Handling Costs Cut by £5,000 a Year
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DY using a crane, as opposed to man
handling, several thousand pounds a year can be saved. Evidence in support of this claim was given by Mr. C. S. Shaw, technical director of K. and L. Steelfoun:ders and Engineers, Ltd., when he read a paper, "Mobile Cranes in Relation to Road Transport," to the Institute of Road Transport Engineers in London, last week.
In his first example he dealt with the unloading and loading of coal. Observations had shown that three men took an hour to unload 10 tons of coal from a railway wagon. To this had to be added 20-25 per cent. for nonproductive time. Allowing 20 per cent., the time taken per ton equalled 0.36 man-hours.
Assessing wages at 4s. 2d. an hour, hand shovelling cost Is. 6d. a ton. A mobile crane, using a .2f-cu.-yd. double
el 8
rope grab, could handle 1,300 tons of coalevery 44-hour week, the actual running time being 40 hours, Such a crane would cost £3,600.
Allowing for overhaul time, the annual tonnage would be about 60,000, and the cost would be £1,900, made up of depreciation over six years, £600; major replacementi, £300; major overhauls, £50; fuel and lubricants, £100; running maintenance, £50; driver and helper, £800.
The cost of handling by crane and grab worked out at 7.6d. per ton, a saving of 10.4d. per ton, or £2,600 a year, as compared with hand shovelling.
Two men, hand shovelling and working as a team, loaded a 10-ton lorry with sand from stock piles in 11 hours. Including 25 per cent. nonproductive time and supervision, manhours equalled 0.375 per ton. At 4s. 2d. per hour, the cost was 18.7d. per ton.
A mobile crane, with a 5-cu.-yd. grab, costing £4,100, could deal with' 2,450 tons of sand in a 59-hour week. Allowing 90,000 tons per year, based on a 44-hour week, Mr. Shaw arrived at the following "figures: Depreciation over six years, £684; major replacements, £300; maidr overhauls, £60; running maintenance, 150; fuel and lubricants, ,£100; driver's wages and bonus (€15 per week), £780. The total cost per year was £1,974 and per ton, 5 3d. The saving, as compared with hand shovelling, was £5,025 per year.
In loading sand by hand the lorry was standing for If hours, whereas the crane completed the operation in 15 minttes. The saving per year, in lorry availability alone, could be as much as £6,750.