. Shield and compressed air tunneling . /r /ac/c Su/A>tecrc/ /Kr//.. Fig. 86.—Plans of tracks, sidingsandswitches in a compressed air tunnel (A-IS). A suitable capacity is a cubic yard more or less. They shouldnot be too wide, because they have to be taken through the looks;a width of 3 ft. would usually be about right. The body of thecar should be low and set low on the trucks, so as to make the 196 SHIELD TUNNELING reach in shoveling as low as possible. A length of the car bodyof about 5 ft. will generally be suitable. A short wheel base isadvantageous for turning the car around sharp cur

. Shield and compressed air tunneling . /r /ac/c Su/A>tecrc/ /Kr//.. Fig. 86.—Plans of tracks, sidingsandswitches in a compressed air tunnel (A-IS). A suitable capacity is a cubic yard more or less. They shouldnot be too wide, because they have to be taken through the looks;a width of 3 ft. would usually be about right. The body of thecar should be low and set low on the trucks, so as to make the 196 SHIELD TUNNELING reach in shoveling as low as possible. A length of the car bodyof about 5 ft. will generally be suitable. A short wheel base isadvantageous for turning the car around sharp cur Stock Photo

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. Shield and compressed air tunneling . /r /ac/c Su/A>tecrc/ /Kr//.. Fig. 86.—Plans of tracks, sidingsandswitches in a compressed air tunnel (A-IS). A suitable capacity is a cubic yard more or less. They shouldnot be too wide, because they have to be taken through the looks;a width of 3 ft. would usually be about right. The body of thecar should be low and set low on the trucks, so as to make the 196 SHIELD TUNNELING reach in shoveling as low as possible. A length of the car bodyof about 5 ft. will generally be suitable. A short wheel base isadvantageous for turning the car around sharp curves, but itshould not be so short as to be easily upset. Side- or end-dump /6 -/^ -2-2 6-6 2-- 2 0! lO ^^ ^ ?<^o ® 2-21 ^ /6 — 1. 2-Z ^ F/ar? r^^r-- ?^~--~- _--—-^^ @

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