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Q & A

Q: What is the definition of a Dropped Object?
A: A ‘dropped object’ is any item that falls from its previous position. This covers all items, materials or objects of any mass / density. Dropped Objects may be classified as static or dynamic


Q: What is a Static Dropped Object?
A: A Static Dropped Object is a any object that falls from its previous position under its own weight (gravity) without any applied force. For example, failure caused by corrosion, vibration or inadequate securing.


Q: What is a Dynamic Dropped Object?
A: A Dynamic Dropped Object is any object that falls from its previous position due to applied force, eg collisions involving travelling equipment or loads, snagging on machinery or stacked items, motion, helicopter downdraft or severe weather.

Q: What are Primary Fixings?
A: The primary method by which an item is installed, mounted and secured as to prevent the item falling, eg bolted connections, screws, pins, buckles, clips, welds etc.

Q: What is Secondary Retention?
A: The engineered method for securing the primary fixing to prevent loss of clamping force or displacement of fastening components, eg locking washers, locking wire, split pins / cotter pins, etc.


Also referred to as Second Barrier or Fail Safe feature in some engineering descriptions.
Note: Double Lock-nutting or Dual Nutting is NOT recommended.

Q: What is Safety or Secondary Securing?
A: An additional engineered method applied to or around the item and secured back to the main structure, designed to restrain the item should the primary fixing fail,  eg rated steel or synthetic nets, baskets, wires, slings etc.

Q: Should I deduct the average person’s height from the fall height when using the DROPS Calculator?
A: No. You never make any deduction in lieu of a person’s height etc as the object may strike a head, a shoulder a leg or a foot. Also, the person may be bent over, crouching or lying on the ground at time of impact.

Q: What assumptions are made by the DROPS Calculator?
A: The Calculator assumes that full PPE is being worn and that the object is blunt (no sharp edges).

Q: Where did the DROPS Calculator derive from?
A: The DROPS Calculator is derived from detailed research undertaken by Shell Expro in The Hague in the 1990s. DROPS reviewed a number of similar calculators applied throughout the Industry over 10 years ago and, by consensus, we developed the DROPS Calculator based on the Shell version. While other calculators are still used in the Industry, over 95% of our membership recognise and use the DROPS Calculator.

Q: How Accurate is the Calculator?
A: The DROPS Calculator is a guide only and is intended to give a general idea of the potential severity of a dropped object. A detailed and specific risk assessment will always deliver a more accurate calculation of potential severity.

Q: The Electronic DROPS Calculator stops at 15m – what about higher falls?
A: Heights above 15m can still be entered into the box above the chart and the outcome will be accurately calculated and presented, however, the point will not be displayed on the visual graph which does not extend beyond 15m.

Ask a question and the DROPS committee will answer it!
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