The risk involved with working in trenches has just been highlighted by an accident which took place in Baltimore in The United States.
Often we hear of workers being trapped or injured while engaging in trench work. The biggest risk involved in trench work is that of the trench collapsing, which is precisely what happened to a 25 year old worker on a construction site in Baltimore. Cave-ins and side wall collapses are also common occurrences.
Poor stability combined with the work processes involved with construction such as use of heavy machinery can cause trench collapses. Also a lack of safety measures can result in a collapse. In Australia any trench with a depth of 1.5metres or more must undergo a series of safety measures.When these measures aren’t taken, collapses like the one in Baltimore can occur and the results may be just as tragic.
The following excerpt from a post on Baltimoresun.com explains more about the fatal incident:
A 25-year-old man was killed in a construction accident Monday in the Severn area when the trench he was digging collapsed on him, Anne Arundel fire officials said.
It took more than three hours for Anne Arundel and Howard County firefighters and Anne Arundel Department of Public Works crews to recover the man’s body after he was buried at about 10 a.m. The Anne Arundel fire department said the man was part of a crew digging in a 7-foot-deep hole next to a home in the 1000 block of Leyton Lane when the dirt collapsed into the hole. The crew was digging the hole to build a deck adjacent to the house, Anne Arundel officials said.
Maryland Occupation Safety and Health department is investigating the incident. The man’s identity has not yet been released.
When trenches collapse there are a number of injuries it can inflict on workers trapped within the trench from broken bones and appendages to asphyxiation due to a lack of oxygen.
The most common causes of trench collapse are:
- trench walls not supported by shoring or trench boxes,
- trenches dug on previously disturbed soil,
- vibration of the land around the trench area due to the vehicles running too close to the trench,
- unsafe distance between spoil pile and the edge of the trench,
- excessively heavy rain falls.
Trench collapse risks can be minimized by shifting the soil weight away from the trench opening as well as by placing trench sheets on both sides of the trench.
Before trenches are dug a suitably qualified person should carefully examine the soil conditions to ensure there are no poisonous gases inside the soil prepared for trenches. The responsibility to reduce risks associated with trench collapses lies with both the employer and workers. Employers need to ensure that workers get the necessary training and workers need to apply the knowledge learnt when working in or digging trenches not only for their own safety but for the safety of co-workers and others in the vicinity.