Thursday, July 14, 2016

SP 5199, a SC&F 69-BP-30-3 (Part1)

Well today we'll be looking over the first part of building a "Southern Car & Foundry #1001 Baggage-Postal".  Follow this link to my Railway Post Office page, which is functioning and I hope to expand it more in the future.

This is a friend's brass 69-BP-30-1.  This car was part of the Sunbeam PSC set.

The Model

This model is being built for a friend who wanted a correct model of an SP RPO for his mail train.  He considered buying a model from The Coachyard, but after talking about the mechanical changes that would be required to an expensive model for service at the La Mesa Model Railroad Club we decided it would be easier to build one of the beautiful one-piece-resin body "Harriman" head end cars by Southern Car & Foundry (link here).

SC&F kit with additional CalScale parts (190-345 Mail Hooks) & Walthers trucks.

I have built two of these models before (SP 5124 & SP 5069) and done some heavy modifications to convert them into 70-BP-30-2/3s for use with the LMRC's San Joaquin Daylight.  The 69-BP-30-series cars were about equally common as the SP's 70-BP-30-series cars, so this model was selected.

SP 5124, painted for San Joaquin Daylight service - In this view the model is about 95% complete, still needs grab irons, stirrups, mail catchers, dull cote on the roof, etc. 

History of the Prototype Car

The prototypes for this model were built for the Southern Pacific and Union Pacific in 1911-1916.  The model I will be building this kit to represent will be the last group of cars in the 69-BP-30-3 series.  Common Standard "Harriman" classes system worked in the following order: 69 (Length in feet) - BP (Baggage-Postal) - 30 (Length of Postal Apartment) - 3 (type sub class, chronologically - note;some class numbers were skipped).

Many of the cars were built for subsidiary railroads that were folded into the SP or UP systems over the years.  The 69-BP-30-3 that I'm building is the SP 5199, built on 10/24/1916 by Pullman Standard.  Electric lighting was installed on 8/22/1929.  Several of the 5199 and 3 sister cars were converted in the mid-late 1950s to Baggage-Express cars and lost their Railway Post Office (RPO) apartment space.

SP 5148 is painted in the 1947-1954 general service scheme. This will be how the 5199 will be finished.
The 5199 transitioned through two of the SP Dark Olive Green paint schemes, and then repainted into the Two-Tone Gray scheme of 1954 sometime before being converted to Baggage-Express service in November 1954 as SP 6165.

I should mention here for those that want to do these cars in other paint schemes, that two sister cars built for the Texas & New Orleans were painted in the Daylight Red/Orange scheme in 1937 for the Sunbeam.

Then in 1950 the Sunbeam changed to Simulated Stainless Steel & Daylight Red letterboard as shown here on T&NO 141.

Start with Cleaning the Castings

I started off with this kit quickly de-flashing the main one-piece body casting and cleaning out the door and window openings.  The car body is cast with plugs in the wind openings.  I carefully cut with a No.11 Xacto blade through the thin membrane of resin connecting the plugs, this allows them to cleanly fall out.  Dressing the inner edges of the door and window openings then with a file to bring them out to the correct size.

I also did some cleaning work, cutting and teasing out the membranes from the door castings.  This wouldn't really be needed until they are installed and ready to be painted, but since I had the file and knife out...  At this point I shifted to focusing on the underframe.


I usually start by working on the underframe of the car.  This is pretty easy, as the parts go together well and lets me get the feel of working with the resin again.  Any mistakes are not going to be very visible on the completed model.

I started by marking what will be the RPO end, the Baggage end, and where the mail apartment bulkhead wall is going to be located.  I mark this both on the top and the bottom to avoid any chance I'll put something on the wrong end of the car.  This does make a difference as the underbody piping crosses over at the B-end or Baggage end of the car.

I also was very careful looking at the instructions as the included drawing is up-side down mirror imaged.  This is because on the real cars, the draftsmen make the drawing as if the car is right side up and you're looking at it and standing on or in the underframe.  This has caught many modelers over the years because they think they're looking at a bottom view, when really it's a top plan view of the car.

The first step with assembling the underframe is gluing the bottom flange caps on the frame I-beams.  This is bonding resin (gray) and styrene (white), so I used a good fresh bottle of ACC for these joints.

Although the instructions say to drill the truck bolster holes now, I am going to hold off on drilling them at this time.  I will drill it later when getting ready to mate up the trucks (which have off-center bolster screws) to the body on the proper truck centers.

The train air line and signal line come next with a piece of 0.023" steel wire and 0.018" brass wire respectively.  I bent the train and signal line to shape, threading them through the notches cut in the truck bolsters, and I bend a hook in the ends so that they are firmly anchored in the end of the car while making fine adjustments to the shape as I move along the the cross members. I use a No.66 drill to make the holes in the centersills and up into the floor at the end of the car. - In hindsight, I should have had the crossover of the train and signal lines be about 2-3ft closer to the center of the car because of the big 6-wheel trucks used.

I secured the train and signal lines at several points along the underframe with a pipe hanger made from 6lb test fishing line.  These hangers are just a hole drilled in the floor and the line looped down around the pipe.  One line was fed through each hole over each pipe.  This allows me to tie the pipes up with only one piece of line per pair of hangers.

Fishing line pipe hangers.  
Next comes the unique "Harriman" diagonal underframe bracing.  These extend outward from just inboard of the truck bolster towards the sides of the car at about a 40 degree angle closer to the middle of the car.  A second set of diagonals then return from the car sides toward the centersill, closer yet to the middle of the car.  These diagonal braces form a diamond shape when viewed from below.  Where these come back to the centersill is the location of the first of three needlebeams.  I stack shim styrene up on the bottom of the floor to provide a place for the diamond braces to attach.  I carefully glue the diamond braces in place with ACC glue.

The diamond braces and the needlebeams are etched brass parts.  There are a set of needlebeams that are cast in resin, but I will use the brass ones.  The needlebeams need to be bent to connect the floor of the car on one side, stretch across under the centersills, and then back up to the other side of the floor.  From my previous builds of this kit, I know these brass needlebeams are a little bit too long, and also stray fingers in the future will likely bump the etched brass needlebeams picking up the model or while I'm building it.  I cut and file some notches in the outer edges of the floor where the needlebeams will land.  This allows me to bend the needlebeams and then bend the slightly longer tips up, forming an "L" which will catch into these notches.  ACC glue is used to secure the three needle beams.

Underframe Details

Next comes the Battery Box and the Brake Rigging.  Looking at photos of the 5199 and sister cars for placement of the brake parts and battery box, the provided cast battery box is a bit too short in length.  It is mounted under the right side of the car, just inboard of the A-end needlebeam.

A quick rummage through my passenger car detail part box yields a Soho battery box from one of the brass Soho projects I've worked on in the past.  This one has an extra bit of styrene sheet glued to the top of it, that's nice, but I've found it makes the boxes sit too low to the rails.  Later in the build, after fitting the trucks I removed the box, cut away the finely detailed cross member beams from the floor casting, and remounted the battery box flush with the floor of the car.

A photo from later in the build when the Battery Box is painted and remounted directly to the floor of the car.

The brake cylinder's a bit of a mystery as the photos don't really clearly show it.  I suspect that it's hiding behind the battery box from the view point of the photographer.  I know the brake piston end should point towards the B-end of the car.  With that worked out I glue it to the underframe, slightly towards the center of the car from the battery box.

I can clearly see the large and smaller tanks under the baggage end of the car's right side.  The control valve should be between the brake cylinder and these air tanks, but I don't see it on the right side of the car.  Also there's not much space left on the right side of the car.  Therefore it must be on the left side of the car with the brake cylinder.  There are rules specifying how far the control valve, the cylinder and the tanks can be from each other.  There are other details like the Steam Traps that I will add later to the car.

I mark out on the unpainted resin floor where the various tanks are going and then drill.  I core the air tanks and control valve fittings with No.73 drill for fitting the piping into them.  Then I drill the holes to mount the large tank with No.61 drill and overbored with Xacto #11 blade.  The smaller air tank was likewise glued together and a small hole drilled for it to mount.

Mounting the Trucks

I do some rough fitting of the truck to the body bolster of the kit.

Check clearances also for the center wheelset, truck sideframe screws, train & signal piping as well.  I notice that the crossover piping was about one or two crossframes too close to the bolster, and may foul the flanges of the inboard wheelset.  The cast bolster cap pieces installed on the underframe also are going to interfere with the truck's side snubbers.

The Walthers HW 6-wheel trucks are a bit odd in their mounting holes for their passenger cars.  I usually elect not to use the cast-in holes on custom installations.  Instead I offset a new hole in the solid end of the truck's bolster.

This particular truck is one of the W-106 series trucks, which has a very high snubber on the outer parts of the truck.  On the SC&F model the full bolster details requirement to cut the top 0.03-0.04" off these snubbers.

I also file down the raised arch of plastic over the top of the center axle.  This will make a level place for the body bolster to ride on the truck.  This is one of the most critical parts of rebuilding a passenger car bolster and truck assembly.  Make absolutely sure the car body is true and square with the truck.  This will ensure the weight of the car is transferred evenly to the truck, and from the truck then to the rails.

Back to the body bolster modifications, I measure a scale 15" outboard off the centerline of the body bolster on the underframe of the car and scribe a line on each bolster.  This will be where the offset holes for the trucks will be located.  You can really use any dimension you want here as long as it is copied when you drill the new hole in the truck bolster.

I cut two sections about 0.25" off a of 0.125"x0.250" styrene strip.  These will be the actual bolster blocks the car body will ride on.  I don't like the fit of the new body bolster block with the kit resin bolster detail piece.  The block is not able to be centered well on the 15" offset future hole location.  This means I'll either need to step the new bolster block to fit over the resin bolster details, or cut back the resin part.  It's better not to mess around with finicky fit issues in regards to the squareness of the bolsters of a car if you can avoid it.  I cut back the resin bolster parts about 0.05" about where the row of bolts are on the resin part.  This allows the new bolster block to sit nicely centered around the 15" offset mark, where the bolster screw hole will be drilled.

I remark the centerline of the car and also the scale 15" offset for the new bolster screw hole.  I drill it for 2-56 tap and clear-drill the plastic bolster block so the threads only engage in the car floor.

In Closing

Additional light filing was needed to true up these bolster blocks to level and square with the underframe of the car.  Also visible is the cuts in the resin bolster piece for the center wheel flanges to get clearance.  I will do additional shimming of the truck later to help get the right coupler height.  But we'll save that for the next part in the blog entry for the SP 5199, 69-BP-30-3 (Part 2).

Jason Hill

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  1. This is fantabulous, Jason! So great to have you do this. Looking forward to more great stuff.

    George Corral
    La Grange, KY

  2. The diagrams and instructions from SC&F are good but not as clear as what you have presented. They should make reference to this site for further clarification.

  3. Here it is in 2023...I have purchased one of these cars from the SC&F rerun. I have th trucks and brake set ready to go. But it has been stuck in the "pile" as I have so many other projects. The priority exists pretty far along side other passenger car and engine related projects. Layout revisions and finishing the mainline strait side tracks come ahead of it as well as LocoFi for steam engine projects. Also, I will paint it in the general service scheme even though I could use one on a San Joaquin. I'm no longer air brushing any models and would not attempt a daylight scheme with my acrylic brush techniques.

  4. OOPs...Ken Adams, Walnut Creek, CA


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