Written by: Hobo
I heard someone asked for a simpleton explanation of how cats work so here it is.
First of all every moving part on a snowcat besides stuff like windshield wipers are powered by hydraulics. This includes things like the tracks, the blade, raising and lowering the cab and rear deck as well as the tiller (the thing that cats drag around on the the ski runs).
Located behind the Snowcat’s diesel engine are two large hydraulic pumps that power all these things. The biggest draw of power are of course the tracks. The tracks consist of five rubber belts bound together by the aluminum growser bars. They roll on rubber tires and are driven at the rear by a large sprocket. When the cat is driving it is steered by slowing down and speeding up the tracks. When you want to turn right, the left track speeds up and pushes the cat right, and to turn left the right track speeds up and pushes the cat left.
This is done with 2 control sticks in the drivers left hand, left and right sticks steering left and right tracks. The driver has a gas pedal to put power to the tracks or the throttle can be locked at a chosen rpm in which case the sticks are moved back and forth for forward and reverse.
Some cats have steering wheels instead of sticks and these cats are driven with the gas pedal only with a button on the thumb for forward and reverse. One thing that surprises some people is that snowcats have no brakes in the sense that there is no brake pedal. When you want to slow down you simply let off the gas or pull back on the sticks and when going down hill the weight and momentum of the tracks pushes against the hydraulic system which pushes against the engine that kicks on the engine brakes to slow you down. There is a parking brake that basically locks the drive sprocket and without it on the cat, will roll away.
The snowcats blade on the front is powered by a series of hydraulic rams and has 12 different functions: up and down, pivot left and right, tilt left and right, curl forward and back, and 2 wings on either side that open and close. The blade is controlled by a joystick on the drivers right hand. Moving the joystick forward and back, left and right gives you 4 functions and pushing a button with your finger gives you 4 more, and pushing different button 4 more, adding up to 12.
Driving a snowcat with good conditions (cold temps and firm roads) is not to hard to learn but warm temperatures and deep snow is when things get tricky. Spinning out your tracks and getting stuck can happen quickly if you’re not on your game. Using the blade is the hardest part of snowcat operation, it is very touchy and digging holes and making a mess of the roads is easy to do when first learning. It takes years of practice to master.