Overview:

Back in November 2024, the Museum acquired a pair of WWII-era Clarktor 6 aircraft tugs from Larry Kelley's Delaware Aviation Museum Foundation. The two, 'well-loved' tugs had only recently been taken offline, but it was clear they would need a generous amount of TLC to make them fully operational again. We had the two tugs trucked directly from their former home at Delaware Coastal Airport in Georgetown, Delaware to our chosen restoration shop, Oehme Brothers War Horse Garage near Lititz, Pennsylvania.

The Museum's two Clarktor 6 aircraft tugs loaded aboard the flatbed in Georgetown, Delaware. They were shipped directly from that location to the Oehme Brothers War Horse Garage in Lititz, Pennsylvania where they are presently undergoing a down-to-the-last-nut restoration.
The Museum's two Clarktor 6 aircraft tugs loaded aboard the flatbed in Georgetown, Delaware. They were shipped directly from that location to the Oehme Brothers War Horse Garage in Lititz, Pennsylvania where they are presently undergoing a down-to-the-last-nut restoration.

When we bought the tugs, we weren't quite sure which specific models we had on our hands, as both of them had a variety of non-standard modifications. We knew very little about their past service lives either. Larry Kelley told us that he had acquired them as military surplus; one from Dover Air Force Base, in Dover, Delaware and the other from NASA Wallops, the former Chincoteague Naval Auxiliary Air Station on Wallops Island, Virginia. However, we had no idea when they might have arrived for service at these locations. If we could determine the vehicle serial numbers, then perhaps that might give us a clue.

NAAS Chincoteague circa 1947
NAAS Chincoteague circa 1947
Dover Air Force Base soon after the airfield was reactivated in 1951. This base is one of the most important heavy cargo air stations in the US Air Force currently, and has grown enormously in the intervening three-quarters of a century.
Dover Air Force Base soon after the airfield was reactivated in 1951. This base is one of the most important heavy cargo air stations in the US Air Force currently, and has grown enormously in the intervening three-quarters of a century.

Tug Details:

Once the tugs arrived at the War Horse Garage, their restoration team was able to determine each vehicle's specific model type and factory construction number. It turns out that the example which purportedly once served Dover Air Force Base is a Mill 33, while the one from NASA Wallops is a Mill 44. The only significant difference between these two variants is that the Mill 44 has a different aft bumper and a beefier powertrain with a four-wheel rear axle, which provides it roughly 30% more pulling capacity than the Mill 33. Their construction numbers proved to be an important find for us too, as with that information we were able to obtain the correct 'build sheet' for each tug.

Build Sheets:

Amazingly, microfilm copies of the 'build sheets' for our vehicles still exist in an archive which the Oehme brothers have access to. The build sheet essentially documents the design features a customer has paid the manufacturer to install on their tug during its assembly. It lists myriad details, such as what kind of headlights to use, the axle, wheel and tyre types, engine, carburetor, etc. ...all the way down to what kind of starter switch to provide. These data will prove invaluable to the restoration team as they determine what each vehicle needs during its rebuild.

From a historical perspective, the build sheet also lists the date when the factory shipped the vehicle to the customer, along with its initial destination. While both tugs proved to have post-WWII delivery dates, their designs are identical in every way to those manufactured during that global conflict.

The build sheet for our Clarktor Mill 44 tug which once served at NAAS Chincoteague and then NASA Wallops. While the microfilm image is rather fuzzy, it is possible to read all of the various items which the tug left the factory with in February 1949. (image via Oehme Brothers War Horse Garage)
The build sheet for our Clarktor Mill 44 tug which once served at NAAS Chincoteague and then NASA Wallops. While the microfilm image is rather fuzzy, it is possible to read all of the various items which the tug left the factory with in February 1949. (image via Oehme Brothers War Horse Garage)

Mill 44 Construction Number CM 44 49 54:

The build sheet reveals that Clark shipped this tug from their factory in Battle Creek, Michigan to Naval Supply Center Penniman in Yorktown, Virginia on February 2, 1949, with the customer being the "Officer in Charge, Cheatham Annex". That facility is still in US Navy hands today, albeit as part of Naval Weapons Station Yorktown. When we acquired this tug from Larry Kelley, as noted earlier, he said that he had bought it surplus from NASA Wallops Flight Facility on Wallops Island, formerly the site of Naval Auxiliary Air Station (NAS) Chincoteague - just a short ferry ride across the Chesapeake Bay from Yorktown. It seems very likely, therefore, that our Mill 44 served initially at NAS Chincoteague and remained at the airfield when NASA moved in during 1959.

According to War Horse Garage, the tug is very complete other than the engine hood side covers, which they will refabricate in-house. It even retains much of its original "Haze Grey" paint.

The Museum's ex-Navy/NASA Mill 44 tug inside the Oehme Brother's storage shed prior to work commencing. Note that the engine compartment is missing its side panels; these will be refabricated and installed during the vehicle's restoration.(image via Oehme Brothers War Horse Garage)
The Museum's ex-Navy/NASA Mill 44 tug inside the Oehme Brother's storage shed prior to work commencing. Note that the engine compartment is missing its side panels; these will be refabricated and installed during the vehicle's restoration.(image via Oehme Brothers War Horse Garage)

Mill 33 Construction Number CM46140: 

The build sheet for this vehicle reveals that the factory shipped it to a facility under the management of General Motors' Buick-Oldsmobile-Pontiac Assembly Division in Wilmington, Delaware on July 30, 1946. Wilmington was just 50 miles by road from Dover Army Airfield (now Dover Air Force Base) in Dover, Delaware, so it seems likely that our Mill 33 spent its entire military career at this location, since this is where Larry Kelley acquired the tug as surplus equipment.

According to War Horse Garage, our Mill 33 has most of its original fittings, but it has been modified over the years. For one, the front fenders and running boards were replaced at some point with crudely made home built examples, and the front bumper has been cut to accommodate a set of internal headlights to replace the original units once mounted on the hood. The vehicle's front has also had a long pintle hook welded on in place of the hitching system the tug initially came with.

The Museum's Mill 33 sitting in the Oehme Brother's storage shed soon after the aircraft tug arrived. Note the incorrect headlight and tow hitch modifications. These will be rectified during the tug's restoration. (image via Oehme Brothers War Horse Garage)
The Museum's Mill 33 sitting in the Oehme Brother's storage shed soon after the aircraft tug arrived. Note the incorrect headlight and tow hitch modifications. These will be rectified during the tug's restoration. (image via Oehme Brothers War Horse Garage)

A closeup showing the cutout for the internally mounted headlights in the Mill 33. This damage to the fender will be corrected, and type-appropriate headlights will be returned to the hood, as per the original. (image via Oehme Brothers War Horse Garage)

Note the crudely fabricated replacement front fender and running board on our Mill 33. These inaccurate parts will be replaced with bolt-on originals of the correct variety. (image via Oehme Brothers War Horse Garage)

The front fenders and running boards for our Mill 44 are of the original design, and will be replicated to replace the homemade examples on our Mill 33. (image via Oehme Brothers War Horse Garage)

The Mill 33 has incorrect wheel hubs and tires, which will be replaced by NOS (New Old Stock) examples from the Oehme Brothers' stockpile. (image via Oehme Brothers War Horse Garage)

The correct type of wheel and tire which our Mill 33 needs. (image via Oehme Brothers War Horse Garage)

What appears to be a Clarktor Mill 44 in operation during the Korean War. Our former US Army Air Forces Mill 33 will likely end up painted similar to this example. Note that its headlights are mounted to the hood, unlike ours, which which had a crude modification to make them shine through the front bumper. The restoration will rectify that issue.
What appears to be a Clarktor Mill 44 in operation during the Korean War. Our former US Army Air Forces Mill 33 will likely end up painted similar to this example. Note that its headlights are mounted to the hood, unlike ours, which which had a crude modification to make them shine through the front bumper. The restoration will rectify that issue.

The Restoration Process:

These tugs will be fully refurbished and returned to the configurations in which they initially entered service, albeit with minor modifications to improve their maintainability and operational safety. The restoration team has already separated each vehicle into its major component parts, sandblasting the bodywork and frames down to bare metal for repairs and repainting. The engines are presently in a local shop being prepared for rebuild. We expect to report on more progress sometime soon!

 

A side view of our Mill 44 tug as it looked part way through the strip-down process, with the engine, transmission and all of the superstructure removed. Note how the original "Haze Grey" paint still survives on most of the structure, with surface corrosion poking through in areas. (image via Oehme Brothers War Horse Garage)
A side view of our Mill 44 tug as it looked part way through the strip-down process, with the engine, transmission and all of the superstructure removed. Note how the original "Haze Grey" paint still survives on most of the structure, with surface corrosion poking through in areas. (image via Oehme Brothers War Horse Garage)

Our Mill 44 tug as it looked part way through the strip-down process with the engine, transmission and all of the superstructure removed. (image via Oehme Brothers War Horse Garage)

Another view of our Mill 44 tug as it looked part way through the strip-down process with the engine, transmission and all of the superstructure removed. The rear differential is still in place, but will receive a full overhaul, as will each of the other mechanical parts in both vehicles. (image via Oehme Brothers War Horse Garage)

The engine and transmission for our Mill 44 tug soon after it was removed from the vehicle. The assembly is currently at a local engine shop being prepared for overhaul. (image via Oehme Brothers War Horse Garage)

A pair of radiators for eventual use in our Clarktor 6 aircraft tugs. (image via Oehme Brothers War Horse Garage)