| |
Direct Sunlight |
|
Heat Build-up |
|
|
PROBLEMS
Exposure to direct sunlight can create a heat build-up on the ship's steel structure. |
PROBLEMS
Work spaces inside the ship's structure, such as tanks, can heat up significantly during the day. Various factors contribute to the heat build-up, including the sun heating up metal structures, heat generated by tools and equipment, and limited mechanical ventilation. Working in hot conditions can result in dehydration and other heat-related problems. |
|
|
SOLUTIONS
Changing workshift schedules so employees do not work during the hottest part of the day can reduce the risk of heat stress. Providing sun-blocking structures can minimize the effects of direct sunlight while still allowing air to flow freely through the work area. Lightweight, portable structures are available that can be moved when work locations change.
|
SOLUTIONS
Where possible, preassembling components in facilities that are adequately ventilated and cooled reduces the amount of time employees must work in hot environments. Where this is not possible, increasing ventilation or providing fans to promote air flow can reduce the heat related risks. Alternating tasks and rotating employees to limit the amount of time any employee must work in a hot environment may be warranted. Rotation times can be coordinated with established breaks to minimize disruption of work flow. Providing adequate rest breaks where employees can escape from hot environments and re-hydrate can reduce heat-related risks. Adequate breaks are particularly important where employees perform heavy manual work in hot environments.
|
| |
|
|
B-22 |
U.S. Department of Labor
Occupational Safety & Health Administration
|
Process: Shipfitting |
| Hazard: Heat Stress |
|
| |
Problem:
Employees are to wear multiple layers of protective clothing and equipment such as welding hoods, leather welding jackets and heavy gloves. Body heat can become trapped under the layers of clothing. |
|
Case History: Heat Stress
 A shipfitter who had been working inside a structural unit in an outdoor staging area was nearing the end of his workshift. The sun on the structural unit quickly heated the interior spaces. The shipfitter
pushed himself to finish the job ahead of schedule. When he finished,
his supervisors asked him if he would be willing to work overtime to
help complete a job that was behind schedule. Without taking time to rest, cool down and rehydrate before starting the new job, the shipfitter carried his heavy tools to the other job site and began to work.
He had to climb ladders several times to access the new job site.
The new job site was located on a unit that had been exposed to direct sunlight all day and was radiating heat. The shipfitter performed demanding alignment, welding, and grinding tasks for the next hour. When he stood up he felt dizzy and stumbled
forward. The shipfitter dropped down on one knee, fell forward and hurt his hand when it hit a metal clip. Nearby employees came to the shipfitter's aid, removed some of his heavy protective clothing and gave him water to drink. The shipfitter's
dehydration and heat exhaustion were serious enough that he had to be moved off the vessel section in a mobile man-lift and be taken to the shipyard medical clinic for evaluation.
|
|
Analysis and Preventative Measure |
Solution:
Cooling vests that weigh less than 5 pounds and maintain a 59˚F temperature for up to 2 hours are available. These vests are designed for use under protective clothing.
Although cooling vests may not be appropriate in every situation, they can reduce heat related risks for employees working in small and tight spaces where there is limited natural or mechanical ventilation.
|
Exposure to excessive heat can take a severe toll on shipfitters. Dehydration and heat stress can cause fatigue and disorientation. If this happens when an employee is performing
a high risk task, such as climbing a ladder or walking near an impalement hazard, there is a risk of serious injury. Prolonged exposure also may result in heat exhaustion and heat stroke. Because hot environments
are inevitable in shipfitting, it is essential that practical steps be taken to minimize the risk of heat stress so employees can maintain productive work practices. Where possible, providing ventilation and spot
cooling by local exhaust ventilation can reduce the effects of heat on employees. Shading structures can
be used to block out direct sunlight. 
Work areas need to have adequate amounts of cool drinking water so employees don't risk becoming dehydrated. Employees need to be encouraged to drink 4 to 8 ounces of water or sports drink
every 15 minutes while working in hot humid conditions. Rotating employees and providing periodic rest breaks can help employees cool down core body temperature and recover from heat-related fatigue. Educating
employees to replace fluids lost through sweating and recognizing the symptoms of heat stress are essential to minimizing heat-related illnesses. Employees should also be cautioned about over hydrating. Limit
fluid to no more than 1 ½ quarts per hour when working in hot humid conditions and no more than 12 quarts of fluid in a 24 hour period. |
| |
|
|
B-23 |
|
Back to Top
