ASPHALT PLANT SAFETY Part 2

In PART 1 we discussed lockout-tag out accidents, burner safety issues and the dangers of poor maintenance practices. In PART 2 we will address some of the other areas of potential hazards and the consequences of taking them lightly.

Numerous other dangers lurk around a plant, awaiting the unwary. Electrical shock injury is common, as are injuries from falls and accidents resulting from the conflicts between the rolling stock around the plant. Burns from hot asphalt oils are also fairly common, though rarely fatal. Portable asphalt plants are especially vulnerable in these areas because of the labor intensive environment and the number of people involved when they are being moved.

The following accidents occurred at portable asphalt plants in the past five years. Again, they weren’t the only ones.

CASE #1:

A portable drum plant was being torn down in preparation for a move to a new location when a 30 year old plant mechanic was severely injured by a fall from the crane ball he was riding. The victim had been on top of the asphalt silo disconnecting the slat conveyor and then rigging the picking cables for the holding silo. Since the silo had no access ladder the man was forced to find another way to the ground after hooking a 100 ton Link-Belt crane’s line to the silo rigging. As they had done many times in the past, workers moved a 9 ton Pettibone crane next to the silo and the victim climbed onto the ball. On the trip down he lost his grip on the greasy cable and fell twenty feet to the ground. This accident was personally witnessed by the author who was at the facility to train a new operator for the company. While supervising the plant tear-down, the author became busy on another issue and failed to spot this bit of stupidity until it was too late to stop it.

CASE #2:

A forty year old plant operator was killed when he was electrocuted while unwiring a 10 horsepower motor on a feeder collecting conveyor. The plant, a Boeing drummer, was running two shifts at the time. The night operator had experienced problems with the belt’s starter. This resulted in one set of starter contacts being burned out and rendered inoperable. No replacement contacts were available at the time, so to get running the operator simply wired around the bad set of contacts, leaving one leg hot at the motor all the time. Around mid-day on the next shift the motor lost a bearing and began to squeal, requiring its immediate replacement. The day operator, unaware of the night man’s wiring modification, failed to turn off the circuit breaker to the motor and lock it out as required by law. Unfortunately, he was standing in two inches of water when he unwired the hot leg and as a result was electrocuted to death.

CASE #3:

An 18 year old novice ground-man was severely injured when he attempted to grease the head roll on a collecting conveyor. The chain driven unit was running at the time and the guard had been removed earlier in the day to facilitate the replacement of a broken chain. In order to grease the drive side of the head roll the victim had to reach through the moving chain to access the bearing which was hidden behind the drive sprocket. When he attempted to pump the grease gun his hand became entangled in the moving chain. In an instant the victim’s hands were drawn into the chain’s pinch-point and around the drive sprocket. Both hands were severely mangled, requiring many operations including the amputation of several fingers on each hand. He will be on SAIF (state accident insurance fund) disability for the rest of his life.

In the final analysis, all three of these accidents were due, in part, to negligence on the part of the victim. And to a greater degree on the failure of their respective companies to provide clear and strict guidelines for use in the situations encountered by the each of the victims.

Case #1: It is simply illegal to ride any cable on a crane unless a suitable man-basket and safety restraint belt are used. This particular plant, an older Boeing, had been moved numerous times over its career. There was plenty of time to install an approved safety ladder to provide access to the top of the silo. At this company it was an accepted practice to ride the crane ball. Evidently, no one gave any thought to the consequences until after the accident. The truly baffling part of this incident is the fact that the OSHA required safety equipment was on the back of a truck within fifty feet of where the victim hit the ground. The equipment was provided by the company who supplied the 100 ton Link-Belt crane and specifically ordered by the author for use in the very situation that led to this accident.

On a related topic: People routinely climb around on asphalt plants while they are being torn down, and surprisingly few of them are even aware that OSHA regulations require the use of an approved safety restraint belt whenever a person is over six feet from the ground. Other people shy away from their use because the devices are awkward and uncomfortable. This seems a petty consideration when compared with the discomfort that results from a high speed impact with the ground after falling from the top of an asphalt holding silo. If comfort were a valid consideration in safety issues one could speculate that there would be a lot more corpses laying around. Few people voluntarily wear hard-hats, safety glasses and gloves.

Case #2: While failure to follow published OSHA Lockout-Tag out regulations was the direct cause of this accident and that issue was discussed in PART 1, this incident is included here to demonstrate the indifference with which some people approach potential electrical shock hazards. In this case the victim didn’t even bother to turn off the circuit breaker as required by even the most basic safety concepts. Instead, he pressed the motor’s stop button and opted to rely on the contacts in the starter. While we will never know for sure, it is easy to speculate that his reasoning was probably that as long as no one pressed the start button for the collecting conveyor the motor wiring would be dormant. He was wrong: dead wrong.

A contributing factor in this accident was the failure of the night operator to inform the day operator of the potentially lethal condition he had created when he by-passed the motor’s starter contacts. Communication is a key safety issue at any HMA (hot mix asphalt) facility. The simple practice of keeping a daily plant diary may have saved a life in this case.

Case #3: Two things combined to cause this accident. First, the ground-man was not sufficiently trained in his new job to realize the dangers posed by moving equipment, especially chain drives. Being young and eager to impress his new boss the kid made a poor choice that will haunt him for the rest of his life.

The second and more important issue in this case is the failure to replace the guard over this drive unit when needed repairs were finished earlier in the day. With trucks backed up and the paving superintendent screaming for hot-mix it’s not hard to see how the pressure of production quotas probably influenced the operator’s decision to leave the guard off. In retrospect, it was a decision everyone involved regretted. OSHA levied heavy fines in this incident and, of course, the lawsuits continue. This particular company instituted a new policy as a result of this accident: Under no circumstances shall a piece of equipment be operated without the appropriate guards in place. PERIOD! There are no exceptions to this rule. Any employee found in violation of this rule is subject to immediate and final termination. Perhaps this is a rule that should be adopted by every asphalt company in this country.

Other Safety Issues:

One area of safety that is routinely compromised at portable asphalt plants is the conflict between truck traffic and the needs of the loader operator to access his stockpiles. Small pits, filled with the aggregate for coming jobs, sometimes offer precious little space to set-up a plant. Compromises must often be made that can and do jeopardize safety. One common practice is to run the truck traffic behind the loader at the feeders until enough aggregate can be used up to permit the construction of an alternate path. In the heat of battle the loader operator is a busy person.

Sometimes, hurried past the point of conscious thought by the need to keep up with the plant, the loader operator backs away from the feeders without checking behind the machine. Since loaders have the right-of-way in almost all pits, the operator gets away with this most of the time. But not always. It seems obvious that the utmost care must be exercised during the time the trucks are vulnerable, yet each year trucks are wrecked and their drivers hurt.

One method of combating this problem is to have a meeting prior to the start-up of operations on the first day. The loader man and all truck drivers should discuss the ways to keep their respective activities safe for the others and work out a plan that is acceptable to everyone involved.

One suggestion: a common C.B. (citizen band) radio in the loader and one in each of the trucks can go a long way toward eliminating conflicts. Again, communication is often the key to safety.

Another potentially dangerous activity around portable plants is the handling of hot asphalt oils. Each year people are burned when they are careless, equipment fails or hot oil is forced into plugged lines. A hose that fails explosively under high pressure can send a surprising amount of oil in a large radius, to the peril of anyone unfortunate enough to be standing near. Properly maintained and operational pressure relief valves can help eliminate a lot of the risks. Also, a remote start-stop station for the off-loading pump can be a true asset if an accident does occur and spraying oil drives everyone away from the area.

The flame used to heat stubborn pumps, lines and off-loading hoses can sometimes cause problems, especially in those area where housekeeping is lax. Asphalt oil fires are difficult to extinguish, once they get going. The best way to prevent fires is to deny them a chance to get started in the first place. Oil messes should be cleaned up immediately. Any leaking fittings, hoses or shaft seals should be repaired or replaced at once. In addition, a liberal sprinkling of five and ten pound fire extinguishers around the off-loading area will go a long way toward minimizing the damage should an incident occur. A shovel and a modest pile of sand can also provide some insurance, and are useful in cleaning up oil spills.

The issue of careless people is a somewhat more difficult to deal with, since some folks only learn in the aftermath of an accident. If a person is consistently careless and puts themselves and others at risk, perhaps it’s time to replace the guy, even if he is Aunt Mabel’s favorite son.

One common thread in all the accidents discussed in PARTS 1 & 2 was a disregard of safety issues in deference to production pressures. Asphalt plant operators often feel tremendous pressure to produce by any means possible. Unfortunately, this shifts the focus off safety and onto money. Perhaps a clear-cut set of guidelines dealing with company policy on safety issues should be drawn up and distributed to everyone involved with the plant. Be sure to include the Paving Superintendent. This individual can exert enormous pressure on the plant operator without even realizing that he is doing it.

Remember: Everyone wants to do a good job and will sometimes go to great lengths to get results. Often, to that end, things are done that normally would not even be considered. Once again, communication is the key to safety.

When dealing with safety issues, one must keep in mind the fact that you need to be safe all the time– you need only be careless once for tragedy to strike.