Back in October 2024, the Military Aviation Museum acquired two ex-military Clarktor 6 aircraft tugs from Larry Kelley's Delaware Aviation Museum Foundation. We were very fortunate to have this opportunity as there is a thriving community of Clarktor enthusiasts who own, restore and operate these charismatic workhorses, making them difficult to come by.
Although our examples were manufactured just after WWII, they are essentially identical to their wartime cousins. Most importantly, however, they will offer a far more authentic experience to museum visitors watching them tow our aircraft on the ramp than the 1980's vintage tugs we presently operate. As noted in a previous article, the latter vehicles are in need of major overhaul, so it made eminently more economic sense to invest our precious resources in period-appropriate vehicles. Having representative examples with actual service-histories from both the US Navy and the US Army Air Forces made the decision easier too, since it perfectly matches the selection of WWII aircraft in our collection!
As reported in mid-February 2025, we had the tugs shipped directly from Larry Kelley's hangar at Delaware Coastal Airport in Georgetown, Delaware to the Oehme Brothers War Horse Garage in Lititz, Pennsylvania soon after we purchased them. The company is well-known for its prowess restoring vintage military vehicles, and also has significant experience both restoring and operating Clarktor 6 tugs just like ours.
The Restoration:
Over the past year, our Clarktors have undergone a thorough, down-to-the-last-bolt restoration. All of the metal parts were media-blasted down to bare metal, repaired, then coated in epoxy primer, with a catalyzed industrial top coat. All of the mechanical components received a full overhaul too, with the major items being as follows:
- engine
- transmission
- gearbox
- clutch
- rear differential
- steering gear
- radiator
- brake system
- wiring harness
Modifications:
While our Clarktor tugs were restored to their original specs, almost to the letter, but we did make a few small adjustments based upon Oehme Brothers' recommendations garnered from their long-time operation of their own Clarktor 6. These modifications were as follows:
- Redirected the engine exhaust to exit from the right side of the vehicle instead of the rear. This makes it easier to perform maintenance on the rear differential, and also much more pleasant for the operator to hook up a tow bar at the back with the engine running... no more exhaust fumes in the face!
- Modified the steering column to accept a reproduction WWII-era Jeep steering wheel. The originals were badly deteriorated and virtually impossible to replace. Reproduction Jeep steering wheels still look authentic, are easy to replace, and have the added benefit of a horn button for safer operations in a busy environment.
- Added basic engine gauges to the dash panel. These are 1940s-period gauges, not-atypical to the Clarktor 6 and will help with the long-term maintainability of the vehicles.
- Added a keyed ignition to each vehicle, in place of the push-button start, for peace of mind when the tug is unattended in the museum.
- Added a 'grounding switch' to the seat mount between the driver's legs allowing for electrical system cut-off in an emergency.
These modifications do not, in any way, detract from either tug's authentic appearance, but they will make the tugs safer to operate and easier to maintain, which are justifiable compromises to originality.Â
The Mill 44:
Our Mill 44 once served in the US Navy at the former NAAS Chincoteague, now operated by NASA as the Wallops Flight Facility. The tug was remarkably complete when it arrived, but needed a new set of engine side covers (the originals being missing) and a newly-manufactured original-style seat to replace the non-standard unit the vehicle arrived with. The vehicle was restored to approximate factory-delivered condition, although does incorporate the minor modifications described earlier in the text.
The Navy Mill 44 tug is seen in the foreground, while the Army Air Forces Mill 33 is just behind it. Note that at the time this image was captured last summer, the Mill 33 had had the appropriate type of rear wheels installed, as the ones it came with were not original to the type—and looked it. The tires on each vehicle are all brand new, period-correct examples, as the original tires were quite perished. (image by Keegan Chetwynd)
A nice view of the beautifully restored transmission, gearbox and drive shaft on the Navy tug (Mill 44). (image by Keegan Chetwynd)
The ex-US Navy Mill 44 Clarktor 6 tug following engine installation last summer. Note there is yellow tape protecting the instrument casings on the rear side of the dash. Oehme added a suite of period-appropriate engine gauges to each tug to help monitor engine health. (image by Keegan Chetwynd)
The Mill 33:
The museum's freshly-restored Clarktor 6 Mill 33 once served at Dover Army Air Field (now Dover Air Force Base) near Dover, Delaware. Like for our Mill 44, the talented team at Oehme Brothers War Horse Garage performed a top-to-bottom mechanical restoration on the vehicle. While our Mill 33 received the afore-mentioned modifications (much like our Mill 44), it required a significant amount of additional attention due to the variety of non-standard features it arrived with.
For one, the after-market rear wheel hubs and driver's seat needed replacing, as did the headlights normally mounted to the engine cover. The vehicle also required significant repairs to its front bumper since someone having cut holes into it for a set of internally-mounted headlamps—a feature alien to this model of tug. This tug also featured an extended pintle hook arrangement welded to the front bumper—another after-market modification which needed rectifying. Furthermore, the bodged-up forward running boards also needed replacing. Oehme Brothers used the original, bolt-on running boards which came with our Mill 44 as a template for fabricating a replacement set for the Mill 33.
A closeup showing the crudely-fabricated front fender and running board our Mill 33 arrived with. While functional, these inaccurate parts were replaced by freshly-replicated bolt-on units of the correct variety. (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 was corrected, while type-appropriate headlights were returned to the hood, as per the original. Note the non-standard pintle hook extension at the bottom of the image. This inaccurate feature was replaced as well. (image via Oehme Brothers War Horse Garage)
The Mill 33 arrived with an incorrect set of wheel hubs and tires. These were replaced with NOS (New Old Stock) examples from the Oehme Brothers' stockpile. (image via Oehme Brothers War Horse Garage)
A nice view of the beautifully restored transmission, gearbox and drive shaft on the Army Air Forces tug (Mill 33). Note that this tug came with a conventional, four-bladed cooling fan. (image by Keegan Chetwynd)
Another view of the US Army Air Forces Mill 33 tug during following the installation of its engine. Note that the tug now has its authentic rear wheels in place, instead of the after-market examples it arrived with. (image by Keegan Chetwynd)
Another view the the US Army Air Force Mill 33 tug following engine installation. (image by Keegan Chetwynd)
A Big Thank You!
Our two Clarktor 6 aircraft tugs now look as good (and probably even better) than they did when first they rolled off the assembly line in Battle Creek, Michigan almost eighty years ago. We are really pleased by the end results, and want to thank the Oehme Brothers for their hard work, and the amazing generosity of our supporters for funding it.
Many thanks also go to Larry Kelley for earmarking these tugs for our museum once he learned of our interest. He had received significant offers from other parties, but felt we would provide them with the best home—where visitors could see them in action whenever we fly. As our Director, Keegan Chetwynd, said in justifying our acquisition of these tugs "WWII was not won alone in the skies over Europe, North Africa, Asia and the Pacific, but by everyone working together! These tugs help represent the people back on the ground who made taking the fight to our enemies possible. They will help provide a more immersive experience for museum visitors, who will have a better glimpse of the many roles uniting the Greatest Generation in our Allied struggle against fascism."
We also wish to thank Clarktor guru, Joe Swelnis, for his help in determining the history of our two tugs. The build cards he forwarded to us, plus other details were essential in this process.
And from a personal perspective, it is great to see the Clarktors finished, having played a small role in their acquisition. We can't wait to put the two tugs to work at the Museum once they arrive in the coming weeks!
