jbrock27:

I've been busy, just got back to this thread.  Thank you for your reference.

All:

Wow, getting into the mechanics, math, axle spacing, unpowered center axles on some engines, etc. of the 1to1 engines was very eye-opening, educational, and a little confusing.  But I can understand all the experimentation by the railroads - every little improvement helps the bottom line (and often employee safety).

However, thank you all for sharing the info (and jward I liked your first paragraph).  And believe it or not I've had some real-world experience with this when, for 16 years, I made my living as an independent contractor bidding on and moving high/wide/overweight items in the US, Canada and Mexico (moved about 155 loads in that time period).  What I'm getting at here is what you all have addressed - total weight per axle (railcar + load + tiedown materials), axle spacing, track condition, bridge restrictions, etc.   However, in this work traction for movement was assumed and not directly addressed.

Donaldon:

You said, "I think maybe this isn't so. While it's true that a loco with six-wheel trucks has 50% more contact with the rails than does a loco with four-wheel trucks, the weight on each axle is only two-thirds as much as what the four-axle trucks have. That's going to make a significant difference in the larger loco's adhesion and will just about negate all of the difference afforded by having more metal on metal."

You're probably right - I've not weighted a 4-axle diesel engine to equal the same amount I do to my SD40-2s (total of 22 to 22.5 oz each).  The reason is - generally not enough room, or I'm too lazy to stuff small cut-off pieces of lead weights into cracks and crevices. However, (and I know you all know this) on a straight weight-added-on basis (to a 4-axle and 6-axle engine) to their "nominal" capacity, our 6-axle engines (all 6 driving) almost always out-pull the 4-axle ones.   

Or - do you have some 4-axle diesel engines that out pull your six axle ones?  You might have - I'll bet some of those powered B units (filled with metal weight from the factory) can out pull some run-of-the-mill 6-axle units.  Interesting - sort of like the real world.

So, what I'm learning is to be careful of what I say about railroad wheel-traction physics (and probably some other technical items.)     The railroads have spent over a century doing this in the real world, and you folks are sharing some of that learning.

Thank you again.

K487 (aka Doug)

rbryce1:

Don't know if this would apply to you, but......

All of my B'mann diesels have 2 to 4.5 ounces of weight added - helps a lot.  But I have to "pay" for the room inside the shell.  How?  By discarding the DCC board - I'm strictly a DC guy anyway.  Also, particularly on GPs and SDs, when I add the weight I bias it toward the front so that the whole weight of the loco is equalized over both trucks; again better pulling power. 

Note that even though just one of my weight-added (4.5 oz) B'mann SD40-2s can start and pull 65 cars (85% with plastic wheels) on level track around my layout, I always use two engines to ease the stress and the train runs a little smoother, and sometimes I use three locos just for my viewing pleasure.

You know, I just had a peculiar thought and I'll share it with you.  I believe that 6-axle diesel locos have by default 50% more pulling power/traction than 4-axle diesels, at least on an ounce-for-ounce basis.  Maybe you could have one or more "leased" 6-axle locos helping your GP40s in consist or as pushers.  At the least it would add some interest even if the 6-axle loco(s) were not needed.

K487

Very clever and very well done, including the varying side windows.

K487

My layout is in my house but it does get dust.  When I'm not using it for a few days or longer I cover it with painters' furniture drop "cloth" (from WalMart.)  It is very inexpensive, very thin, very light-weight clear plastic sheet and it does a great job of catching all of the dust.

Having said this, and given your situation in the basement, I would also recommend getting some thicker (1 or 2 mil) plastic sheets and staple them on the underside of the ceiling joists, and run that plastic far beyond the borders of the train layout.  If this works it would be relatively cheap, easy and quick.  Oh, and if you still get some dust on your layout see paragraph 1.

DougC

Jeffery, you got my vote:

"i think you said it all right there. truck mounted couplers in a larger scale. lionel used o27 and 031 curves which were 13.5r and 15.5r respectively. did it work? yes, sorta kinda. could you reliably back trains around those curves? highly doubtful. did it look atrocious? absolutely."

K487

As friendly info:

From all of this sound advice by many men with a lot of experience, I'm going to point out a rare exception.  Might be helpful to some in the future.

I have on my HO layout 3 loops and a figure 8 (all in an L shape).  The figure 8 track carries one ore train: an A----s RS32 pulling 32 old AHM ore cars* and a caboose. 

Now Please Note:  The track radius on each of the figure 8 curves is 11" (yes, that is correct - eleven inches radius.)  The diameter of both curves is exactly 22" track-center to track-center. 

So, how much did I have to alter/adapt/whittle on the RS32?  None what so ever; the engine took those curves right out of the box (surprised me; tested other locos and they all failed). 

Does the engine slip down when pulling the train around those curves?  No, not at all.

Okay, does it look kinda funky?  Believe it or not it does not (at least to me), probably because of the short loco and the shorty ore cars, and you can't see the whole train at any point on the layout.  I enjoy seeing ore car after ore car come out of one tunnel and go into another.  It IS functionally a 32-car unit train (plus caboose).  And I run the train very slowly.

How does the track look and function at 11" radius with easements?  Smooth as silk.  It's all Atlas NS Code 100 flex, and soldered just about perfectly (if I do say so myself - over the past 20 years I figure I've soldered at least 200 rail joints and only had one on a curve come loose; that's a lot of experience.)

* The ore cars are "loaded" but the loads weigh almost nothing.  About two decades ago I took some 3/8" or 1/2" florist styrofoam (from Hobby Lobby), cut oblong pieces to fit in the cars, used a knife blade at a 90 degree angle to the foam and scraped out a gentle hump, applied Elmers yellow glue thinly, turned the piece upside down and pushed it into a pile of scale ore (light reddish HO ballast), let it dry some, trimmed off the excess glue/ore around the the four edges, and put them in my railcars.  I have loaded cars that pull easy (no weight) and can be made empties REAL easy, AND if I have a derailment and a car tips over I don't get get a big mess on the layout.

K487

And thank you Roger for the additional clarification.

K487

Piyer:

Thanks for the clarifications and additional info.

K487

RAM:  I agree about the costs.

Jeffrey:  As usual, good observations.  I have a couple of observations:  (A) I didn't know about using an engine on an adjacent track to carry a brakeman from of the train to the other end (I grew up on a single-track railroad), but even when fouling a second line it made sense.  (B)  My understanding of the introductory use of Rear End Devices - REDs - (often referred to by railroad operating employees as FREDs (F-------- Rear End Devices) was, um, disliked because of the perception that they caused lost jobs.  And as a result many of the devices were accidentally destroyed during operations.

Desertdweller:  I certainly agree with you.  Regarding the train's slack running out when the train started moving, it was always a guess if the caboose was going to go from zero to 1 or 2 mph or from zero to 6 to 10 mph in a nano second.  Always had to be prepared for the worst (and if my memory is correct, Rule 107 of the ((older)) Railroad Operating Code said, "When in doubt the safe course must always be taken.")

K487 

"Scary stuff!"   Yes!

Here's a copy of a true story I posted on another model railroad site where a poster had asked why cabooses were eliminated.  I added the story to show one reason why – railroads' costs of injuries to the men in the cabooses.

This was on a 6 day per week train from Bismarck MO to Poplar Bluff MO (and return).

I was an extra board brakeman for the Missouri Pacific RR out of Bismarck MO in the late 1970s, and rode in cabooses about 140 times as rear end brakeman (and about the same amount as head end brakeman in the engine.)  Regarding the following incident I was in the caboose and wasn't seriously injured.

Once after about two days of heavy rain in the area and it was still raining, we were heading south doing about 45mph getting a run at Gads Hill* (in the Missouri Ozarks) with about three engines and 100 cars, we had a washout in the middle of the train - unbeknownst to us. Just before we in the caboose hit the dip (about 60' of rail and ties hanging/drooping down in the air) I heard the train brakes go into emergency, so I got up from my seat in the cupola to go check it out. Just when I stood up the front of the caboose dropped 1' then immediately jumped about 2' to 3' up and came back down. This did two things: 1) the front of the caboose rose off its kingpin (kept on by gravity only) and came back down on it but not through the hole in the car bolster, but on top of the pin. So the caboose was cocked in an "up" slope position (while we were still moving.) And 2) when that caboose dropped, the underside of the cupola roof banged me on the head (I'd just stood up as much as I could to climb down the ladder). It gave me a headache, but when the Trainmaster arrived later he asked me if I was okay, and I told him "Yes" (as I was okay by then - the headache had gone away).

[Regarding caboose crew injuries and costs, could this incident have caused more serious injuries (costing the RR big $$$$)? Yup.]

The conductor was okay through all this. Also, a loaded 50' open top hopper had hit the dip when it was less bad but it broke the back (center) of the hopper anyway - the hopper stayed on the rails but its center dump chute was dragging on the rails.  And as I remember it a couple of other cars derailed.

When the engineer called the dispatcher in North Little Rock and told him we had a wash out with a derailment at the foot of Gad's Hill, the dispatcher wouldn't believe him. I heard the conversation on the caboose radio, and it took three tries to finally convince the dispatcher we were telling the truth. We actually passed by a "high water" detector but it hadn't been activated (if so it would turn on a light on the dispatcher's panel). It turns out the detector was set to go off when the water reached to top of the rails, but the water had only reached about an inch or two above the rail base when the "lake" in an adjacent field pushed through the ballast. (It was later speculated that the rhythmic pounding of the train going over the soaked ballast area could have assisted in setting off the the wash-out, and the water culverts under the roadbed were not up to the current volume of water – also  they were probably plugged up at least a little bit.)

I remember a quick thought that scared me some after the caboose jumped up and came back down in a cocked position - and we were still rolling: I hoped the caboose body wouldn't slide off the lead truck, bust loose from all the brake rigging,  then roll over down into the "lake" (with a high probability of drowning for yours truly.)

*  Regarding Gads Hill:  As info, at 3pm on January 11, 1874, the first train robbery in Missouri occurred.  Jesse James' gang and the Younger gang got on the train when it stopped at the station at the top of Gads Hill and robbed the passengers.  I'm glad to have missed that occasion by about 140 years.

K487

I'll admit I'm learning while I read this thread.  Thanks to all for your input.

K487

ebtnut:  Excellent point!    K487

This Subject is currently being discussed by some very knowledgeable people on modelrailroadforums.com here:

http://www.modelrailroadforums.com/forum/showthread.php?34023-Most-significant-diesel-electric-locomotive-of-all-time

I've found it extremely interesting and informative, and I think you will too.

K487 

Well, no one's mentioned it, but there's always Bull Frog Snot.  I don't use it but from what I read it helps a lot.

K487