So I was driving behind a cement truck the other day, and noticed something. Now most people understand that the drum rotates in order to agitate the cement mixture and keep it liquid during transport to a construction site; what I’m talking about is how that is accomplished. The mechanically easiest way to make something on the back end of a truck turn presumably would be to just hook it up to the drive axle (or whatever that piece is called), since that’s exactly what it does for the rear wheels. That would make the drum turn at a rate directly related to ground speed. This clearly is a problem, as stoplights would give the mixture chances to solidify. You might think the solution would be to get away from such complications by just having a separate engine or motor running the drum, not related to that of the truck. However, my observations while following it showed this is apparently not the case. This may be due to the problems that could arise in terms of a power supply or fuel source for that, being in some ways redundant. It seems the rotation of the drum is directly related to the engine speed of the truck, keeping it moving at idle and changing as the truck accelerates from a stop and goes through its gears. That’s all quite well and good while on the road, and solves a number of other problems, but leaves one more that I have to ask about: Can cement trucks park, with the engine off ever other than at the end of the day after being cleaned out?

Share This

#