Safety Alerts – Antares Engineering Services

Safety Measure Kills

Cathal — Sat, 04 Nov 2017 17:52:24 +0000

Is it possible that the implementation of safety procedures or safe design features can reduce levels of safety? Unfortunately the answer is yes. Recently a tragic example of a worker killed by a widely used safety feature, shows the risk of inadvertently creating a hazard by trying to eliminate a different one. Explosion proof equipment is designed to eliminate the possibility of a quantity of gas or dust combusting in an explosive manner. Many designs of this type of equipment use air to ventilate possible ignition sources such as electrical equipment. In the tragic accident detailed in the link below, the explosion proof equipment was pressurized while the worker was carrying out maintenance. While removing a cover on the device, pressurized air propelled the cover forward and fatally wounded the worker.

Safety Equipment Causes Tragic Death

Lifting Accident Alphen aan den Rijn

Cathal — Sun, 14 Aug 2016 19:24:36 +0000

Last year in a town in the west of the Netherlands, two cranes which were lifting a bridge section toppled over and caused extensive damage to nearby homes and businesses. The YouTube video below, which was produced by the Dutch Safety Board, clearly describes the accident and the reasons why it occurred. If you have anything to do with lifting heavy objects or work with barges, this video will be especially interesting. It highlights what can go wrong if adequate risk assessments are not carried out before a major lift goes ahead.

Tank Implosion in Canada

Cathal — Sat, 21 May 2016 23:09:00 +0000

We take atmospheric pressure for granted. It is unbelievable just how powerful a force it can generate over a large enough area. A recent incident in Canada led to a tank implosion when the tank flare line was plugged due to contamination. The following pdf describes the incident: Tank Implosion. The YouTube clip below also demonstrates the awesome force that atmospheric pressure can exert.

Air in Hydraulic Systems can be Deadly

Cathal — Fri, 21 Aug 2015 21:49:13 +0000

Air in hydraulic systems can have very serious consequences. Drill rig masts and mast raise cylinders have been destroyed due to the fact that a mast raise cylinder was partially filled with air. Loads have being dropped due to failure of winch motors because of air being entrained into the hydraulic system.

A dropped mast incident is described in the following safety alert: mast raise cylinder failure. Another incident is described here: telescoping cylinder failure. One drill rig manufacturer recommends that a drill mast should be raised and lowered gradually from the mast rest. The manufacturer recommends that the mast is initially raised approximately five degrees from the mast rest and lowered. This is repeated at ever increasing angles until the mast is fully raised. This ensures that if air is present it will gradually be removed. A better solution would be to install a bleed valve at the highest point in the cylinder and bleed air from the cylinder prior to lifting the mast.

In the example in the above link, the technician thought he was working “by the book”, but was unaware that the pump was sucking air through it’s suction and constantly supplying air into the system. He would have noticed the problem before anything serious happened if the cylinder was connected to the mast and if he followed a procedure similar to that described above.

Another serious failure occurred when a motor in a closed loop winch system failed catastrophically due to cavitation. See a picture of the failed motor below. This occurred during load testing of an offshore crane to its maximum rated capacity. The load fell to the deck and luckily no one was injured. During the test, cavitation occurred in the suction of the motor due to an incorrect hose size fitted. As air was being entrained into the system, the motor lost its load holding capability and rotated freely.