Briggs Models MLW RS-3 Build Thread

[BCR 570]

My next locomotive project will be to build three MLW RS-3s for my layout.  These will replace two older models which I built many years ago.  As the RS-3 is common to many railways in Canada and the United States, I thought I would offer a build thread as I go along in case this project is of interest to others.

Older Models
I will begin with my older models, as they represent a significant development in the history of N Scale locomotives.  They began as Atlas/Kato ALCO RS-3 models and came out of the first carton to arrive at Pacific N Scale in 1983.  I was working in the store at the time and I recall the reaction among the local modelling community when this model arrived on the scene.  It set a new standard for N Scale locomotives and there was no looking back.  It looked better and ran better than anything else on the market.  It was soon followed by the RS-11 from Atlas, and then Kato entered the North American market themselves with the EMD GP-38 if I recall correctly.

My models were built at a time when few detail parts for Canadian modellers were available.  The footboard pilots were adapted from other brass pilots, the carbodies were perforated for carbody filters and brass screens added.  The top mounted bells were scratchbuilt and the 570's five chime horn was cobbled together from two Eric horns.  A friend painted the models with custom mixes of Floquil paints, but there were no decals for British Columbia Railway in the 1980s so they ran for many years without decals.  They ran annually at the local train shows and racked up many miles, rarely missing a beat. 

Eventually, Microscale introduced a decal set for BCR locomotives, and it was finally possible to finish the models properly.  They also received some weathering:




In 2005 I began construction of my layout, and the two RS-3s were used for initial track testing with DC power.  Once the DCC system was hooked up and conversion of my locomotive fleet began, the two RS-3s were retained in DC mode for track testing, and for operation at shows.  Now that the layout is fully operational, it is time to build some RS-3s which can operate on the layout.


The Prototype

In 1977 the British Columbia Railway operated 17 MLW RS-3s and two ex-LS&I ALCO RS-3s.  I elected to model three locomotives each from a different series for a little variety.

PGE 567 was one of eight PGE RSC-3s received new in 1951-1952 and re-trucked to B-B circa 1954.  Later modifications included an enlarged fuel tank and carbody filters.  This series was distinguished by the rectangular front auxiliary headlight housing.  I chose 567 because it was still in PGE livery in 1977:




BCR 570 was one of three PGE RS-3s purchased in 1953; this series came with larger fuel tanks and later received the carbody filters.  They had a twin auxiliary headlight housing on the front end:




BCR 574 was one of three PGE RS-3s delivered in 1954.  This series had larger longitudinal fuel tanks, carbody filters, and twin auxiliary light housings on the front and rear ends:




New Models
The arrival of updated RS-3 models from Atlas/China offered an opportunity for some new models which could be converted to DCC with sound.  Briggs Models introduced a set of replacement sides in resin for the BCR RS-3s with the carbody filters, and eventually a full carbody in resin to mate with the Atlas cab and sill.  There were versions for BCR and CP Rail.  Then came a 3D printed version of the RS-3 shells, which is what I will use for my models.  At my request, Jeff produced three different versions of the BCR RS-3 shells to represent the three series I wish to model.

Here is a photograph of the three shells as they come out of the 3D printer:




The parts inside the short hood are a circular screen for the radiator fan, and the exhaust stack.  Note the support material inside the shells, which is easily cut away with sprue nippers or a sharp Xacto knife.  After doing so, I cleaned up the inside of the shells with files.

After removing the support material, the long and short hoods will join together with a slight overlap to lock them together.  This photograph shows the three shells after de-spruing.  In order to fit onto the Atlas mechanism, some material inside the cabs must be removed.  You can see that I have already done this with the shell on the left:




The replacement shells fit over the Atlas mechanism very well once this modification is made, and they mate very well with the Atlas cabs.  Here are the three models with replacement shells and Atlas cabs installed on the Atlas mechanisms:






And a few close-up shots:






I will be taking these over to show Jeff tomorrow, but I am fairly pleased with the results so far and expect to be able to push ahead on them in the coming weeks.


Tim

[Cajonpassfan]

Tim, that two-tone green has got to be one of the most attractive paint schemes ever!
Looking forward to see what you do with these😎
Otto

[craigolio1]

I’m looking forward to seeing these progress as well.

 Craig

[johnb]

Waiting for more pictures, BC Rail is my favorite Canadian road, circa 1985, when there was both paint schemes in use

[mandealco]

Tim, that was some great work you did on the old Atlas/Kato RS-3s.  Looking forward to seeing what you do with Jeff's 3D printed shells.  I have one of the CP Rail chop nose RS-3 shells from Jeff, not a pretty prototype, but some nice 3D printing.
Cheers
Steve

[BCR 570]

The two biggest jobs ahead of me with these locomotives are replacement of the pilots, and replacement of the fuel tank on 574.

The BCR RS-3s had footboard pilots and the correct versions are available as resin parts from Kaslo Shops.  The longitudinal 1200 gallon fuel tank is available as a kit from Kaslo Shops, and Briggs Models also has one.  Seen here from left to right - Kaslo Shops pilots, Kaslo Shops fuel tank, and Briggs fuel tank:




The installation of the pilots will require sanding away the original pilots and gluing the Kaslo ones on.  The fuel tank is a different matter.  The replacement tanks are narrower than the Atlas part (as they should be) and the mechanism will have to be milled down to accept the narrower tank.  I did this with my RS-10s and RS-18s but they ride on the older Atlas/Kato mechanisms.  The newer Atlas/China mechanisms use the contact strips, and milling the frame to accommodate the new fuel tank will mean losing  the contact strips:




Not sure exactly how to proceed with this just yet; more thought required.

Tim

[mandealco]

Hi Tim
Thanks for the kind words in the Weekend thread about my RS-3.  As you will see from the following photo, the fuel tank on the CP RS-3 is simply 2 pieces of angled styrene on the shaved frame.  Works easily on the older chassis but doubt if it will be much use on the Atlas Classic version.  Hopefully the photo may inspire an idea.  The other option is to do away with the contact strips as they are and modify them as discussed on another thread.  Not a lot of room for that in this case, but it may work.


Cheers
Steve

[BCR 570]

Hi Steve:

Thank you for your post; yes I am thinking that the strips will likely have to go and b replaced with flexible wire down to the tabs on the trucks.  I have seen this work well; first on the initial M-420 Jeff built, and most recently on the newest iteration of the Atlas C-630.  I will have to go this route with replacements of my RS-10s and early RS-18s as well as the M-420s so it is probably time to climb that mountain.

Tim

[BCR 570]

After meeting with Jeff this weekend and seeing his use of the flexible wire connection to the trucks on his SDL-39 model, I have opted for the same with 574.  He has a method for ensuring adequate truck swing so I have entrusted this task to him, and he will also print a suitable fuel tank for me.

The next most challenging job with these locomotives is removal of the molded pilots on the deck/sill assemblies.  In order to fit new footboard pilots, the existing pilots must be filed away back to the nearest end of the steps.  The trick is how to do this and keep everything square.  I opted to try using my NWSL True Sander in this application but had to find a way to keep the deck stable and square against the sanding block.  (the decks are quite flexible and not easy to hold steady for this purpose.)  I built a styrene jig to hold the deck level and square against the sanding block:






I made sure that the jig itself was square and that it held the deck at a perfect right angle so that I could rely on the block to keep the deck square against the sanding block.  I also made the jig large enough so that it was easy to hold during all the sanding.  It was then just a matter of working slowly and methodically, taking care to keep the jig and sanding block steady, and checking my progress frequently as I sanded away:




After a few hours I had all six pilots removed, and I had nice smooth and square surfaces on which to mount the replacement pilots:




My next step is to fill in the back  of the top step in each stepwell, which is open on the models and closed on the prototypes.  I will then mount the replacement pilots, prepare them for the couplers, and install the various details such as cut levers and trainline air hoses.  I am really glad to have this job behind me, especially as it went so well.


Tim

[craigolio1]

Great job Tim!  I love the sanding jig. Looking forward to seeing this progress.

Craig

[BCR 570]

A little more progress with the back of the top steps now filled in.  A strip of .040" styrene was not quite tall enough so I had to take strips of .060" styrene and cut them down to fit.  This was a bit of a hit and miss exercise and it is very fiddly to file parts this small down to correct size.  Eventually I had enough of the right size and glued them in place with plastic cement:




I installed them long and then cut them down to near correct length, and then filed them back flush with the outboard edge of the steps:




The decks are now ready for the installation of new pilots.  Initial test fits with the Kaslo Shops pilots indicate that they are in fact too tall for these models, and will potentially contact the rails.  Jeff is working on correctly sized pilots for the Atlas/China RS-3s which will also incorporate a few detail corrections for the RS-3s from the RS-18 pilots.  When those arrive I will prepare them for installation of the details and then get them mounted.

All for now,

Tim

[BCR 570]

While I have been working on removal of the original pilots, Jeff has been working on replacement of the fuel tank for 574 and the requisite frame and mechanism modifications.  He began by rendering and 3D printing an accurate 1200 gallon longitudinal tank, and then milling the frame halves to accept the new tank.  Essentially this requires removal of the four outside blocks which retain the copper contact strips in place.  After they are gone, a little more filing and the new tank is a snug press fit on and off the chassis:






Once the fuel tank has been mounted successfully, the next step is to restore the lost pick-up from the trucks.  The solution is to solder super flexible wires to the tabs on the trucks and run them up to contact the frame.  This has to be done in a way which will still allow the trucks to swivel back and forth freely.  Jeff attached the wires to opposite sides of a piece of insulating styrene which slides in between the frame halves.  The advantage of this system is that the interface with the frame can drop out with the trucks if they need to be removed for any reason (like when it is time to modify the frame halves for decoder and speaker installation).  This is difficult to photograph, but this view should show the wires coming up from the trucks:




This is the front end view illustrating the styrene insulation between the frame halves, and the truck swivel:




And the same idea at the rear end:




And here is the modified mechanism with new fuel tank and new pick-ups:




I will take it for a test run at the train show in a few weeks, and try and get a video of it running.  A big thank you to Jeff for conquering this challenge for me.


Tim

[BCR 570]

The three replacement body shells have been primed and sanded, and the lights and pre-drills for details have been drilled out.  The shells were printed in black resin which has yielded the best prints to date, but makes it hard to see details.  Now that the shells have been primed, there is a world of details to be seen.  The new shells incorporate the carbody filters and modified doors, and the large headlights and auxiliary lights specific to the BCR units, which will save me a lot of difficult work.

Front left oblique view - from left to right 567, 570, 574:




Rear right oblique view - from left to right 567, 570, 574:




These are now ready for the addition of the exhaust stacks which are provided with the shells, and the required detail parts.


Tim

[mmagliaro]

This is very neat work, Tim. I just caught up on this thread and read through the whole thing. I have a suggestion about the styrene contacts. I think a piece of 2 sided PC board would be a perfect fit, and easier to make. But I really like the idea of the shim so that the trucks can still be easily removed!

[BCR 570]

This is very neat work, Tim. I just caught up on this thread and read through the whole thing. I have a suggestion about the styrene contacts. I think a piece of 2 sided PC board would be a perfect fit, and easier to make. But I really like the idea of the shim so that the trucks can still be easily removed!

Thank you, Max, and an interesting suggestion.  Not sure if I have any PC board lying around, so might get some next trip to the electronics store.


Tim