# UP "Giant of the West" - EMD DDA40X Centennial, UP 6936



## SD90WLMT (Feb 16, 2010)

This is the beginning of a very long project....!!!!! :~}

Owner: Matt Abreu, of Granite Bay, CA,... aka "Cab-forward" on these pages! 

Builder: Dirk Carmichael, of Dragoon, AZ,... aka "SD90WLMT' to You by now ...

Project: build as close as possible, a 1/29th scale/45 mm, model of UP 6936 


One unit (6936) has been retained as a part of UP's "Heritage Fleet" based in Cheyenne. It is currently painted in a "Lightening Stripe with Wings" scheme.

"Castle Gate, Utah, 2011" 


 




Union Pacific's Centennial locomotives were the largest railroad locomotive in the world. These distinctive giants dominated the railroad's western mainlines from 1970 through early 1980, and were seen on all of the railroad's most important trains. Built as a unique-to-UP design, they were constructed by the Electro-Motive Division of General Motors Corporation.

Numbered as UP 6900-6946, they were known as "Centennial" locomotives because the initial deliveries started on the 100th anniversary of the May 10th 1869 driving of the golden spike at Promontory Summit, Utah. UP 6900 was rushed to completion to allow it to be part of the various ceremonies that took place in Utah on May 10th 1969. Delivery of the rest of the units began a month later and continued until September 1971. The 6900s were delivered in two groups: UP 6900-6924 (delivered in June to December 1969), and UP 6925-6946 (delivered in June 1970 to September 1971). The two groups were identical except for some very minor differences.

These 47 locomotives were the longest diesel locomotives ever built, at 98 feet, 5 inches. Their frames were too long for EMD to manufacture and were fabricated by the John Mohr Company of Chicago. Their fuel tanks were also the largest of any diesel locomotive, with a capacity of 8,000 gallons of diesel fuel, making the fuel tank weigh 30 tons fully loaded.

Union Pacific experimented in the 1960's with high horsepower double diesels from all three major builders - EMD, GE & Alco. The ultimate double-diesel was created in an effort between the UP Mechanical Department and EMD. They had the latest state-of-the-art mechanical and electrical components at the time - including two 16 cylinder, 3,300 HP 645-E3A prime movers for a total of a reliable 6,600 HP! These were released to the railroad during UP's Centennial year - 1969. For that reason, they were called "Centennials". These units were, at the time, "The Worlds Most Powerful Diesel Locomotive". UP finally had 47 of these giants which were used throughout the system.

The Union Pacific Railroad earned a reputation for using very large and powerful steam locomotives and in 1941 began using the largest of them all, the Big Boy, to carry freight over the Rocky Mountains.

In the diesel era, the tradition continued with the use of the most powerful locomotives available. In 1969 UP purchased the very largest and most powerful diesel ever built, the DDA40X, with 6600 HP provided by two diesel engines (prime movers) mounted on one frame,

These 270 ton, 98 foot long behemoths were built by the Electro-Motive Division of General Motors Corp. (EMD) and were named "Centennial" in honor of the 100th anniversary of the "Driving of the Golden Spike Ceremony" (May 10, 1869). In all, 47 units were purchased (numbered 6900-6946) beginning in May of 1969 with deliveries continuing through 1971. They were numbered using the "6900" series to mark the '69 dates.

The "Centennials" were designed for high-speed freight and by 1980 had successfully run up an average of 2 million miles a piece. With the decline of freight movement in 1980 the fleet of DDA40Xs were taken out of service and put in desert storage at Yermo, CA. Then in March of 1984 an economic recovery brought a demand for more motive power and 25 were returned to service. However, high maintenance costs caused the retirement of most of them by the close of 1986.


Rob Leachman wrote on August 26, 2004:

The Centennials were all equipped with experimental "advance excitation" of the traction motor fields. They could get a forwarder train up to speed faster than anything on the rails. I remember Jack Bowen, UP General Superintendent of Transportation, stating in a staff meeting that substituting any other power for Centennials on the North Platte - Ogden segment of the Overland Mail train would require adding 45 minutes to the schedule (just because of the time difference accelerating out of terminals, restrictive curves and slow orders). I also recall that in the early 70s, UP would regularly add a unit in Pocatello to the 2 Centennials that brought WB forwarder trains out of North Platte. (Another unit was needed for tractive effort to get over the steep grades on the Northwestern District. A similar policy was adopted for South Central District hot trains west of SLC.) The extra unit was often added on the point. When these trains started up, one could see and hear the Centennials bump the leading unit. The walk-over plates on the extra units (typically GP30s, GP35s, GP40s, or SD40-2s) were always dented in because the Centennials would be pushing them along whenever the power was accelerating. By 1975, UP was powering the forwarder trains with 3 Centennials (one LA RT started getting four) instead of with mixed units, just because any other power could not keep up with the Centennials. In the late 70s, when "Big Mac" lash-ups (2 Centennials bracketing a high-geared "fast forty" SD40-2) became the norm, I bet they still could not quite match the same running times as the previous all-Centennial lash-ups, even at the same HPT.

Rob Leachman wrote on January 24, 2009:

Before the Centennials were stored (early 80s), they were very popular with the engine crews. They were a tremendous source of pride throughout the company. After they came out of storage they weren't the same. Problems with the units, rare in the 70s, became more common as their age was showing and the harmful effects of long-term outside storage were apparent. From a railfan point of view, the show after they came out of storage was much less impressive, with only one or two Centennials on a train, usually mixed with SD40-2s, in lieu of the impressive 3-unit and 4-unit lash-ups of Centennials common back in the 1973-75 era.

Very smooth riding and pretty quiet in the cab compared to its contemporaries. The acceleration beat the pants off of anything else. In Omaha we found that a set of Centennials on average could make the run North Platte to Ogden 45 minutes faster than any other motive power at the same horsepower per ton. On the Hinkle - Kenton run down the Columbia Gorge, a good engineer on a set of Centennials with green signals the whole way could do the run in three hours. Impossible with any other power back then.

The Centennials were normally assigned to hot trains with high horsepower per ton, so when you were called to take a train with a 6900 on the point, it almost always meant you were going to get a good run.

The Centennials were high-speed merchandise engines. They were not mountain luggers. The engineers in the Blue Mountains preferred to have a set of SD40s. But just about everywhere else on the system, they were the favorite of the crews.




This model is being built from a variety of parts; including - parts from 2 - SD45 locos, 2 - GP38 hoods, 1 - SD45 cab/1 - SD 40 cab/1 - SD70Mac cab. And any hand built parts as needed, walk ways from box car roofs. It will run on a custom set of spliced "Siamese motor blocks", using 4 - SD70 power blocks as donors. That is 4 motors in one loco! OR twice the typical pulling power.



Enjoy the thread folks, 

Dirk
DMS Ry.


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## up9018 (Jan 4, 2008)

OH **** YEAH!!!!! Can't wait to see this build! 

Chris


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## Nebill (Oct 8, 2011)

Very interesting post! I have seen the loco come thru the yard at No. Platte a few times in the last 5 years. I rode with an engineer over the Yoder subdivision, which has the only tunnel on the third district, and he once ran the 6900 series through the tunnel. The tunnel is on a curve, and no one knew if it'd fit or not! He said the conductor went out on the walkway and kept an eye on things, but it cleared the walls just fine!


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## SD90WLMT (Feb 16, 2010)

Say Matt, why don't you tell your side of this story! Why you started it and what you did to begin it? What do you want to do with such a Large loco? 


Dirk 
DMS RY.


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## SD90WLMT (Feb 16, 2010)

Where it all began! 


 



Dirk 
DMS Ry.


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## SD90WLMT (Feb 16, 2010)

GeeeeeZzzzzzz, 

I think it looks a bit long here, must be screen res. or something like that, eh! 

With a long flat hood it feels more like a DDA35 loco, than a DDA40X BIG BOY! 

mmmmm, what to do? 

Dirk 
DMS Ry.


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## SD90WLMT (Feb 16, 2010)

I know. 

It's a "stretched limo" or sum'n thn' 

Dirk 
DMS Ry.


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## d_sinsley (Mar 29, 2011)

I had one of these on my very long ago n scale railroad. It was dang near as long as an HO loco. To long in fact it didn't run worth a damn on my tight corners and steep grades.


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## vsmith (Jan 2, 2008)

This thing will be around 4' long and need what, 20' diameter curves ? Yikes! :O


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## SD90WLMT (Feb 16, 2010)

Yes, It is 98ft - 2in long... hence 40 5/8 in. over the pulling faces. ( 1/29 ) 

The designed curved was for a 10ft. radius min.. so far so good... 

The completed trucks are a full 4 axle, fully flanged wheel set, all 4 axles driven by two motors....for each motor block!! 

The individual trucks actually will get around a 60" radius curve, but installed on the frame, the running unit - having run a full test lap at Dennis Sirrine's in Mesa, AZ, which has a few 10ft. radius curves,... the wheels "squealed" on two curves. So it is "right there". I will be doing some fine tuning to get it to run smoothly around a bit smaller curve, just under 10 ft. 

Dirk 
DMS Ry.


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## SD90WLMT (Feb 16, 2010)

Matt's layout was built with 10.5ft min. curves,.. btw. 

Dirk


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## Jerry Barnes (Jan 2, 2008)

It stopped here in Lex one time and I got some pix of it.


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## NTCGRR (Jan 2, 2008)

I hope you can pull it off, someone needs to finish one. My DD35is sitting someplace??? Waiting for next winter to finish it.


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## SD90WLMT (Feb 16, 2010)

Ya, Marty sometimes we all have just toooo many projects. What else are hobbies for !! Than again, what happened to your last winter, the one that just ended?!! me thinks the big stuff bite you,.. hard!! nice going to btw!! 

I keep working at it, 3 steps forward and 5 back while I relearn what it takes to build one of these monster locos. 

Jerry, you bring up an interesting point with your Truck side frame pic above. Which frame series to build? Seems 2 styles were built over the course of all the DDA40x's built. One has a slight angle or wedge effect to the bottom supports mid frame and I will have to guess that a later set has the same portion on a line that matches the rail head, or straight. For this build the horizontal line is being used, and seems to match UP 6936 better! 

UP 6915 




UP 6936 


 

I do not have any history on why the changes were made...? different molds perhaps... 

Dirk 
DMS Ry.


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## SD90WLMT (Feb 16, 2010)

Ya know Marty, yours is a DD35A loco... 

why, it has a cab!! 

A DD35 is "cab-less" 

Dirk 
DMS Ry.


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## NTCGRR (Jan 2, 2008)

DD35 A ,sorry.


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## SD90WLMT (Feb 16, 2010)

Marty, There Ya go!! 

Dirk 

The Frame: 

Most man made projects tie all components together using a frame. This is where we all start!! Matt sent me his project to work on, having done some of the work himself. It started with using 2 frames from A/C SD45 locos. AS I got into the project and got my feet under me and shared that I thought it was too long to match the real deal, I went back and reworked and shortened the frames to it's current length correct for the model at hand. I added 1/2" aluminum angle below to stiffen it up and tie both frame sections together. 

 

 

 

The basic frame, something to start with! 

 

At this point it was a sound platform to work from and move forward, but I learned there was much to do still. Cut-outs for the walk ways - see thru decking style I was not even aware of at the time. No pictures were taken of such detail, until I found one pic that changed my mind. And the plans did not clearly show this detail item either? mmm So there has been much to learn on this loco!! Fun and headaches both!! 

Dirk 
DMS Ry.


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## aceinspp (Jan 2, 2008)

I remember seeing this loco during the Topeka train fair. Got pics some where. Matter of fact it was the year that the freedom train was touring the country and all was in Topeka. Later RJD


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## SD90WLMT (Feb 16, 2010)

Once there was a frame, it needed a fuel tank. Space is allotted for the power trucks, as they by nature just cannot be an exact match. So it becomes a balancing act to get a nice fit and look for both the trucks and tank. Here the tank is spliced from 2 tanks after re-arranging some components of the tank into their respective locations, fuel fill tubes and level gauges on the sides come to mind here. 

 

Brackets to mount it on the frame bottom get added, and primer. 

 

A little playing around with a camera, some work in the cut and paste dept. turn the trucks into 4 axle units below give it a first look!!! Use a SD70 cab for a rough idea.. 

 

Dirk 
DMS Ry.


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## SD90WLMT (Feb 16, 2010)

OH - Marty, 

My thoughts were that Matt has this one, a DDA40X, you have a DD35A, and I was hoping I'd have time in my future life to build a DD35 ( cab-less ) version. 

Between us there would be a model of each version built!! 

Dirk


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## NTCGRR (Jan 2, 2008)

There ya go. I'm out installing concrete roadbed under my ride on trains now. 
Oh to be young again.!!!


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## bnsfconductor (Jan 3, 2008)

Posted By SD90WLMT on 10 Apr 2012 11:08 AM 


The completed trucks are a full 4 axle, fully flanged wheel set, all 4 axles driven by two motors....for each motor block!! 



Here's a thought... Why not take some HO scale or similar motors and figure out a way to install them as traction motors. Then instead of 4 motors total you could have 8 total.  Realistically that would be the correct! As a side note, I wonder how long it would take the model train industry to get to that point? G gauge is definitely easier to work with in regards to this, compared to HO scale. Can you imagine the pulling power of something that had 8 traction motors?

Craig


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## cabforward (Feb 18, 2008)

This project has been in the works for years... 
It went from simply glueing to sd45's together like George Riley Curry did a number of years ago. 
Are goal is to have a finished model by Marty's get together in September. 
The engine will have 2 Phenix sound cards with the speakers mounted under the exaust fans and run off the 10 amp Revolution board with self contained batteries 
Matt


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## SD90WLMT (Feb 16, 2010)

I think one problem using such small motors - that would fit plus related gear train - slot car / side winder style stuff - would probably be the reduction in over all power to a truck.... 

Lots of work here, wan'a build one Craig? even a test motor block? 

Just a 3 axle unit to play with.. 

I have to admit, getting to the full powered 4 axle unit did not come over night. It was a long - not deliberate - approach. Our expectations did not start with we wanted a 4 axle motor block... It started out with just a 3 axle block unit and a tag along 4th axle to make it look like it was correct.... Having all 4 axles powered came as an after thought, and more by evolution and accidents than anything else, just from working with it so much. 

Dirk 
DMS Ry.


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## SD90WLMT (Feb 16, 2010)

Once I got more familiar with the details of the loco, I started seeing so many items that needed work! Turns out the side frame step/ladder needed a spot to sit next to the fuel tank, which resulted in a back cut angle of the fuel tank corners. This allowed the steps to not exceed the loco width. 

 

 

 

Installed on the frame - 

 

Here a strip of Box car roof decking is used to create the decking on both sides of the frame. It works so well, that light shines off the upper tank surfaces even. So it should add a great deal of impact to the completed loco!! 

 

for now!!, 

Dirk 
DMS Ry.


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## Robby D (Oct 15, 2009)

Can't wait to see the finished locomotive!


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## DTI356 (Jan 3, 2008)

Dirk, 

You do some really clean crisp work......nice job!


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## SD90WLMT (Feb 16, 2010)

Thanks Robby and Brian!! 

Umm, years of fabrication in steel, custom body work and painting, show thru on occasion in My model work!! Just hoping to stay on track thru the entire project. 

A trip to My Dad's in So. Cal. this weekend, helped with this model also. I got to "stand" on a DDA40X loco at the Pomona Fairplex, UP 6915. First visit to see one of the these large monsters, and also UP 4014, Big BOY...!!! My Wife kept looking at the loco - it's SO BIG, what is it she says?? "Honey", it is the same loco we ran in the World's Longest Model Train... 3 of 'em - As soon as I pointed that out she "Knew" the loco!!!!! 

I have saved most every pic off the internet for the DDA40X loco build, but there is a lack of really good close-up detail shots of critical parts..The side radiator grill work, the side step ladders by the tank, and the corner steps at both ends. I took many close-ups of just these pasts for now to help with the model!!! 

These will help Me move forward with work on it. Also took My own set of all 4 corners showing the access covers - part of the cooling sections at each end of the hood! These are nearly complete currently, but this will also help. 

Pics tomorrow - Dirk 
DMS Ry.


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## SD90WLMT (Feb 16, 2010)

I will try to reconstruct what we lost last week so we can get on with life again!!! And building trains..... 

I did get pix of Me on the monster loco, DDA40X, and next to an even larger BIG BOY loco while on our recent trip to LA to visit My Pop!!! 

 

What's this - does this fit here? It's big, and Oh so black!!! OH A BIG BOY, got it!!! 

 

A close up of the front and all the detail work to do someday! Lots to work from in a pic like this also. 

 

The radiator cooling grills are the most often missed item for a DDA40X in close-up pix. SO these were My number one thing to get good pics to work from for this build. Once seen, they do not look so intimidating to recreate in miniature. Just needed to know what they were really like, not like a SD45 radiator either, so don't be fooled by the similar shapes here overall!! 

 

These are the correct side frames that will be copied for this loco, they are from UP 6915, but clearly the same as UP 6936 frames are! 

 

The side fresh air cooling section right behind the cab on the Engineers side of the loco. Many details here, access covers and related items for them are easy to see here, for each side of the loco, followed by the Fireman's side next... 

 

 

I should also point out that some parts are much different on UP 6915, and this is why UP 6936 is always the loco used for any final reference work before any building is undertaken. So there is always a hunt for the right and correct detail, yet many pix are needed to get the right feel also, some of which may not be from UP 6936. All this takes a fair amount of time to sort thru. And sometimes gets confusing also!! What FUN!!! 

So with that lesson, here is a section I built copied from a photo always at hand and right next to the work in progress. 



This wall section and the other 3 matching walls have been the most challenging for Me to build so far. These will be glued to the mid-sections for the engine bays using GP-38 hoods cut up. We'll get into that later tho! I built a small jig for these walls so they would all be the same, building 2 lefts and 2 right sides, and even adjusting the small stops for the grill work on each side. Again, I will get into this more next time I check in here. Until then,.. safe modeling!! 

Dirk
DMS Ry.


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## bnsfconductor (Jan 3, 2008)

Lost post addition per Dirk. 

A good source for MU hoses (not the train line) is O scale glad hands. I believe this is the part number from P&D hobbies PSC04050 Air Hose w/angle cock & glad hand (4) Found at http://pdhobbyshop.com/show_product...=Detailing Parts&manufacturer=Precision Scale Or here's another source I just found. Similar product http://www.irishtracklayer.com/Irish-Tracklayer-Glad-hands-5/dp/B005SGC356

The glad hands are small enough to be in scale for the smaller MU hoses. And they are functioning and able to lock into each other. Remember the 3 hoses face different directions.
















The main res. hose should face inward like the train line, and the outer two should face towards the outside. I've thought about trying to model all of the underside piping before, but it would be quite the project.


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## Pete Thornton (Jan 2, 2008)

Awesome work ! Awesome loco!! 

Why not take some HO scale or similar motors and figure out a way to install them as traction motors. 
As an aside, for anyone considereing "axle-hung, side-suspended traction motors" - we have been playing with that idea for our EBT M-1 model, which essentially used Brill streetcar trucks with a motor on each axle. NWSL used to make a "Magic Carpet" drive but have abandoned the gauge-1 version. This is a UK-sourced equivalent. (Google "nwsl magic carpet drive".)


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## NTCGRR (Jan 2, 2008)

WOOOOOO and I thought all this time you was a young buck.????? surprise surprise...


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## SD90WLMT (Feb 16, 2010)

Marty, As Young as You are!! 

Say - just wonder'n here Marty, Your not getting Me confused with Matt are You..? He acquired Your UP Aux support tender, & You ran trains with him at Pomona.


We have barely been face to face..............

Matt is 40 years younger than I am......mmmm

Dirk


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## harvey (Dec 30, 2008)

Hello Dirk,
This is quite the project you've taken on here, I thought reworking the GP9's was a major undertaking. I'll have rethink that one.
Some of the links being provided by others on this build and mine are most helpful and are certainly worth keeping in a project file.
The idea of using individual motors on each axle is something maybe the commercial manufactures should consider looking at, even if it was offered as an option. I know there would be a significant cost increase with such an option, but for some of us I think this would be pushed aside by the increased pulling power and general overall performance improvements.
I'm really looking forward to watching your progress on this engine, it is quite the monster.
Cheers.


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## SD90WLMT (Feb 16, 2010)

Harvey and others, As far as single axle motors go - I think it would be incredibly novel to build a set of trucks based on the concept!!! 

I was not ready to get into the power trucks yet, but the door seems to have opened here, so now is as great a time as any!! :~} 

I am not sure of power increases however in the true sense, in model form! A single motor as shown in a previous post above are much smaller than say a given USA SD70/SD40 motor currently used in power trucks. Power would than be combined from several smaller motors, and would need to exceed the larger motor already used in power trucks. There are other issues surrounding the practical aspect of using multi-motors also!!!! As the current load goes up, as a result of using more motors, they will need increased battery capacity to provide a reasonable run time. 

Having traveled this road for two projects, I have reached some conclusions regarding making more power in a loco. 

One issue regarding increased power centers on the completed locos weight, and it's ability to create "traction", for a given increase in power as We know it. If one simply added more power in a stock loco, not much will result, as the driver traction will not have increased, and it will simply be easier to spin the wheels, something they can do now!! To prevent the wheels from slipping, more weight needs to be added on the drivers to help them achieve their potential to "use" the increased power. There have been enough discussions here regarding the choices of using traction tires, - they break, ammm - prevent slipping - which I disagree with, purely from having seen a loco spin the tires, under increased weight conditions. ( if a 20 pound loco can spin traction tires, why cannot a 10 pound loco do the same? ) 
Traction tires are tougher on the gear train also... 

So we have limits to achieve traction that can really be used in model form. 

Battery supply - in current capacity, is the next issue in powering more motors for more power! Read Amp hours here!!! How long do you want a loco to run? Track power will also be a issue, either way, multi-motors "consume" more current to feed and run!! So planning is required here also.. 

For this loco, a two motor unit was eventually created to power the DDA40X model. It is based on 2 USA Trains SD70 motor blocks, built into a unit given the needed wheel base to match the side frames. The gives us all 4 axles powered per truck. 

But it needs to be "fed" now by more battery power also, to match! 

Here is what I developed for this model!! Compare it with a "stock" SD70 block on the far left side, and also in the middle a dual-motor "re-placement", 3 axle block, that will go into a SD70, or in this case one of My own SD90 Mac loco projects!! 

All of these multi-motored trucks "have been run" on a layout. They have pulled cars and some issues where found, nothing to stop the concept from proceeding further, except for the issue for battery power needed to run a decent length of time! 


 

Yes, I think more power is possible.. but at what cost? 

For the DDA40X, Matt also had me build a SD70Mac. It is simply a battery loco, and therefore is up-powered. Wiring runs between the two at the rear of the DDA40X. There are provisions made to allow a battery box car behind the 70 Mac even for additional power... The DDA40X carries its own batteries too! 

Battery expense can become an issue. I have seen some operators running 3 locos, in a set, with the center loco just as a battery loco, leaving 2 powered units to pull a train. This looks cool, but adds cost for an un-powered loco! 

I'm reaching a conclusion to go with single locos, with their own batteries that can be powered and coupled into units of 3 or 4 or 5 locos, and pull a train. This is looking like the most practical way to go for more power and the best run times also! 

Using My SD70Mac as an example, it will pull 8 - 8 1/2 pounds at the coupler. This is well beyond 100 cars on level track. Running it at say 50 to 60 cars keeps it at a very conservative and practical load setting, while allowing decent run times, from a 9 Amp hour battery set, on board. Matt's loco is mostly for running his 30 plus passenger car train, not a freight drag, tho he has mentioned pulling 100 hoppers at times with me!! 

There is much to bear in mind when powering up Your favorite loco! The design weight for the DD will be about 24 pounds. It will not be running traction tries! 
I can say that My heavier 70Mac runs "very smoothly" - couples at incredibly slow speeds, sits and rides well on rails. It just feels like a real loco!! It is an armful to carry too!! 

Dirk 
DMS Ry.


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## SD90WLMT (Feb 16, 2010)

Harvey - while your rethinking your build levels, here are two other projects of mine! 

A SD60T, a stretched SD70 frame - adding 3 inches, standard cab, and dual motor trucks!! Reworked 70Mac hood.. added SD45 steps, and replaced the tank with a stretched SD45 tank, not shown at this point...and heavy duty coupler mounts... 

 

The beginnings of a SD90Mac, completely scratch built frame - complete with full length I-beam frame, stretched fuel tank, custom hood to come, mods to cab still. 

 

Dirk 
DMS Ry.


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## harvey (Dec 30, 2008)

Hello Dirk,
Thanks for the information update and the photographs of the extended four axle truck.
I'm toying with the idea of building some three axle flexicoil trucks. but just need to figure out what to do about that centre axle.
One thought I have was to extend a standard USAT GP9 truck with a shaft extension to the third axle and make the centre wheels independent with no through axle. Something like and independent rear suspension used on some vehicles today.
It's no wonder we don't sleep at night!!
Thanks again for the info.
Cheers.


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## SD90WLMT (Feb 16, 2010)

Sleep - who needs sleep? hehe!! 

We all dream - all the time I think. 

Harvey, What does not show in the stock 3 axle up-graded power block are only 2 powered axles, for each end. The center axle floats in the side frames, unaltered bearing supports which are free to float up or down, against spring pressure, and is not powered. I just got lucky on most of this and the results that came on their own! 

To maintain the stock wheel base I was not able to power the center axle. Frankly, it all worked out well.. 

What loco do you want to put your flexicoil trucks under? 

Dirk 
DMS Ry.


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## harvey (Dec 30, 2008)

Hi Dirk,
If I'm able to gather up enough dimensional data I would like to have a go at scratch building a GMD1.
I'm going out this weekend to have a look at one in a museum about three hours from here. I've taken some photographs of the one's remaining with CN, but they get a bit snitty when I get too close. Maybe if I went through official channels I might get better access. I think I could certainly get good access to one if I visited Cuba again. CN seems to be selling them of to Cuba, heck I might even get to drive one there.
Cheers.


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## SD90WLMT (Feb 16, 2010)

I understood you to be looking for a 6 axle loco, but to My surprise this is a 4 axle indeed, nice choice! 

Ya, right on My part, as soon as I searched some more, I found both 4 axle & 6 axles versions...mmm!! 


How am I doing now? hehe!!! 


Dirk


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## SD90WLMT (Feb 16, 2010)

Harvey, where are you located? 

Dirk


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## SD90WLMT (Feb 16, 2010)

The SD60T above uses a SD40-2 truck side frame in the pix!! As it should..but, 

Again, what is hidden - a wolf in sheep's clothing here! - is the dual motor truck under discussion. 

It works with both a SD40-2 or SD70 truck side frame.. 
......and coming soon also - a Dash-9 side frame in the works. 

Dirk 
DMS Ry.


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## harvey (Dec 30, 2008)

Harvey is located in Edmonton, Alberta....most of the time. However, his mind and body are not always in the same place at the same time! 
Cheers.


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## SD90WLMT (Feb 16, 2010)

Harvey, do you have a split personality?!! he,..he.. 

You could send the body portion down here to help me on My layout sometime!! Give your "Mind" a rest!! 


Seems Harvey is located directly North of me in AZ!!! along ways North tho! 

I have a 'nother Canadian Buddy - temp. in Texas till retirement, who plays with trains also! He loves the CP and CN stuff, but is building His own Canadian rail system Co., as a interchange rail group working between the CP & CN. WE have an idea where he also ships thru out N. America meat products - Canadian bacon - to major distributors, for redistribution beyond. I will have the S.W. Division warehouse on My layout, and this gives me an excuse to run his equipment on my line here!!! More variety and color here for me to play with also!!! And great added business opportunities also for the layout! 

Dirk 
DMS Ry.


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## Bryan Smith (Jan 2, 2008)

Looking Good Dirk! Hmm SD60T i wonder retired SD40T-2 built new tunnel motor SD60T ? that be cool! I STILL holding off UP GTEL8500 the Big monster turbine ! i like finish my monster turbine i can match my little turbine my GTEL4500.


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## SD90WLMT (Feb 16, 2010)

Bryan, get to work on your Turbines!!! make those puffers RUN!! 

The SD60T - was simply a short cut to a mock up for testing my motor blocks for a much more complex build, a nearly all scratch built SD90 Mac. It would have been much longer to get it running,.. just to prove if My idea would work! 

IT did - so I have started a scratch frame for a SD90M so far!! 

Waiting on a final choice to paint the 60T, and details, let's see - in the family - SP / DRGW or up next UP, or a private road, then theres' RJ Corman, with lots of pretty red tunnels running around today!! and CP has been repainting lots of former SOO stuff, in the SD60 family also. That would be fresh red also! 

OH,.. I like RED!!! 

Dirk 
DMS Ry.


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## SD90WLMT (Feb 16, 2010)

got some glad hands from P&D Hobby Shop today. 

item #5676 

 

item #4279 

 

item #4050 

 

Dirk


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## bnsfconductor (Jan 3, 2008)

Is #5676 the one that has the rubber hose? #4279 looks like it would work quite well to and has the added detail of including the pipe bracket. I bet the metal is soft enough that you could bend it slightly to take the stiffness out of it... 

Craig


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## SD90WLMT (Feb 16, 2010)

No rubber hose was included with any of the items shown above... 

Dirk


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## bnsfconductor (Jan 3, 2008)

Humm. My hose I have is ~0.055" with a wall about ~0.015"-0.020" I recall it coming with the glad hands.


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## kc6uvm_George (Sep 30, 2012)

Looks like a good project. Has anyone come up with 3D cad models (.dwf or .dwg) of the 4-axle flexi coil truck that may be scaled up/down in any cad software?


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## Enginear (Jul 29, 2008)

Dirk, looks like some fantastic work you've got going on. 
I've been staring at my SD70 sideframes and wondered if they could be altered. Mine are too wide for my trucks. I've put it off as there's too much else to do. I can't get the body's side grills perfect. They're driving me nuts.


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## SD90WLMT (Feb 16, 2010)

George, I am currently unaware of any serious and accurate drawings for a DDA40 loco, which makes building one even more difficult and a big guessing game!! I am forced to rely heavily on lots and lots of photos to compare to while I work on it!! 

Joe, Whose SD70 side frames do you have to work with? What's up with the grills - the screens looked great, I was even looking for the roller while gone this weekend!! Post a close up of your work on Your ACe thread OK, & let me look at what you got!! I know about the driving ya nuts part... some comes from learning how to build a loco when it is a new process to learn. Some comes from creating ways to solve a new process not done previously!! And it seems to me there are few modelers to share and draw from to help or learn from each other in G-scale also! So all we can do is reach out and help and work together to complete our models - and have more fun!! Learning on the way... 


Dirk - DMS Ry.


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## SD90WLMT (Feb 16, 2010)

Joe, .. tried to send a pm to ya!!! ? Or email would be easier!! 

Dirk


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## Greg Elmassian (Jan 3, 2008)

Dirk, just a note on our previous conversation about motor draw. 

I re-read the whole thread, I see you are using 2 SD-70 USAT blocks per truck. 

You seem concerned you were running 4 motors and needed "more" decoder. 

The Aristo SD trucks already have 2 motors each, 4 per loco... 

True that the USAT motors have a low impedance (resistance effectively), but the 10 amp QSI will have no problem. I believe even the 6 amp one will be fine. 

You should remove any traction tires from the loco. I'd suggest around 15-18 pounds total weight. 

Regards, Greg


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## SD90WLMT (Feb 16, 2010)

Ah, finally some one that speaks to my Crazy MinD!! THX Greg!! 

What I did was an exercise in... increasing Horse Power, and pulling load increases... 

If I could 'double the H.P. - then I should be able to double the load pulled' ( trains cars ) 

It was a challenge to create more power.. Yes, A/C does have 4 motors per loco, but very different motors, but think this thought, How could one increase the H.P. in an A/C motor block that is full of motors? ... no room left..... 
USA motor blocks have room,.. I just had to find it! 

My general goal has been to increase the pulling power. This means more power. One can then pull more cars.. I am comfortable pulling 50 cars in a conservative setting and layout with My SD70Mac research loco, My Red one. I figure If I can increase power two fold - that a loco could pull 100 cars instead ...This 'would ' require more decoder current capacity, while I agree with your statements about not using or drawing more current than a stock loco will, pulling the same 50 cars!! But My goal was to pull 100 cars which by nature require a higher amp supply to provide the power. ALL by one loco.. 

So My intentions where based on results and data collected from the Red SD70, equipped with volt and amp meters that provide real time results while pulling cars on any given layout and compared and related to coupler pulling loads ( draw bar or tractive effort ) for a given train load. I have exceeded 7 Amp. continuous on high grades pulling 70 cars! I have run a 50 car train running a much better 3-5 amp load range, but still reaching 5-6 amp continuous on the same high grades. 

This leads My conclusions to see a need for 15 amp minimum for any power boards. Second I am creating a design parameter that gives a safe zone .. I want to run my motors at 50% capacity - the power boards at about 50% capacity... I have matched and balanced my design work so as not to be operating any one component at or near it's maximum load range, but more in the 50-60% range to reduce long term heat build up and prolong component life overall! This lead to a 30-35 amp ESC in the SD60T which has worked well so far. 

All while pulling 100 cars all day with one loco... 

So I want more decoder for .... more pulling power,... not for the same load !! 

Ironically, during the time I have spent on this portion of My project I have come to see results that indicate to me My 'theory' may have been flawed... 

I made the assumption that 2x H.P. would pull 2x cars!! 
I now see that to do this, I also need 2x the loco weight....! A rather exciting conclusion, 
As My red 70 now weighs a hefty 19.5 pounds, it would be impossible to have the same loco weight become 38-40 pounds...!!!!! 
Plus there is the run time cut in 1/2 with a given battery pack size, with out consideration given for extra battery power someplace??? 

It has been a good learning experience, but may not be truly practical in practice. I will keep My running example of the SD60T for further testing and thought, but may not build anymore in that 4 motor family! Still interested in how it runs long term and anything I may have missed to date. Pulling with more power may show something I do not see at this point in time. 

As for Matt's loco, it most likely will not be over worked in the end. So board consideration may change, currently Matt is set on the upcoming new board from AirWire, choosing to stay in the same family as His other current loco boards... 

Dirk - DMS Ry.


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## Greg Elmassian (Jan 3, 2008)

Based on your goals, and decision to use the USAT motors, I would recommend 2 decoders.... and get the 10 amp ones, and have the fans as the manufacturer recommends. 

Yeah, you will also need more weight, of course depending on grades, but I'd be looking in the 20 to 25 pound range. 

Oh, so Matt is stuck on the AirWire, too bad ha ha!. That will limit the current output capability. I would expect to fan cool the AirWire board, but you will definitely not be able to "over engineer" the capability with that setup.

Also, look at the AirWire specs carefully... the boards were rated 10 amps but also at 12 volts... i.e. 120 watts... if you are running 18 volts and 10 amps you would be running 180 watts. Remember to check the specs carefully. Several people got "burned" because they thought 10 amps was 10 amps no matter what the voltage.

I do believe that there's enough output on the receiver that a single receiver could power 2 QSI boards.Then you should be able to run 20 amps max, and 14 amps all day.

Too bad, he'll miss all the really cool stuff the QSI can do over whatever sound only decoder he will use with the AirWire drop in. 

Greg


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## SD90WLMT (Feb 16, 2010)

How does the new 15Amp Airwire coming out work...? 

My weight goal by design for the DD40 is in the 24-25 pound range currently! 

Dirk


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## SD90WLMT (Feb 16, 2010)

You are correct in the amps/volts vs. watts combination issue on those boards - I have been in several discussions trying to explain that issue and what it really means.... 

not always winning over the 'hearer'.....mmm


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## SD90WLMT (Feb 16, 2010)

We were also discussing radio range,...! 

While the QSI format looks very interesting even to Me, I do have unusual needs for my equipment here... 

I really want to have reliable ranges in the 250- 300 ft range.. 

Why I am using old air/craft radios and looking at the 2.4 stuff, again for aircraft


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## Greg Elmassian (Jan 3, 2008)

No problem, won't mention it again, if he has decided, then he has decided. 

The wattage thing is hard for people to get, because amps and volts are not really clearly understood by many people, even using the water and pipe analogies... while technically a great analogy, many people do not get it. 

I have the best luck getting people to understand watts when they have an RV or camper that can work on 12v batteries or 110v shore power... they realize how many more amps it takes from batteries that are 1/10 the voltage. 

Just looking at a battery cable vs. an 110v wire helps... 

The range of airwire is limited because it is 900 MHz and power limited by FCC... add to that the fact that it is not a full duplex system, it makes it even less reliable. 

You need DCC and multiple base stations for coverage, but that would require track power... (that's what I do)... that would give you pretty much unlimited range... a layout about the size of a football field is doable. 

If you are battery, then you clearly need something like model aircraft use and external antennas on your locos. 

Greg


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## SD90WLMT (Feb 16, 2010)

And I'm more than a foot ball field!! ha


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## Greg Elmassian (Jan 3, 2008)

The AREA of a football field... in lineal feet like a loop, conservatively about 30 * 100 feet, or 3,000 feet. 

Regards, Greg


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## SD90WLMT (Feb 16, 2010)

Yep,...a little more than a 'football field',.. indeed. 

more like a couple hundred thousand square feeeeeeeeeeet!.......! 

Dirk


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## SD90WLMT (Feb 16, 2010)

OK Greg, What do you know of the latest AirWire 15 amp board? 

Dirk - DMS Ry.


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## SD90WLMT (Feb 16, 2010)

And I recall a football field being 100 yards long..... or 300 feet...mmmmm


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## jake3404 (Dec 3, 2010)

Not to derail your thread too much Dirk,

But I thought you'd get a kick out of these two photos.



















This is #6925 in its current state. I took these two pictures this last weekend in Chamberlain, SD. This is the Dakota Southerns railyard. 6925 is not in working order from what I could tell, the Dynamic brakes have been stripped and from what I've been told they have caniballized other parts for other locomotives. She is now a glorified fuel tank.


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## SD90WLMT (Feb 16, 2010)

Jake, This is the place for DD40 stuff by all means!!! Indeed!! 

Added pictures, info, & input is definitely welcome. What a sad ending for a big loco, a stationary fuel tank eh! 

Anytime, Thanks !! 

Dirk


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## Randy Stone (Jan 2, 2008)

So what was the reason for the hole in the middle?


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## Scottychaos (Jan 2, 2008)

Posted By rlvette on 01 Oct 2012 04:50 PM 
So what was the reason for the hole in the middle? 


It's essentially two complete locomotives on one frame. One locomotive powers one truck, and the other locomotive powers the other truck..
the "hole" in the middle seperates the two locomotive units..not sure why the hole is actually needed though! seems they could cover it up..
it's probably there for some maintenance purpose..

Scot


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## SD90WLMT (Feb 16, 2010)

While it seems there maybe a variety of reasons for the hall or tunnel, one more could be that it is a much shorter trip to the other side on a very long loco. There was ample room for the equipment, and in the inside roof or ceiling are a few pipes - probably cooling fluids - but not much else, and does not appear there are any access hatches or covers. This area did not get filled with any equipment, as it would typically be the very rear end of the long hood. Yet they needed room for the radiators and cooling needs above. 

Dirk


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## SD90WLMT (Feb 16, 2010)

Here is a pic of the passage way in the middle of the hood. Mostly of the upper coolant lines and fittings, the rest is just smooth flat surfaces with no hatches! A place to walk thru is about it! 

 

Dirk


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## Totalwrecker (Feb 26, 2009)

What's the doohickey on the rear half that blocks part of the N and looks like a flattened homeplate? 
John


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## SD90WLMT (Feb 16, 2010)

just a dooo-hickey is all!! 

I like that! 

IT is ... a sand box - one on each side, as there was no room in a standard hood rearranged for this loco, which also would have been some distance from the rear truck. It is sitting on the rear side decking, but usually is hard to notice - actually hangs over the decking edge some 4''-6'' also, to create enough space for the sand supply. 

Dirk


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## Totalwrecker (Feb 26, 2009)

Thanks, I was afraid I'd gotten too technical! 

John


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## SD90WLMT (Feb 16, 2010)

Ya had me think'n for a minute is all John!! 

Mind tried after our long trip, and today I'm hauling lots of water, we were out this morning.... arrgh .... :`/ 

next, on to the garden without water for three days....


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## SD90WLMT (Feb 16, 2010)

well - time can really fly, eh!!!! 

On a different thread here, a discussion about sound options for this bad boy loco was running along side this one, so I wanted to add a link for those that may have missed out or did not relate it back to this project!! 

Bells, Whistles, and Prime Movers!! 

http://www.mylargescale.com/Community/Forums/tabid/56/aff/36/aft/126031/afv/topic/Default.aspx ..., just cut and paste if need be........ 

This was a good thread about the 'sound options' for a DDA40X model. I learned allot also. So much so that I got all the pieces needed to put together a complete system to test and learn more. I will use own My personal loco, My Red SD70 - a Research loco for the installation to get this working and sounding off! What better excuse to learn more! 

I got these parts, as listed below;.. 
... QSI 'Titan' - Magnum version - 10 amp / 20 amp max 
... QSI - G-wire receiver to use a Air wire throttle 
... Air wire T5000 throttle 
... a 'Visaton' FRS-8 speaker, a 3.0'' - 8 ohm unit 

In installing these in My loco, I will also retro fit the 2 battery packs - 18 volts/ 4.5 amp hr. (9.0 amp hr. combined) for a single 24 volt @ 4.5 amp hr. pack. This has the effect of increasing the watt/hours over a single pack, but it is a bit shorter in run time compared to the 9.0 amp hr rating I have been using. 

I feel the components will function better using a 24 volt base, over the existing 18 volt packs. 

The Visaton 3.0 in. speaker has been started to be installed into a spare fuel tank.. a spacer needs to be fabricated to mount it from or thru the bottom of the tank - not from the top side down in.. 

 

sometimes you can't win for loosing, here you catch the guy with the camera - look close!! 

 

and My Research loco for this conversion... 

 

So moving forward, using My loco as a test bed to get a much better idea of how to best approach the DDA40X build, and hopefully achieve the best results the first time on the 40!! 

So winter progress will be spent working this all out! 

stay tuned!!.... 

Dirk - DMS Ry.


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## NTCGRR (Jan 2, 2008)

Hows the body coming? I finally got back to this thread. 
Few more projects then maybe I can get back to my DD35


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## SD90WLMT (Feb 16, 2010)

Up early Marty!!? You must be getting your G 'wind' back again, thinking about g trains more we are now!! good!! 

No hood work recently... 

wanted to get chassis together - sound in place, painted - with fuel tank.. 

more test runs to sort out turning issue , squealing on a 20 ft circle at Dennis S. layout. 

but - alas,... I do not have a nice warm shop like you Marty, pick my building sessions when it is not cold... everything on hold fer a bit.. not easy to live like that when there is so much I want to work on....oh well, some day life will be different...until.... then.... 

Dirk - Merry Christmas to All!!!!


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## ddgoose6991 (Jan 6, 2013)

Nice Build so far!!!! I have a centinnal in o scale and i thought that was a beast. look forward to seeing the finish product!!!!


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## bnsfconductor (Jan 3, 2008)

Posted By SD90WLMT on 21 May 2012 10:23 PM 
got some glad hands from P&D Hobby Shop today. 

item #5676 

 

item #4279 

 

item #4050 

 

Dirk 


Dirk,

Bringing this thread to the top again. I think that the part I ordered from P&D was #PSCO4649
Here's a comparative shot showing the airhoses I've modified.








Left to Right. USAT trainline molded plastic hose, USAT molded plastic MAI hose, my O scale hoses with flexible tubing, note that the Main Res. hose is slightly longer than the AI hoses. The nuts above the hoses are a bit over sized, but it was what I had on hand at the time. The nuts represent where the MAI hoses screw into the hard piping. Far right is the brass castings from P&D. The glad hands will actually connect together, but I have not permanently MU'd any locomotives together so I leave them alone. 

Craig


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## DKRickman (Mar 25, 2008)

If you really want to get technical, the main reservoir hose should be slightly larger diameter than the actuating and apply & release hoses. Still, VERY well done, sir!


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## bnsfconductor (Jan 3, 2008)

Posted By DKRickman on 10 Jul 2013 07:11 AM 
If you really want to get technical, the main reservoir hose should be slightly larger diameter than the actuating and apply & release hoses. Still, VERY well done, sir! 
I know







But the gland hands from P&D came with the rubber hoses. It's a bit stiffer than heat shrink, so I'm not really sure what I could use to make it slightly thicker. You and I (and other rails) are the only ones who would know the difference. Next step trying to find a decent glad hand for the train line... On my GP30 project I'm tempted to run the piping for the MAI lines and include the angle cocks. Humm..

A company offers 'working' glad hands in 1/20.3 and 1/32. But nothing in 1/29 yet. But not working according to my definition as they are magnetic and thus the glad hands can't be spun 180 degrees.. 
http://www.thetraindepartment.com/protohands-working-glad-hands/
I'm wondering if the 1/32 ones may work okay or they will look undersized. 

Craig


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## SD90WLMT (Feb 16, 2010)

There is also some thing not mentioned yet,... 

I use stranded copper wire, cutting longer sections than needed and pulling/sucking the stranded wire from the insulation, leaving a very nice - drum roll please - ''hose'' to now cut to the length you need for an air line!! 

Using wire insulation gives one the options of using many different sizes of ''Air hose'' to build air lines with... 

Model on guys !! have fun - My kittens are 'picking on me' today. They are watching me dig in a rock ditch off the front porch here!! darn ...eventually will get thru the rock and add more water lines, 1/1 scale stuff here tho! ha!! 
PS - the kittens got so tired watching me dig and load a wheel barrow with rocks and dirt, they are sleeping on my bed now!! I'm on break - eating breakfast - already one big drip from the heat!!

Dirk


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## SD90WLMT (Feb 16, 2010)

So it's time to press on ward here.. to confirm by any sparkies here, I am going to use 4 - 2 1/2'' speakers in the fuel tank.. seems that if I use 8 ohm speakers, and run them in a series / parallel affair, I will still end up with a combined 8 ohm load.. 

Using one channel of a QSI sound driver, will the driver still be happy driving all 4 speakers? 

Dirk


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## McDOZ (Jun 11, 2017)

*DDA40X Scale 0 - 1/45*

Hi guys!
Im new here at mylargescale.com and this is my first post.
Im trying to build a DDA40X in scale 0 its 1:45 in Scandinavia.
Found this particular thread and just want / need more.
So wot happends here 2013? No more posts?

But Thx annyway Dirk for all the pixs.
My Best // Gert Persson, Malmö Sweden


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## Paul Burch (Jan 2, 2008)

http://forums.mylargescale.com/11-public-forum/79433-our-friend-dirk-carmichael-not-doing-well.html


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## Gary Armitstead (Jan 2, 2008)

Paul Burch said:


> http://forums.mylargescale.com/11-public-forum/79433-our-friend-dirk-carmichael-not-doing-well.html


Paul,

Dirk passed away a couple of months ago........April 20th. Sad indeed.


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## Paul Burch (Jan 2, 2008)

Gary,
His passing is in the link that I posted.


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## McDOZ (Jun 11, 2017)

So sad to here.
But thanx for letting me know.
Rest in peace Dirk
// Gert


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## Greg Elmassian (Jan 3, 2008)

Paul, I often change the attributes on a link to bold and underline, and then people more often recognize it is a link.

I miss Dirk.

Greg 1,145


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## ewarhol (Mar 3, 2014)

Greg Elmassian said:


> .
> 
> I miss Dirk.
> 
> Greg 1,145


Me too. I'm missing the daily chats with him.


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## Scott (Jan 29, 2008)

So sorry to hear the news of Dirks's passing. Top bloke, he will be missed.


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