|High resolution photo|
|Fiat Allis 16-B|
Rendered here is VanNatta's favorite dozer. The 16-B is a mid 1970's rendition of the classic Allis Chalmers HD16. This is a D-7 class machine with 195 HP which weighs in at around 50,000 lbs.
With the advent of the B series, AC finally got behind it the heritage of the cable controlled blades and actually integrated the hydraulic system into the machine instead of having it as a 'hang on' attachment. the earlier versions of this machine had a hydraulic control unit on the front of the dozer in lieu of a the cable control unit which was driven off the front of the crankshaft. This model has a 'real' hydraulic system with the pump driven off of the converter, and a pressurized hydraulic tank beside the Diesel tank.
The engine is a downrated HD-21 engine which was derived from its Buda origins. This is an excellent engine for a dozer and is famous for being easy to start (for a diesel). This is one of the reasons that loggers have liked them for 'tail cats' for their high lead logging operations because this application requires that the machines be started and stopped frequently just to move the machine a short distance. The lower photo shows the same machine after we converted it to a winch machine. The Hyster W8K powershift winch makes a powerful towing machine out of this dozer, particularly with the addition of the Young integral arch shown here.
We find this class machine 'right sized' for scarification work and light road building. The 2 barrel ripper with a single shank is good for pulling stump roots. The machine is light enough to spread a load of rock without smashing it to oblivion, and almost big enough to dig rock. Indeed we have used it to dig rock, but it won't even scratch some places where the larger FA-31 will roll out the rock. Indeed since we acquired the larger dozer we have made a studied effort to keep this dozer out of the rock digging mode. We had finished off a set of rails and pads digging rock, and when we replaced them, we bought standard pads instead of the more expensive 'extreme service' pads so we really don't want to put it in the rock now. The extreme service pad is a much heavier pad which in particular has a thicker grouser. It is, of course, appropriate, where you are going to work in rock applications but provides no advantage in dirt applications.
Over the years a dozer of this class has always been popular as sort of a 'compromise size'. In the 50,000 lb class it is about as large a dozer as can he hauled on a traditional 5 axle lowboy, and although the blade is 'overwidth', it is not so much so as to make permitting difficult. It is the smallest size dozer one would consider for heavy work such a rock ripping or road building. It is also at the upper end of the range of dozers that are quick and nimble.
A cynic would say that it is too small to push rock and too big to level your yard, and the optimist would say it is good for both. We bought it as a site preparation machine to stack brush in preparation to forest regeneration, a task for which it is well suited. It is also big enough to retrieve a truck stuck in the mud and to do modest road building. I say this only conditionally however. You have to remember that it only weighs in a 25 tons, and dozers do a pretty good job of retrieving things that don't weigh more than they do. Loggers, especially those who do cable logging usually have a big tower or something around that weighs over 50 tons, and this sized dozer doesn't cut it when a 50 ton tower or shovel is mired down. A D8 class machine (around 80,000 lbs) is more or less standard fare around such sites. They aren't that much more powerful, but the weight and mass gives them a fair shot at helping a 50 ton machine which has a problem. Besides, if a logger knows how to move a 50 ton tower or shovel, a 40 ton dozer won't be a problem. In fact now in most places in the US permitting loads under 50 tons and under 14 feet in width is not all that difficult. It may take 8 or 9 axles and depending on the road, flag cars, but it can be done.
Since you can't just call 'triple A' if you put a giant toy in the ditch there is much to be said for having something around to retrieve it when you do.
|Fiat Allis 16-B|
A dozer operator is often called a 'cat skinner' which bears some explanation. First off understand that the 'Cat' is really a reference to Caterpillar Tractor, largest American manufacturer of dozers and something close to the inventor of them. It happens to be a trade name of theirs but is often used generically to describe all dozers, though the latter use will get you 3 lashes by Cat's trademark police.
The 'skinner' part of the description is really a 19th century term. The bull teams that were used extensively prior to the 20th century as beasts of burden where driven by 'bull whackers' or 'bull skinners'. Both terms refer to the fact that the team driver used a leather whip to control the team. It is only natural that if the guy driving a bull team is a bull skinner, then the guy driving the cat is a cat skinner. Oh, well!
I often get questions about how you run one of these things, and the answer is that it isn't too hard if you have the usual number of arms and legs, though an extra arm or two helps. If you just think of a dozer as a vehicle with 2 wheels you will begin to understand how it all works. Under normal conditions, both tracks are engaged to the engine with no differential. This means that the machine more or less goes straight. Now there are some dozers with differentials but that is a different story. The classic dozer has no differential, and both tracks (think wheel) are locked together. Now to steer such a dozer, you simply disconnect the power to one track. With power to only one track the machine will turn, not as readily as you might assume, but it will turn. to make sure it turns, besides a disconnection of the power you are provided a brake so you can force the disconnected track to stop.
You will find some variations of this theme from machine to machine, but the concept doesn't change. For example, one brand may have both brake pedals and both steering clutches located to be used with the left hand, while the traditional solution is one lever/pedal combination for the left and right hands/feet. Yet another brand has the brake incorporated into the steering clutch lever so pulling the lever partway releases the drive and all the way also sets the brake.
In deference to right handed folks, the blade is nearly always configured for the right hand, and if it is a power shift, the shifter will be in reach of the left hand. However, if the machine has a manual transmission (which is not common any more), look for a hand clutch for the left hand and a gear shift on the right. This allows you to set the clutch and work the blade at the same time. the controls don't vary much based on the size of the dozer so if you can skin a small dozer you can likely work a large one as well.