You are a shift manager at a site owned by a large multi-national chemical organisation. The organisation manufactures, uses, and stores large quantities of toxic and flammable chemicals. The site itself is extensive and comprises of many buildings and plant (see supporting document 1). The main entrance to the site is accessed directly from a major public highway. Close to the main entrance is an office building, with a car park to the side. Behind the office is the main process plant, that is situated in the open air (ie not enclosed in a building). The process plant is a complex arrangement of reactor vessels, pipelines, and equipment where raw materials are chemically reacted to form a range of products. The organisation is constantly innovating with new products, but largely uses or adapts existing process plant to achieve this. The manufacturing processes are normally continuous (24 hours a day, 7 days a week), and are run by process operators working shifts. In total the site employs 800 people. Most liquid chemicals used as raw materials in the processes are stored in an open-air tank farm that is some distance from the main process plant. The tank farm consists of a complex of large vertical and horizontal steel storage tanks where the final product is also stored. A pipework system connects the tanks to two process vessels that are inside the main process plant. The tanks are grouped into separate bunds because of the incompatible chemicals. Each group is surrounded by a 1.5-metre-high concrete bund wall. Each bund has a capacity of 110% of the largest tank. Recent bund inspections by shift managers have revealed that there are some small cracks in the wall in which vegetation has started to grow. The bund has drain valves that empty into the main surface water drainage system. Recently, there have been a series of thunderstorms, with heavy rain and high winds. The raw materials stored in the tank farm are replenished regularly by road tankers. To reach the tank farm from the sites main entrance, tanker drivers need to navigate sharp bends and narrow roads. The drivers arriving on site are usually provided with a site map to direct them from the site entrance to the tank farm. However, recently, maps have not been given out to drivers. Minor collisions of delivery tankers into the bunding walls is a regular occurrence. Congestion sometimes occurs due to multiple deliveries at the same time. There have been several near misses involving vehicles and pedestrians. The drivers work to a busy schedule and complain that the site is difficult and time-consuming to navigate. Workers who leave the office carpark onto the public highway need to be aware of large road tankers. Vehicular access to the site from the public highway is controlled using a powered gated barrier across the entrance. This is operated remotely by security guards from a nearby security hut. There is also a lockable side gate for pedestrian traffic. The process plant can be accessed using a four-storey external steel walkway and associated stairs. Its main large cylindrical reactor vessel measures around 4 metres in diameter and 5 metres tall, and has an internal steam heating coil. This is used to heat reaction mixtures to the required temperature. An electrically-powered stirrer is fitted at the top. Baffles (fixed plates) are attached to the vessels internal vertical surfaces to aid the mixing of contents. Raw materials are added in through a hatch at the top of the vessel. The completed product is then drained via an outlet valve and pipelines at the bottom (see supporting document 2). During normal operation, the reactor vessel contains large volumes of suspended solids, and volatile flammable and toxic liquids. Over time by-products have caused an accumulation of solids around the internal heating coil and baffles. Process operators have reported that this has started to affect production efficiency. This is the first time that this issue has been encountered. You decide that the vessel should be cleaned during the next scheduled shut down for maintenance. At the next shutdown, you initially plan to use cleaning methods that avoid the need for workers to enter the reactor vessel. The reactor is emptied of the hazardous, flammable, and toxic chemicals, filled with water, and boiled for 24 hours to remove any residue. The contaminated water is drained, and the vessel opened to the atmosphere for a few days to dry it off. However, there are still solids stuck and trapped in between the large heating coil and baffles. You consider other options that might still avoid the need for reactor vessel entry, but discount them based on cost and your assessment that the residual solids are probably not very hazardous. You decide to clean the reactor vessel manually using an electrically driven high-pressure water jet washer. You are close to finishing your shift for the day, so after a brief discussion with the next duty manager (who has just come on shift) you leave the planning of the cleaning work to them, including the issuing of the permit-to-work (PTW). When you come back on shift late the next afternoon, you go to the reactor to check on progress. Preparations already seem to have been made and the jet-washing work is about to start. You find two recently-employed workers outside the vessel, as they have been asked to watch over the activity and stand by in case of an emergency. Breathing apparatus is also nearby, if required. A worker trained in confined space entry, wearing nylon overalls and running shoes, is just about to climb down a ladder from the top hatch to the base of the reactor to start the water jetting work. You ask the worker not to enter the vessel yet, as you want to review the PTW first. The PTW has been prepared and authorised by the previous shift manager who had just gone off duty. Keen to get the job finished before it gets too dark, you presume all isolations and disconnections have already been made. The plant has been shut down for a while, so you think there is no need to physically doublecheck. You note that a small access cover near to the bottom of the reactor has been removed. Although this access point is not large enough for a person to fit through, it will allow some natural ventilation. This is supplemented by a small fan taken from the nearby office, and placed outside of the reactor vessel. The inspection cover is removed and the fan forces a little more air through the vessel. The workers show you monitoring records from initial atmospheric tests they have just done. These show that oxygen levels are normal, and no toxic or flammable vapours are present. In view of these results and the provision of ventilation through the vessel, you agree with a supervisor on site that no further atmospheric tests need to be carried out during the job. The plan is to work from a ladder, water jetting from the top to the bottom of the vessel. The vessel heating coil will be switched on to medium heat to help loosen the solids. During the work, contaminated wastewater generated from the water jetting collects at the bottom of the reactor vessel. This will need to be disposed of. It will be pumped directly from the bottom of the reactor vessel via a flexible hose and isolating valves to a 5m 3 frame tank container (a type of horizontal tank held within a rectangular metal frame designed to enable stacking or loading onto trailers for onward transport by road, rail, or sea). The tank container has a vertical access ladder at one end, and a walkway on the top for access to top hatches and valves. The tank container is 2.6m high. The empty tank container was delivered the previous day on a trailer; because room was limited, the tank had to be unloaded from the trailer and manoeuvred into position onto a level concrete hardstanding. A side loader forklift truck with a top lift attachment was used for this (this is a special type of forklift truck designed for this purpose). After the water jetting work is finished, the full tank will be put back on a trailer using the same forklift truck and taken to a hazardous waste site for disposal of the wastewater. Satisfied with your PTW review, you allow the job to continue. The worker, wearing a harness attached to a lifeline, climbs down the ladder into the vessel. The plant is not well lit and, as it starts to get dark outside, it becomes increasingly difficult to see. Although portable lighting is being used in the vessel, it is still poorly lit, and the worker inside cannot see clearly. As the worker starts water jetting, the solids on the heater and baffles begin to break up and fall away. The worker is unaware that this is slowly releasing oily deposits and vapours from volatile chemicals that have been trapped inside the solids from previous chemical processes in the vessel. As they carry on water jetting, the worker begins to have difficulty concentrating. As the job progresses, the worker feels increasingly unwell and unsteady. Water from the jet washer hits the lighting system which begins to flicker. Distracted by the flickering, and feeling unwell, the worker accidentally runs the jet washer over their foot, cutting through their shoe and skin, screams, and nearly falls off the ladder. They pull vigorously on their lifeline to get the attention of the workers above. The workers standing by outside the reactor vessel manage to pull the injured worker out of the vessel using the lifeline and a winch. A later investigation into the accident recommends that vessel entry for future manual water jetting must be avoided. Money will be made available to hire a high-pressure hurricane jetter (automatic jetting machine) that avoids the need for workers to enter the vessel.

Task 9 - What do you need to consider when planning for, and carrying out, the lift of the frame tank container? (40) Note: You should support your answer, where applicable, using relevant information from the scenario.