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Stone SlingerTM



Introducing the

Stone Slingertm OS7

The ONSITE solution for precise material placement in high-volume projects. 

Your New “Sling Cycle”

• Transport the OS7 to the Jobsite by float

• Deliver and stockpile your stone by conventional dump trucks

• Position the OS7 to optimize placement productivity

• Feed the OS7 hopper with available loaders or excavators

• OS7 places material continuously all day long!

100% Stone Slinger™

The new Stone Slinger OS7 mounts the industry’s preferred high-speed aggregates delivery and placement technology on a self-propelled all-terrain platform built entirely by Gravel Conveyors Inc. 

– no truck chassis required!




The OS7 stays on-site to give you continuous production all day! Produce more and reduce costs with the genuine “Stone Slinger” high-speed conveyor placement system.


The OS7 is a self-propelled, remote-operated platform that stays on-site to place up to 225 tons of material/hour! 

Conveyor Placement System

• 7 yd3 hopper, level full (not including wing extensions)

• 19' throw conveyor c/w W.K. Dahms ½” high cleat belt

• Hydraulically operated wing extension (each side operates independently)

• Hydraulically operated hopper leveling via toggle on the transmitter (12˚ each direction off of level)

• 32" apron chain centers, 26" wide live-bottom unloading system

• 2-speed hydraulic motor & planetary gearbox with live bottom unloading

Drive Systems

• CAT C4.4TA (Tier 4F), 131 HP fuel-efficient, self-contained diesel power with direct-coupled hydraulic pumps

• Engine and system control via Hetronic / Sauer Danfoss CANBUS

• Danfoss closed loop piston pumps and motors on the drive system

• Danfoss variable displacement pumps and load sense valves on Stone Slinger functions

• 7" color display screen (engine and control system diagnostics and controls)

• Piston style motor and 10-1/2" diameter rubber covered drive roll

• Planetary gearbox with a direct-coupled hydraulic motor on swing frame for conveyor rotation

• Dana Motion planetary drive axles with steering

• 4 steering modes controlled via transmitter ~ front, rear, articulated & crab

• 12 ply, rugged tread, flat profile 15-19.5NHS Carlisle, high floatation TRAC-CHIEF tires

Overall Length: 260" (6604 mm)



136 ¼" (3461 mm)


Max Width:

102" (2591 mm)


Max Height:

108" (2743 mm)

Loading Height (Rear): 74" (1880 mm)


Operating Weight: 18,600 lbs (8437 kg)

Heavy Duty Apron Belt Bearings And Shafts

• Long life, trouble-free operation

Apron Drive With Direct Coupled Gear Box

• 2 speed, high torque, long life design

Double Pivot Swing Frame With 250° Working Pivot Radius

• Widest working radius - increases flexibility and production

Chain Drive Swing Frame Positioning

• Provides precise control over swing motion

End Drive Throw Conveyor

• Increased throw efficiency, accuracy and distance

Dependable Electrical Wiring

• Protected harness and weathertight connections for years of reliable operation

Twin Hydraulic Heat Exchangers

• High-efficiency heat exchangers are thermostatically controlled, ensuring long hydraulic component life

Wide Apron Belt Design

• Expands the range of materials you can place without bridging Innovative

Live Bottom Apron Belt Design

• Precise material flow for superior placement control


Super-Shield™ Power Drive

• Matches the conveyor belt speed to improve control of material on the belt

All-Terrain Mobility

• 4 remote-operated steering modes to navigate rough terrain and operate in tight conditions

Low Loading Height – 74"

• Allows efficient loading with smaller loaders, mini-ex’s and skid steers

Low Overall Profile – 108"

• Able to access indoor work sites

Hopper Wing Extensions – 131" wide

• Reduce material spillage and waste; feed with larger loaders and excavators

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