protocraft couplers. Anybody got any suggestions for a good strain gauge I can mount to a pair of Atlas truck assemblies?

I don't know about a "strain gauge" but, how about placing a fish weighing spring type scale between the coupler on the engine and the first car?

 

Please use some other couplers as controls - 804 and 805.  That will put your testing into good perspective for all

 

engine(s), fish scale car,  --- so how is that car to be coupled to the engine?

 

Protocraft test cars and then start stacking up Kadee cars for weight. ---- I'd look for a car you can connect directly to controlled dead weights and not to other cars with couplers involved; barbell weight, lead bricks, etc.....

 

Possibly.  But, let's not get OCD over this either..unless that works for you....then by all means embrace it totally.

 

I'm just curious to see what the results are from a well thought out and executed test.

 

Might be an interesting note to publish,

Eric, when you mention a train that is 65 pounds (or 100 pounds) on the coupler, I assume you referring to the actual weight of the train, rather than to the tractive effort required to move it.

 

I weight my freight cars to about one pound each, so a 40-car train weighs about 40

pounds. But that does't mean the coupler of the engine pulling the train has to be able to support 40 pounds. That would only happen if the train were trying to go straight up in

the air at 90 degrees.

 

In other words, the engine doesn't have to exert one pound of pull (and the coupler doesn't have to withstand a load of one pound) in order to move an O-scale boxcar weighing one pound (even without roller bearings).

 

 

Without belaboring the point, the weight of the train is not the same as the force at the drawbar.  Steel wheels on steel rail enable a lot of tonnage To move very efficiently.  I have heard it said that the only more efficient way to move stuff is a barge down river.

 

That said, there was a test setup that involved a pulley and a platform suspended beneath the railroad.  The locomotive would pull horizontally, and the platform would be lifted.  Put a hundred pounds on that platform, and I bet there is no O scale locomotive that will lift it - well, maybe Gerry White's Triplex, but that one was half the nation's lead supply in one locomotive.

 

And no - the Hi Sierra/Clouser coupler was a brass AAR copy of the Janney freight coupler.  To pull it open would mean shearing off the internal shank or busting the knuckle casting.  Good couplers, and expensive.

 I use only KD. I don't have much high end equipment. I do run long trains in both O scale and G. I have been saying for years how amazing these trains are to pull so much.

 In G scale, the (plastic) gears inside of some engines will fail if you don't add helpers to long trains.

 In O scale, I was snapping the older Atlas couplers on a fairly level layout. I have one grade that maybe rises around 3/4" spread out well as it navigates the basement.

 I can't compare much with your level of equipment and I run differently. I run mainly modern era so using rear or even mid-train helpers smooth everything out for me. Even when I pull out the steam era, if I don't have a helper the train will fail somewhere. The G scale equipment needs modifying to just get the couplers all at the same height. Still there's vertical coupler movement from terribly designed mounting pads. Almost every brand is different. So I'm used to using helpers and swapping out all new equipment to KDs in both scales.

 I feel your pain!!

I weight my freight cars to about one pound each, so a 40-car train weighs about 40 pounds. But that does't mean the coupler of the engine pulling the train has to be able to support 40 pounds. That would only happen if the train were trying to go straight up in the air at 90 degrees.

 

Mr. Smith

 

Thank you for pointing that out to our OP.  If he could take an actual measurement at the drawbar force to move that train I'd bet it is a whole lot closer to 10 pounds than it is to 100.

 

I have a 24 car brass mail train- each car exceeds 5 lbs. most are 6.5-7 lbs.

 

An 8000 scale ton passenger train?  Yikes!  As Joe said, distributed power would be realistic.

 

Why do the cars weigh 2 to 3 times the scale weight of the Ferdinand Magellan?  Are the sides and windows bullet proof?

 

3 Key PA's do pull it fine. And yes the drawbar is over 100 lbs.

 

I doubt three Key PAs can produce 100 pounds of drawbar pull even with depleted uranium weights and Goodyear Eagle traction tires. 

 

In all seriousness, the force needed to lift such a heavy train up a 3% grade at nearly 50 smph is only about 7 1/2 pounds.  The added power requirement on the grade would be about 10 watts or 0.8 amps at 12 volts.  That would be in addition to the rolling resistance of the train at that speed on level track.  If your power supply has volt and amp meters do you see values in that range when you run the train onto a grade ?

 

If you are experiencing excessive drawbar forces pulling this train perhaps you should look at the rolling resistance of the trucks rather than just looking at the strength of the couplers.

 

Wow Mr  Hikel I'm impressed!!

Your a legend------ no your just plain INCREDIBLE !

A blessing to us all-- you solved it! It's all solved - TimDude cancel the bid were done!


       

Your a legend------ no your just plain INCREDIBLE !

Erik

 

I hope that isn't (too) sarcastic. 

 

Just remember in O scale it is all about 110592. 

 

B Smith and Bob2 were right on. You have a very, very heavy train to move but your couplers don't have to lift the whole train vertically.

 

At 48 SMPH (one real mile per hour) you are traveling about 1.4 feet per second.  Even on a 3% grade you are only lifting the train about a half an inch per second.  That takes some real work, but only about 10 watts.  Be aware that 10 watts is the work output, the input will be higher.  And the level rolling resistance, which is likely quite substantial, will take more power as well.

 

If your PAs really could produce 100 pounds of drawbar pull at 48 SMPH they would be putting out about 200 watts or 1/4 HP.  That would be one heck of a lot of model railroading power.  A fraction of that should get the job done.

 

 

 

Sounds to me like you need helpers on the rear

Micromark has a model railroad specific version of a fish scale if anyone is interested.  For unit trains I use dummy couplers cause a loaded unit coal train (once I get it all together) will weigh over 300 pounds.

On Tuesday, February 3, 2015 8:17 PM, O Gauge Railroading On Line Forum <alerts@hoop.la> wrote:


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On Tuesday, February 3, 2015 2:02 PM, O Gauge Railroading On Line Forum <alerts@hoop.la> wrote:


Reply By Erik C Lindgren: San Juan evolution and Protocraft couplers uncoupl...== To reply by email, write above this line. == Hello, Alan Hummel: We're sending you this notification because you are either following the forum, the content, or the author listed below. New Reply To Topic
| Subject: San Juan evolution and Protocraft couplers uncoupling due to length and weight. Limits? Reply By: Erik C Lindgren In: Train Forums / 2-Rail SCALE | |



This train is around 65 lbs on the coupler.   This post contains 1 photo. View This Reply
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Sincerely, O Gauge Railroading On Line Forum https://ogrforum.com To adjust your email notifications for this site, please update your notification settings. To suspend ALL email notifications from this site, click here. Powered By Hoop.la   Allan, where is all this extra text coming from (highlighted in red) every time you post? You absolutely MUST fix this or I'll have to suspend you again. I cannot keep cleaning up the mess you leave every time you post! |

  View This Topic Reply
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Rich,

It looks like he's copy/pasting the text from an email notification rather than replying directly to the same comment in-thread.

 

---PCJ

I bet that's it.  I find it really confusing, so I just skip his posts.

"so I'm thinking pulling a 13-15 car train in O scale around no less than 50" curves  should be a problem but I'm only "guesstimating" here"

 

  My last O scale layout had 46 inch radius curves and could handle 20 car trains all right. The only problem I recall was when a 4 wheel front runner intermodal car was coupled to an 89 foot pig flat and got thrown off the rail from mis match or coupler overhang beyond  truck mounts. 

   To test breaking strain of couplers one wouldn't need a train, just screw the coupler to something solid and pull on the scale till it breaks or until you get tired. I can't recall ever breaking a Kadee O scale coupler so 20 car freights must be well within their rating.

    For any layout big enough to approach the breaking strength of couplers I'd use kadees since a layout that big will likely never be finished to fine scale standards and operations will probably be the focus instead of details? ........DaveB

 

Thank you Dave,that was kind of my thought coming from HO the strain should be equivalent.

All I have up so far & that's in the planning pretty much is 5 tracks on a 40' section of my north basement wall. You know that planning can be 1/2 the enjoyment sometimes. 

Thanks again,

Al Hummel

Sounds like quite a train as 3 lbs a car implies a 100 car train or 2 lbs a car implies a 150 car train. I'd sure like to see that.

It seems as though there's still some confusion about the total weight of the train versus the tractive force necessary to move it, or to lift it up a grade. A real-life unit train with a total train weight of 14,000 tons does not require couplers on the engine that can withstand a load of 14,000 tons (28,000,000 pounds). In fact the knuckles will fail at around 500,000 pounds (or about 650,000 with the heaviest modern design, as I think I have recently read in a Trains magazine article), which is only a small fraction of total train weight for the hypothetical 14,000 ton example.

............a lot of cars that are weighted too heavy.

"All I have up so far & that's in the planning pretty much is 5 tracks on a 40' section of my north basement wall. You know that planning can be 1/2 the enjoyment sometimes. '

 

  Hi Alan, Yeah I'm still planning my new layout even as I build the benchwork and install the backdrops. I'm even not yet sure if it will be S scale or HO scale but I'll have to decide soon I guess. Even though most O stuff will run around 46 inch or tighter curves I'd still try to keep the curves as broad as you can for appearance. Unless you are running large steam I don't see much reason to go larger than about 60 inch radius. At 60 inch the trains look nice and a turn back curve still takes up 10 feet of width. Your 50 inch radius choice seems about right to me for a diesel powered layout....DaveB 

 

Hi Eric

I had this problem when running 40 Atlas fish belly hoppers on a train and had to switch all of the cars to the metal Kadee 805 couplers. The Kadee long shank 746 with a metal coupler box might be a good option for the passenger cars? 

Don