Thiokol 601

[mtncrawler]

I am not an expert on the machines by any means. I am posting what I think to be true however I hope anyone will correct me where I am mistaken so I can learn more about these machines. Sometime in the early '50s the University of Utah built several prototypes of low ground pressure machines for Morton Thiokol for use in missile testing programs taking place on the salt flats. The most sucessful of these was the 4VL. It had a drive system where the the engine power went into a gear box where it was split into two output shafts each running through its own clutch and brake. Then two separate driveshafts took the power to two truck style differentials welded together with the outboard axles turning sprockets to drive the tracks. Pulling back on the steering lever first disengaged the clutch, then applied the brake when pulled further, turning the machine. This drive system was most likely very difficult to keep properly adjusted and at any rate not very strong. The last body style used had the reverse sloped windshield and would become the 601 series. The 601 drivetrain went with a Ford inline six cylinder engine, 4-speed standard transmission, and a OC-15 steering differential. The military spec machines used the Ford 240 cu.in. and the civilian version could be ordered with the Ford 300 cu.in. engines. Oliver Tractor Corp. made crawlers using Clark steering differentials, notably the OC-4 and OC-12 which were used in the Thiokol Spryte, or 1200 series, machines. The OC-4 was also used in the Thiokol Imp. They did not build an OC-15 crawler so I believe this differential was made for military contract. The military 601 was mostly used for airfield recovery. I am somewhat puzzled by the example I own since it has the 300 engine, no roof hatch over the passenger seat, yet was originally painted blue (Air Force). I have heard these vehicles refered to as "Trackmasters" and have a maintenance book cover that says that too. They are very heavy duty especially by snowcat standards.

 

[mtntopper]

They are very heavy duty especially by snowcat standards.

Can you give us some specs such as weight, width of tracks, ect. and your general impression as to how this machine (601) would compare to your Spryte as a snow cat. As I understand the Trackmaster specs were written by the University of Utah and built by Morton Thiokol??? Or did the University actually build the Trackmaster????

 

[mtncrawler]

Well here I am already having to correct myself. Oliver Tractor DID build an OC-15 crawler. I think University of Utah was mostly involved with the early prototype machines. I know a guy in Denver who has one and it has a plack in it with University of Utah information so I know they built at least some of those. Once a machine went into commercial production though, the manufacturer has probably secured the design rights. While preparing an A-Model Spryte for paint I found "Thiokol Chemical Corp, Logan Utah" on the origninal paint on the doors. I wonder if this was a company vehicle. As far as a good comparison between my 601 and the Spryte lineup I haven't run the 601 other than on and off the trailer. Once I finish it I will run it around on packed trails but I know it won't be much in the powder. Gives me an idea for a new thread. What exactly constitutes a snowcat?

 

[weatherby]

I have a 1963 601 that i am just beginning to restore which i have had setting for many years. In that time i have tryed to learn as much about this unit as i could such as it history at least as the one i have is concernd. I also obtained an original owners manual from THIOKOL CHEMICAL CORP. So i would be glad to share what info i may have that you do not..

 

[mtncrawler]

Is your machine the twin driveshaft unit (4T2 - 4T10) Trackmaster or the later varient with the OC-15 drive. Mine has the OC-15 and I can't find much information on them. Does this owners manual list this as an option?

 

[weatherby]

Is your machine the twin driveshaft unit (4T2 - 4T10) Trackmaster or the later varient with the OC-15 drive. Mine has the OC-15 and I can't find much information on them. Does this owners manual list this as an option?

I am not really sure what drive I even have I think it is a OC12 I have been trying to find this out. The manual dose not state what make of drive unit is in it. It just shows an exploded view of the unit. However the manual states that some machines were equipped with a fabricated steel case. cast aluminum cases were used in later machines. My 601 has one drive shaft and cast aluminum case a top access plate with 22 bolts bolting it on. If you would like I will try to learn how to post some pics. of it.

 

[mtncrawler]

Pictures would be great. Have you started this restoation yet? Single driveshaft alumium case drive should be OC-15. Has anyone heard of a factory equipted Trackmaster 601 with the OC-12? How about an OC-15 with reductions? Is yours the full cab body?

 

[weatherby]

Yes I just started the dismantling process. I will try to send some pics. but being the first time I don't know for sure what I am doing. So just bear with me.

 

[BigAl]

I will try to send some pics. but being the first time I don't know for sure what I am doing. So just bear with me.

Do the best you can .. If they really care ,they will understand .... WAIT! Are we still talking snowcats here .
!!!!keep those pictures coming !!!

 

[Eric L]

OK, someone help a Tucker guy understand how these things work... I assume the yella thingies on the rearend are basically hyd. slave cylinders, right? and they operate wet brake set-ups within the main housing? really just a "steering brake" like a tractor.. or just like if I installed separate master cyls. for ea. side on a standard (open) diff automotive style axle?



Eric

Edit: P.S. weatherby, I dont see a refrigerator in your shop... whats up with that? I'm not sure you priorities are in line...

 

[mtncrawler]

You got it. These Clark differentials were made for crawler tractors in the first place.

 

[weatherby]

OK, someone help a Tucker guy understand how these things work... I assume the yella thingies on the rearend are basically hyd. slave cylinders, right? and they operate wet brake set-ups within the main housing? really just a "steering brake" like a tractor.. or just like if I installed separate master cyls. for ea. side on a standard (open) diff automotive style axle?



Eric

Edit: P.S. weatherby, I dont see a refrigerator in your shop... whats up with that? I'm not sure you priorities are in line...

Yes that is what those yella things are slave cylinders. they sometimes refer to those rear drive units as brake steer units. As far as the coolerator is concerned well thats up stairs.

 

[Thiokol2track]

weatherby,
your machine looks like its in nice shape. How many miles/ hours??
I Like the stands too,makes things a lot easier.....

 

[weatherby]

weatherby,
your machine looks like its in nice shape. How many miles/ hours??
I Like the stands too,makes things a lot easier.....

Thanks The machine is in good shape aside from the fact that it has sat for about 15 years. It has 6,600 mi on it. If you go to the snocat restoration page and click on my thread THIOKOL 601 RESTORE you will see my progress so far on restoring it back to original

 

[Thiokol2track]

Keep up the good work! Looks great.
I have a 1961 trackmaster 4t2 w/12,800 miles sheduled for restoration next year.
Have to wrap up this years project.....chek out photo gallery pics.
not enough hours in a day

 

[Thiokol2track]

Pictures would be great. Have you started this restoation yet? Single driveshaft alumium case drive should be OC-15. Has anyone heard of a factory equipted Trackmaster 601 with the OC-12? How about an OC-15 with reductions? Is yours the full cab body?

Is the 601 rear the same as the oc-12 without the drop boxes???

 

[mtncrawler]

No, the 601 uses an OC-15 which is larger. I have never heard of a 601 with the OC-12 from the factory - is why I asked if anyone with more experience than I was aware of this combination. OC-12 without reductions were used in early B-Model Sprytes however.

 

[Mainer]

I have only seen 601's with the OC15.
From what information I have the 601 started in 1963 which was the next generation drive train up from the 1961/62 Trackmasters (4T2-4T10) with the dual drive shaft model. I'm sure you've seen the warning memo from Thiokol that talked about how the connecting on some of the Trackmasters broke loose. That connecting shaft between housings was then beefed up as a fix and then the OC15 came in the next year.

Attaching a couple of views of the Trackmaster drivetrain out of interest. Again, these are prior to the 601/OC15.

 

[Mainer]

One more interesting difference... or at least I think so.

Check out the track design difference between the 601 and the TM.

You see that they used the tire tracking brackets on the inside of the track on the Trackmasters. You also see how the center of the track is elevated which I believe was due to the fact that the TM was designed to go over many surfaces from salt flats to snow so you wouldn't want the entire track to generate excessive friction on 'other than snow' surfaces. So, they built up the outside of the track.

But then on the 601 they took the 'build-up' out of the track as well as the angled brackets on the inside of the track (anyone know the technical term for these?), and simplified by using a shaped grouser to track with the tire while keep that 1.5" difference between surface/track contact point and the rest of the track.

fun-fun.

 

[seskelson]

Hello. Just a little note of correction. I am the son of Ross Eskelson. The correct univeristy is Utah State University - then known as Utah State Agricultural College in Logan, Utah. My father was one of the original designers and builders of their earliest snow cats. The original one at USU was the Frandee Sno Shu named after its designers Roy France (still alive) and Emmett Devine. My dad helped build and engineer it. Later he developed the patents that became the Trackmaster. In 1960 he convinced Thiokol to start their Logan plant and Thiokol then bought the patents for the Trackmaster from USU. Dad was the operations manager and in charge of all research and devleopment. His friend Blaine Rich was the general manager and he had worked for Thiokol in Brigham City. Merrill Brown was the production superviser and had worked with dad in building the original Trackmasters at USU. Dad desiged the 1200 Spryte and it's first really big claim to fame was its use at the 1964 Innsbruck Olympics for snow grooming. rm. Tucker was a visitor in our hom in the 1960;s and dad corresponded with John Arman Bombardier from the earliest days. He left Thiokol in 1971 and did the initial design work for Bombaradier vehicles. We built two of their prototypes in our garage in Utah (including their first hydrostatic vehicle) and then shipped them to Quebec for testing. I know--- as I built the tracks myself by hand. Dad passed away in 2008. We still have his last vehicle which he made out of a Ford F250 pick up. We are restoring it. He believed in using readily available parts.

 

[Snowcat Pat]

Hi seskelson and welcome. Thanks for the post. I'm guessing that you might find this forum amusing......and full of errors! By all means continue to make corrections!

-Pat

By the way I'm currently building my second set of tracks by hand, (cleats and tireguides, backing plates and all).

 

[snotrans]

Hi Scott; Glad to have some one that is knowledgeable of the Old Days of Thiokol and USU I have in my collection a Frandee Seawolf machine that is being restored . I also have a ID Plate Serial number "1'' Frandee Sno Shu that Lyndon Strother removed from the machine in a Alaska dump, many years ago,and gave to me . It is in a Thiokol picture frame in my office,along with a lot of other Thiokol, Tucker, and Bombardier historical pictures and data accumulated in our 35 years of snowcat Sales, Leaseing and Service. If you are ever in Weiser Idaho stop buy and I would love to buy dinner and discuss The "Good OL DAYS " In the mean time I do have some questions on some of the data I have and would like to contact you if that is ok . PS: I did send PM for contact information Thanks. Bill@snotrans.com

 

[Mainer]

Hello. Just a little note of correction. I am the son of Ross Eskelson. The correct univeristy is Utah State University - then known as Utah State Agricultural College in Logan, Utah. My father was one of the original designers and builders of their earliest snow cats. The original one at USU was the Frandee Sno Shu named after its designers Roy France (still alive) and Emmett Devine. My dad helped build and engineer it....

Great to have you on the forum! We spoke a couple of times and I appreciated your input then but having you on here now will be fantastic!
This little gem has some strong historical info from USRF/USU that pre-dates Thiokol patent ownership... The wooden tracks will be great to rebuild.
Anyway, great to have you on, welcome! If you can share photos from back then it would just be fantastic to everyone here!!! There are so many information holes to fill that we can all easily consume your time but I think I speak for the group that if you can capture your thoughts on this forum in text it will form hard fact rather than consuming alot of your time in discussion that may get lost. It would also be great to figure out how to interview/capture thoughts from some of the folks from those days and document here.... selfishly I'm most curious about how the Air Force conversations first started and the evolution of those discussions through their perspective of the 4T series and into the design of the 601...their perpsective on power divider moving to OC-15 diff... following that cycle from beginning interest to deploying many into the field.

 

[Doc]

Hello. Just a little note of correction. I am the son of Ross Eskelson. The correct univeristy is Utah State University - then known as Utah State Agricultural College in Logan, Utah. My father was one of the original designers and builders of their earliest snow cats. The original one at USU was the Frandee Sno Shu named after its designers Roy France (still alive) and Emmett Devine. My dad helped build and engineer it. Later he developed the patents that became the Trackmaster. In 1960 he convinced Thiokol to start their Logan plant and Thiokol then bought the patents for the Trackmaster from USU. Dad was the operations manager and in charge of all research and devleopment. His friend Blaine Rich was the general manager and he had worked for Thiokol in Brigham City. Merrill Brown was the production superviser and had worked with dad in building the original Trackmasters at USU. Dad desiged the 1200 Spryte and it's first really big claim to fame was its use at the 1964 Innsbruck Olympics for snow grooming. rm. Tucker was a visitor in our hom in the 1960;s and dad corresponded with John Arman Bombardier from the earliest days. He left Thiokol in 1971 and did the initial design work for Bombaradier vehicles. We built two of their prototypes in our garage in Utah (including their first hydrostatic vehicle) and then shipped them to Quebec for testing. I know--- as I built the tracks myself by hand. Dad passed away in 2008. We still have his last vehicle which he made out of a Ford F250 pick up. We are restoring it. He believed in using readily available parts.

Awesome. Sure glad to have you on the forums with us. to your dad. Very kewl.

All please note, Do not reply to the email notifications you get in your email box. They go to a junk mail folder that I review once in awhile. I've seen a number of replies go to this dead area and there is nothing I can do to figure out who it was meant to go to. the most recent one was a reply to Bill in this thread.

PM each other or email each other all you want but if you reply to a thread post notification no one but the junk folder gets it.

Enjoy!!!!!

 

[mattfidaho]

welcome. and it is nice to have another one from idaho falls here... LOL

 

[fritz]

I have a 1963 601 that i am just beginning to restore which i have had setting for many years. In that time i have tryed to learn as much about this unit as i could such as it history at least as the one i have is concernd. I also obtained an original owners manual from THIOKOL CHEMICAL CORP. So i would be glad to share what info i may have that you do not..

I know this is a really old post , but I was wondering if you still have the manual for the 63 601?

 

[GMoose]

I know this is a really old post , but I was wondering if you still have the manual for the 63 601?

You might try Dan gates at snowcatinc in SLC, he has tons of manuals, I bought one from him for my 62 201 Spryte.

 

[fritz]

You might try Dan gates at snowcatinc in SLC, he has tons of manuals, I bought one from him for my 62 201 Spryte.

Thanks for the info. I will check it out

 

[alryA]

Nice to have you here with us Mr Eskelson. We have an frandee parked at a ski area near us.

 

[GMoose]

Nice to have you here with us Mr Eskelson. We have an frandee parked at a ski area near us. View attachment 135636

I am not sure Scott Eskelson (son of Ross Eskelson) is on the Forum but I know he has contributed to it in years past. I believe the picture you provided is of a modified model D (5 bolt idler wheels as opposed to 8 bolt on the model E), looks like it has been repowered with something other than the original flathead ford 254 straight six. Looks like it also has an automatic transmission now. Front axle differential has been cut out and replaced with a pipe. I like the wider cab as compared to mine, a little more elbow room. You should acquire this unit and restore it.