Sawmill Analysis: Difference between revisions
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Modern sawmills are highly productive devices, so assume 1250 person Village size, the largest size for analysis. Allow 15 year construction period, followed by maintenance and remodeling. Thus 6.67% of construction lumber is needed per year. Allow 1% replacement lumber per year for maintenance and 2% for remodeling, thus 3% per year after construction. Given those numbers, it seems reasonable to build two units with 3.33% annual capacity each. The second unit is either recycled after 15 years or sold off. | Modern sawmills are highly productive devices, so assume 1250 person Village size, the largest size for analysis. Allow 15 year construction period, followed by maintenance and remodeling. Thus 6.67% of construction lumber is needed per year. Allow 1% replacement lumber per year for maintenance and 2% for remodeling, thus 3% per year after construction. Given those numbers, it seems reasonable to build two units with 3.33% annual capacity each. The second unit is either recycled after 15 years or sold off. | ||
Standard wood frame home construction consumes about 6 board-feet (1x12x12 inch volume of wood) per square foot of floor area. Allow an | Standard wood frame home construction consumes about 6 board-feet(bf) (1x12x12 inch unit volume of wood) per square foot of floor area. Allow an additional 6 board feet for other wood used such as workshops, fences, and furniture. USA average dwelling size is 750 square feet per person. Therefore 750x12 = 9000 board feet of finished lumber/person is needed for construction. Allow 20% defects and drying loss and 10% waste during construction, thus 70% net used lumber. So initial cutting need is 9000/70% = 12,850 bf/person. | ||
1250 people x 3.33% annual construction = 41.67 cutting need per year. 41.67 x 12,850 bf = 535,400 bf/year/machine. Assume 240 working days per year. Thus daily production would need to be 535,400/240 = 2230 bf/day/machine. | |||
Revision as of 13:32, 12 May 2011
Preliminary analysis based on requirements at Sawmill - Design Rationale. As more details of the rest of the village system is developed, this will need to be updated in an iterative fashion.
Production Requirement
Modern sawmills are highly productive devices, so assume 1250 person Village size, the largest size for analysis. Allow 15 year construction period, followed by maintenance and remodeling. Thus 6.67% of construction lumber is needed per year. Allow 1% replacement lumber per year for maintenance and 2% for remodeling, thus 3% per year after construction. Given those numbers, it seems reasonable to build two units with 3.33% annual capacity each. The second unit is either recycled after 15 years or sold off.
Standard wood frame home construction consumes about 6 board-feet(bf) (1x12x12 inch unit volume of wood) per square foot of floor area. Allow an additional 6 board feet for other wood used such as workshops, fences, and furniture. USA average dwelling size is 750 square feet per person. Therefore 750x12 = 9000 board feet of finished lumber/person is needed for construction. Allow 20% defects and drying loss and 10% waste during construction, thus 70% net used lumber. So initial cutting need is 9000/70% = 12,850 bf/person.
1250 people x 3.33% annual construction = 41.67 cutting need per year. 41.67 x 12,850 bf = 535,400 bf/year/machine. Assume 240 working days per year. Thus daily production would need to be 535,400/240 = 2230 bf/day/machine.