Colliery Engineer Volume 35

Colliery Engineer Volume 35

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1915 edition. Excerpt: ...tried for collars instead of the I beams, and so far are giving better results. Where wood is subject to dry rot the use of steel has been very successful, but where there is a constant squeezing or heaving it has been found inadvisable to substitute it for wood. A very considerable saving in timbering maintenance has been made to this time by the use of steel, and its use is being extended. All turnouts and permanent openings, where timbering is necessary, are being supported with steel, and sections of various sizes up to 70 pounds per foot are used, according to the requirements. It is probable that the average life of a set of steel supports in a gangway will be at least 10 years. The average life of timber sets in a gangway is 3 years. In many instances timber has lasted 15 years, and in many others it has lasted less than 1 year, depending entirely upon the conditions. There are also many instances where it was almost physically impossible to hold open certain stretches of gangways until after steel supports had been installed. FlO. 2. Cross-section Through Panther Creek Valley At Lansford Colliery On Line Of Nos. 4, 5, And 6 Shafts Figuring the average life of timbers as 3 years, and steel sets as 10 years, the saving made by using steel will be fully 100 per cent. A notable instance in the economy of using steel was shown in the case of a turnout which had to be retimbered every 9 months at a cost of $20 per set for labor and material, where steel costing $40 per set for labor and material is still sound. It will be seen from this that the saving amounts to more than $60 per set to the present time. This company uses peeled timber, although at times it is unable to procure it. It is experimenting with steel supports that replaced...show more

Product details

  • Paperback | 536 pages
  • 189 x 246 x 27mm | 948g
  • Rarebooksclub.com
  • United States
  • English
  • black & white illustrations
  • 1236914414
  • 9781236914415