Builders and excavators!!!
Today we are revisit one of those responsible for building the Allied Victory in WWII. Some time ago, we talked about the hydraulic version of this girl... but today, we will talk about the "early and brute" option of this impressive, robust and powerfull machine. Let's meet the Caterpillar D7 Bulldozer with LeTourneau R7 power control unit.
 |
| Caterpillar D7 with LeTourneau R7 PCU and LeTourneau WCK7 angledozer moving ground, at the construction Battalion Training Center, Camp Endicott, US Navy. Davisville, Rhode Island - USA - fall of 1943 |
History:
The Caterpillar D7 is a medium bulldozer manufactured by Caterpillar Inc.. The first D7 appeared in 1938. The D7 dozer was the primary earthmover for construction of survivability positions and antitank ditches. It had to be transported by trailer due to its poor mobility.
 |
| Caterpillar D7 crawler tractor 3/4 front right view |
 |
| Caterpillar D7 crawler tractor 3/4 rear left view |
During WW II crawler tractor / bulldozers were used by Allied military for combat construction in Europe, Asia, in the Pacific, literally all over the world, in all fronts. They also served as prime movers for artillery, and for a multitude of other tasks.
 |
| A commercial Caterpillar D7 (notice DIESEL in the side of the engine hood) under trials with M1 gun 155mm Long Tom, as artillery prime mover. |
 |
| Caterpillar D7 with LeTourneau R7 PCU and LeTourneau WCK7 angledozer from 65th Engineer Combat Battalion, cleaning the terrain in Lynx Red Road Luzon, Philippines - May, 1945. |
 |
Caterpillar D7 Heavy Tractor, M1 818th Engineer Aviation Battalion France - 1944 |
 |
| Caterpillar D7 dragging medical supplies on a wooden sled at Depot M-402T Carentan, Normandy - 1944. |
 |
| Caterpillar D7 "Booger Kid"with LeTourneau R7 PCU and LeTourneau WCK7 angledozer in a damaged French village, shortly after the Normandy landings. Markings in the rear tractor are 3A - 628E - LE 3rd Army - 628th Light Engineer Company. France - 1944. |
 |
| Caterpillar D7 "Booger Kid"with LeTourneau R7 PCU and LeTourneau WCK7 angledozer filling bomb craters on a Normandy country road, west of St. Lo. Notice the right side rack with Germans jerry cansFrance - 1944. |
 |
| The charred remains of the the Panzer IV n.532 being bulldozed by Caterpillar D7 into a heap amongst the rubble. St Gilles, Normandy, France - July 1944 |
 |
| A Caterpillar D7 with LeTourneau R7 PCU and LaPlant-Choate R76R Trailbuilder dozer from US Army gives an LCM(3) a helping push... This photo was taken moments after another photo, a little further down in this article... Operation Plunder - Crossing of the lower Rhine Germany - March, 1945. |
The crawler tractors had unsurpassed capability to move and tow in the muddy jungles of the Pacific islands which made them especially prized by the Americans Seabees, Marine Corps and Army units in the Pacific Theater. When equipped with a bulldozer blade, they could level ground for roads and airfields as well as clear debris, construct fortifications and much more.
 |
| Caterpillar D7 with LeTourneau R7 PCU and LeTourneau WCK7 angledozer moving ground, at the construction Battalion Training Center, Camp Endicott, US Navy. Davisville, Rhode Island - USA - fall of 1943 |
 |
| Same vehicle and place from the color photo above. The navy blue-gray color pattern is evident on this vehicle |
 |
| Right side view of Caterpillar D7 from US Navy Construction Battallion tractor Camp Endicott, US Navy. Davisville, Rhode Island - USA - fall of 1943 |
 |
| Caterpillar D7 serving with US Army, cleaning the thick jungle after the Battle of Guam, 1945. |
Caterpillar D7 described:
The D7 was a big machine with 4.114 mm long and 2.539 mm wide (without any attachments), but it was also a phenomenal worker.
Fitted with Caterpillar engine model D-8800, 4 cylinder, 80 horsepower, 13.617 cc liquid cooled diesel, it had a maximum drawbar pull over 11.500 kg.
With five speeds forward, four in reverse, it could work equally well in either direction.
They can be fitted with a LeTourneau-type angledozer on which the blade could be manually adjusted to cut right or left, or to doze straight ahead. The power control unit can be front mounted, but. still relied on cables to raise the blade, A Hyster D7N 15 tons winch can be mounted at the rear, Weighing 14.400 kg, the D7 could tow loads exceeding 11.500 kg.
Caterpillar D7 Bulldozer variants (WWII era):
- D7 7M series, manufactured 1940-1944, approx 10,000 produced. D8800 engine, 74 inch track gauge (1.880mm)
- D7A 1T1001 series, manufactured 1943, 138 produced. Armor plated 7M with twin hydraulic cylinders, rear mounted Hyster D7N winch
- D7 3T series, manufactured 1944-1955, over 28,000 produced
- D7 4T series, manufactured 1944-1945
- D7 6T series, manufactured 1945
During WWII, the D7 was one of the bulldozers collectively known as "Tractor, Heavy, M1." Equivalent tractors were produced during WW II by Allis-Chalmers Co. (Model HD10W, G-98) and International Harvester Co. (Model TD18, G-101).
.jpg)
About one thousand Caterpillar D7s were also produced by American Car & Foundry under license when WW II military orders exceeded Caterpillar's capacity.
Main Auxiliary Equipment:
- Hyster D7N Towing Winch: It was a robust, single-speed, direct-gear, reversible winch with enough power and strength to utilize the tractor's engine power to pull loads beyond those that could be handled on the tractor's drawbar. The winch must be operated with the tractor stationary.
 |
| Hyster 07N towing winch installed in the rear of a Caterpillar D7 |
 |
| Caterpillar D7 with LeTourneau FTD7 PCU, LeTourneau A7 tiltdozer and Hyster D7N towing winch 77th Combat Engineer Company, 25th Infantry Division Korea War - 1951 |
- LeTourneau FTD7 Power Control Unit: the FTD7 power control unit (PCU) was a single-drum unit mounted in the front of main frame of Caterpillar D7 tractors, below the radiator, for controlling a dozer blade used with the crawler. Could be used in conjunction with a rear mounted cable control unit or a towing winch . This front PCU was driven by the tractor engine. The cable drum of the PCU was connected with the dozer blade up over the sheave of A-frame and down to the dozer blade. By spooling or unspooling the cable on or off the cable drum , the PCU could controls the raising or lowering of the dozer blade. The operator operates the aparatus moving the control lever at the right of the tractor seat.
 |
| LeTourneau FTD7 power control unit installed in front position of Caterpillar D7 tractor see also the cable arrangement and control lever |
 |
| A very dirty Caterpillar D7 with LeTourneau FTD7 PCU, LeTourneau WCK7 Angledozer and Hyster D7N towing winch in the rear |
 |
| Caterpillar D7 of a Naval Construction Battalion (Seabees) with LeTourneau FTD7 PCU to operate the LeTourneau WCK7 Angledozer and a LeTourneau R7 PCU to operate any towed equipment. Eniwetok, Marshalls Group - 1944. |
- LeTourneau R7 Power Control Unit: the R7 Power Control Unit (PCU) was a double-drum unit mounted on the rear of the steering-clutch case of Caterpillar D7 tractors to control a wide range of equipment like dozers, scrapers, rooters, cranes etc. A take-off shaft (spline-shaft) connects the PCU with the tractor upper transmission-shaft, and by the tractor engine. Control cables (wire ropes) extend from the cable drums to the equipment that is being operated by the PCU. Two control levers (one for each drum) extend up behind the tractor seat and are within easy reach for the operator. Moving these control levers, the operater can spool or unspool the control cables on or off the cable drums, thereby operating the various working parts of the equipment being operated by the PCU.
 |
| LeTourneau R7 PCU installed in the rear of Caterpillar D7 tractor see also the control levers |
 |
| Caterpillar D7 with LeTourneau R7 PCU and LeTourneau WCK7 Angledozer, removing debris and rubble at Roncey, France. 2, August, 1944. |
 |
| Caterpillar D7 with LeTourneau R7 PCU and LeTourneau XD7 Bulldozer assisting a International Harvester M426 5-ton 4x2 tractor truck out of the mud at an Ordnance Depot. Normandy, France. |
- LeTourneau A7 Tiltdozer: the A7 Tiltdozer consisted mainly of the steel blade or "bowl" across the front of the tractor; the pushbeams, that supported the bowl in front of the tractor; the trunnion brackets, on which the rear of the pushbeams pivots; and the front and rear A-frames and the ridgebeam on which rotated the sheaves over which the cable from the PCU travels to raise and lower the blade. The A7 Tiltdozer could be operated by either LeTourneau front or rear mounted PCUs. The bulldozer required only one cable drum, and when it is operated by a rear-mounted R7 PCU, the spare drum may be used to operate other equipment. By engaging the clutch of the power control unit, the blade will be raised. By releasing the brake, the blade will be lowered. Its design combined features of the bulldozer and the angledozer. The Tiltdozer blade can easily be tilted. The adjustment was performed by the blade tilt adjusting-screws, at the front of each tilting brace. The adjusting mechanism was protected by a curved guard. The sharp pointed end blades are a distinctive feature of the A7 Tiltdozers blades. The A7 Tiltdozer was introduced in 1943 but it is possible that the U.S.Army did not receive any before 1944.
 |
| Cutaway view of LeTourneau A7 Tiltdozer controlled by LeTourneau R7 PCU in a Caterpillar D7 tractor. Notice the pointed sharp ends blade, typical of this blade. |
 |
| Seabee Caterpillar D7 tractor with LeTourneau R7 PCU and LeTourneau A7 tiltdozer. The left curved guard is missing. Salomon Islands - 1945 |
 |
| Caterpillar D7 with LeTourneau R7 PCU and LeTourneau A7 tiltdozer. Notice the curved guards (red arrows) and pointed sharp ends (green), distinctive features of the A7 Tiltdozer blades Korea War - 1951 |
- LeTourneau WCK7 Angledozer: The LeTourneau WCK7 angledozer was composed of the steel blade or "bowl" across the front of the tractor; the yokes and sidearms, which supported the blade in front of the tractor; the trunnion brackets, on which the rear of the yoke pivots; and the front and rear A-frames and the ridgebeam which supported the sheaves over which the cable from the power control unit passed through to raise and lower the bowl. By operating the PCU control-lever, the dozer blade was raised and lowered as the tractor moves forward. The angledozer bowl could be adjusted into the angled position and into the tilted position. The WCK7 angledozer required only one cable drum, and when the tractor was equipped with a R7 PCU, the spare drum may be used to operate other equipment. The WCK7 angledozer was introduced in 1942 and it became the standard LeTourneau angledozer type for the military D7.
 |
| LeTourneau WCK7 Angledozer Notice the possibilities of horizontal and vertical angulation of the dozer |
 |
Caterpillars D7 with LeTourneau R7 PCU and LeTourneau WCK7 angledozer (angled 30° right, in foreground) clearing debris from a demolished bridge over the Meurthe River. 7th U.S. Army Engineers - France, 1944. |
 |
Caterpillars D7 with LeTourneau R7 PCU and LeTourneau WCK7 angledozer preparing the header of a double Bailey bridge near the Arno River - Italy, 1945. |
 |
Caterpillars D7 with LeTourneau R7 PCU and LeTourneauWCK7 angledozer clearing mud in ItalyMignano Sector, Italy - 1944. |
- LeTourneau XD7 Bulldozer: The LeTourneau XD7 Bulldozer consists mainly of the steel blade or "bowl" across the front of the tractor; the pushbeams, which support the bowl in front of the tractor; the trunnion brackets , on which the rear of the pushbeams pivots; and the front and rear A-frames and the ridgebeam which support the sheaves over which the cable from the PCU travels to raise and lower the blade. Engaging the clutch of the power control unit will raise the blade, returning the control lever to the neutral position will hold the blade in the raised position, and releasing the brake will lower the blade. The XD7 Bulldozer can be operated by either LeTourneau front or rear-mounted PCUs. The bulldozer requires only one cable drum, and when operated by a rear-mounted R7 PCU, the spare drum may be used to operate other equipmen. The XD7 Bulldozer was introduced in 1940. Its knock-down construction with detachable blade and pushbeams made it superior to a standard bulldozer like the WEK7 Bulldozer with its rigid bowl as it permitted easy disassembly for compact stowage or transportation, which is always good for logistics.
 |
| LeTourneau XD7 Bulldozer Notice the adjustable eyebolts at the upper corners of the bowl. By tightening or loosening the screws, the bowl can be slightly tilted forward or backward to change the digging angle of the blade when needed. |
 |
| Seabee Caterpillar D7 with LeTourneau R7 PCU and LeTourneau XD7 Bulldozer, leveling an airfield. Notice the adjustable eyebolts at the upper corners of the bowl. Iwo Jima, Japan - June, 1945 |
 |
| Caterpillar D7 with LeTourneau R7 PCU and LeTourneau XD7 Bulldozer. |
- LaPlant-Choate R76F and R76R Trailbuilder: the R76F (front) and R76R (rear) trailbuilders consists mainly of the steel blade across the front of the tractor; the pushpoles and the main frame, which support the blade in front of the tractor; the tractor mountings , on which the rear ends of the main frame pivot; the front overhead group, the overhead beam and the rear overhead-brace assembly which support the sheaves over which the cable from the PCU travels to raise and lower the blade. The R76F or R76R trailbuilder was a cable-operated angledozer that can be operated by any type of front or rear-mounted PCU. The standard combinations for Caterpillar D7 tractors in service with the U.S. Armed Forces normally were: LaPlant-Choate R76F Trailbuilder with LeTourneau FTD7 front-mounted PCU and R76R Trailbuilder with LeTourneau R7 rear-mounted PCU. The blade of the Trailbuilder may be angled 30° right or left or used as a straight bulldozer. The blade may also be tilted up or down at either end by removing the front pushpole pins and changing the position of the pushpole in the jaws blade locks.
 |
| LaPlant-Choate R76F and R76R Trailbuilder Notice the possibilitie of horizontal angulation of the dozer (left below) and vertical tilt (center below) |
 |
| Caterpillar brochure photo showing a D7 tractor equipped with LaPlant-Choate R76F Trailbuilder dozer controlled by a LeTourneau FTD7 PCU and a Hyster D7N Trailer Winch in the rear. |
 |
| A Caterpillar D7 with LeTourneau R7 PCU and LaPlant-Choate R76R Trailbuilder dozer working at the beach. South Pacific, 1944 |
 |
| A Caterpillar D7 with LeTourneau R7 PCU and LaPlant-Choate R76R Trailbuilder dozer from US Army gives an LCM(3) a helping push... Operation Plunder - Crossing of the lower Rhine Germany - March, 1945. |
- LaPlant-Choate R71 Trailbuilder (hydraulic): the R71 trailbuilder was a hydraulic-operated angledozer, designed for the same operations as the cable-operated R76F and R76R trailbuilders. The R71 trailbuilder consists mainly of the steel blade across the front of the tractor; the main frame and pushpoles with runner shoes which support the blade in front of the tractor; the tractor mountings, on which the rear ends of the main frame pivot; the hydraulic system which includes a hydraulic pump, control valve, piping, oil reservoir and two hydraulic jacks. The hydraulic pump is bracked-mounted to the fan-belt pulley of the tractor engine and provides the hydraulic power to operate the jacks of the trailbuilder to raise and lower the blade. The trailbuilder is attached to the outside of the track frames on pivot-type mountings, and is lifted and lowered by means of two jacks. The jacks are double-acting, which allows down-pressure to be applied to the blade, as well as lifting-power. The blade may be used in the straight or bulldozing position, or angled 30° or right or left-hand delivery. The blade may also be tilted the same way as with the R76F and R76R trailbuilders.
 |
| Caterpillar D7 equipped with LaPlant-Choate R71 Trailbuilder (hydraulic) with blade angled 30° to the right. |
 |
| Caterpillar D7 tractor LaPlant-Choate R71 trailbuilder dozer clearing debris from street at Nantes, France - 1944 |
 |
| Caterpillar D7 LaPlant-Choate R71 Trailbuilder (hydraulic) and the LeTourneau R7 PCU in the rear. The bulldozer is clearing rocks from roadway between Colli and Cema Italy - 1944. |
 |
| "We can do it" A british girl operating a civil Caterpillar D7 LaPlant-Choate R71 Trailbuilder (hydraulic). Somewhere in the countryside of England, 1943. |
Glossary:
- Bulldozers: (fixed blade) are used for moving rock , uprooting trees and stumps, leveling land, grading and maintaining roadways, digging holes and filling, stripping. A bulldozer blade was initially operated (or pushed) by a team of mules or horses. Early bulldozer blades, mounted on tracklaying tractors, were controlled by the operator by means of hand wheels. In the mid- to late 1920s, a hydraulic-controlled bulldozer blade was invented by LaPlant-Choate, and R. G. LeTourneau introduced a cable-controlled bulldozer, operated through a front- or rear mounted power control unit. With the time, the name bulldozer became associated with the complete bulldozer-equipped tractor, and not any longer with the attachment alone.
- Angledozers: (blades capable of being angled and tilted) are used for clearing, stripping, leveling, side-hill sloping, ditching, carving out roadways, building levees , and for airfield construction.
- Power control unit (PCU): used to operate other mounted equipment like bulldozers or angledozers and towed equipment like scrapers, graders or rooters.
- Pipelayers: are side-mounted cranes powered by the tractor, and will lift, lower, carry or bend pipes in pipeline construction. They are also useful in handling and placing poles and piles, setting machinery and in heavy loadlifting.
- Anglefillers: used for trench filling in combination with pipelayers, and eliminate the use of a separate backfiller or bulldozer.
- Winches: designed for towing purposes and for moving heavy loads that are too heavy to be properly handled with the tractor 's drawbar. They are also very useful in recovering disabled or stuck vehicles
Specs:
| Caterpillar D7 bulldozer LeTourneau R7 power control unit | |
|---|---|
| Type | Crawler heavy tractor M1 |
| Place of origin | United States |
| Service history | |
| In service | 1911-1945 |
| Used by | Allies |
| Wars | WWII, Korea, Vietnan |
| Production history | |
| Designer | Caterpillar Inc. |
| Designed | 1938 |
| Manufacturer | Caterpillar Inc.- American Car & Foundry |
| Produced | 1938 - |
| Number built | + 39.000 |
| Variants | see text |
| Specifications | |
| Weight | 14.400 Kg |
| Length Widht Height | 4.114 mm 2.539 mm 2.40m |
| Crew | 1 |
| Engine Transmission | Cat D8800 Diesel, 60/90 HP 4 cyl. 13.617 cc. 5 gears fwd. x 4 rev. |
| Speed forw. | 18 Km/h |
| Speed rev. | 11,2 Km/h |
| Fuel tank | 247 liters |
| Fuel consum. Traction cap. Eletrical sys. | 22 liters/ hour 11.500 kg. 6 Volts |
The kit:
For this commission job, my client request a Caterpillar D-7 with LeToureau power control unit...he thinks the steel cable system for lifting the dozer blade is really cool...
 |
The Devil is that the idle kit for this is discontinued and when we find one to buy, it costs a cornea and a kidney... The option was " militarize" the civilian version:
 |
| When life offers to you a lemon, make lemonade!!! |
The protagonists of this modeling "stage"... As I said, it's a commission job and the client wants these two beauties on his shelf, as fast and perfect as possible... Kojak is excited about the task!!!
 |
| The bald one is a very brave man!!! |
 |
| The engine is more complex than many complete kits... zillions of details and little pieces... But let's be strong!!! |
 |
| And while we're talking about details, why not go into more detail where it's needed: fuel injection ducts, made with thin copper wire |
 |
| Much better... |
 |
| fuel injection ducts, going from the injection pump to the individual injectors in the cylinder heads... |
 |
| Of course, all these countless little pieces drive anyone crazy!!! |
 |
| As Captain Edmund Blackadder would say: Wibble!! |
 |
| It's crazy, but the engine is a beauty... |
 |
| Installing the engine on the tractor chassis right view |
 |
| The engine on the tractor chassis left view |
 |
| Completing the construction of the tractor cockpit... right view |
 |
| Notice the tractor's semi-elliptical equalizer spring... |
 |
| The two track-roller frame assemblies, after its construction, waiting next to the tractor chassis |
 |
| The two track-roller frame assemblies, glued in position... Left view |
 |
| The alignment of the track-roller frames are fundamental for the final finishing of the kit. Right view |
 |
| Rear view. Notice the rear end of the tractor's drawbar, supported by a plate which allows the drawbar to swing freely, or to be pinned in any of five positions. |
 |
| Seabee badge |
 |
| Seabee 34th Naval Construction Battalion shield |
 |
| The real 34th CB badge (left) and the redrawn drawing, right. |
 |
| Seabee 34th Naval Construction Battalion badge |
US Navy vehicles were painted in the typical blue-gray. My idea is to make the vehicle externally in this color, but keeping the "internal" olive-drab color, like a US Army production line vehicle that has been repainted to the Navy colors. In this case, the engine and the internal parts of the engine hood would be olive-drab. But first, a color profile:
 |
| Preparing for the "internal" painting... Notice new details in copper-wire in the engine Right side |
 |
| Notice new details in copper-wire in the engine Left side |
 |
| Olive drab in the engine and internal parts of engine hood |
 |
| Adding color details to engine and a little washing... Diesel engines are very "oily"... Right side view |
 |
| Color details in the engine with washing... Diesel engines are very "oily"... Left side view |
 |
| Top engine cover glued in place. Many details are lost, but still, it's a beautiful sight... Left view |
 |
| Top engine cover glued in place. Notice the air filter in place. Right view |
 |
| Mea culpa...mea culpa!!! |
The drums of the PCU are very, very "disgusting" to build, with dubious and unresolved parts and fittings... I consider this the SECOND WORST PART of the kit's construction... because believe me, there's something worse than PCU drums ahead...
 |
| Built the drums of the LeTourneau R7 PCU is annoying... Self-harm is more fun... |
 |
| These drums are just complicated to build... |
But the worst comes now: built the secondary pulleys of the PCU... Man, I'd really like to say some nasty words to the engineer who designed this!!! Tiny parts, but really minuscule... and with different materials, ie plastic and metal together, in impossible fittings and with no spare parts. If one of the tiny pieces goes flying out of your tweezers (and it has happened several times at this stage...), the only option is to find the damn thing!!! There is no plan "B"...
 |
| The PCU secondary pulleys are a true HORROR!!! |
 |
| This is the WORST PART of the kit!! |
Sorry, I could not take detailed pictures of these stages because I just couldn't... If you stop the building to take a picture, something disappears, misaligns or falls out... Unbelievable...
I'd rather pull a tooth out without anesthesia than build something else like that!!!
 |
| I swear I prefer... |
But not everything is horror and madness in this project... The good news is that the kit comes with ALL the parts of the military version. You just use the Instruction Manual of the military version (which you can download from the MiniArt website) to transform this civilian Caterpillar D7 into a uniformed girl!
Well done, MiniArt!!
 |
| The "Treasure Map" for you to transform the tractor from the civil version into a military one. |
 |
| Notice the steps and headlights in the tractor's rear. Military version, by the Military booklet!! |
But my joy was short lived...I found out that I was drawn with a kit that came from the factory with a tree of parts missing... The Hc one... with parts Hc 1,2, 3 and 4.
 |
| Missing tree and parts... Man, let's do this in scratch... We can do!! |
The good news is that the PEa1 part (in metal) is practically a template for the front A-frame pulley set that is missing...I'm going to use the metal piece of PE as a template to cut two pieces of 0.7mm thick plasticard...
 |
| First, let's draw the outline and cut two identical pieces out of plasticard, with a scalpel and patience... |
 |
| Once the pieces are done, let's unite with the rest of the kit... |
 |
| After 15 minutes of work, the missing front A-frame's pulley set is ready... |
 |
| The front A-frame's pulley set in position left view |
 |
| The front A-frame's pulley set in position...And that's a relief... right view |
 |
| Immortal Gods!! Am I doing something wrong??? |
But it was just a matter of checking the original photos and the schematic drawings to make sure that the A-frame is really offset to the right. Man, this kit is really trying to scare me to death!!!
 |
| Notice the rear A-frame offset to the right |
After that little scare, let's get back to scratching the rear pulley system...
 |
| The rear pulley done... Notice the the endings of the ridgebeam It's a relief to finish those details that were missing... |
 |
| Final details: bolts (red arrows) and testing the cover of ridgebeam (blue) left side |
 |
| Final details: bolts (red arrows) and testing the cover of ridgebeam (blue) right side |
And now for the ultimate HORROR: time for damn link-by-link tracks... And I JUST HATE any and all link-by-link tracks. They can be beautiful and wonderful, but even so, I viscerally hate these Devil inventions!!! First of all, cut ALL the damn pieces involved in the process... THERE ARE NO EXTRA PARTS!! DO NOT LOSE OR BREAK ANY OF THEM, or you will regret it bitterly... and, in addition, separate the pieces in an orderly manner, as their construction DOES NOT ADMIT MISTAKES. I know, as I built a kit similar to this a few years ago and the memories are very vivid!!!
 |
| Tibetan monk patience, now... Main parts cut and separated. The Dc3 and Dc2 parts cannot be lost or broken... They are EXACTLY in number...as well as the pads of the links... The Dc1 pins come with a lot of extras... don't worry... |
Forget the MiniArt instructions... the sequence I used is much easier, faster and smoother... Here's the Treasure Map: After cutting (from sprue) all the pieces (cleaning the burrs will be later...), separate them into marked containers and start gluing 70 pieces Dc3 with the Dc1 pins. DO NOT GLUE TWO Dc3 PIECES...leave them alone, as they will be very important to "close" each track, at the end of construction... These two pieces are the "Dc3 alone"
After assembling the 70 sets, you can start "cleaning" the parts, as it is easier to hold and the possibility of the part disappearing or breaking is much smaller. Thus, cleaning is safer and faster!!!
Installing the tracks on the suspension sponsons. Note that the final connection was made with a 1.1mm Plastruct rod, instead of using a Dc1 pin...Much easier. IMPORTANT DETAIL: OBSERVE THE DIRECTION OF THE LIKS...
With the two tracks installed, glued together, dry and tight, you can use a sharp scalpel and remove the burrs from the Dc2 pieces that were still dirty. With everything in position, the final cleaning of the tracks is much easier and safer...
 |
| Build 70 sets with Dc3 and Dc1 pieces... Leave 2 Dc3 pieces without pins (Dc1) Notice the burrs in the little parts... |
 |
| The 70 sets after cleaning: no more burrs!! |
Now, let's build the first track: for this, separate 35 Dc3+Dc1 sets, one Dc3 alone piece and 36 Dc2 pieces (still "dirty"...)... Look at Dc3 and Dc2 pieces: they have a smaller hole and a bigger one. The smaller one has a small external protrusion and it is in this hole that the pins is glued. In the larger hole, the pins "spin". Start by placing a Dc3 set in the larger hole of the other set. With the two engaged, place the Dc3 alone piece on the pin that would be the end, and the first Dc2 piece of the sequence, which locks the first link. Then just repeat the sequence... The important thing is that the Dc3 alone piece stays at the end (or the begginning...). See the picture and photos below. This "cake recipe" is for making one track. To make the other, just repeat the process...
 |
| The Map of Treasure... Notice the the places to glue and not glue, so that the track can be malleable... |
 |
| The start of a track... Work with method and patience... it seems to be horrible, but it's just boring!!! |
 |
| First track under construction... |
 |
The two tracks done... Notice the absence of the pads... They will be installed last... |
 |
| "Closing" the track with Plastruct rod... Easy!! |
The links look like a lying "V". The aperture of the "V" points, in the upper portion of the track, towards the front. See below:
 |
| Notice the the direction of the track links, at its top. The future position of the pads depends on the position of the links... Right track: The aperture of the "V" points forward, in the top portion of the track. |
 |
| Left track: the same care when installing the links: The aperture of the "V" points forward, in the top portion of the track. |
 |
| Notice the links, clean and burr free... right view |
 |
| Track links, clean and burr free... leftt view |
Next step: the pads of the tracks!!! In the ventral part of each pad of the track there are 4 small holes, that must fit in 4 small pins in the links of the tracks. These holes follow the shape of a "V", with the "teeth" of the pads pointing towards the front of the vehicle, when the track is in its upper position. See pic below:
 |
| The ventral view of pad, where the holes and pins should line up for the glue. This is why the orientation of the "V" opening was important... |
 |
| Gluing the pads to the links, with the teeth of the pads pointing forward... |
 |
| A good tip is to enlarge the holes of the pads with a 1mm diameter dental drill, manually rotated, to allow a better adjustment of the position of each pad... |
 |
| Something like that... note that the hole shouldn't go through the thickness of the pad. That's why I used the drill by hand... |
 |
| Left track ready!!! |
 |
| ..and the right, also!!! |
Well, the worst part is really behind us... without the damn LBL to muddy the ideas, we can dedicate ourselves to the final details, following the military version booklet, of course... and to celebrate the new phase, I decided to make a small detail in scratch: a quieter exhaust, based on real photos:
 |
| The idea: notice the exhaust... right view |
 |
| The evidences of the real detail... Please, quiet!!! |
 |
| Left side: a little big detail... Notice the headlights in the front A-frame, too... |
 |
| Dozer time, now!!! Gluing the parts... |
 |
| The dozer in position... Notice the radiator armour in place... |
 |
| The LeTourneau WCK7 angledozer is really beautiful very well done, MiniArt!!! Left view |
 |
| Notice the hoist sheave installed above the dozer... |
 |
| The LeTourneau WCK7 angledozer in position right view |
 |
| Rear view The dozer is in dry-fit... |
I was forgetting the right drum control lever of the LeTourneau R7 power control unit...There are so many small pieces that we end up going crazy. This type of piece breaks very easily when handling the kit. So I left it to install in the final steps...
 |
| Man... lever in position, with a plastic block to support in the correct position while the glue dries... |
And now, the best part: painting and markings... First of all, let's protect the color of engine: before painting, we'll insulate the engine area from spray paint with toilet paper. I insert pieces of soft toilet paper with tweezers and place these papers carefully, so as not to fracture the details (levers, knobs, etc...). Then, with a brush moistened with clean water, I "adjust" the wet paper on the edges and corners, allowing for a good sealing... Don't forget the wire rope in the right drum of PCU...
 |
| Notice the "isolation" of the motor area and the wire rope of the PCU. right view |
 |
| "Isolation" of the motor area left view |
With the insulation in place, let's apply a thin coat of white primer, on the kits and some accessories...
 |
The white primer applied to kits and accessories. I am painting and applying decals together with the |
With the dry primer, we will cover the kits with the US Navy color: bluish gray.
 |
| The two Seabee girls with colors!!! US Navy bluish gray |
 |
| My cake recipe...Attention: I'm not a poster-boy for Vallejo!! I like and use this awesome paint... as well as many others... At this point (and many others...) I'm not a radical or Shiite rivet counter! |
 |
| Fifty shades of Navy grey... Exciting isn't it??!! |
 |
| The angledozer with shades... |
 |
| and the two Seabee girls with a good layer of Pledge to avoid the infamous silvering... |
While the paint (and Pledge) dries, let's get to the decals: I'll show you a step by step on how to make and apply your own decals.
Monochromatic Decals Tutorial:
Step 01 - Choosing your markings: After your research, draw or get drawings of the desired markings. Something like this:
 |
| Caterpillar D7 Seabee markings |
Step 02 - Transform your drawings into vector files: Vector files are "drawings" that maintain sharpness and proportionality, regardless of the size of the image or drawing. Unlike JPEG or GIF files, which warp (and blur) when enlarged or reduced, vector files are ideal for reproducing images at any scale. But for that, you need the drawing (or art) to be clear and you will need the REAL size that this drawing (or art) will have after being ready, in the vectorization program. To make the primary drawings, large and simple, in JPEG or GIF, I use a free software called PhotoFiltre 6.5.3 (but it can be any image editor, like Photoshop or much simpler...). For vectorization, I use CorelDRAW software. let's see an example: Below, you can see the print screen of my computer, with Photofiltre sofware
 |
| Print screen of my computer... You can see the markings and the Seabee badge in detail, in the left of the screen. I copy this art with Control+c and paste the image in the CorelDRAW software (see below) |
 |
| The Seabee badge is paste in the CorelDRAW. |
Step 03 - Getting the measurements of your future decal: Now, you will measure where the badge will be in your kit (I use the metric system) and with the space in millimeters obtained, you will put this value in the CorelDRAW software for it to convert the JPEG image into a CDR image (vectored).
 |
| Getting the size of the space where the badge will be installed... |
I'm not going to explain all the steps here, because they are long and complicated, but there are "n" tutorials on the Internet about it... The important thing is to know how many millimeters your full-size image of the kit will have to fit in the desired space. In this case, the size of the Seabee badge was 8mm in diameter. Repeat this measurement on all the drawings on your decal sheet...
 |
| All drawings in their actual sizes, vectorized and grouped for future printing. |
Step 04 - Printing your decals on plain paper (field test): After all the drawings are ready in the CorelDRAW software and in their respective sizes, print your "decal sheet" on an A4 sheet to do a "field test", that is, to test if the sizes you obtained with your ruler were correct.
 |
| The "decal sheet" printed in paper A4. Notice the size of the drawings... |
Now, cut the paper with fine scissors as close as possible to the drawing and, with a drop of water, apply the "decal" in the desired place to test the size... A picture is worth a thousand words!!!
 |
| The "paper-decal-sheet" in front of the kit... The sizes seem correct to me...Let's see individually... |
 |
| The engine hood area: the Seabee badge is perfect, the number 59 needs to be reduced a little the census number is correct and the Allied Star in the top of the hood can be increased a little... |
 |
| Yes..no doubt: the Allied Star can be increased a little... |
 |
| Rear markings: the Star and number 59 are perfect; the markings in the Power Control Unit It needs to be reduced a little... |
 |
| Front view; the letters are ok and the Allied Star also... In this case, I'll use a stencil, for painting the star, not a decal... The holes would turn the decal installation into hell!!! |
Step 05 - Printing the decal: After the size corrections, the drawings are ready for the "true" impression. In this case, I'm going to print the two decal sheets (Caterpillar and Chevrolet G7107) as they will all be in black (which makes the decal a lot easier) and I can group the work in just one step. Detail: to make the Chevrolet decals, I repeat all steps of measurements and proofs of the sizes of the drawings... Here's a picture of the thing:
 |
| Print screen of my computer: above, the Caterpillar D7 decals; below, the Chevrolet G7107 ones. |
Now, I print the "artwork" in the center of an A4 sheet, so I can then place a piece of transparent decal over that print.
 |
| The artwork printed in a A4 paper sheet. Notice the size of the area that will be covered by the clear decal sheet. |
The transparent decal sheet cut and applied over the printed designs, with two strips of adhesive tape. These adhesive tapes cannot invade the area of the drawings, of course. Use high quality tapes, so there is no danger of these tapes "rolling up" in your printer.
 |
| The transparent decal sheet over the primary impression, stabilized by the two strips of adhesive tapes. Everything clean and organized... |
Once this is done, you will return the prepared A4 sheet to your printer's feed tray, in the same position as the "primary" print and command a new print, which will be printed exactly on the decal area. The result was this:
 |
| The decal sheet printed in my Laserprint... |
 |
| Notice the adhesive tapes in position, away from the drawings... |
Step 06 - Using the decal: Cut the decal sheet from the host sheet (this is so Alien...)
 |
| Removing the decal sheet from the A4 host sheet |
 |
| The decal sub-sheets, in front of each girl... Now, just apply!! |
Don't forget that the decal sheets are one-piece. that is, you will have to individualize each design by cutting as accurately as possible. Then, just apply the decals, according to the established standards!!! But I'll avoid the nightmare of putting a decal on the perforated radiator front armour. I'm going to paint the Allied star with a nice Jurassic Verlinden stencil!! Oldie, but goldie!!! First, markings with pencil to centralize the Star:
 |
| References.... |
 |
| Adapting Verlinden's metal stencil on the Cat D7's nose... Verlinden rules!!! |
 |
| A very, very good stuff US stars template no. 1 - Verlinden |
 |
| Painting in black, with Andrea Colors... Indeed, Kojak love many brands of paints... |
 |
| And the result: good job, Sailor!!! |
 |
| Now, Panzerserra decals... |
 |
| Painting and decals togheter!!!! |
 |
| Installing the angledozer in position.... Indeed, a good job!! |
 |
| Right side!! |
 |
| Front view |
 |
| rear view |
 |
| Left view |
 |
| The front steel cables... left view |
 |
| The front steel cables... right view |
 |
| The steel cable from Power Control Unit. I choose run my wire rope directly from the PCU drum to the tractor's A-frame rear pulley, as in many original photos. I didn't run the cable through the PCU's "butterfly" pulleys for sanity's sake... |
And after a sand and earth based weathering typical of the Pacific theater of operations, my girl was ready: With you, Caterpilar D7 with LeTourneau R7 Power Control Unit and LeTourneau WCK7 angledozer, belonged to Seabees (US Navy), 34th Naval Construction Battalion, working in the construction of Halavo Seaplane Base, in Florida Island (Solomons Islands), in September, 1943.
 |
| Caterpilar D7 with LeTourneau R7 Power Control Unit and LeTourneau WCK7 angledozer - Seabees (US Navy) 34th Naval Construction Battalion Florida Island (Solomons Islands) - September, 1943. |
 |
| Caterpilar D7 with LeTourneau R7 Power Control Unit and LeTourneau WCK7 angledozer - Seabees (US Navy) left view |
 |
| Caterpilar D7 with LeTourneau R7 Power Control Unit and LeTourneau WCK7 angledozer - Seabees (US Navy) 3/4 left rear view |
 |
| Caterpilar D7 with LeTourneau R7 Power Control Unit and LeTourneau WCK7 angledozer - Seabees (US Navy) left rear view |
 |
| Caterpilar D7 with LeTourneau R7 Power Control Unit and LeTourneau WCK7 angledozer - Seabees (US Navy) left rear view |
 |
| Caterpilar D7 with LeTourneau R7 Power Control Unit and LeTourneau WCK7 angledozer - Seabees (US Navy) right view |
 |
| Caterpilar D7 with LeTourneau R7 Power Control Unit and LeTourneau WCK7 angledozer - Seabees (US Navy) |
 |
| Caterpilar D7 with LeTourneau R7 Power Control Unit and LeTourneau WCK7 angledozer - Seabees (US Navy) 3/4 right front view |
 |
| Caterpilar D7 with LeTourneau R7 Power Control Unit and LeTourneau WCK7 angledozer - Seabees (US Navy) 3/4 left front view |
 |
| Caterpilar D7 with LeTourneau R7 Power Control Unit and LeTourneau WCK7 angledozer with Kojak and Rover, the dog. |
 |
Caterpilar D7 with LeTourneau R7 Power Control Unit and LeTourneau WCK7 angledozer two heavy-duty girls!! |
 |
Caterpilar D7 with LeTourneau R7 Power Control Unit and LeTourneau WCK7 angledozer |
 |
| Two Seabee girls, side by side: Caterpilar D7 with LeTourneau R7 Power Control Unit and LeTourneau WCK7 angledozer and Chevrolet G7107 4X4 1,5t cargo truck (G506) |
 |
| Caterpilar D7 with LeTourneau R7 Power Control Unit and LeTourneau WCK7 angledozer - Seabees (US Navy) 34th Naval Construction Battalion Florida Island (Solomons Islands) - September, 1943. |
Colleagues, this project was very, very difficult. The kit is simply outstanding, but definitely not a beginner's kit. The pieces fit perfectly, but are overly detailed, in my opinion... The booklet lacks in some points, the main one being the steel cables through the pulleys... But the final product is really spectacular...
...and remember:
 |
| (dedication painting to the Seabees, at the Seabee Naval Museum) |
