In the sand-casting production line, the automated mold-making machine costs $120/hr and is tended by hourly personnel at a rate of $45/hr. The match-plate patterns used in the mold-making machine are fabricated at a cost of $600 each and can be used for 2500 molds/pattern before wearing out. Although the mold sand is recycled, the average cost of new sand per mold is figured at $0.12. The cost of energy to heat the molten metal for pouring = $0.06/casting and the hourly cost rate of the pouring line, including heating crucibles = $33/hr. The hourly rate of the three workers who operate the pouring line = $60. The buffer storage system used for cooling the castings has a cost rate = $40/hr. Finally, the cost of the two workers in the break-away area = $38/hr. The cost rate of the break-away area is negligible. Each complete casting produced on the line weighs 4.3 kg; this includes the weight of the gating and riser system, which is 1.8 kg and is recycled. Cost of the casting metal = $1.55/kg. The production rate of the line, with pouring as the bottleneck operation in the sequence, is 164 castings/hr.
Determine the total hourly cost to operate the line.