Knuckle Boom Loaders

Model BL-3 - Knuckle Boom Loader

Knuckle Boom Loaders for Sale

The model BL-3 is a 20 ft. knuckleboom loader that is permanently mounted in front of a roll-off.  You can use your existing roll-off boxes with this system.

  • Loads into multiple containers without ever leaving the route
  • Available with walk-thru or top mounted controls
  • Accommodates most containers
Knuckle Boom Cranes for Sale
Knuckle Boom Loaders for Sale


Knuckle Boom Loaders – Standard Features


knuckle boom trucks for sale


Greaseless dual walk-thru controls operational from either side of truck. Petersen also offers QUADSTICK® controls and stationary top mount controls with joysticks or valvehandles.


Out and down outriggers improve safety in traffic and reduce damage to streets.


Boom swing does not have any exposed pinion or bull gears. Petersen’s rotary actuator boom swing method is lower maintenance.


Four foot tip extension adds flexibility and maneuverability. Tip extension hoses are enclosed and protected.


Petersen Industries manufactures and installs both the grapple loader, including bucket and controls, and the trash dump body.


The standard dual walk-thru has an overall height of 11’3″.


Boom cylinders have counterbalance valves, and outrigger down cylinders have pilot operated check valves to prevent leakdown or collapse in the case of hose rupture.


Continuous rotation for convenience.


Reduced downtime due to elimination of hoses in bucket jaw area.


Reverse curve motion of bucket helps prevent scalping of lawns.


Three year structural, one year hydraulic.

Knuckle Boom Loaders – Specifications

knuckle boom truck

System Description

knuckle boom crane truckPetersen Model BL-3 loader is mounted to chassis between the cab and the cable roll-off hoist,
which is mounted on a long wheelbase cab chassis. The loader operates from a fixed platform
located behind the truck cab. All hydraulic components for the loader system are provided.


Reach (from centerline rotation) 20 ft
Main Boom and Tip Boom 15 ft
Tip Extension 4 ft
Unit Weight (Empty) 5,585 lbs
Outrigger Span 11ft 8in
Storage Height (above frame) 8ft 4in


Lifting Capacities

10 ft 7,100 lbs
15 ft 4,400 lbs
20 ft 3,200 lbs


Weight of bucket and/or attachments must be subtracted from lift capacities shown. Standard bucket weighs appx. 1000 lbs. Capacities shown do not exceed 85% of vehicle tipping moment with outriggers fully extended on firm, level ground.

Bucket Features

The bucket is 4ft long with an opened width of 5ft between pickup blades. Anti-scalping bucket sides are pivot mounted to provide a horizontal closing action rather than a vertical digging motion. Sides are mechanically linked to single hydraulic cylinder to ensure that both sides close and open together. No hydraulic hoses below bucket rotator.

Recommended Chassis Specification (Minimum)

Gross Vehicle Weight Rating 50,0001bs
Cab-to-Rolloff Dimension 52 in
Frame RBM 1,500,000

Actual roll-off unit, estimated loads, and container length dictates the selection of the chassis.

Operator Controls

Dual manual controls (greaseless) for outriggers and loader on both sides of the truck for easy access and visibility. Also available with QUADSTICK® dual joystick controls. Stationary top-mount control seat is optional.


A-frame pedestal design allows ftexing under repeated load shocks. Replaceable Cast Nylon bushings used in head assembly. Head assembly is stress relieved. Reinforced connection points with hardened pins and replaceable bushings. Counterbalance valves used on boom cylinders and pilot operated check valves used on vertical outrigger cylinders.

Knuckle Boom Loaders – Options

Dual Walk-Thru Controls

knuckleboom loaderGreaseless dual controls are operator friendly and maintenance free!

• DUAL CONTROLS: Control platform to be located directly behind conventional cab to allow operator access from the truck cab without ever having to touch the ground. A single bank of control valves to be mounted at the mid-point of loader, with control handles accessible from the operator platform on either side of truck. Control handle pattern must be the same on both sides of the truck for superior visibility. Control handles shall not require lubrication. A “Grip Strut” serrated steel walk platform is included.


QUADSTICK® mechanical controls

boom crane truck options

Completely mechanical! No high maintenance electronics!

• JOYSTICK (dual walk-thru): Petersen mechanical QUADSTICK® controls. Each of the four joysticks has six functions to control loader operation. Outriggers are controlled by two joysticks at the center of the operator platform. When applicable, body dump is controlled by a single lever at the center of the operator platform.

PATENT #7,353,652 B2


Stationary Top mounted controls

knuckle boom truck for sale options

PI Stationary Top Mount controls give the operator a good view into the body for sorting.

• TOP MOUNT: Operator station is located on a stationary platform above the truck cab. The control valves are mounted under the seat, with the control handles between the operator’s legs for easy access. A ladder, safety railing, padded seat with arm rests, and seat belt are provided.


Top mounted joystick controls

knuckle boom crane joysticks

Mechanically linked! No high maintenance electronics!

• JOYSTICK (top mount): Two mechanical six function joysticks located on either side of the operator seat control loader operation. Outrigger controls are located to the left of the operator seat.


Outrigger pads

knuckleboom loaders for sale outrigger pads

4x12x12 rubber pads mounted on bottoms of outrigger feet help prevent outriggers from causing damage to curbs etc.


All purpose trash grapple


Petersen’s trash bucket is actuated by a single double-acting cylinder and capable of continuous rotation with no need for physical stops. The bucket motor, Model RE, has a 5,500 in. lbs. torque rating. Petersen buckets have the capability to be rolled over on the load without damage to any components, allowing for a maximum load while keeping boom height within acceptable limits. An anti-scalping feature is standard and advantageous for jobs requiring increased precision (ex: sidewalk removal).

The bucket also incorporates:

  • 3/16″ plate, smooth steel clamshell scoop for leaves and sand
  • End plates minimum of 5/8″ thick and of A-572 grade 50, 50,000psi steel
  • A minimum of 5 ribs per side to handle branches, logs and appliances
  • A trample ram in the center for compressing trash in body.
  • Replaceable bolt-on bucket blades made of high impact tempered steel

The bucket is 4 ft. long with an opened width of 5 ft. between pickup blades. Anti-scalping bucket sides are pivot mounted to provide a horizontal closing action rather than a vertical digging motion. Sides are mechanically linked to single hydraulic cylinder to ensure both sides close and open together. There are no hydraulic hoses located below bucket rotator.


Crab – front load container attachment


No more chains!

The crab attachment can lift all sizes of standard front loader containers.



Head-Mounted Dual Strobes


Dual strobes mounted on the pedestal head.


Hose Guards/Shields


Metal guards cover the valve bank and back of head assembly to protect operator on walk thru platform from hydraulic fluid in the case that there is a leak at these connection points.

Hose sleeves also available.

Only on walk-thru type controls.


Double wire braided hose


3/8” 100R2 double wire braided hoses. 4,000 working pressure. 16,000 burst pressure.


Grating Heat Shield for Walk-Thru Controls


Designed to shield operators from the radiant heat produced by the truck. Includes a flap of PVC belting that is bolted to the platform to cover the gap between the chassis cab and the platform, and two overlapping sheets of 18.5 in. wide 14 gauge sheet metal installed below the walking area of the grip strut platform.

Knuckle Boom Loaders – Videos