Скачать или смотреть Risk Mitigation Strategies for Mobile Elevated Work Platform (MEWP) Usage in Industrial Settings

SCENARIO

The manufacturing site of a large international chemical organisation is located on the outskirts of a town. This site is close to a main road and residential homes. Tall mature trees line the perimeter of the site to provide a visual barrier between the residential and industrial buildings.

The chemical manufacturing operations involve many different types of processes that normally run continuously (24-hours a day, 7-days a week) by process operators working shifts. Shift patterns include 06:00 – 14:00 (day shift), 14:00 – 22:00 (afternoon shift), and 22:00 – 06:00 (night shift). There are approximately 400 workers on the day shift and 400 on the afternoon shift. The night shift has the smallest team with approximately 200 workers. A dedicated car park for workers is located at the north end of the site, next to the main road and main entrance. There are often queues getting in and out of the car park during shift changeover times.

The manufacturing processes use hazardous chemicals (including those that are toxic and flammable) as raw materials. As a result, large quantities of hazardous chemicals are in use and stored on site in storage vessels, intermediate bulk containers (IBCs), and 205-litre drums to ensure there is always sufficient stock available.

One of the manufacturing processes is in the middle of a six-week scheduled maintenance shutdown, where most of the hazardous chemicals have been safely removed from associated process vessels. This process plant (equipment, vessels, and associated pipelines) is located outdoors and is accessed using external steel walkways and stairs over four floors. The walkway floors are made of steel grating. Pipework, several vessels, and some electrically driven pumps are located on all these floors.

There are dry powder fire extinguishers located at various places around the process plant. The plant is fitted with a water-based foam sprinkler system. The process plant also includes a number of combined safety shower and eyewash stations that can be used in an emergency. These stations can be utilized to wash off hazardous chemicals to which workers may have been exposed. Using the stations automatically alerts the shift manager and an on-site emergency rescue team to the scene.

At either end of the ground floor, there is a manually activated plant evacuation alarm. The alarm has an intermittent tone and flashing red beacons. Activation has the same effect as a fire alarm, prompting everyone to evacuate the process plant immediately. The evacuation alarm can also be activated remotely from a central process control room. A two-way radio can be used to ask for remote activation. Workers at the plant are trained what to do in an emergency in their induction training.



Deliveries

Road tankers ranging from 2.4 to 3.6 metres in height deliver chemicals to the site. Deliveries are scheduled every fortnight on a Monday afternoon between 13:00 – 17:00. Smaller quantities of raw materials are delivered in IBCs and 205-litre drums every Wednesday morning on a weekly basis; however, there are frequent ad hoc deliveries of IBCs and 205-litre drums to cope with fluctuations in manufacturing operations. Delivery times also vary depending on local traffic conditions, which has been known to cause congestion.

Delivery drivers ranging in age, experience, and nationality arrive at the main gate and sign in with a security officer. Using a separate entrance next to the main gate, the drivers navigate across the site to the chemical storage area located at the south end of the site. The two-way internal road network within the plant is also used by other vehicles such as those used by waste management organizations, internal maintenance, external contractors, and the plant’s forklift truck operators. Most of the process operators work inside a network of buildings connected by these internal roads and walkways. These internal roads have a speed limit of 16 km/h (10 mph) and mini roundabouts with a raised surface. Due to potholes, a temporary diversion route has been put in place near the south end of the site while the road surface is repaired. However, some workers have complained that the temporary road system is difficult to navigate due to its narrow width.

Operators across all shifts work in and around the chemical storage area, managing deliveries (receiving, decanting, and processing). Chemicals delivered via road tankers are then transferred directly into the storage vessels. The delivery drivers unload from the bottom of the road tanker using a hose attached to a loading valve. Sometimes the delivery drivers need to climb to the top of the road tanker using an access ladder for maintenance or to check the levels. The handrail at the top of the road tanker is then automatically raised using a switch on the tanker at ground level, and then interlocked to the ladder. Sometimes the handrail needs to be manually raised if the mechanism is corroded.