1.  Straight ahead 2. Angled to the right 3. Angled to the left When the combination blade is angled to either side, it throws snow to that side. The combination blade is usually used as a V-plow when the first pass is made to open the center of a wide pavement. After this, it is angled to throw the snow to the right or left, depending on the direction the traffic travels on the road. If the pavement is short, it will take longer to reverse the blade angle than it will to deadhead for another pass to the right. Blowers Augers on a snowblower (fig. 14-41) feed snow into high-speed augers, rotors, or fans that blow the snow a great distance. The fan and augers are powered by an auxiliary engine independent of the truck engine. This power is transmitted  from  the  rear  (auxiliary)  engine  to  the  augers and fan by a drive shaft between the engine clutch assembly and the blower assembly. This has a shear pin that  will  break  any  time  the  blower  assembly  gets  an object in it that will not pass through the blower. In some instances, the fan and each auger have a shear pin instead of the drive shaft having one. Aircraft chocks, fire extinguishers, and rocks are three of the items that break many shear pins and cause much damage to blowers. Movable items should  be Figure   14-41.—Snowblower. removed before snowstorms. Once they are covered with snow, they can be picked up with the snow and jammed into the blower fan and shear pin and damage the blower. On the other hand, rocks may not do much damage to the blowers, but when they are blown out of the blower, they may hit aircraft or equipment or even people.  If  you  must  blow  snow  where  there  are  rocks, raise the blower a couple of inches off the ground to prevent picking up too many rocks. Engaging the blower clutch too fast, engaging it with the rear engine running too fast, or engaging it with the blower assembly clogged with snow will shear a pin. Remember that the shear pin is a safety device to prevent breaking any other part of the blower. For this reason, you  should  carry  extra  shear  pins  with  you  when operating  a  blower. The blower is for removing snow that is too deep to be plowed or that has been plowed into windrows. The chute on the top in the center above the fan is for directing the flow of snow. This chute can be rotated to blow the snow to the right or left. Snow is usually blown to the right. It can also be extended to control the angle and distance that the snow is blown. If you adjust the chute properly, snow can be blown into trucks to be hauled away. Blowers are operated by throttling the auxiliary engine to full-governor speed and by adjusting the truck speed so the blower operates at full capacity. When the truck speed is too fast, the blower will clog and shear a shear pin. A foggy discharge will result when the truck speed is too slow. When the truck speed is just right, the snow is compressed by the fan and the discharge from it pulsates. One good way to tell when you are operating to capacity is by a good even roar, not lugging, but with the governor letting it work. Graders Graders can be used to remove snow from streets, parking  lots,  roads,  runways,  and  taxiways  to supplement  the  other  snow  removal  equipment. A grader is often used during clean-up operations after the major snow removal job has been accom- plished. If slush is to be removed with a grader, many times the cutting edge is removed from the moldboard. A strip of hard rubber is bolted to the moldboard in place of  the  cutting  edge.  This  prevents  possible  damage  to the  pavement  surface,  thus  saving  a  great  amount  of maintenance work in the spring. 14-34