There’s a right way and a wrong way to transport heavy construction equipment.
At about 6 p.m. on February 13, 2006, Michael Conley of Holcomb, KS, became an Internet poster child for how not to load an excavator. He had put a 64,600-pound Hyundai 290LC-7 excavator on a trailer with its bucket facing forward and its “elbow” (the joint between the stick and the boom) folded upright. The top of the elbow exceeded the allowable clearance for a bridge over Interstate Highway 70 near Hays, KS. Conley was driving about 70 mph when the excavator sliced a 45-foot gap through the bridge’s reinforced-concrete deck.
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Photo: Interstate Trailers |
The impact destroyed the excavator and trailer. The truck kept going. Conley was uninjured. Ever since, photographs of the incident and commentary about it have been circulating on the Internet.
“You have to raise an excavator’s bucket to load it, but if you don’t lower it, you’re going to run into something,” remarks Treye Phelps, sales manager of Interstate Trailers Inc. in Mansfield, TX. He says a better way to load the excavator would have been with its boom facing the rear of the trailer and lowered and the bucket tucked underneath the boom.
“With the boom facing the front, you can’t lower it far enough because you’ll hit the cab of the truck,” notes Mel Holle, district sales manager for Landoll Corp. in Marysville, KS. “If you turn it around, you set it on the rear wheels of the trailer. Some manufacturers make trailers with boom troughs; they drop the cross-members in the frame. That’s where you lay the boom in, so it’s only 5 or 6 feet off the ground.”
Conley made another mistake—not obtaining proper permits. If he had applied for them, he would have been directed elsewhere. “Permitting goes along with safety,” comments Dan Willis, Atlantic region service manager for Miami, FL–based Neff Rental Inc. “A big factor is making sure you have the proper permits to haul what you’re hauling. That means making sure your blanket permit is current, and knowing when you need an overheight, overwidth, or overweight permit.
“When you call to request permits, they give you a specific route from location A to location B, and you cannot vary from that route. Had [Conley] bothered to get an overheight permit, he would have been routed around that bridge. It was known to be too low. Now he’s probably lost his commercial driver’s license and may never get another one.”
In a different bridge incident, an inexperienced driver for Neff put a backhoe and a Bobcat on a trailer and then went under a bridge that was lower than the highest point of the backhoe’s boom. “The backhoe hit the Bobcat first, which destroyed the Bobcat because its frame was twisted,” Willis says. “Then the backhoe came off the truck, rolled about 150 feet down the road in heavy lunch-hour traffic, and miraculously didn’t hit anything other than asphalt—but the $45,000 backhoe also was destroyed.”
The moral of that mishap, Willis says, is “know your load. The legal height limit is 13.5 feet. Anything higher could hit a bridge. When you load a backhoe, you can’t load the boom in the upright position. You have to put the boom down and stretch it out a bit to get below 13.5 feet.”
Unchained Misery
Bridge accidents aren’t the only way in which improper loading of heavy construction equipment on a trailer can lead to mishaps en route. Improper load securement also takes a toll.
Merle Felling, president and chief executive officer of Felling Trailers in Sauk Centre, MN, tells of a large bulldozer loaded on a fixed-neck, step-deck trailer. “The driver had to hit the brakes on the truck,” he says. “Due to being chained very lightly, the bulldozer snapped the chains and rolled forward on top of the tractor’s rear tandem wheels. The turning wheels propelled the bulldozer forward over the cab of the truck and killed the driver. Once those large track machines connect with the back end of those big tires, they walk forward right up onto the top of the cab. The guy never knew what hit him.”
Section 393.130 of the rules and regulations of the Federal Motor Carrier Safety Administration, an agency of the US Department of Transportation, requires any equipment with a gross weight of 10,000 pounds or more to be secured with a single chain and binder at each corner. In addition, all attachments must be secured, and articulated equipment must be secured at the articulation point. Thus, a backhoe takes six chains.
Neff Rental requires double chaining—with two independent chains and two independent binders at each corner—for any excavator the size of a Kobelco 200 (48,500 pounds) or larger. Willis explains why. “Early in 2006 a truck driver was hauling a Kobelco SK290LC, which weighs 66,350 pounds,” he says. “By all witness accounts he was doing everything right—in the correct lane, within the speed limit, approaching an intersection with a green light. Then a trash truck pulled out in front of him and made a right turn. He locked up his brakes. All of his chains snapped. The excavator slid straight forward on the trailer and wiped out the gooseneck.
“The truck driver didn’t hit anything. He did a phenomenal job of handling his truck and load. The excavator could have come off the trailer, but it did not. Only the trailer was damaged, but it could have been really ugly because there was a lot of traffic. That incident caused us to start requiring double chains.”
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Photo: Felling Trailers |
The Right Rig
Of course, before any mishap en route can occur, the equipment being moved must be loaded onto a trailer—the right trailer. “Be sure the equipment you’re loading will fit on the trailer size you’ve got,” cautions Phelps.
“One trailer will not do everything,” Holle declares. “For the big stuff—dozers, motor graders, excavators, asphalt reclaiming machines—use a low-boy, a detachable trailer with a double-drop design. It has a load space of 20 to 26 feet behind the gooseneck and in front of the rear wheels. It loads from the front of the trailer and carries the load at a low height, 22 to 24 inches off the ground.
“To haul asphalt laydown machines, skid loaders, asphalt rollers, man-lifts, anything with a very low ground clearance, use a hydraulic tilt trailer. The axles move forward hydraulically and the front of the trailer comes up hydraulically, putting the trailer in a loading-ramp mode. The lower the loading angle, the better. It can load and unload from the ground or a loading dock.”
Many hydraulic tilt trailers have a winch with remote control. The winch guides the machine being loaded into the correct position, eliminating side drift. From the machine’s cab, the operator controls both the winch and the machine’s steering. “It’s a major convenience and safety tool and decreases the amount of time required to load equipment by about 30%,” Holle says.
A third option is a traveling-axle tail trailer, essentially a trailer with a built-in ramp 12 feet or 15 feet long. “Most manufacturers today use the tail as a loading ramp but can’t haul a load down the road on it,” Holle says. “Landoll’s tail can carry a 24,000-pound load. The axle assembly sits under and supports the tail.”
If a ramp is used, it should have a shoe or leg that makes contact with the ground when the machine’s full weight is on the ramp, says Bud Wilson, sales manager for Winston Trailers in Haleyville, AL. “It’s a fine line. If the legs are too short, the rear of the trailer will go down too far. If they’re too long, they’re into the dirt or the pavement before you get the ramp down. The legs need to be 2.5 inches above the ground with the ramps on the ground, and they need to be built with a design so they don’t kick out from under the trailer when you load it.”
The right trailer must be hooked up to the right tow vehicle, Felling says. “The truck’s GVWR [gross vehicle weight rating] must equal the trailer’s GVWR, or at least come close.” This can involve some complex calculations, taking into account the length of trailer and the location of the axles. “It’s better to have a heavier truck and a lighter trailer,” he says.
Another consideration is the decking and ramp materials. “You don’t want to load a steel track machine on a trailer with a steel deck,” Holle says. “Steel on steel is like driving on ice. You’ll slide off.”
On Level Ground
Before you begin loading a piece of machinery onto a trailer, read the instructions for the trailer and the load, Felling advises. “Pay attention to the manufacturers’ precautionary warnings,” he urges. “For example, the skid-steer makers recommend that you back their machines onto the trailer. Most skid-steers have a 60-40 load transfer, with 60% on the back axle, 40% on the front. As you climb an incline, more of that load is distributed to the back, which can tip the skid-steer over backwards. By backing onto the trailer, you alleviate that potential.”
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Photo: Felling Trailers |
Everyone says heavy construction equipment should be loaded onto a trailer on level ground, but Wilson concedes that “99 out of 100 construction sites don’t have a level place to load. If it’s terribly unlevel, you may have to take the machine and scratch off a level place.”
If the loading site can’t be completely level, Wilson says, “The front of the trailer should be just a tad higher than the rear.”
Before loading begins, the brakes of the transport vehicle and the trailer should be on and the wheels should be chocked to prevent the trailer from lurching forward when the weight of the machine being loaded shifts from the ramp onto the trailer.
Another pre-loading precaution is making sure the ramps and trailer bed are clean. “Oil, debris, or mud could make the machine slip as you’re loading,” Phelps says. “If it’s going up and the back tires start slipping, the machine could be forced to one side, and it could fall off the trailer.”
Other preparations for loading should include ensuring that the highest point of the machine won’t contact power lines and that the loading area is free of vehicles and people. The attorney for one trailer manufacturer once reviewed an instruction manual and inserted this statement: “Do not stand in front of the trailer while loading or unloading.” The attorney was concerned that someone might want to stand and eat a sandwich on the front of the trailer while it was being loaded.
Getting It On
Problems may arise when a truck driver unskilled in operating a piece of heavy machinery tries to load it. “If you don’t know how to run the machine safely, get a trained operator to do it. Don’t just drive it,” Phelps says.
Wilson says inexperience can create problems for people who aren’t used to loading track-driven equipment. “When you get up the ramp to the tip of the dovetail, there’s a breakover point when the whole 36,000-pound machine is riding on 8 inches of track. At that time it can get a little hairy, but you’ve got to go on with it. You’re at the point of no return.
“If you hold up, anything can happen,” he says. “Everything is on hydraulics now. Transmissions are a thing of the past. One track may keep going and the other stop. When you get airborne, you have to let the machine balance itself on down. For a split second that whole machine is teetering on a few inches of track, and momentum is what carries it onto the flat deck.”
To avoid such a balancing act, some operators load heavy equipment over the side of a trailer—an approach with its own perils. Trailer manufacturers fear side-loading. If a trailer is off the ground, hooked to the semi, and an operator drives a Caterpillar D8 bulldozer over the side, it could bend the trailer frame. Another approach to side-loading is to lay the trailer on the ground and chock-block it on the side from which the loading takes place. That works if it is done properly, but it’s still somewhat risky, and trailer manufacturers don’t recommend it.
Interstate Trailers offers an optional safety rail, a lip along the side of the trailer that prevents operators from driving a machine off the side or side-loading a machine. “Only about 5% of our customers want it,” Phelps says. “It’s in the way. You can’t carry anything overwidth. If an operator tries to drive up on it with his machine, he’ll bend it. We sell it only to municipalities. They tend to be more safety-conscious.”
Wilson says some excavator operators load by driving up the rear of a trailer facing the rear of the truck cab and then turn the machine around to keep from having to back off. “With the counterweight swinging around, turning puts a lot of pressure on the trailer’s side rails and cross-members,” he says. He watched one customer drive a 38,000-pound trackhoe onto a 20-ton trailer and turn it, with the counterweight extending about 8 feet off the side of the trailer. “I thought he was going to turn the trailer over,” Wilson recounts.
When a loading or unloading mishap occurs, an operator wearing a seatbelt stands a better chance of avoiding serious injury or death. Willis recalls an incident in Alpine, CA, where a straight-mast forklift spent a cold, rainy night atop a rental firm’s trailer. The next morning, the driver unchained it, released the parking brake, and put it in gear with his foot on the brake. The forklift skidded sideways off the trailer and landed on its side. “The driver walked away with a sprained wrist,” Willis says. “If he hadn’t had his seatbelt on, he probably would have been thrown off and crushed underneath the forklift.”
For aerial personnel lifts, the US Occupational Safety & Health Administration requires the operator to wear a safety harness to avoid being thrown from the platform. “The base is so heavy it won’t roll over, but if you make a mistake and the machine moves suddenly, or you’re 100 feet in the air and someone hits the base with a piece of equipment, you could go flying through the air,” Willis says.
Position Is Everything
Once a machine is on the trailer, it has to be positioned properly. “People who load the same machine all the time will know where to position it for proper tongue weight,” Phelps says. “If you don’t know, go to a scale and find out.
“If the machine is too far forward, if it has too much tongue weight, you’re applying too much weight to the truck and taking it away from trailer. The trailer will act squirrelly and will fishtail behind you.
“If the machine is too far back, it takes weight off the tongue and picks up the rear end of the truck so you lose safety, and with too much weight on the back axle of the trailer, you’ll start blowing tires and bending the axle.
“Construction equipment has a center of gravity, but it’s not always in the center of the machine. With a loader or dozer the engine is in the rear. With a backhoe, it’s in front. There’s no secret formula. You just have to go weigh the load and figure it out.”
Wilson says tag-along trailers designed to be pulled behind a dump truck are particularly sensitive to proper tongue weight. “If you don’t get 15% of the total weight of the trailer and load on the tongue, and you go over a hump at 50 miles per hour, you get into negative tongue weight,” he warns. “That creates sway and lifts up the rear end of the truck, especially if it’s empty. If the rear end of the truck is up and it goes off the road or over a railroad crossing, the driver has absolutely no control.”
Getting It Off
Some people say unloading is just the reverse of loading; others disagree. “For unloading, I prefer a slight uphill slope,” Wilson says. “When you’re loading a heavy crawler-type machine, it’s trying to drag the trailer backward. When you’re unloading, the machine is trying to push the trailer forward.
“Say you have a 20-ton trailer that weighs 8,500 pounds and it has a 35,000-pound machine on it. You put that machine in gear and turn the tracks, and the trailer tries to move before the machine does. That puts a lot of strain on the running gear of the truck. The brakes have to be in good shape, and everything should be chocked up. You see chock blocks being used less than half the time. Lots of people don’t bother to do it.”
Phelps counsels a slow and steady approach to unloading, especially if the deck and ramp are slick from grease, ice, mud, or snow. He recommends the use of compression buckets (metal supports for the ramp). “If you just start backing the machine off behind the axles, the front of the trailer will come up,” he says, recounting an incident in which a truck driver unloaded an all-terrain forklift for a sheetrock company. Making matters worse, the truck and trailer were positioned at a steep downhill angle. “The driver picked up the rear end of the truck, which released the brakes, which sent everything rolling downhill,” Phelps says.
Willis expresses similar concerns. “Gravity coming down can work against you,” he says. “If you don’t have your truck on level ground, if it’s on a slope left or right, the machine can come off the side instead of off the end.”
The weight distribution of a machine and its attachments also can be problematic, Willis warns. “If you’re unloading a backhoe that’s sitting stretched out with the boom toward the rear of the trailer, when you throw the weight to the back and the front wheels come off the ground, you can’t steer anymore,” he says. “When you back it off the trailer, your boom needs to be as upright and retracted as possible.”
When a piece of equipment with hydraulically operated brakes loses hydraulic pressure, getting it off a trailer poses additional perils. “Hydraulic brakes are spring-applied and hydraulically released,” Willis explains. “If you lose hydraulic pressure, your brakes lock up. It’s a safety thing that ensures braking regardless of what else goes wrong. If you have to move such a machine, you mechanically release the brakes. Then you can move it where you need it, but it doesn’t have brakes.
“We send a mechanic out and he uses a winch to put the machine on the trailer. Now the time comes to bring the machine off and go down the ramp. Hopefully he has a remote winch he can control, or someone behind him with another piece of equipment to keep him from freefalling off the end of the trailer.”
Willis says unloading holds particular angst for people who aren’t familiar with the equipment they are hauling. He tells of a new truck driver inexperienced with big excavators. While trying to unload one at a job site, he was seated in the cab on the left side of the machine when he drove the right track off the right side of the trailer.
“An excavator has two sticks, each controlling one track,” Willis explains. “You pull one way for reverse, the other way for forward. An excavator will spin 360 degrees so you can drive in reverse while going forward. To turn in a short radius to the right, you have to push your left joystick toward you and push the right one away from you. That spins the machine to the left, on a dime. You can get out of whack really fast and run into problems.
“In this instance, the right track was in the air, the undercarriage frame of the excavator was resting on the trailer, the cab was tilting at an angle, and the truck driver panicked. He didn’t know what to do, and he was scared.
“We sent another, very experienced truck driver out there. He swung the excavator to the right, put its bucket on ground, balanced the excavator on the bucket, and slid it back onto the trailer.”