Productivity and Cost of Integrated Harvesting of Wood Chips and Sawlogs in Stand Conversion Operations

Table 2

Regression equations that describe predicted delay-free cycle times in minutes for the integrated harvesting system.

Process		Independent variables				Average delay-free cycle time
	Regression model for delay-free cycle time	Mean	Range	𝑅^2	𝑛	(minutes)
Felling/bunching	= 4.16			0.66	766	0.52/tree(s)
	+0.09 (no. trees)	1.10	1–3
	+0.03 (DBH cm)	27	15–66
	+0.22 (loaded swing degrees)	117	0–270
	+0.04 (no. grapples)	0.30	0–10
	+0.02 (travel distance m)	1.54	0–25
Shoveling	= 3.81			0.69	363	0.62/tree(s)
	+0.18 (%slope)	20.29	5–50.
	+0.37 (no. grapples)	1.90	1–10
	+0.28 (loaded swing degrees)	126	0–360
	+0.11 (no. trees)	2.93	1–10
	+0.04 (no. compactions)	0.55	0–11
	+0.02 (travel distance m)	2.27	0–51
Loading (whole trees)	= 4.60			0.63	440	8.08/truck
	−0.13 (%slope)	10.19	5–35
	+0.41 (no. grapples)	1.90	1–11
	+0.32 (loaded swing degrees)	101	0–270
	+0.05 (no. compactions)	0.98	0–7
	+0.01 (travel dist m)	0.10	0–10
Hauling (whole trees)	= 2592.8			0.18	70	32.50/trip
	+0.12 (loaded spur distance m)	488.89	27–982
	−0.01 (loaded single land dirt road distance m)	13.41	0–117
Unloading	= 4.00			0.65	258	3.46/truck
	+0.48 (no. grapples)	1.29	1–5
	+0.28 (loaded swing degrees)	125	90–180
	+0.10 (no. pieces)	3.42	1–12
	+0.04 (no. compactions)	0.15	0–3
	+0.01(travel distance m)	0.14	0–15
Sorting/processing (sawlogs)	= 4.02			0.65	311	0.66/tree(s)
	+0.53 (no. grapples)	2.10	1–10
	+0.20 (loaded swing degrees)	125	90–360
	+0.14 (no. pieces)	2.26	1–15
	+0.02 (no. compactions)	0.39	0–5
	+0.01 (travel distance m)	0.55	0–15
Chipping	= 2.32			0.22	117	0.44/tree(s)
	−0.42 (no. trees)	1.79	1–6
	+1.83 (DBH cm)	28	15–76
Loading (biomass)	= 1.83			0.47	375	5.84/truck
	+0.04 (no. scoops)	0.99	0–3
	+ 0.20 (travel loaded distance m)	23	0–80
Loading (sawlogs)	= 3.82			0.49	107	9.22/truck
	−1.06 (loaded swing degrees)	108	90–180
	+1.12 (empty swing degrees)	110	90–180
	+0.28 (no. grapples)	1.64	1–5
	+0.03 (no. compactions)	0.76	0–6
Hauling (biomass)	= 615.35			0.79	46	43.87/trip
	+0.05 (loaded primary dirt road distance m)	5,260	0–6,807
	+0.06 (loaded secondary dirt road distance m)	1,129	0–5,071

𝑛: number of observed cycles.