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Cap Removal & Initial Inspection <br />The mineshaft is known to have floored 2330 feet below the shaft collar, and underground <br />workings were developed on at least 3 levels. Because as-built documentation is not readily <br />available for the Horse Draw Mine closure, Shell proposes to perform an initial video inspection <br />to gauge the condition of the shaft and entrances to the various mine sub-levels. <br />This will require orderly removal of the existing concrete cap on the vertical mineshaft to <br />perform the video inspection and possibly a preliminary reconnaissance using a manned <br />inspection capsule lowered via portable hoist or crane. <br />Based on the initial examination, the shaft conditions and rehabilitation scope of work can be <br />more accurately estimated. <br />If delays between the video inspection/possible manned inspection and the next steps of this <br />research project occur, a temporary closure will be installed over the mineshaft. This closure <br />will equal or exceed the DRMS Inactive Mines Program specifications, and will consist of a steel <br />bar grating deck supported by steel beams. <br />If there is a decision to abandon the project after the initial inspection, or at the end of the <br />project, a temporary (semi-permanent) closure will be installed, similar to the existing cap. The <br />cap will be a segmental pre-cast concrete cap, which will be similar to the existing temporary <br />closure. The cap may also include embedded lifting slings for handling with a crane. <br />Within the existing chain link fenced area, at the shaft collar, a second area will be fenced off <br />using plastic construction fencing and steel t-posts, with appropriate sign, age. This small area <br />will control access to the shaft collar while the cap is off, and fall protection measures will. be <br />required within this area at all times until either the temporary bar grating deck has been <br />installed, or a temporary concrete cap is re-installed. <br />The existing reinforced concrete cap will be disposed of offsite in accordance with Federal, <br />State, and County regulations. <br />Installation of Temporary Mine Works <br />To allow for the safe access and execution of this work scope, essential mine access and safety <br />equipment will need to be re-installed on a temporary basis. <br />To access the mine levels down to 2230', a hoisting system (consisting of a temporary steel head <br />frame structure, hoist, and cage designed and manufactured to fit the existing vertical shaft <br />guides) will be erected. <br />This hoist system may require the pouring of some temporary concrete footers. Should these be <br />necessary, they will be constructed with embedded lifting slings to allow them to be easily <br />removed from the site upon completion of this work. Some re-grading and addition of fill to <br />raise grade around the shaft collar may be required. The headframe and hoist system may <br />require removal of the existing security fence around the immediate shaft collar area. In this