Installation Equipment Requirements for Chance® Instant Foundation® Systems
A guide to drive head torque, operating pressure, and soil types for the installation of wire-ready deep foundations.
Previous Post Does Soil Type Matter?
Written by Gary L. Seider, PE on August 14, 2023
Chance Instant Foundations are a popular foundation option for any pole based application that requires wiring – such as roadway lighting, area lighting, EV charger foundations, small cell poles, and railroad infrastructure. A possible barrier for contractors interested in installing Chance Instant Foundations is not understanding the equipment required to install the one-piece steel screw-in foundations. Most contractors will agree that Chance Instant Foundations are much easier and faster to install when the right equipment is available; but the wrong equipment can prove to be very frustrating and costly. This article will provide guidance on choosing the right equipment.
After you've read this article, be sure to learn how soil types factor in to equipment selection.
Chance Instant Foundations are installed with hydraulic torque motors mounted to construction machines such as:
The type and size of the installation machine and torque motor required will depend on the soil type and size of the foundation being installed.
The table below is a simple guide for torque motor selection based on foundation length. Simply put, the minimum recommended drive head is one that can provide at least 12,000 ft-lb of torque. To ensure sufficient clockwise torque and downward pressure when installing foundations into the ground, a two speed drive head is recommended.
The minimum recommended drive head should be two speed and provide at least 12,000 ft-lb of torque.
|Drive Head Torque Rating Guide|
|Foundation Length||Minimum Torque in ft-lb|
|≤ 7 ft||12,000|
|≤ 12 ft||20,000|
Key parameters for hydraulic torque motors are:
The RPM depends on the flow rate and the gear reduction.
The output torque depends on operating pressure and gear reduction.
Generally speaking, poles up to 30 ft tall can be supported by a 5 ft to 7 ft long screw-in foundation and can be installed with a 12,000 ft-lb hydraulic torque motor. To run a 12,000 ft-lb torque motor properly, the machine it’s mounted to must provide the necessary hydraulic flow rate and operating pressure to provide the necessary torque and RPM. For example, a typical drive head available on the market today requires 40 GPM and at least 1,500 psi operating pressure to turn at 14 RPM to provide 12,000 ft-lb of torque.
Most 10,000 to 12,000 thousand pound mini-excavators can install up to 7 ft long helical foundations in most soils ranging from soft/loose to medium-dense/stiff. Longer length helical foundations will require a digger derrick truck or a 10-ton mini-excavator for proper installation. In soils that are dense and very stiff, a 20,000 ft-lb drive head is required to install helical foundations. Higher operating pressures are required to turn a higher torque ft-lb drive head. For example, a typical drive head available on the market today requires 45 GPM and at least 2800 psi operating pressure to turn at 15 RPM to provide 20,000 ft-lb of torque.
Installation Examples -->
Up to 7 FT Long Foundation
8” or 10” Diameter Foundation in Dense/Stiff Soil
Up to 12” Diameter x 12 Ft Long Foundation
|Hydraulic Flow Rate||40 GPM||45 GPM||61 GPM|
|Operating Pressure||1,500 psi||2,800 psi||1,800 psi|
|RPM||14 RPM||15 RPM||15 RPM|
|Required Torque Output||12,000 ft-lb||20,000 ft-lb||31,000 ft-lb|
The numbers in the table above are generalizations. Consult with the hydraulic torque motor manufacturer for specific requirements. Pro-Dig, Eskridge, Dinamic Oil, and Digga are a few manufacturers of hydraulic torque motors.
It is critical to verify the machine the hydraulic torque motor is mounted to can handle the output torque, the flow rate, and the operating pressure.
Match up the hydraulic torque motor and machine needed to install the Chance Instant Foundation specified. A 12,000 ft-lb rated drive head is the minimum recommended. Stiff/hard or dense soils require higher rated torque motors and heavier machines.
Read this article to learn more about soil types and pre-drilling before you select your equipment.
Doing your homework up front with equipment selection will save you time and money down the road. Email us with any questions you may have. We want to help ensure success on your Instant Foundation installations.
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