Monday, September 13, 2021

SPMW 7021A (Part 1) Wrecker - Rail & Tie Car

This is a repost of the SPMW 7021A, which was the last car in my Kitbashing OwlMtModels F-50-Series Flatcars (Part 1) article.  I've done some more work on this project, so look forward to SPMW 7021A (Part 2) Wrecker - Rail & Tie Car.

SPMW 7021A after 1958 repaint into light gray. - David Willoughby collection.

SPMW 7021A - Rail & Tie (switch) Relief Car

This is going to be my 'New' OwlMtModels replacement for assignment to the Bakersfield Wreck Outfit, replacing my 15-20 year old kitbash using a Walthers/TrainMiniature flatcar.  Originally F-50-5 class, SP 41224, the prototype car was converted to MW service at Bakersfield for the Wreck Outfit on the 19th of October, 1939, showing as a Tool car in the Derick Tender (DT) catagory.

My original SPMW 7021A, with scratch built over-deck rack.  I'll be trying to do a better job of this with the new build.

While the Tie-Rack on my original Walthers/TM SPMW 7021A was a blast to build, the new one will be built without any good side shots of the car from Bob's Photos, only three 'over spray' photos of the adjacent cars in the Bakersfield Wreck Outfit show the last couple of feet of the 7021-A.

Yes, this is SPMW 7021B, however at the far left you can see the end of SPMW 7021A! - Eddie Sims collection

As the car was converted in 1939 and I don't have a good photo of the the sides of the car to see which brake system it had on it, I'm selecting the K-brake system for the SPMW 7021A.  Many revenue cars kept the K-brakes past the replacement date for interchange of 1953, into 1955 being used on the SP and its subsidiaries.


The changes to the basic body of the 7021A will be mostly from  involve removing many of the characteristic sub-deck support blocks, but not removing the stake pockets.

SPMW 7021-A with marked Deck Overhang for removal.

The first step I took on the deck modifications to the 7021A is removing all of the overhanging deck sections.  I went ahead and mounted the underframe centersills and some of the cross-beams below the weight cover.

SPMW 7021A Underframe detailing

I went ahead and put on some of the rest of the underbody assembly before cutting off the Sub-Deck Blocks.

SPMW 7021A K-brake brakets, Kadee 0.015" Red Truck Washer.

Vulcan Truck Changes

The photos of SPMW 7021A that I do have show it to have Vulcan Trucks, so I'll be changing out the T-Section Red Caboose trucks for Kadee Vulcan Trucks (KD-573).

Vulcan Truck Kadee-573 assembled with the clip on the screw to keep it together.

I'm using one of the new 'HGC' versions of the Vulcan truck, not the older cast metal sideframe version with the very fine wire springs, which create a un-prototypical see-through look to the spring package in the truck.

Kadee Truck Collars, on the left is stock version, on the right is the shortened version, cut down by 0.035"

I've modified the bolster hat collars to allow the trucks less rocking left-right, but still able to turn, per-LMRC standards.  I also installed the height shims for the Accurail trucks provided in the OwlMtModels kit, although these are shaved down to only be the shim, and allowing the KD collar to form the center bushing.

In the end I gave up on using the Kadee collars, and used the OMM Hat-shim pieces instead, as directed for use with Accurail trucks.  The Kadee truck frames were glued up rigid with ACC and allowed to dry square on a flat surface.

Modifying Subdeck Blocks

I scribed the top and bottom with a No.11 X-Acto blade, then easily cut them on the score marks with my fine P-B-L flush-cutting sprue cutters.  A quick few passes with a mill file clean up the remaining board ends, even with the inner edge of the Stake Pocket cut-outs.

The completed narrowing of the Deck Boards.  End gaps will be rescribed later.

The process of cutting out the sub-deck blocks is fairly easy to do by scribing with an No.11 blade along the edge of the narrowed deck between the stake pockets.

Process of removing the Sub-Deck Block - left to right, block, scribed block top, scribed through block and removed.

Continue the scribes, until the block is loose.  Try not to carve away the stake pocket mounting rivets or the stake pockets themselves.  The SPMW 7021-A didn't have any of the L-brackets under the blocks left, so I'll take the whole block down to the sidesill frame.

High-angle view of the SPMW 7021A with Sub-Deck Blocks removed.

Here's two photos of the car with the Deck overhangs and Sub-Deck blocks removed.

Side view of the car without the Sub-Deck Blocks and upgrade to the Kadee Vulcan trucks.

As with the other two projects, this completes the main body kitbashing to the SPMW 7021A.  The next major steps of this kitbash will be building the new over-deck Tie Rack.

Building Bulkheads for Rack

Plugging the inner end stake pockets

As the flatcar deck is going to be covered by the tie rack, the inner stake pocket should be plugged with some strip styrene.

Plugged deck stake pockets and some side stakes shaved off.

I roughed some 0.010" styrene sheet for the two bulkheads... Note that these are not the same height.  The shorter bulkhead is on the B-end of the car.

Bulkheads with laminated 4x4 collision posts.

Collision posts are fabricated from two 2x4s each.  I used a strip of larger styrene as a spacer while gluing the collision posts to the bulkhead sheet.

Bulkheads coming into place.

Stake pockets in the deck are plugged, but will stand out being bright white, compared to the gray ABS deck plastic.  I removed the stake pockets next to the roping staples before installing the castings.

Otherside of the car, which has needed a bit more filling putty.

Squadron White putty used to fill in some of the gouging when I removed the sub-deck blocks on the right side of the car.

Moving Stake Pockets

Stake pockets shaved off to reposition.

After reviewing the prototype photo, it really started to bug me that the stake pockets really should be much farther apart and only 6 pockets per side.

Roughed in bulkheads

Here's the roughed in bulkheads... but I'm starting to think they are too short!  Oops!

Repositioned stake pocket

Bulkheads have exterior top chords of 0.010" x 0.060" strip glued in place.  Respaced stake pockets with 0.015" holes drilled for short pins to hold the stakes when I get them fabricated.

Other end of the car with respaced stake pockets.

Respaced stake pockets.  Grab irons and stirrups installed as well.  Weathering has also been added to the deck.

In Closing

Getting into the serious modifications in Part 2!

In SPMW 7021A (Part 2), I'm getting into designing and researching the rack dimensions, and then scratchbuilding the new tie rack.

Jason Hill

Related Articles:

Kitbashing OwlMtModels F-50-Series Flatcars (Part 1)

Modeling SPMW 7021 the Bakersfield Wreck Outfit (Part 1)

Modeling an MOW Supply Train (Part 1)

Modeling SPMW cars with Musical Parts (Part 1)


  1. Jason,
    I’ll provide a good home for those T-section trucks, if you’re not using them!

    1. Lol! Well, I actually started with a kit without trucks! Fun part of doing a car that had replacement trucks is that I can start with either kit, as the trucks usually included in the kit aren't used. Those Kadee trucks are expensive! :P

      I suspect this might actually be why everyone's been ordering our 2002 kits... to strip the trucks from! :O


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