Sunday, February 2, 2020

Upgrading Walthers 25-Ton Crane - SPMW 4049

Southern Pacific hand a small fleet of light weight, self propelled cranes for a variety of supply and maintenance jobs around the system.  Small cranes of 10-15 tons or less tended to be used around material yards to move what a couple of men could not.  The 25-ton cranes were the next step up in size, able to move more, but generally not enough to be classified as a 'wrecking crane', which could lift car-bodies out in the field, etc.

SPMW 4049 in the westward siding at Caliente.

I did this series of modifications during my early years modeling at LMRC, probably in the 2000-2004 range.  I could probably do another round of detail additions with the newer information and skills I've gained in the last 15 years by adding things like work lights, rear headlight, additional details etc... but for the time being it will stay the way it is.

SPMW 4049 Locomotive Crane

The Southern Pacific MW4049 locomotive crane (self-propelled) 25-ton crane model started as a Walthers/Train Miniature 25-Ton Brown Hoist crane and has been modified with a series of upgrades and modifications.  The crane now only seems to be available as a donkey 'grabber' on top of a 40 foot steel flatcar at Walthers.  Many of these models are still around on the used market or new-unopened stock websites, such as Ebay.

Typical stock Walthers/TM 25-Ton Brown Hoist crane - assembled, - Photo of random Ebay sale

My reference for the SPMW 4049 came from a photo in Bruce Petty's Southern Pacific Maintenance of Way book.



Rear of SPMW 4049

The Walthers/Train Miniature model is of a later model diesel crane.  The SPMW 4049 in the photograph is a updated steam crane.  The main external visual difference is the larger exhaust stack from the boiler on the steam crane.

To model the exhaust stack I cut a piece of plastic tubing of about the right size and length, mounting it to the top of the crane body with glue.


Top view of SPMW 4049 with brake wheel, stack, and roofwalks installed.

The next step in making the model look more like the prototype is adding the steel roof-walkway material to the top of the body.  I used a Tichy Train Group 40ft boxcar square-pattern roofwalk which I cut into smaller pieces to cover most of the top of the crane.  The walkway material was supported by 0.025" PB wire bent to form support frames. 

Detail view of the roof and additional details.

These frames were fitted into holes drilled in the crane body and glued in place with ACC/CA glue.  The roofwalks were then glued to the wire frames with ACC/CA glue to complete this modification.


I added clear plastic doors made from 0.015" or 0.020" material to cover the door openings in the Walthers/TM model.  The photo of the crane shows the doors closed and secured for movement.  The model has them molded open, but the interesting bit is that the doors areas on the SPMW 4049 were actually larger than the more modern Walthers crane, so having more areas of 'doors' is not a bad thing.

Right side of SPMW 4049 with new closed door.

The doors with the windows were simply made by painting the door and leaving the areas of 'windows' unpainted.

Left side of SPMW 4049 with new closed door.

Next will probably be adding 'canopy cement' or other 'gallery glass' products to put the panes of glass in around the front of the crane, which currently doesn't have any glass.

Brake Wheel

Single brake wheel is installed into the deck of the crane.

Cranes should have a hand brake to secure them from moving when not in-service or under control by a train with air-brakes.  Per the photo, I added a typical brake wheel to the top of the frame deck, under the inner corner of the crane's body, where it could be accessed from the side.  There's not a lot of room there for adding the geared mechanism which normally would be under the brake wheel, so the wheel has to be enough on this model.

Completing the Crane

The rest of assembly is completed per the Walthers/Train Miniatures instructions and typical crane rigging of the boom.  The model is finished with over-all black paint.  SPMW decals from Micro Scale complete the model with basic reporting marks.

SPMW 4049 en train behind SP 3765 on Jan 6th, 1953 exiting Tunnel 10 at Walong.  Looks like the 4049's handling some ties.

This crane is regularly now seen in company with a gondola or flatcar as a 'boom tender' as the crane's boom can not stay over the length of the SPMW 4049's frame.  The crane is often assigned various duties on the Tehachapi and surrounding Divisions handling anything from revenue unloading from flatcars and gondolas in places which don't have a overhead crane, to unloading rail and bridge girders, etc.

In Conclusion

SPMW 4049 & SPMW 1140 at Tehachapi in the clear for trains between work windows

As of this January 2020 blog post, the SPMW 4049 is assigned to track work and repairs to the Company Water System at Tehachapi, Calif. clearing up a few issues in January 1953 since the 7.5 Earthquake 6 months ago dropped the water tank.

Jason Hill

Related Articles:

Kitbashing Mystery SPMW 215 (Part 2) "Extra Gang" Crane Tender - Probably will be assigned to SPMW 4049 Walthers Crane

"Musical Chairs" Modeling of SPMW Cars - The game of parts swapping

Modeling an MOW Supply Trains (Part 1) - Overview of Supply Cars and Supply Trains

Tehachapi Operations: Part 1 - Mountain Work Train - Overview of Work Train Operations

Triple Trouble Tehachapi - A Weird Day on the Hill - A day on the work train takes a left turn at Caliente.