The Mysterious Case SI

A 1948 Case SI with Steel Wheels and a Two-Speed Winch Drive is this the Only Survivor From a Run of 100?

| March/April 2003

  • Kirk Unzelman's 1948 Case SI
    Kirk Unzelman's 1948 Case SI, serial number 5212750, after restoration.
  • Case SI's Original Build Card

  • Magneto

  • Case SI Two Position Pan Seat

  • Belt Pulley Kirk

  • Evans Winch Gearbox

  • Old Abe

  • Kirk Unzelman's 1948 Case SI
  • Case SI's Original Build Card
  • Magneto
  • Case SI Two Position Pan Seat
  • Belt Pulley Kirk
  • Evans Winch Gearbox
  • Old Abe

I have restored a wide variety of antique farm equipment in the last few years, and each project has given me the satisfaction of seeing a proud and sturdy piece of machinery put back to shape performing its original function. Except for one item: A 1948 Case SI tractor.

It's not that the restoration didn't go well, because it did. After a lot of cleaning, fabrication of missing parts, painting and carburetor and clutch work, the tractor looks and runs just fine. The problem is I can't figure out what it was used for, and I'm hoping an alert Gas Engine Magazine reader will be able to fill me in on the details. But first, some background.

The Case SI

I found this tractor in the vicinity of Mt. Rainier in Washington. The seller had bought it from someone who had tried to use it as a garden tractor, with understandably poor results. After getting it home and cleaning it up, I found that it was a 1948 Case SI, serial number 5212750. It sits on spoked steel wheels, the rears wearing extension rims fastened with cleats, and it doesn't have a three-point hitch or a PTO - and it doesn't have a belt pulley, either. Instead, at the pulley location there is a two-speed gear box, which has this imprint:

A copy of the Case SI's original build card, which confirms the tractor was equipped with steel wheels and was shipped to the Evans winch company.

The Case SI as found. The original silver paint, as well as some of the original decals, is still visible. Note the adjustable, two-position pan seat.


The original paint appears to have been silver, with decals - my research shows the SI usually shipped with the traditional Case Flambeau red/orange color, or occasionally olive drab. Further, the tractor has a very prominent 'Old Abe' eagle cast into the differential housing, and a very prominent 'CASE' embossed into the radiator housing.

I have found mention that some steel-wheeled Case SIs had winches, but all the ones that I have investigated have had PTO-powered winches, while mine seems unique in having a winch (or other accessory) powered from the pulley shaft. In my discussions with other tractor enthusiasts, I have heard many suggestions about the possible uses of tractors of this type, including; a lumber mill tractor, a foundry tractor, a barrage balloon tractor, a loader tractor, a beach tractor and others. The rear wheel extensions are sometimes referred to as 'sand wheels' and may indicate the tractor was intended for use on the beach or sandy or soft soil.

Researching this tractor, I found that while the Case S family (including the agricultural SC) was quite popular, Case produced only about 4,800 SIs between 1941 and 1954. In the first few years of production they had a heavy leaf spring on the front end and a rounded grille, while in later years they used a rigidly mounted I-beam axle and a flat grille, like mine. For 1948, production of this tractor was a mere 450 units.

My research got a real boost after I contacted the Case factory and the staff there located and sent me a copy of the 'build card' for my Case. The card says that the tractor was manufactured on May 20,1948, and confirms that it was equipped with steel wheels when built. It was shipped the following day to the A. L. Evans Winch Co. in Gloucester, Va. The staff also told me my tractor was one of 100 identical units shipped to Evans the same day and on the same order.

In addition, the Case factory was able to provide operation and parts manuals for this tractor, and the parts list includes page of parts specific to the 'Evans' tractors, but with no explanation of its purpose. So far, I have not been able to find any information about the Evans Winch Company.

View of the magneto side of the Case. Note the extension rims on the rear wheels, which are held on by the cleats only. The tractor was supplied with a hand crank, in addition to having an electric starter.

The lack of a 3-point lift and PTO shaft, and the unusual brake rigging running across the back of the tractor, identifies it as an industrial type. The absent PTO makes room for a large cast image of the famous Case 'Old Abe' eagle. The dashboard, steering wheel and fuel tank are identical to the Model SC.

Close up shot of the Evans winch gearbox mounted where the belt pulley would usually go. The gearbox is a two-speed with neutral. The original shift lever had a welded extension, which has been removed.

Close up shot of the belt pulley Kirk fit to the Case SI by using a chain drive from the winch gearbox. Kirk found an old Case pulley and used a pair of flange-mount pillow blocks to support the shaft. A #60 chain and a pair of sprockets transmit the power, and the two-speed gearbox gives a choice of pulley speeds.

Steel Wheels in 1948?

Now we get to the real puzzle: Why would a 1948 tractor ship with steel wheels? Why were 100 identical tractors made? If there was a special application, what was it? Was the winch gearbox used for a winch, for a sweeper, a loader, a crane or some other purpose? There was a tractor known as the Case SI Airborne, and some hard-rubber-tired SI tractors were used as airport tugs. I have also seen some tractors of this era with winch-operated cranes mounted on the front end. In addition, Case made a hydraulic loader tractor they called the Model 30 Powerloader, which used the SI as the power unit - but none of these seem to match my tractor.

One speculation is that these SI tractors were sent to Gloucester to be fitted with the winches, and then shipped to a single, large customer. But 100 tractors seem like too many for a farm - or even an industrial outfit - and I think these might have been built for government or military use. There are a number of Navy installations near Gloucester, and these tractors could have been destined for one of those bases. And how did this tractor end up in Washington state? I still don't know.

The Rest of the Story

I couldn't stand to see the winch attachment go unused, so I added a sprocket to the winch gearbox and built a shaft support on the front of the tractor. The shaft has a sprocket at one end to carry the chain from the gearbox, and a nice, wide belt pulley at the other end so I can run any belt-powered implements I have. By coincidence, the belt pulley is an original Case unit with the 'Old Abe' emblem cast in the spokes. I also built up a safety guard and fabricated another Case logo and eagle emblem from steel to give it an authentic look.

Now that it's finished, my Case SI is capable of doing some useful work again, but I am looking forward to hearing from anyone who knows the original purpose of the Evans winch attachment.

The Origins of 'Flambeau Red' and Decoding Case Serial Numbers

Flambeau Red

In 1939, the J. I. Case Co. announced a series of new tractor models carrying a strikingly different color from the previous drab gray. The new color was called 'Flambeau Red,' a name taken from a Wisconsin river, the Flambeau, which was home to the legendary eagle Old Abe, who became Case's trademark. Flambeau is French for a flame or a type of torch that burns with a bright red glow. The color remained a distinctive color for Case for over a decade.

Decoding Serial Numbers

From 1939 to 1956 Case tractors used serial numbers with the date coded in. For six-digit numbers, decode by using the first and fourth digits of the number as the starting point, then subtract three to get the final date. For seven-digit numbers, take the first two digits of the number as the starting point and subtract four to get the date. For my tractor, the number 5212750 gives 52 for the first two digits. Subtracting four gives 48, giving the build year as 1948.

Kirk Unzelman has been, at various times, a cowboy, rancher, farmer, army medic, truck driver and mechanic. Contact him at: 4635 130th Ave. S.E., Bellevue, WA 98006


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