Dropped Objects (DROPS) Prevention

Editor's Notes

• #5: Statistics speak for themselves. Of 412 fatalities, 88 were directly attributed to Dropped Objects. Access latest statistics at Bureau of Labor / OSHA
• #6: First let’s make sure we understand what a dropped object is. Let us look now at how we define dropped objects and understand their causes and consequences. >>What is a Dropped Object? Ask the class. >>(Reveal answer) A dropped object is any item or object that falls from its previous position. (use your prompts around you. A projector, a screen, a picture frame, an airconditioning unit, a lighting fixture…basically anything stored, fixed or used at height. Let’s say you select a lighting fixture. If this fell from the ceiling, it would be a dropped object) It is important for us to analyse these objects and define them further. Ask delegates to describe different kinds of dropped objects. Try to include examples from all activities – even home and leisure. Note that some industries and regions may use different terms such as falling items, struck by, material fall – and in some cases we may report dropped objects as other types of injuries. Crush injuries for example can be caused by items being dropped on hands and feet. It is important for us to analyse dropped objects and define them further – so we can understand how they happen and what we can do to prevent them. Ask delegates if they know what the two definitions of dropped objects are. Try to use a visual example – perhaps something in the worksite or classroom. You could even use a pen attached to a piece of string… >>Static - any object that falls from its previous static position under its own weight – the weight of the pen causes the knot in the string to fail and it falls. Gravity is one of the hazards identified in our Hazard Identification Wheel. >> Dynamic - any object that falls from its previous static position due to applied force from equipment/machinery or moving object – the pen is struck or is snagged, causing the knot to fail or the string to snap. Think Gravity, plus mechanical, motion, pressure – even electrical (electric shock from power tool results in drop etc) >> Also consider kinetic potential - any object that falls from its previous static position due to failure caused by repeated cyclic loading and movement – the pen swings continuously in a noisy, vibrating, windy environment – perhaps extreme temperature changes too - for days, weeks, months, causing the knot to fail or the string to snap or even the pen clip to fail due to the continuous wear. Consider more combinations of potential hazards that affect items secured or stored at height – or even stacked against a wall. If we add other factors such as corrosion or poorly selected and installed fittings, we begin to identify potential scenarios around common working activities that can cause dropped objects. Discuss some more examples / real incidents. Determine which were static, which were dynamic and which were kinetic. We will study these in more detail later on. >>
• #9: Consider this image. What can you see. It is a potential dropped object. Identify the individual components (housing, bracket, t-bar mount). Identify the primary fixings. Consider how this could fall (static or dynamic). What would cause it to fall (collision, corrosion, poor maintenance, vibration etc). Any other fixings that may prevent the light from falling (power cable, safety wire)
• #10: Have a closer look. The primary bolting uses a washer system as secondary retention (ie maintaining the torque). The arrangement here shows two washers. This is not good practice. It is apparent that this would not be Original Equipment Manufacturer recommended either (note evidence on bottom arrangement – inner washer covers view-hole and thread appears short). These primary fixings must be considered as potential failure points and should be reviewed against OEM guidance.
• #11: Now the safety wire. This has been retro-fitted, is not good practice, already shows signs of corrosion etc. All safety wires, nets etc must be carefully considered, ideally in association with OEM. Always focus on primary fixings.
• #14: This short video shows the result after a 220g bolt was dropped from 27m – through 3 stands of drillpipe.
• #15: There are a number of tools and techniques available for classifying the potential consequences from potential dropped objects. Many companies will use their own tool or technique and all the tools are for guidance only. There are simply too many influencing factors/variables for any tool to accurately predict the consequences of a potential dropped object. Some of these variables are difficult to quantify and build into a simple model, eg the shape of an object and its impact on the person, the operations and controls already in place. Hence the reason why this is a tool and guide to provide some starting point for investigation. One such guidance tool, known as the DROPS Calculator, is offered by the DROPS Workgroup. >>The legend may require some explanation,
• #16: Be sure to inspect all tools before using them for working at height. Ensure approves tools are selected. Never use inappropriate or home-made securing devices.
• #18: Barriered Areas are No Go Zones, unless you have been included in the TBRA/ JSA and PTW processes. Never cross a barrier… Discuss what is missing from this movie example (Signage)
• #19: Red Zones or Restricted Access Areas feature on all Company operated drilling packages. However the principle can be applied to any asset zone where personnel may be exposed to dropped objects – as well as other hazards such as moving equipment, remotely operated equipment, high pressure and other hazards determined by risk assessments for the task in hand. Areas defined as Red Zones are clearly marked. Personnel within the Red Zone must be required for the current operation and authorized by the relevantTeam Leader. The Team Leader must ensure all personnel entering the Red Zone are aware of all moving equipment such as the top drive, drawworks, pipe handling equip and so on. It is equally important for personnel who are authorised to work within the Red Zone. Personnel must identify Step Back Safety Zones and look to limit physical time spent working within any Red Zone. Yellow Zone – Personnel with specific work related tasks to do may enter subject to Team Leader and Permit to Work authority. Green Zone – Anyone may enter as long as there are no additional barriers in place. In the case of visiting the dog house, it is always advisable to call ahead and plan any visits to eliminate unnecessary distractions. These same principles are in force on many rigs worldwide, not just our organisation. Simple rule of thumb is never enter the drill floor area unless you are part of the drilling crew, have an appropriate permit and authority to enter or have the express permission of the Driller.
• #20: We are typically very good at spotting potential Static dropped objects. We can almost sense when they will happen, perhaps due to our natural perceptions of gravity, height and weight. But when there is an activity that involves motion, do we always consider all of the potentials for Dynamic dropped objects? Let’s imagine our task today is the removal of the table cloth from the dining table in the background. Our two young volunteers are planning to remove this quickly without causing any damage to the crockery. What hazards can you identify? Hot liquid? Sharp edges? Spills?
• #23: A wealth of technical experience and knowledge: - Over 35 years combined in Drilling - Over 30years combined each in Asset Integrity and Renewables - Over 24years combined in CFD - Over 20years combined in Failure Analysis
• #24: A top drive is a mechanical device on a drilling rig that provides clockwise torque to the drill string to facilitate the process of drilling a borehole. It is an alternative to rotary table. It is located at the swivel place and allows a vertical movement up and down the derrick. An advantage of a top drive is that it allows the drilling rig to drill longer sections of a stand of drill pipe. A rotary table type rig can only drill 30-foot (9.1 m) (single drill pipe respectively) sections of drill pipe while a top drive can drill 60–90-foot (18–27 m) stands (double-triple respectively. A triple being three joints of drillpipe screwed together.), depending on the drilling rig type. Having longer sections of drill pipe allows the drilling rigs to drill deeper sections of the wellbore, thus making fewer connections of drill pipe. Another advantage of top drive systems is time efficiency. When the bit progresses under a kelly, the entire string must be withdrawn from the well bore for the length of the kelly drive. With a top drive, the draw works only has to pick a new stand from the rack and make two joints. The savings in time reduces the risk of a stuck string from annulus clogging. Several different kinds of top drives exist, and are usually classified based on the "Safe Working Load" (SWL) of the tool, and the size and type of motor used to rotate the drillpipe. For offshore and heavy duty use, a 1000 short ton, top drive would be used, where a smaller land rig may only require a 500. Motors are available in all sizes, and come in Hydraulically powered, AC, or DC motors.