Three Factors to Consider in Crane Safety
There are three factors to consider in crane safety. One of the major factors on any construction site is how the weather conditions severely affect all rigging operations. Industries such as marine, construction and others that involve outdoor construction thoroughly need to consider weather conditions while planning and executing their operations. Heavy wind, dust or fog can cause serious injuries to the workers and also heavily damage rigging hardware. Weather conditions affect the stability, design and performance of the structure. The construction industry needs to make note of such conditions as most of its operations are performed in the open and subject to all kinds of weather. This means there is a far bigger risk involved for the rigging equipment and the workers using it.
The following article discusses the cause and effect of three weather conditions that mainly affect all construction sites and its workers:
Cold weather can affect construction adversely, so it is always advisable to take necessary precautions to combat its effects. It is advisable to follow the building codes recommended by the American Concrete Institute (ACI) for concrete work and Brick Institute of America (BIA) for masonry.
Perhaps the most critical factor in construction operations carried out in cold weather is ensuring that mortar and grout get adequate heat for normal cement hydration. Lower temperatures either completely stop or slow down the process of cement hydration due to lack of heat, which reduces the masonry’s bond strength. Frozen masonry units must be melted and dried before use. Measure the unit temperature using a metallic surface contact thermometer or flat, instant-read thermometer. It is advisable to heat bricks even when ambient temperatures are above 20 ºF (-6.7 ºC). Preheated brick will have the same absorption characteristics as those laid at normal temperatures.
It is important to protect mortar from freezing temperatures. A frozen mortar mill significantly reduces the compressive strength, the bond strength and also decreases the water penetration resistance of masonry. Also, mortar with water content more than six percent of the total volume may be damaged, as the frozen ice may melt to increase its volume thereby reducing its bond strength.
Consider alteration of mortar constituents and proportions within the possible range to reduce the impact of cold weather. Also increasing the sand content can give a stiffer mortar mixture. Using lime content will allow mortar to loose water easily.
Hot and Dry Weather
Hot and dry conditions can also pose major problems for the construction industry. The building codes as mentioned earlier also have a rule of codes for building hot and dry weather. The primary concern in hot weather condition is rapid evaporation and absorption of water from mortar. Lack of moisture can have dramatic effect on the building materials.
It is important to keep masonry units away from direct sunlight in cool shaded places. High temperatures may cause the mortar to settle prematurely. A premature mortar will not have enough water content for the brick lay to hold onto. This will decrease the overall bond strength between the brick and the mortar which may cause leaks in the structure.
Sprinkle some water on the bricks before laying them. Due to the hot weather, bricks rapidly absorb water and lose moisture. This in turn makes them absorb water from the mortar mixture which will decrease the bond strength to a great extent.
Dry weather means lack of moisture, which may also cause formation of dry dust. Large amounts of dust clouds hovering around the construction site can be dangerous. Dust also generates dirt which can cause unnecessary complications in the machinery and also risk the health and safety of the workers. Many equipment and machinery used on site have filters, which need to be cleaned and fixed with properly on regular basis. Dirt and dust can enter working parts and cause breakdowns. It is important that all equipment and machinery are cleaned and lubricated regularly.
High temperatures can also reduce the elasticity of seals and sealants resulting in failure and damage to the hardware. Replacing these sealants can be expensive, so it is advisable that you take proper care and protect these from UV rays and extreme sun exposures.
Wind and Storm
A great deal of judgment is required to perform any crane hoist in a windy atmosphere. It is important to know what kind of equipment can handle maximum wind speed. This information is generally not available in the user manual, so you need to check with the equipment manufacturer to get the exact details.
Before performing an operation in a largely windy area, it is important that you make necessary arrangements to tackle the risks. Also, it is recommended you contact the meteorology department for possible thunderstorm in nearby areas. You can also consult a well known and respectable smart phone app like the Weather Networks app.
Another option is to have a mobile wind anemometer available to give you accurate wind readings on site. As reliable the weather app will be, wind speed is usually measured at airports or major buildings within city limits. An anemometer gives accurate location right on site. The downside is it is an added cost in equipment. A quality anemometer can be anywhere from $850 to $2500.
It is important to remember that wind speed increases with the height. So make sure and calculate how high you want the load to be lifted. If the wind is blowing from the front of the crane boom, it might result in backward fall. But if the wind blows in from the rear, it might cause the load to swing away from the crane and cause a crash.
Carrying out hoisting and lifting operations in windy conditions can cause load swinging and rotating. This may not only pose a danger to the riggers but also cause the crane to overload and crash. Assess the load size and shape to determine whether lifting it in windy conditions can pose any danger.
With the above information the crane operators can eliminate the impact of weather and improve their working conditions to make it safer. Determining the weather conditions and making required arrangements will always reduce risks of injury and loss. Weather condition not only affects the construction equipment and operation, but can also injure the workers involved. Serious ailments like fatigue and dehydration can affect workers in hot weather. Workers in cold weather face serious conditions like frost bites, hypothermia and trench foots.