When pumping concrete, it is hard to imagine that anything can ever go wrong with the system, especially if you have observed all the safety rules of concrete pumping. But even so, you can't foresee mechanical faults that may arise, some of which pose safety concerns. Hose whipping, for instance, is one fault that can cause fatal injuries to workers who are dealing with concrete pumps.
What Exactly Is Hose Whipping?
Hose whipping is the rapid and wild movement of the rubber hose fixed at the end of a concrete pump system. Mostly, the uncontrollable motion of the hose is as a result of air getting trapped in the concrete delivery system. Air can enter the system through different routes. For example, it can get into the system when the machine is being started, when concrete has been allowed to fall freely once the machine has been shut down, or it can access the system after a blockage has been cleared from the lines.
The air itself poses no threat; it turns catastrophic only when it is compressed. When concrete is pumped, the air inside the system is compressed. And hence, after the air is released, its energy transfers to the hose and forces the hose to whip violently.
How Can You Avoid Getting Whipped?
Unfortunately, you can't tell when the hose will start to whip because the process starts at random. However, there are protective measures you can take to limit the damage caused by the whipping. One is to stay far away from the end of the delivery system when the machine has started to pump concrete. This is to give the air locked in the system some time to get out. A safe distance is one that is longer than the length of the hose. If the hose measures 10 feet, you should not be within a 10 feet radius of the concrete delivery system, starting from the point where the hose is fixed to the pumping machine. Only approach the machine when concrete has started to flow freely.
Another tip is to remove metal objects like ram horns and metal connectors from the end of the placing hose before the concrete pumping machine begins to operate. Metal items can not only cause injuries, but also death.
And because there is a possibility that debris may be thrown out of the hose when the locked air is released, remember to wear protective gear like a hard hat on your head.