Are you blind to your equipment's blind spots?

One of the big safety challenges for those of you who operate construction equipment is to maintain constant awareness of your blind spots. For many types of machinery, these unseen areas can be quite large. On a busy construction site, a laborer can easily wander close enough to your machine to be struck when you move it.

Blind spot diagrams Imagine for a moment that you're looking down on your machine from a height of 100 feet. Picture your machine at the center of a circle about 200 ft. in diameter. Now imagine that circle is divided into a set of slices like a pie. Some are light and others dark; the light regions represent those areas around your machine's circumference where you can see the ground and any nearby obstructions. The dark regions are blind areas - places where people and other obstructions aren't visible because of size and shape of the components and attachments of your equipment, the position of the operator's station and other factors. What's significant about these "pie slices" is that the farther you go away from the machine, the larger their area becomes. Considering the often unpredictable nature of construction job sites, equipment operators must exercise a high degree of situational awareness, keeping one eye on other machines and people working nearby, and watching for any of them that move into the immediate operating area. Sounds obvious, right? You know all about your machine's blind spots. But that's not what OSHA's list of top workplace injuries shows. "Struck by" and "crushed between" accidents remain stubbornly near the top of the list; both are part of OSHA's dreaded "Fatal Four" - the greatest causes of work-related deaths in the U.S., year after year. So let's take a closer look at blind spots by machine type, to remind you to treat them with respect and be alert for the unseen hazards they may contain:

Skid steer loader These diminutive workhorses are the Swiss Army Knives of the jobsite, handling a variety of production and cleanup tasks. The operator sits inside of a rollover protective structure - a cage that keeps him safe - with the engine directly behind him. Because of this unique design, a skid steer loader operator has excellent visibility straight ahead of him, limited visibility to the sides (because of the ROPS enclosure, boom arms and hydraulic cylinders) and near zero visibility behind him. What makes skid steer loaders especially dangerous is their ability to move in the way that their name implies: They can quickly turn within their own radius. Also, because they are small machines, laborers on the job site are more likely to walk up to the machine to talk to you. If you aren’t aware that someone has entered your work space, you could quickly spin your machine around, injuring or killing the person. Skid steer loaders can also be unstable when in motion, especially when traveling over rough or uneven ground. The jerky movement of the machine can cause the operator's hands to move the control levers, amplifying the loader's motion and making it buck like a bronco. During times like these, the machine could get away from the operator and strike people or nearby machinery. When your loader starts bucking like this, the best remedy may be to remove your hands from the controls and let it come to a stop. Then resume travel, albeit at a slower speed.

Wheel loader Like the skid steer loader, the wheel loader has significant blind spots just behind the operator's cab, because the rear unit - the part of the machine that's behind the articulation joint - likely blocks your view of what's directly behind it. The machine's mirrors provide some level of visibility along the sides and rear of the loader. The wheel loader's cab is higher off the ground and has windows facing all four directions, so your view forward and to the sides is restricted only by the posts of the steel ROPS structure. Wheel loaders are frequently used to load trucks, which they typically do in a V-pattern when moving between the pile of material and the side of the truck. After it has dug into the pile and has a bucketload of material, the wheel loader backs up quickly, while at the same time turning in the opposite direction of the truck. This maneuver swings the front unit and bucket around to face the truck. The loader then moves forward, raising its bucket and dumping its load into the truck. It's during those back-and-turn maneuvers that you must be especially careful for nearby laborers who may be lurking in the blind spot.

Hydraulic excavator Hydraulic excavators have their cabs offset to the left side of the machine. This gives them significant blind spots behind and to the right of the machine. The boom, stick and bucket also obscure a narrow swath of ground in front of the machine. The biggest risk here is a laborer stepping within the excavator's swing radius when it's working, because the machine’s large counterweight is completely out of view. If you operate one of these versatile machines, check your left-hand mirror frequently to see if anyone is passing behind you. As you turn to dig material and dump it, visually scan the area for any nearby workers. Watch where they're headed. Situational awareness is critical when working with one of these large, powerful machines.

Crawler dozer Small dozers used for site preparation and finish grading have surprisingly excellent all-around visibility. There are only two small blind spots, immediately in front of and behind the machine. Still, you should use care when operating one, because its relatively small size means workers may walk right up to the machine to talk with you. If you're not aware that someone has walked up behind you, they could be seriously injured when you back up.

Tractor loader backhoe Like small dozers, today's modern tractor loader backhoe tends to have excellent visibility - especially since the operator's seat can be turned around to work the bucket at its front or the backhoe at its rear. For this reason, manufacturers have equipped them with high-visibility cabs that give you an excellent 360-degree field of view. Nearby laborers aren't at as much risk when working near a backhoe, because these machines tend to sit and work in one place for long periods of time. Still, when moving a backhoe from one location to another, you should take extra care to watch for workers, other equipment, supplies and other potential obstructions. Interested in relate products? See: Silver Series Training Programs NOTE: A great source of blind spot diagrams is on the NIOSH website.