Rock-armour grab
each block is placed.
Synthetic image.
It takes natural blocks, irregular, heavy.
Laying rock armour is not loading a heap:
each block is placed.
Other names for this tool: rock armour block grab, rock armour claw, rock grab, revetment grab.
- Family
- Demolishing and breaking
- Classes (t)
- Medium and large
- Coupler
- All, by plate
- Power source
- Hydraulic — flow and pressure: we calculate it with you for your machine
What it is for
Right: a flat jaw slips on the natural rock and the block gets away from it.
What sets it apart:
it is made for the irregular — a flat jaw slips on natural rock, a claw anchors in it.
Computer-generated image.
Each block is placed: you are not loading a heap, you are building a riprap.
Synthetic video.
Rock armour is built block by block:
you present, you wedge, you turn, you lay again.
A grab holds the block by squeezing and makes it possible to orient it, which no sling allows you to do as finely.
It is met with on bank protection, revetments, block walls and slope rock armour.
The work is often done on a cross slope, at the water's edge or at the foot of a bank — positions where the stability of the carrier counts as much as the squeezing force.
A block held by squeezing is not a slung load. It holds as long as the squeezing force holds, and the shape of the block has much to do with it.
The rules for working under the load and the organisation of the site are not deduced from an attachment's data sheet:
they are settled with the firm, before the first block.
On which machine?
The rock-armour grab fits excavators from 2 to 65 t, via a mounting plate, on all couplers.
On a mini-excavator from 2 to 5 t: a grab from 230 to 470 kg.
On an excavator from 5 to 10 t: from 230 to 770 kg.
On an excavator from 10 to 20 t: from 470 to 1 500 kg.
On an excavator over 20 t: from 1 500 to 3 400 kg.
What the tool does
This tool is used for rock-armour work.
Its weight ranges from 230 to 4 900 kg depending on the size.
Also available in a rotating version, through 360°, to be checked with you.
What is needed on the hydraulic side
It needs an auxiliary hydraulic circuit, at 200 to 320 bar depending on the size.
The flow: we calculate it with you for your machine.
Figures taken from 7 models on the market.
Your study sets the exact value for your machine.
Have your machine checked.
Describe the structure:
nature and size of the blocks, slope, access, distance at which the machine will have to work.
It is the reach that governs the sizing here.
- Your machine Its make and its tonnage.
- The auxiliary circuit Its flow in l/min, its pressure in bar, single- or double-acting.
- The coupler in place Its system and its class.
- The work The use, and the material.
Without these details, the study still begins: we will ask you for them.
Or call 01 84 16 55 49 · our lines are open 7 days a week, from 7h to 22h.
Written study within 3 working days, once the file is complete.
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Block grab
Principle — jaws, often lined, that clamp the block by its sides without marking the stone.
Use — it places regular blocks at a precise spot: wall, stairs or precast element.
What determines the choice
- 01 — The shape and mass of the blocks An irregular natural block is not gripped like a sawn unit.
- 02 — The opening and travel of the arms They fix what the tool can actually grip.
- 03 — The rotation Laying a block in its place calls for orienting it without moving the machine.
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04 — The working position
Cross slope, bank edge, maximum reach:
that is where the carrier is most heavily loaded.
What is checked before ordering
- The mass of the blocks and its spread The biggest stone decides, not the average.
- The load chart at the real reach On a cross slope and arm extended, not at the foot of the machine.
- The hydraulic functions One for the squeezing, a second for the rotation.
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The safety devices chosen
Check valves, limiter, signalling:
they are decided with the site, not afterwards.
- Family
- Demolishing and breaking
- Classes
- Excavator from 10 to 20 t
- Classes
- Excavator over 20 t
- Compatibility
- The seven criteria in detail →