Once the roller operator has the answers to these and similar questions he can begin to plan how to get the job done. Once he knows the width of the mat, for example, he can figure out how many rolling passes he'll need based on the width of his drum. A 12-ft. paving pass, for example, is 144 in. across. If the operator is using a roller 66-in. wide he's going to need to go across three times to make sure to cover that mat. If he has an 86-in. roller he can do it in two passes, so the width of the mat and the width of the roller are essential in determining the number of passes and the rolling pattern for the job.
Two of the most important factors for the roller operator are time to the paver (and back) and the temperature of the mix and air. We used to refer to this as the "rolling zone" but now we call it the "temperature zone" of the mat. By knowing the mix temperature and the air temperature the operator can determine how much time he has to roll the mat before it gets too cold and he can't achieve proper compaction.
This is where a temperature gun comes in, and every crew, every roller operator, should have and should use his own gun. Even though these temperature guns only show the surface temperature (and even though it's only a ballpark figure) the gun gives the operator an idea of where he's at on compaction. As he becomes more experienced as an operator he will learn what that gun is telling him about the mat and what he needs to be doing to complete the rolling process effectively.
It's also important to know how much water (in gallons) the roller holds. This might not seem significant but here's why it is: How many gallons the roller holds determines who long before the operator has to go fill it up. It's a time issue. The operator wants to make sure he fills it at the right time, that he has the water truck right there when he's ready to fill so he doesn't delay the paver and so the paver doesn't have to stop. If the roller runs out of water the paver has to stop or it will get too far ahead and then the roller operator won't be able to achieve the necessary compaction and density once he starts back up.
The same goes for fuel. The roller operator would hate to run out of fuel on a pavement because if he does it could take 15-20 minutes to get the roller filled and restarted. Time is money on a paving job, so check the fuel tank and know how long the roller can run on a full tank.
Who can be a roller operator?
But the roller operator is not just going to roll, either; he's also going to have to be able to pitch in and pick up a shovel, rake, lute, use a plate compactor, and handle a maul or tamp shoes when the need arises because he's not always going to be sitting up above everyone, looking over the field. In fact, a successful roller operator is more than just a professional roller operator; he's a jack of all trades.
And that shouldn't be a problem for him because the roller operator will usually come from the crew of laborers. It's the first step up for people who want to be promoted in a paving crew, so it is open to any worker who has done well on the shoveling, luting, and raking part of the job and who is developing an understanding of how a finished pavement is supposed to look.
He is someone who is getting a good understanding of the overall paving process because the type of mix, thickness of mat, temperature of the air, speed of the paver and roller, and pattern of rolling all affect how he does his job. The roller operator needs to be more than aware of all these factors, he has to understand them and understand how they influence what he does.
And he needs to be paying constant close attention to what's going on with the mat. An applicant for roller operator needs to be quick to spot defects or potential problems, quick to know how to fix them, and quick to act to fix them. Why? Because when operating the roller he's not just out there rolling along, relaxing in the sun. He's looking at the mat to make sure there's no shoving, no checking, and that the mat's not cracking. He's inspecting the mat on each and every pass because only by keeping a close eye on the mat can the operator tell that the mat depth hasn't changed, that the temperature is where it should be, and that the mat's staying consistent. The roller operator is always inspecting and looking for imperfections.
The roller operator also has to be vigilant. Even with flashing strobes and backup alarms crew members (or worse, the public) can easily get in the path of the roller so the operator needs to constantly be aware of what's going on around him.