Understanding Digger Derricks: A Comprehensive Overview
Learn about digger derricks, funded by the IHUM Consortium, designed for heavy lifting and digging tasks. Explore the components like the derrick, boom, pole grabbers, controls, and more. Discover how these versatile equipment are operated and their essential features.
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. Download presentation by click this link. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
E N D
Presentation Transcript
This workforce solution is funded by the IHUM Consortium which is 100% financed through a $15,000,000 grant from the U.S. Department of Labors Employment & Training Administration. The product was created by the grantee and does not necessarily reflect the official position of the U.S. Department of Labor. The Department of Labor makes no guarantees, warranties, or assurances of any kind, express or implied, with respect to such i This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. Digger Derricks
Digger Derricks A digger derrick is a truck-mounted, hydraulically operated piece of equipment designed to do two basic jobs: Lift heavy loads Dig with an auger
The Derrick The derrick is the part of the truck that does the lifting It consists of a pedestal/turntable assembly The pedestal is mounted on a truck chassis Where the pedestal is mounted determines it classification If the pedestal is mounted at the back of the truck it s a rear mount unit If the pedestal is mounted directly behind the cab of the truck it s a center mount unit If the pedestal is mounted at the rear of the truck but off center (usually to the passenger side) it s a corner mount unit Digger derrick typically have outriggers located at each corner of the bed that are used to stabilize the unit
Pole Grabbers Boom Tip Sheave Auger Pedestal Outrigger
Cont The Derrick The boom is attached to the pedestal and typically has two or more sections that can be extended or retracted The boom can be raised, lowered and rotated 3600 Pole grabbers located at the end of the boom are hydraulically operated and are used to grab a pole Winches can be mounted on the tip of the boom or on the pedestal
Controls of a Digger Derrick The controls of a digger derrick are mounted on the pedestal (remote controlled digger derricks won t be discussed in this lesson) The pictures and examples used in this lesson are one type of unit; controls and how they operate will vary depending on the manufacturer How a digger derrick responds will depend on the lever that s selected and whether you push or pull on the lever There is a throttle located on the pedestal to control the speed of the truck s engine .increasing the speed increases the power
The Digger The digger mechanism is a hydraulically operated motor that drives the auger ..augers come in a variety of sizes The digger is attached to the under side of the boom by the digger hanger bracket The auger, which resembles a large drill bit, is connected to the shaft of the digger mechanism by a large pin When not in use the auger is stowed in a bracket mounted on the side of the boom it remains in the bracket with the use of a stow lock When preparing to use the auger the stow lock is released and the auger is unwound with a hoist line attached to a hook located near the top of the auger
Operating a Digger Derrick The maximum lifting capacity of a digger derrick depends on three factors: The stability of the unit and the surface it s on The structural strength of the derrick The power of the hydraulic system Also, whether or not a digger derrick can it s maximum capacity depends on the position of the boom there are two factors: The hook radius The sheave height Most digger derricks have a chart located near the controls that indicates the lift capacity of the unit with the boom in various positions
Digger Derrick Operation CAUTION!! ENSURE THE BOOM WILL HAVE CLEARANCE FROM ENERGIZED LINES BEFORE TAKING IT OUT OF THE CRADLE!! The first step in using a digger derrick is to plan the job; the plan will include where and how the truck is positioned If possible, position the truck so all the work can be done off the back Once the truck is in position and the work area is marked and coned off (if applicable, and per the Manual of Uniform Traffic Control Devices) The next step is to engage the power take-off and lower the outriggers to level the truck. Often the outriggers need to be lowered onto wooden or metal pads (this can vary depending on applicable safety rules)
Cont Digger Derrick Operation Following is a typical procedure for digging a hole: First, make certain all underground facilities have been located prior to conducting any excavating activities (Iowa One Call Dial 811) Raise the boom to a 450 angle Rotate the boom until it s positioned to the back so it will clear the truck when unrolled Make certain the boom is fully retracted Make certain all personnel are clear of the auger before it s unrolled Unpin the auger or open the stowage lock and unroll the auger; this is usually done in a counter clockwise manner Once the auger is fully unrolled and free of the hoist line position it over the location where the hole will be dug
Cont Digger Derrick Operation When the point of the auger is placed on the location to dig the hole the person on the ground will assist in making certain the auger is straight up and down (typically the person on the ground will position them self 900 from the truck operator) To begin digging the auger is turned clockwise while at the same time applying slight down- pressure with the boom Once the auger is full of dirt it s lifted out and positioned next to the hole The auger is cleaned by slowly rotating it counter clockwise when personnel on the ground shovel the dirt from the auger Depending on the ground conditions and length of the pole being set, the hole likely will need to be dug in increments The formula for determining how deep to dig the hole is 10% of the length of the pole plus 2 feet (Example 10% of a 40 pole is 4 feet .plus 2 feet the depth for the hole is 6 feet)
Mini Derricks Mini derricks are used to dig, set and/or remove poles, haul equipment and in some instances used as an aerial lift in locations that are not accessible to full sized equipment Often the tracks of the unit can be retracted so it will fit through a gate in a chain link fence If a mini derrick is going to be used to set or replace a pole is can be used to haul the pole to the work location As with a regular digger derrick, it s essential to make certain the unit is appropriately stabilized These units are often remote controlled ..whoever is operating the unit must be familiar with all aspects of the controls
Call before you dig.its the law!! These are the standard industry color codes used when marking/location underground facilities Iowa One Call must be contacted prior to performing any excavating activities. They can be reached at 800-292-8989 or Dial 811 Except in an emergency, notice must be given to Iowa One Call 48 hours in advance (not counting weekends or holidays) of any excavating activities occurring
