There are a number of things in life most of us simply don’t think about. Like, say, how the centerline is painted on the highway.
This 2004 Sterling is in service for the Missouri Department of Transportation and is located at their district office here in Jefferson City. I’ve seen it periodically, and a few phone calls proved to be quite useful in getting a closer look. This being heavy truck week, a rig like this definitely fits the bill.
I met with Brandon, the supervisor of the striping crew. In addition to this machine, he has an identical one that he also supervises at another location sixty miles south of here. In all, the DOT has seventeen of them around the state. With 32,000 miles of highway, Missouri has the sixth largest highway system in the United States and these machines stripe all of it.
The weather needs to be above freezing with a pavement temperature above 45 degrees Fahrenheit for the stripe to stick to the road. In other words, from late October to late March this machine is dormant. However, winter is the ideal time to clean and prepare it for the next season. Brandon stated there are a number of handrails that have been removed for access to the various components…
…and assured me there isn’t usually a plastic bucket hanging on the front. The important pieces are all still in place, so let’s explore this very complex truck.
Paint is pulled onto the machine here on the right side of the truck. There is a tap for both yellow and white. The beginning of the season is in March or April (weather plays a huge factor); the annual goal is to have painted the interstates and major highways in Brandon’s district prior to Memorial Day. In that time, Brandon anticipates using around 100,000 gallons of paint between his two stripers. That same volume, if not more, will then be used during the rest of the season.
Each tank on the striper holds about 800 gallons. Brandon’s crew also has a nurse truck for each striper to keep the tanks replenished throughout the course of the day. On a typical highway in the United States, each skip along the centerline is 10′ long with a 30′ space between them. On roads having a lot of no-passing zones, the crew will rapidly go through a tank full of paint.
To provide reflectivity at night, glass beads are dropped onto the fresh paint at a rate of six to eight pounds per gallon. This is the bead tank.
The paint and beads are applied concurrently to the roadway surface with these guns. There is a set on each side so a centerline and edge line can be painted simultaneously. The two operators will sit in the back to control paint application and ensure the lines match. Striping is performed at a speed of about six to ten miles per hour.
Hauling all this material and equipment makes for a very heavy machine. While I failed to determine the curb weight of this truck…
…I did learn it is powered by an 8.8 liter Cummins diesel engine. Fuel economy for the two stripers averages about three miles per gallon. The truck powers a number of functions with the striper, so it does have to be left idling when being refilled with paint.
In order to provide air for the paint and beads to flow through their respective systems, there is also an additional four-cylinder diesel engine mounted crossways on the bed. The bulk of the plumbing for the paint and bead systems is constructed of stainless steel.
This truck was manufactured by M-B Companies of Chilton, Wisconsin. I learned there is a considerable amount of time that will elapse between order and delivery for these trucks, but that is to be expected. Any truck that cost $325,000 ten years ago and is such a specialty item is going to be custom built to a certain degree. Each customer is going to have unique needs such as power output, gearing, and capacities.
While the dual steering was optional, resale options are definitely much broader as this machine could easily go to work anywhere in the world without requiring steering modification.
All controls for the operation are addressed from the back. This console controls air pressure, downward pressure on the carriage, paint temperature, and application rates. There is a lot to do and I’ve been told six miles per hour can be mighty fast when a lot of things need to be addressed at once.
The driver and operator need to be in constant communication with each other regarding curves, hills, and traffic, so there is an intercom system in this truck. The steering wheels in the rear cab (there is one on each side of the operator compartment) will move the respective carriage that holds the paint and bead guns. Matching the existing line is something Brandon’s crew takes very seriously because their work is seen by countless people. Plus, not matching the existing line makes for an ugly highway, something the crew does not care to be associated with.
Depending upon the time of year, this truck may be painting twelve or more hours per day, seven days per week. It will apply several hundred thousand gallons of paint during the season. With the complexity of the system, there are a lot of lines and many things can break.
This machine will also get quite grimy during the season and the paint will build up on the walls of the tank. Winter is a great time to overhaul maintenance intensive components, do general clean-up, and address any issue that may have been identified during the season.
In addition to the nurse truck mentioned earlier, each striping crew will have up to three trucks with a mounted attenuator in the train behind the striper. It is unfortunate, but this striper has been hit a few times as have the attenuator trucks. The attenuator trucks serve as a buffer between the slow moving striper and traffic buzzing by at full speed.
While getting behind this truck can be an inconvenience, it and a crew of people are working diligently to keep highways safe and provide a highway that can be better seen at night. If you ever see such a sizable machine, you can now amaze everyone with your new found knowledge.