This article was previously posted on Construction Collector, but we enjoyed it so much it seemed time to share it with a wider audience.
Classic Construction Models builds a big bulldozer
Review and Photos by Bill Cawthon
Published in Model Railroad News, March 2006
MODERN earthmoving operations demand big machines. Not only to mine the volumes of ore and coal necessary for modern society, but to restore the land for other uses. All with an eye to cost-efficiency. The more earth that can be moved in each pass, the more productive the operator and equipment can be.
While we often think of the giant draglines and hydraulic excavators filling a continuous stream of huge dump trucks, there are a number of other earthmovers that also perform important functions, especially when the job calls for mobility or the ability to maneuver in a space too small for the big diggers. That’s the time the smaller wheeled and crawler tractors really shine.
Of course, smaller is a relative term. Some of these machines weigh in at over 100 tons and are more than two stories tall.
One of these is the Caterpillar D11R Carrydozer, the top bulldozer in the Caterpillar line and second only to the Komatsu D-575A3 as the world’s largest crawler dozer. Now Classic Construction Models has produced a limited-edition brass model of this magnificent machine and loaned MRN one for a close-up examination.
The Caterpillar D11R CD crawler dozer was designed for high-volume earthmoving applications such as mining and quarry operations and large land reclamation projects. Everything about the D11R CD is big, from its operating weight of nearly a quarter-million pounds to its 425-gallon fuel tank. With a 63-gallon capacity, the cooling system alone holds more fluid than three typical passenger-car gas tanks.
|A couple of construction workers check out Classic Construction Models’
D11R Carrydozer while giving you an idea of the true size of the prototype.
Note the see-through engine covers and the delicate hydraulic control lines.
The D11R CD stretches thirty-five feet six-inches from the leading edge of the blade to the back of the ripper. It stands fifteen-feet six-inches tall from the base of its three-foot wide treads to the top of its rollover protection system, called a ROPS in the trade.
It takes a big engine to move such a massive tractor. The D11R CD is powered by a twin-turbocharged, 2,105 cubic-inch Caterpillar 3508B diesel engine that cranks out 850 horsepower. That much horsepower doesn’t translate into speed; the D11R CD can’t quite hit twelve miles per hour in its top gear and when it’s in first gear, it can’t keep up with a brisk walk. On the other hand, just about anything you’d care to hook up to the D11R CD will find itself moving. This includes most houses and your choice of North American locomotives.
As you would expect, such a big machine can do some mighty big jobs. The blade can dig a maximum of just over thirty inches and, depending on configuration, can move up to fifty-seven cubic yards of material at a time. To give you an idea of how much that is, it’s enough to fill four typical dump trucks and start on a fifth. The rear-mounted hydraulic ripper, used to break up earth and rock to facilitate their removal or to prepare former mine sites for reforestation, has a seven-foot blade with maximum pryout force of 142,390 pounds.
Based in Beaverton, Oregon, about 240 miles north of MRN’s offices, Classic Construction Models is entering its sixteenth year as a manufacturer of museum-quality brass replicas of construction and earthmoving equipment. In that time, CCM has become one of the most respected names in the field.
|The D11R CD can move fifty-seven cubic yards of material with each
pass making it the perfect machine for major land reclamation projects.
The CCM model captures each detail including the holes drilled in the blade.
As those of you with a brass locomotive or railcar know, it’s the ultimate medium for creating a prototypically accurate replica and allows detail unobtainable in any other material. Considering the number of brass models I have been privileged to review in recent months, I was expecting a top-flight model. The CCM Caterpillar exceeded my expectations. World-class, museum-grade – call it what you will – this is an incredible model.
As CCM works very closely with the manufacturer, it comes as no surprise that the model scales out very well compared to manufacturer specifications. Most of the measurements I was able to take were within a few tenths of a scale inch of precise 1:87 scale. The major variations I found were mostly easily explained by differences in the equipment shown in the base D11R specifications and that fitted to the machine that served as the prototype for the CCM model. For example, the specs for a D11R were based on a dozer with twenty-eight-inch-wide shoes, the term for the individual links in the crawler track. The CCM model is fitted with the D11R CD’s wider extreme-duty shoes, which add sixteen inches to the track width.
The only major variation I couldn’t explain was the blade. The one on the model is a scale fourteen inches wider than the blades listed for the D11R CD in the Caterpillar specifications. However, as close as the model is in every other measurement, I feel sure the explanation is that, as with the shoes, the model is based on a different prototype. (Please see Author’s Postscript at the end of this article.)
Marvelous details are found everywhere you look. You start with the free-rolling tracks, functioning tensioners and positionable blade, and ripper with an adjustable shank, and then you look more closely. The hydraulic pistons work smoothly, replicating the movements of the prototype and major hydraulic lines are reproduced including the flexible control lines leading to the blade and ripper.
|The super-size ripper can dig into hard-packed soil and rock to break
it up for removal or to allow for replanting after mining has ended.
As you can see from the pictures, the side engine covers are perforated, allowing you to look in at the engine and radiator fan detail. What I couldn’t get in a photograph is the see-through grille. Of course, the various rails and grab irons are properly sized for the hand of a scale figure, and the cab looks ready for a miniature operator to climb in and fire up the engine.
One minor detail I like is the way Classic Construction Models does the headlights. As you can see in the picture, they look like real headlights. Realistic headlights are a difficult effect to create, requiring a parabolic surface and a mirror-like finish. It would seem to me that any model priced north of four hundred dollars should have them, but a surprising number have painted lights that don’t live up to the quality of the rest of the model. That’s definitely not the case here.
While this isn’t a toy to toss to your four-year-old on his way to the sandbox, I was pleased to see how sturdy the CCM model really is. The joints are strong and you can position the various moveable components without fear the whole thing will come apart in your hands. As this model was on loan to us, I didn’t put it through its paces, but I would think you could actually lower the blade and move some earth or break up some packed dirt with the ripper.
As is the case with most brass models, CCM’s Caterpillar D11R CD is a limited edition. The run was limited to a total of four hundred pieces, divided into one hundred-fifty each of Caterpillar yellow, and a special anti-glare paint scheme, and a hundred in mine white. The base Cat yellow model retails at $409.95; the others are each ten dollars more. Our loaner was number 364 in the series, supplied in the Caterpillar yellow and flat black anti-glare paint.
If you’re a fan of the big machinery of the modern era, the Classic Construction Models Caterpillar D11R Carrydozer is definitely a worthwhile investment. Whether it’s parked on the shelf with your most prized locomotives or working on your layout and dwarfing everything around it (it’s three scale inches taller than an AC6000CW), you will be one of a very small group of people who get to enjoy one of the most detailed heavy equipment models in HO scale.
When I wrote the above review, I mentioned that I didn’t have sufficient information to check the scale accuracy of the blade. After this review first appeared in print, Classic Construction Models was kind enough to let me know the prototype for the blade on their replica is a special high-capacity model Caterpillar offers only on the D11R Dozer. I hope no one takes my comments as a criticism of this outstanding model. -Bill Cawthon