US Army Armoured Bulldozer
History: Caterpillar was formed in 1925 by the merger of C.L. Best Tractor Company and the Holt Tractor Co. The D7 then known as the RD7 9G, was produced from 1935-1940. In 1937 Cat dropped the R designation from the name.
These had a four cylinder diesel engine producing approx. 69 draw bar h.p. and 82 belt h.p. The D8800 engine was started by a “pony engine” that had a hand crank called a “grip” by Caterpillar. This was a gas powered engine that had two cylinders. Earlier D7’s had the crank protruding thru the left lower side skirt below the pony engine and later versions had it sticking up through the left front of the hood. The operator could start the engine from standing on the tracks.
Two main levers steered the tractor via clutches in the rear drive. Other controls such as gear selector, throttle, and blade controls were at the driver’s disposal.
These vehicles, whether it was Caterpillar, Allis Chalmers, IH, or Cleveland tractor, were all originally just tractors. They were purchased as prime movers. Until the advent of the accessories like blades, winches, cranes, and other mounted items, they were mostly used as tugs.
The first armored bulldozer was developed by the British during World War II. This was a conventional Caterpillar bulldozer fitted with armor to protect the driver and the engine. The work was carried out by Jack Olding & Company Ltd. of Hatfield. The bulldozer was one of several strange armored vehicles that were collectively referred to as "Hobart's Funnies" and were operated by the British 79th Armoured Division in support of assaults.
The bulldozers were produced in preparation for the Battle of Normandy with the tasks of clearing the invasion beaches of obstacles and quickly making roads accessible by clearing rubble and filling in bomb craters.
As Allied armies advanced through Europe, the armored bulldozer was found to be too slow.There was a need for well-armored, obstacle clearing vehicle that was fast enough to keep up with tank formations. This need was met by various tank-mounted dozers such as the Centaur or Sherman.
This kit is a Caterpillar D7 armored cab with a LaPlante-Choate R71 manual angled blade and is a later version based on the grip position. The blade was raised by hydraulics which replaced the cable lift type. Le Tourneau and LaPlante-Choate were one of the most used versions in WW2.
There are a ton of pieces in this kit!! The box states 767 parts for this kit. They are all molded in a nice grey plastic and are all in appropriate bags. The kit is the same base model as kit 35195. The extra sprues are for the winch and armored cab assemblies.
This is the huge bag of goodies. As we all know, there are some issues with the earlier plastic. It appears that Miniart has corrected the formula that plagued their earlier efforts. I did have a couple of small parts break but I will mention that later.
The A, B,C, and F sprues are shown above. These contain most of the core parts for the build.
The “D” sprues contain a lot of the sponson's parts and the tracks. The tracks are all individual links with three other attachments that will be mounted to the pads.
“G” has the extra cab parts.” The “He” sprue has the winch pieces.
The decals, clear parts, and a small etch fret is bagged separately.The instructions are really well done and are truly a book!!
The back cover has some nice color plates for painting and decal placement. There are 80 steps to build this beast.
This is an example of the clarity and complexity of the engine. I stopped counting parts at approx. 100. The rest of the instructions are as good as the example above.
These are for building the engine, transmission, and radiator assemblies.
This is a view of the completed engine with the radiator and hydraulic lines attached. The injector pump has perfect tips to install the fuel lines to the injectors on the other side of the head. The missing water line is also added.
This is the left side of the massive engine. Although hidden, the diesels injectors are located behind the exhaust manifold. The throttle shaft for the pony engine is also attached. The vertical shaft near the front of the engine is the starter shaft for the pony engine. The engine has two cylinders and can also be wired to the ignition magneto under it.
The exhaust from the pony engine is shown entering the cooling chamber to warm the main engine's coolant. This is just one of the features of the little engine.
The radiator has excellent detailing. The core is very well molded but is unseen when the model is done.
The transmission assembly with the oil filters on it. The instructions show to attach it to the engine. I did NOT glue it to the engine. The next steps will show why. I also left off part C27 until step 29. This was because the line up of the tube was a grey area until the floor pan was set on. It will come together nicely.
Steps 19- 29
These steps work with the final drive, operator controls, and some miscellaneous engine/frame parts.
This is the final drive with the transmission attached. This was my way of doing it after I discovered a clearance issue. Make sure the transmission is FLAT as alignment of the levers will be affected!!
This is a view of the assembled engine, transmission, and the final drive. I ended up cutting the transmission off the engine due to fitting and clearance problems; more on that topic ahead.
This gap where the pencil is pointing is not an issue. Without the gap, there is a problem.
Part C81 will fit there easily. The gap actually helped with the fit a little. My other observation and reason for gluing the transmission to the rear end assembly is that when the linkages for the steering levers and brakes are attached, they would be too short if the transmission was on the engine and the gap was at the rear.
I had another small issue in that the instructions didn’t show where the clutch arm, C83, actually mounted. I didn’t want to guess, so I checked references and found the answer.
Page 6, step 17 is where this is found. Not a big deal, but I thought it mattered.
The front “suspension” and linkages are in these two steps. Mini Arts drawings are good enough; they even show the mold seam on the spring!!! No, it shouldn’t be there.
The seat assembly, some of the hydraulic lines, and air cleaner are involved in these steps.
This is the front spring assembly in place. You might notice the painted sub assembly. I had to do this, as I went, due to all the angles and hiding spots.
The underside with the skid plates, spring, front and rear tow attachments, and fenders. Make sure when doing the fenders, the braces Da11 and Da10, are mounted with the longer side to the fender.
As I mentioned before, the kit had some inherited damage. These are a couple of photos of my hydraulic lines. As much as I noticed the improvement of the new formulated plastic, these lines were smashed again in the box. I think they are a victim of bad positioning on the sprue and packaging.
This is the left side showing the clean fender. The instructions show the tool box mounted there but if you do the door won’t open. It goes on the back of the cab. The grab handles also were broken so I replaced them with solder wire.
A quick note, I found switching assemblies 36 and 37 makes the seat go together easier.
My hydraulic tank had a weird lump on it and a warped area next to it. It did clean up OK as it is visible when done.
A fit issue I had with the air cleaner involved re-boring the hole. It was oval and really messes up the fit to the front cab plate. I set it in place but do NOT glue it in place yet!!
The above photos are what you will have assembled up to step 38. This will include the seat, fenders, air cleaner, my repaired hydraulic lines, skid pans, and front springs.
These are the two steps for building the winch. It doesn’t come without questions regarding assembly.
The two hubs mostly assembled. The instructions don’t show where or what the loose cable ends do. They aren’t mentioned if an eye is attached, or if a hook is used. I know there is an upper assembly that is used for other applications but Miniart leaves you to guess.
The winch levers were another victim of what I think is a packaging issue. They were repaired with CA glue.
The completed winch assembly and repaired levers.
The cab, front radiator supports, air cleaner, headlamps, exhaust, and front sheet metal are in this group.
The cab with the front panel taped together as the air cleaner needs to fit thru it. The cab has to fit exactly in place to make this all come together.
The rear of the cab showing the tool box mounted in the correct location. I chose to leave the rear cover open to try to see the interior. It really limits any visual benefit by doing this. The door open is the best option. I will mention the supports for the covers are VERY delicate. Mine broke trying to take off the front ones but the rear ones survived. The option is offered for being open or closed.
I will recommend painting the complete interior of the cab and the driver’s area now. It is impossible to paint after it is assembled.
An additional observation is the maintenance crew or whoever fueled this dozer had a very awkward job.
The track and sponsons assemblies are next. If you haven’t done one of these track assemblies before, you’re in for a treat! The tracks are complex and not that precisely molded at the line up holes for the side links.
Mini Art does an awesome job of actually molding a coil spring in one piece. I had slack in the tracks so I left the front idler assembly loose and slid it forward just like the real deal. The amount of movement didn’t seem to affect the fit of the idler.
One of my front idlers had the outer rims crack when I pushed them onto the wheel. They seemed to fit fine then snapped. I filled the crack with CA glue and sanded it.
The following photo is showing my jig and process for building the tracks. It might be the same way others have come up with, but after a few of these kits it worked best.
I will try to keep this simple. I laid out the track pads in a line. The side links are numbers 2 and 3. I attached #2 to the pads. I did about 5 links at a time. I then added the pins and after these dried, attached part #3. This was not the way the instructions directed but it works well.
Take care in cutting off the parts Dc 2 and 3. The tiny line up pins don’t align with the indents on the underside of the pads well. You can feel them a little using this method I came up with. I did use the correct amount of links.
These are the last building steps to the kit. It involves assembling the blade. There are choices during the build to keep the blade straight or angled. I decided to do this one with it angled, BUT there is an issue. It is the same issue that kept me from doing it to other kits in this series.
The side arms or the blade width aren’t scaled correctly. If you install the side arm at the pin, it won’t make it around the lift point. The issue is only at the short side. I played with the mount area and slid it in a little but applied a little heat to the side arm and it worked. It is the only way all the blades I’ve done will work in my experience.
The left side view with the blade partially raised.
This is the view of the rear showing the winch and correct tool box mounting.
This is the right side view and the repaired hydraulic tank. Also note why the front panel of the cab is so important in lining up with the air cleaner.
The top view shows the angled blade and again the importance of the air cleaner alignment.
Miniart noticeably improved the plastic breakage issue. The breakage I experienced, I believe, is due to the packaging process. There is just so much stuffed into the bag and with the pressure on the box seems to break some fragile parts. They have been pretty much the same ones broken in the three kits I have received.
The air cleaner/ front plate mounting is awkward. Pre-fitting the cab is imperative to making this assembly work. The track building system I came up with makes it much easier to assemble them.
These kits aren’t for the novice in my opinion. They have a ton of parts and tough fits. They are a nice change from a tank or soft skin and offer a great choice for building dio’s or vignettes. I will still do another…
Reviewed by: Mac Johnston
Upper Valley Model Club, AMPS, Granite State Modelers Club
My thanks go out to Dragon USA for this review sample and to AMPS for affording me the opportunity to review it.
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