Infrastructure and Transportation

Chapter 27 - Infrastructure and Transportation
Number	Topic	Rule of Thumb
27.01	Surface Haul Roads	Mine haulage costs at open pit mines may represent 50% of the mining cost and sometimes as much as 25% of the total costs, which include processing, marketing, and overheads. Source: A. K. Burton
27.02	Surface Haul Roads	In general, 10% is the maximum safe sustained grade for a haul road. For particular conditions found at larger operations, it has often been determined at 8%. It is usually safe to exceed the maximum sustained grade over a short distance. Source: USBM
27.03	Surface Haul Roads	The maximum safe grade for a haul road over a short distance is generally accepted to be 15%. It may be 12% at larger operations. Source: Kaufman and Ault
27.04	Surface Haul Roads	The maximum safe operating speed on a downhill grade is decreased by 2 km/h for each 1-% increase in gradient. Source: Jack de la Vergne
27.05	Surface Haul Roads	Each lane of travel should be wide enough to provide clearance left and right of the widest vehicle in use equal to half the width of the vehicle. For single lane traffic (one-way), the lane is twice the width of the design vehicle. For double lane (two-way), the width of road required is 3½ times the width of the vehicle. Source: AASHO
27.06	Surface Haul Roads	The cross slope on straight sections of a haul road (from a central crown or right across) should be ¼ inch per foot for paved surfaces and ½ inch per foot for gravel surfaced haul roads. Source: Kaufman and Ault
27.07	Surface Haul Roads	The cross slope on curved sections (super elevation) of a haul road should not exceed 6% on paved haulage roads, nor 8% on gravel surfaced roads. Source: OGRA
27.08	Surface Haul Roads	A crushed rock fill safety berm on a haulage road should be at least as high as the rolling radius of the vehicle tire to be of any value. A boulder-faced berm should be of height approximately equal to the height of the tire of the haulage vehicle. Source: Kaufman and Ault
27.09	Surface Haul Roads	The coefficient of adhesion (resistance to skidding) can be reduced to 10 -12% of its value on a dry road surface when the road is ice covered. On melting ice (“black ice”), it may as little as 5%. Source: Caterpillar^®
27.10	Surface Shops	Surface shops should be designed with one maintenance bay for six haul trucks having a capacity of up to 150 tons. This ratio is 4:1 for larger trucks. The shops should also include one tire bay and two lube bays. Additional maintenance bays are required for service trucks (1:20) and support equipment (1:12). Source: Don Myntti
27.11	Surface Shops	Service shops for open pit mines should be designed with plenty of room between service bays for lay-down area. As a rule of thumb, the width of the lay-down between bays should be at least equal to the width of the box of a pit truck. Source: Cass Atkinson
27.12	Surface Railroads	For preliminary calculations and estimates, a granular ballast depth of 24 inches may be assumed. The top half of the ballast will be crushed gravel (usually ¾ - 1½ inches) and the bottom portion (sub-ballast) graded gravel (typically No.4 -1 inch). This depth assumes the bearing capacity of the sub-grade (native soil) is 20 psi and the maximum unit pressure under wood ties is 65 psi. Where the sub-grade capacity is known to be less than 20 psi, it may usually be assumed that the required bearing capacity will be obtained with the use of geo-textile filter fabric. Various Sources
27.13	Surface Railroads	The maximum railroad gradient on which cars may be parked without brake applied is 0.25 - 0.30%. Various Sources
27.14	Surface Railroads	The cross slope on straight sections of a railroad (from a central crown) should be 48:1 (2%) on top of the base and the sub-ballast. Source: AREA
27.15	Surface Railroads	The shoulder of the top ballast should extend 6 inches wide of the ties, and both the shoulder and the sub-ballast should be laid back at a slope of 2:1. Source: AREA
27.16	Surface Railroads	A rotary dump on a unit train will average 35 cars per hour. Source: Hansen and Manning
27.17	Surface Railroads	The tractive effort (TE) (Lbs.) for a diesel locomotive is approximately equal to 300 times its horsepower rating. Source: John Partridge
27.18	Surface Railroads	The fuel efficiency of the engine in a diesel locomotive is near 30%; however, when the power required for operation of oil pumps, water pumps, governor and scavenger blower is taken into account, the efficiency at the rail is reduced to 23%. Source: John Partridge
27.19	Transport	It is cheaper to ship 5,000 miles by ship than 500 miles by truck. Source: Marc Dutil
27.20	Transport	The cargo bay of a Hercules aircraft is just wide enough to accommodate a Cat 966 Loader or a JDT 413 truck (drive on - drive off). Source: Unknown
27.21	Parking Lot	The capacity of employee parking lots can be determined by the sum of the vehicles used by the day and afternoon shift personnel. Provisions should be made for future expansion at the outset. Source: Donald Myntti
27.22	Harbor Design	A container ship with 4,000 TEU capacity requires a 43-foot draft at dockside. A container ship of 5,000 TEU capacity requires a 45-foot draft.
		(20 foot container = 1 TEU, 40 foot container = 2 TEU)
		Source: Engineering News Record