Mini-horizontal directional drilling
Mini-HDD equipment is usually used in the installation of ducts and conduits for local distribution utility companies like electric power, cable systems and communication systems. It is also used in the installation of gas lines beneath the streets, private properties and right-of-ways. The small versions of the horizontal boring equipment is used in the pilot bore hole with the reaming operations accomplished through fluid jet cutting and/or cutting torque provided by the rotating drill string. A manually operated overhead receiver or a remote tracking/steering system will follow the progress of the initial pilot bore.
Maxi-horizontal directional drilling
The maxi-horizontal directional drilling equipment is required for installations that are beyond the capabilities of the mini-HDD equipment. The horizontal boring equipment used in maxi-HDD has the capability of accurately boring holes in the order of a mile in length and placing pipes that are more than 48 inches in diameter at depths of up to 200 feet. The thrust and pullback capacity as well as the torque can be as much as 100,000 pounds and 80,000 ft-lbs. The equipment used for this purpose can weigh as much as 30 tons or more so that installing pipes in rivers as well as under major thoroughfares can become possible.
Factors to be considered before the installation project
Any background information will significantly assist the engineer and the contractor when planning the project. Information usually includes evaluation of the surface and sub-surface conditions to determine the compatibility of the site with the proposed drilling operations. It is also important to consider whatever utilities are installed below the ground so as to prevent damage to those lines. A typical mini-HDD undertaking may require only a single day for a road crossing or even less for the installation of a service line. However, if a community’s utility distribution lines will be upgraded, it can be considered as a large scale project that may require months to complete. Sometimes it is more feasible to use the mini-HDD equipment as opposed to the larger maxi-HDD equipment because of soil conditions, locations of local utilities and the environmental aspects that can affect the community.
During the preliminary planning it is also wide to consider the size of the project and the anticipated duration of completion because it can be a distraction for a community. Information that has been gathered at an earlier stage will help determine whether there is a need for more thorough inspections and investigations on the locations before finally pursuing the plans.