Tool crib can be defined as a collection of various methods and their associated tools that can come handy in any trenchless construction project. Sometimes unexpected subsurface geology is encountered while drilling in spite of conducting a thorough geotechnical investigation.
In such circumstances, instead of being caught off guard, the contractor should be prepared and well-equipped with tools to resolve the problems. Foresight is essential in assembling an effective tool crib.
A tool crib can also refer to the spare parts and repairing tools that are stocked for replacement or repair work during a project. Usually, a tool crib attendant is responsible for stocking and taking inventory of tools. When a tool is required, the tool attendant will quickly supply the same.
A well-equipped tool crib can prove to be a very time and cost-saving alternative especially in cases when a different soil type is encountered.
Tool Crib of Trenchless Methods
A trenchless tool crib is essentially a collection of trenchless methods that a contractor is equipped with, like that of Jack Eisner of Eisner Contracting Ltd. A contractor dealing in trenchless technology will need to have a tool crib from which he can pull out the necessary tools to bid for taking up new projects and to successfully complete existing ones.
A successful contractor usually has most of the trenchless methods such as horizontal directional drilling (HDD), horizontal auger boring (HAB), pipe ramming, moling, microtunneling, etc. in his toolbox including survey equipment.
For example, HAB is preferred for soft ground conditions, while HDD can be used for a variety of soil conditions including silt, sand, rock, and clay. Since subsurface soil situations can sometimes change without notice, it is wise to have other methods handy.
The different soil types that can be encountered are sand, shale, clay, cobble, hardpan & gravel, and rock. Sometimes a combination of these types can also be encountered in a particular subsurface location. All these types require different types of drill bits. Some drill bits in the HDD industry can take on most soil types except rock as they are made with more carbides than a regular blade.
Tool Crib of Spare Parts and Equipment
A tool crib should also be equipped with spares of parts that are prone to wear and tear and require frequent change. In any trenchless project time is money, and the better the tools available in the tool crib, the faster and better a contractor can work and get the job done.
Many trenchless projects take place in remote locations and getting back to civilization can take time. Unavailability of spare parts during an equipment breakdown can lead to severe time delays that will translate to cost overruns and loss of profit.