A couple years ago, I was hauling dangerous chemicals, such as PCBs, spent acids, and all kinds of weird liquids. They had to be picked up anywhere in Canada and transported to a disposal centre, where they would either incinerate it or clean and separate the product, for reuse.

The trailer was a single compartment, (straight bore) with the discharge valve at the rear of the tank. (Hose hook-up for unloading) The valve was manually controlled. (open & close) There was also a spring loaded emergency shut down valve just ahead of it. It was opened by pumping up a hydraulic jack unit. When the control valve was activated, the lost pressure would instantly release the spring tension and drop the valve closed, cutting off the product flow. There was also a hydraulic line travelling up the side of the tank to the left front trailer fender, terminating just a couple feet from the drivers door. If necessary, in an emergency, and you cannot get to the shut down at the rear of the tank, you grab the stem on the front fender, and bend it to break it off. This will open the hydraulic line and let the fluid out, releasing the pressure, and closing the emergency shut down valve, instantly.

On this particular trip I had a load of contaminated acid, for recycling. The plant was near Montreal, Quebec. Some products have a tendency to jell up or solidify, even at high temperatures. This load was one of them. To compensate for it they preheat the load to over 300 degrees F. and load it into an insulated tank. If for some reason the product cools down to much and starts to solidify, you attach a steam hose to the heat coils in the trailer, and bring the temperature up to the flow point. Then unload.

I pulled into the plant, and found a place to park. There was one truck ahead of me unloading. With this type of load you hook up an air line from the tractor, load compressor, (mounted on the truck) to the top of the tank trailer. You pump air into the tank, till you get the pressure up high enough, then open the valve and force the load off with air pressure. (Eliminating moving parts in dangerous fluids)

I did not have a load compressor on my truck at this time. Usually these plants have an air supply that you hook up to, for unloading. Unfortunately this was a plant with an attitude. They would not let anyone hook up to their air supply. I was standing around, talking to the other driver, (unloading) and worked out a deal, for him to hook up his compressor hose to my trailer when he was finished, and supply me with air pressure. It would save me sending to one of our local terminals for another truck and driver to come out. ( waiting up to 6 or 8 hrs. for one to be available.)

The first driver finished and pulled ahead. I backed up to the receiving pipe. It was sticking out of a brick wall. It had a drain canal between the wall and trailer, it was about 3 ft. wide and 18 in. deep, draining into a catch basin, inside the building. It was up to the customer to hook up the hose and unload the tank. It was up to me to supply the unloading air pressure. Which I did via the other truck. They had an empty storage tank inside the building that had just been repaired, that they were going to use. It had the capacity to hold the complete load with room to spare. I tried talking to the unloading receiver, but it was a lost cause. He hated drivers, so it seemed, and he knew what he was doing, so he thought. I went over to the other driver, and we chatted, and a 3rd waiting driver came over and joined us in conversation. We were well out of range of the unloading zone, and did not require to suit up. (Don rubber, acid proof gear & respirators) The unloading, was in complete control of the receiver.

Well about 10 min. passed, into the unloading and everything seemed to be moving along smoothly, I just happened to look over towards the rear of the trailer, and it didn't seem right. The receiver had gone inside the building to monitor the flow into the storage tanks. Another minute passed and I directed my attention to the rear of the trailer, and I just couldn't believe what I saw. I yelled to the other 2 drivers and a couple of employees in the yard to get out. The acid hose was not hooked up, and under pressure. It was spraying off the brick wall like a high powered fire hose. Everyone disappeared out of site, in a flash. You really don't want to have your next shower in hot acid. No one was there to control anything. I took off toward the truck, planning on breaking the safety shutdown plug. As I approached the front of the truck, a river of hot, tocsin acid flowed out from under the tractor, and was headed directly towards me. I pulled to a screeching stop. My fastest ever. The flow was under pressure, and the canal could not control that kind of volume. The storage tank was spewing it out also, adding to the problem.

There was a 3 foot high retaining wall along side of the trailer, (to create a separate stall from unloading & shipping) The adrenaline was sure working this day, I jumped over the wall, ran up alongside it, then jumped back over again and landed on a small dry strip behind the rear trailer tires. The acid was shooting straight back and into the wall, then spraying off to the sides for about 20 feet. With my back to the trailer, I slid my arm around to the rear of the trailer and stretched till I could barely reach the emergency shut down valve. I gave it a smack, and it worked. the flow was completely shut off. I looked down and the product was a couple of inches from my feet. I made a last leap to the small retainer wall, and cleared it completely. I am not geared for that high speed body moving, at this stage, of my life. I guess when you are being chased by a river of hot acid, you tend to move a lot faster than usual.

I got away out to the end of the yard, I could smell the fumes. then out of nowhere, came a giant front end loader with a bucket full of sand. he dumped it on the river of acid, containing it's flow. Then another loader came and did the same thing. They had the scene under control in a jiffy. In the meantime the fumes set off the alarms and they started coming from all directions, in acid suits & full tanks of oxygen. The cleanup began.

Our Mr. unloader, wasn't as knowledgeable as he thought he was. When he hooked up the discharge hose, he should have used a stainless steel coupler. Instead he used a brand new coupler, that was an acid proof plastic material. It would have worked fine, except that he did not take into consideration that the load was hot, and over 300 deg. F. As the product was moving through the coupler, the hot acid melted right through the plastic, and it burst.

They would not let me near my tractor for about 4 more hours, testing it for tocsin fumes. I called in to my local branch, and they dispatched the safety supervisor immediately. By the time he got there every thing was under control, and the cleanup, in progress. I told him word for word what happened, and that I was starving, after expending all that energy. He promptly rushed me over to the Chinese restaurant, where I almost ate them out of stock. At my company's expense of course.

As far as the receiver is concerned, I have no idea what the future held for him with the chemical company.

What should have been an uneventful unloading, for about 2 1/2 hrs. stretched into a 21 hr. hyper experience. Then for the next while, the trips were routine and uneventful. ---- Till the next incident.

   ---------------  William (Diesel Gypsy)  Weatherstone                            RETURN TO STORY MENU