This page is deliberately short on specifics, for a reason worth stating first.
The detailed procedure belongs in a Filling and Installation Manual that has not been issued, and the safe working loads and filled weights belong in a product data sheet that has not been issued. Two answers in FES’s own reference material defer to the first and five to the second.
On a lifting operation, inventing plausible numbers is the worst available option. What follows is the arrangement and the principles. Anything specific to your bag size comes from the engineering team.
The arrangement: a single attached ring
The units are rigged from a single attached ring, not from four corners.
This is worth being precise about because the site previously said four corners on the offshore page, and it was corrected during the August 2026 accuracy review. If you are working from older material, check it.
The practical consequences of a single-point lift:
- The unit hangs from one point and finds its own orientation
- There is no load-sharing calculation across multiple legs
- There is no risk of one leg taking a disproportionate share through unequal rigging
- The load path runs through a single connection, so the condition of that connection matters absolutely
Capacity, worked properly
The bank covers how required crane or excavator capacity is calculated from bag weight and placement reach, and what working radius contractors should use when checking capacity.
The principle that matters, and the one most often skipped:
Capacity is not the machine’s headline rating. It is the rated capacity at the working radius you will actually use, from the load chart, with the rigging and any attachments counted as part of the load.
An excavator that can lift a given weight close in may not lift it at full reach over a bank, and the reach required to place the outermost units is usually the governing case rather than the nearest.
Work it from:
- Filled weight of the unit, which depends on aggregate density as well as size. See fill stone selection
- Maximum working radius for the placement, not the average
- The load chart for the machine, at that radius, in that configuration
- Rigging weight included
- Ground conditions under the machine, because a load chart assumes a firm, level standing. The bank covers ground-bearing checks
What is supplied and what is not
The bank addresses which lifting accessories are supplied and which the contractor provides. Establish this before mobilisation rather than on the morning, because a crew that arrives without a compatible connection is a crew that does not work that day.
Related: pre-positioning emergency stock notes that stock held in reserve without the means to lift it is not response-ready.
Placement control
The bank covers what controls help prevent impact damage while lowering a unit into place, and whether there is a maximum allowable drop distance.
The principle is that a controlled lower is gentler than a release. Dropping a filled unit the last part of the way concentrates impact on the mesh, on the fill, and on whatever it lands on, and on an irregular bed it also reduces placement accuracy.
The specific maximum drop distance is a manual question and this page does not state one.
Working over water, and the safety context
Placement is frequently a lift over water with a landing point nobody can see. The hazards specific to that are covered in safety during emergency placement, and they apply on planned work too:
- Suspended loads over water, where a dropped load cannot be retrieved or inspected
- Blind positioning, worked by measurement rather than by eye
- Plant on ground that may itself be the failing ground
- Reach at the limit of the machine’s capacity, which is where things go wrong
- Exclusion zones under and around the load, which are the control most eroded by people trying to see what is happening
None of that is unusual for marine and river construction, and all of it belongs in a lift plan prepared by someone competent, not assembled from a web page.
Pre-lift checks
The bank lists checks to complete before a filled unit is lifted. The principle level:
- The opening is properly secured
- The rigging is correctly attached, untwisted, and not fouled by fill
- The unit is filled evenly and to the approved amount
- The connection and its condition have been inspected
- The lift plan, radius, and capacity have been confirmed for this lift
- The exclusion zone is clear and the signal arrangement agreed
What this page will not give you
- Safe working loads
- Filled weights per size
- Maximum drop distance
- A rigging specification or connection detail
- A lift plan
Those come from the data sheet, the manual, and a competent person on your job. Two of the three do not exist in published form yet, and saying so is more useful than producing numbers that look authoritative.
Send the bag size, the reach, and the plant available through the quote form and the engineering team can give you the current position. For imminent work, call.
Where to go next
- Equipment selection
- Filling a rock bag
- Safety during emergency placement
- Underwater placement
- The rock bag FAQ for the full equipment and access section
- The installation hub for the rest