Briggs Models MLW RS-10 & RS-18 New Build Thread

[BCR 570]

Introduction
This new build thread replaces the earlier one as the new kits have rendered much of the previous thread no longer relevant.  In this new thread I will also be including the RS-10s which are very similar.

RS-10 Prototypes and Older Models
The Pacific Great Eastern Railway purchased eight RS-10 locomotives from MLW; these were mechanically similar to the earlier RS-3 units but were housed in a high hood carbody.  All remained in service until the mid 1980s, but six were modified during the 1970s for yard service with the short hood cut down.  The other two units retained their high short hoods until the end of their careers.

Years ago I modelled one of the high hood units and one of the chop nose units using the old Atlas/Kato RS-11 models as starting points.  A lot of work was required to create accurate bodies, including filling the corner notches, plating over the carbody filters, replacing the aftercooler intakes, and adding a host of details.  The chop nose unit required cab windows and headlight/number board housing.  Resin parts from Kaslo Shops were used for the fuel tanks and pilots.

Here is a photgraph of BCR 581 in the 1970s:




And here is a very old photograph of my model prior to painting for illustration of construction:




BCR 584 was one of six modified for yard service with the rear short hood cut down:




And here is my model, again prior to painting for illustration of construction:



After painting they looked like this:




My plan is to build replacements for these two locomotives using the newer Atlas/China RS-11 mechanisms and the new 3D printed shells and parts which Jeff Briggs has produced for me.


RS-18 Prototypes and Older Models
The Pacific Great Eastern purchased a total of twenty-nine RS-18s in seven batches between 1957 and 1966, resulting in numerous design changes between successive batches.  All twenty-nine units survived into the British Columbia Railway years, and during my chosen era of 1977 were either still in the PGE two tone green with map herald scheme, or the first BCR two tone green with dogwood logogram scheme.  In 1990 BC Rail embarked on a program to rebuild the fleet with Caterpillar engines and they continued to serve the railway until the CN takeover in 2004.

Modeling the RS-18s has been a significant challenge; while the ALCO RS-11 models have provided a suitable chassis, a lot of work was required to create an accurate body for the early models.  With their mix of high and low carbody doors, the later models were even more of a challenge.  In 1985 I purchased three Atlas/Kato RS-11s from the first batch to arrive at Pacific N Scale.  They underwent a long conversion process, hampered by novice modelling skills and a lack of suitable parts.  The following in-progress photographs illustrate some of the challenges in modelling the RS-18s, including lowering the short hood, building the cab face, removing the rear battery boxes, and filling the corner notches, changing the carbody filters, aftercooler intake, pilots and fuel tanks, to name a few.  Much of the conversion work was similar to that for the RS-10s except for the low short hood and the carbody filters.  I did not attempt any of the later RS-18s with the mix of low and high doors due to the challenges involved.  I built two RS-18 locomotives based on the old Atlas/Kato RS-11 models to represent PGE 607 and BCR 613, seen here in old photographs prior to painting:






After painting they looked like this:




While the installation of TCS M4 decoders enabled my RS-10 and RS-18 locomotives to operate on a DCC layout, their tendency to stall when reversing direction was a source of some frustration.  I eventually noticed that the chassis actually shifts slightly when reversing direction, which caused the stalling.  As the process to convert the fleet to sound came along, I realized that these units would not be suitable candidates for conversion, and after seeing the difference in performance between 1985 models with early decoders and 2004+ models with LokSound, my decision to replace them was made.

After numerous operating sessions I also realized that some additional RS-18s would be nice to have, and during the last release of the new Atlas/China ALCO RS-11 model, I acquired four for future conversions.  I have subsequently decided to model a fifth and have sourced another Atlas/China RS-11 from the last run when possible.  I have not attempted to build five locomotives at once before, but a batch build makes sense to me, so here we go. 

I wanted to select prototype units which were known to have operated in the north during 1977, units which represented the variety within the fleet to some degree, and units in different paint schemes.  Thanks to friend Ross Pugsley who lived in Fort St. John and took many photographs of the railway during my time period, I have some nice reference photographs to work from.

BCR 602 represents the first four units which were delivered as high short hood, long hood forward.  (All subsequent units were delivered as low short hood forward.)  In 1977 601-604 were still with high short hoods and were operating up north.  602 had been repainted into the BCR scheme and is pictured here at Fort St. John in 1977:




PGE 607 will be a direct replacement for my older model.  It belongs to the first batch of low short hood units.  It remained in the PGE map scheme well into 1978 and in addition to working on the Fort St. John Subdivision was also photographed on the Dawson Creek Subdivision:




BCR 613 will be another direct replacement for an older model.  It is from the second batch of low short hood units and has a different dynamic brake grid arrangement on top.  Like 607 it has the earlier style carbody with even height doors, and the earlier 1200 gallon rectangular fuel tank.  In 1977 it had been repainted into the BCR dogwood scheme.  I also wanted this engine because it served as helper during the Provincial Museum Train's visit to the north end in 1975.  It is seen here departing Fort St. John in 1977:




BCR 617 sports the later style of carbody with a mix of high and low doors, and a revised filter arrangement.  It also carries the later 1600 gallon fuel tank with angled sides.  It was photographed on the Fort St. John and Dawson Creek Subdivisions during 1976-1978.  In this 1978 photograph it still sports the original pilots with MU retainers:




PGE 628 belongs to the last three units delivered; these were distinguished by their winged snow plows similar to those seen on the C-630Ms, M-630s and M-630Ws.  628 was one of the last RS-18s to wear the PGE map scheme, seen here still holding out in November 1979:




Tim

[BCR 570]

New Models
As mentioned, my new models will be based on the most recent run of the Atlas/China ALCO RS-11, which provides the correct length chassis and correct trucks:




This exploded view shows the carbody, deck/sill assembly, and the mechanism.  The carbodies will be discarded entirely, the deck/sill assemblies will be rebuilt with new pilots, steps and handrails, and the mechanisms will be modified for the new fuel tanks, short hoods, and DC equipment:




Briggs Models has progressed from offering various cast resin parts for RS-18 conversions, to full cast resin carbodies and parts, and now to 3D printed carbodies and parts.  Following the successful release of his ALCO RS-27 and RS-36 shells with integrated decks and hoods, we discussed doing the RS-10s and RS-18s the same way.  These parts are produced on the photon printer and in a new resin, and I have to say that they are the closest to injection-molded models I have seen, so are definitely worth the upgrade from the former cast resin parts. 

A disadvantage of integrating the deck and hoods is that they will have to be masked for painting, but the advantage is a much better structural integrity; the parts are solid and straight.  In these pictures you will see that the parts have yet to be removed from the support material, and some sanding work has been done on the top curved surfaces.  The new resin drills, files and sands well.  The deck/hood units all have the correct steps and the pilots will plug onto the ends of the decks.

These are the parts for the two RS-10 locomotives, with those for high short hood 581 above and those for low short hood 584 below:




These are the parts for high short hood RS-18 602 (similar to the high hood RS-10 but with carbody filters and dynamic brakes):




These are the parts for RS-18 607 with low short hood and early style long hood:




The 3D printing process allows for easy changes where needed.  RS-18 613 had the early style long hood but with later style dynamic brake housing:




These are the parts for one of the two later style RS-18s (617 and 628) with later style long hood and dynamic brake housing:




These parts are for the 1200 gallon rectangular fuel tank at left and the later 1600 gallon angled fuel tank at right:




And these parts are for the RS-10 and early RS-18 pilots at left, and the later RS-18 pilots at right:




Jeff has prepared frets for the RS-18 handrails and other detail parts.  This is the early version for 601-604 with deck-mounted handrail stanchions:




And this is the late version for 605-630 with the sill mounted handrail stanchions:




And finally, friend Philippe Whyte has prepared for me a nice set of decals for the five RS-18s including striping, cab logograms and numbers, and number boards:




I now have everything on hand to continue with this project.  All I need now are some free evenings . . . 


Tim

[BCR 570]

The Mechanism
The latest iteration of the Atlas/China ALCO RS-11 runs very well, and provides us with the correct trucks and distance between truck centres.  The chassis is stamped 2006 and is advertised as "decoder ready" with a lighting board on top which can be readily changed out for a decoder such as the TCS AMD4.  Unfortunately, this model comes with a colossal fuel tank which will have to be replaced:




The fuel tank is easily removed from the chassis, allowing us to see how much metal is inside the fuel tank.  Note that this portion of the chassis, while fortunately beneath the motor, retains the contact strips collecting power from the trucks and transferring it to the chassis halves.  A portion of this metal inside the fuel tank, specifically that holding the contact strips, must be removed in order to fit a prototypically-sized fuel tank:




While a milling machine would work for this job, the metal is fairly soft and can be milled  by hand with a large flat file if necessary.  This work is best accomplished with the frame halves held in a vise.  Prior to undertaking the work it is best to remove the entire drive train and trucks, and then reassemble the empty frame halves.  After milling and reassembly, the underside of the mechanism looks like this:




Note that the contact strips and the metal portions of the chassis retaining them are now gone, but the Briggs Models 1200 gallon rectangular fuel tank will now fit snugly onto the mechanism.  There is a problem with the later style 1600 gallon angled tank as it is approximately 33 scale inches shorter and will not fit without the removal of more metal.  The next photograph shows the modified mechanism with 1200 gallon fuel tank in place:




For the model to run, the pick-up from the trucks to the chassis halves must now be replaced somehow.  Jeff's solution was to attach tiny super-flexible wires to the pick-up tabs on the trucks, run the wires up between the frame halves, and attach them to either side of a piece of styrene to provide the required insulation from each other.  The styrene board will likely be replaced with something a little more substantial when we come to the DCC conversion process, but for now this method of pick-up works very well.  We have seen Atlas adopt this method with the latest version of their C-630, and I suspect that when a future run of the RS-11 comes with DCC and sound, it may well have factory wire pick-up.  When installed the pick-up wires and the styrene insulator plate are hard to see:




For five of my units, the mechanism must also be milled at the front end to accommodate the low short hood.  The height of the chassis is lower than one might expect for a high hood unit due to the need to accommodate the large LED for the headlight.  This means that the front of the mechanism needs to be lowered by only about .040" in height.  Again, removal of the drive train is recommended to avoid contamination with metal filings.  In this comparison photograph, the model on the left is un-modified, while the model on the right has had the front end lowered to accommodate the new short hood:




After modifications to the mechanism and conversion to wire pick-up, we want to be sure that the model still retains its excellent running characteristics.  Prototypically accurate models are great to look at, but we want them to be able to operate well too.  The following video shows David Morgan's mechanism running with replacement fuel tank after the conversion.  It was filmed running in DC mode with an old Tech II power pack.  This set up will be used to run in the mechanisms, after which their operation should improve even further:

Dave Mackinnon has suggested a modification to the pick-up.  The plate in between the frame halves is occasionally prone to slipping and can result in a loss of contact.  Dave has suggested running the wires from the trucks up to a pair of thin metal washers which will go on either side of the insulating bushing between the frame halves.  This will guarantee continual contact between the trucks and the frame halves.


Tim

[BCR 570]

New Fuel Tanks
The RS-10s and early PGE/BCR RS-18s came with a 1200 gallon rectangular fuel tank, and the later PGE/BCR RS-18s came with a 1600 gallon angled fuel tank.  Briggs Models offers both, and this installment illustrates the assembly and fit of the latest version of these parts printed in a new resin.

The 1200 gallon fuel tank kit comprises the body, the bottom plate, air reservoir tanks, and fuel filler pipes.  Here are the main parts after de-spruing and clean-up with files:




The bottom plate fits nicely onto ledges at the bottom of the tank, and the air reservoirs clip onto locating ridges on each side.  The fuel filler pipes locate into depressions on each side next to the fuel filler gauge.  I elected to substitute fuel filler pipes by Miniatures By Eric as i had them on hand and I thought they would be more robust.  Here are the completed tanks after assembly:




The tanks fit nicely onto the Atlas/China RS-11 mechanism after the chassis has been milled to accept them:






The 1600 gallon fuel tank kit comprises the body in two halves, and the two air reservoir tanks.  The fuel filler pipes are printed on.  Here are the parts after de-spruing and clean-up with files:




Assembly consists of mating the two halves of the tank, and locating the air reservoir tanks on each side:




There were several problems with this kit.  I found it difficult to get a good joint between the two halves, and the fuel filer pipes were very delicate and some broke off during handling.  There is also excess resin inside the tank which interferes with the fit on the chassis.  Jeff is working on a revision of this kit so I have left off the replacement filler pipes for now. 

These tanks are shorter than the 1200 gallon version and also shorter than the portion of the chassis between the trucks.  Unfortunately this portion of the chassis cannot be shortened without compromising the motor so it has to protrude out the front of the tank, hence the missing front wall.  These tanks did not fit well due to excess material inside the tank and the locating ridge inside the rear wall.  Here is an attempted fit on the Atlas/China RS-11 chassis:






So I will now wait for Jeff's revisions on the 1600 gallon tank, and in the meantime will press on with the body shells.


Tim

[Iain]

Would it be possible to purchase the detail fret and 1200 gallon fuel tank separately for upgrading RS11s?  I'd like to do Carolina and Northwestern (The real C&NW  ) 11 at some point.

[BCR 570]

Hi Iain:

The 1200 gallon  fuel tanks are appropriate for some ALCO RS-11s and can be ordered as a separate part NP10 - see his catalogue list: 

http://www.briggsmodels.ca/catalog-list.php

The frets were in a limited sign-up quantity so you you would have to contact him to see if any are left over.  I do not see them listed in his catalogue but at some point hte various RS-18 parts will be bundled together as a conversion kit, at which point further frets will have to be produced.


Tim