Because the skidding systems were investigated under different stand and operating 

 conditions, total skidding time was broken into minor elements to facilitate comparative 

 analysis of the data. Production elements directly related to output per turn (skid- 

 ding) were added to obtain round-trip time. Breaks in the round-trip time were clas- 

 sified as productive and nonproductive delays. Productive delays include items such as 

 hang-ups, straightening out chokers, and moving stumps. Nonproductive delays include 

 operator breaks, machine down time, and operator discussion with the study team. Be- 

 cause of scheduling problems and the demands of other work necessary to complete the 

 study, only a portion of the actual production process was timed on each area. Lee 

 Creek was timed 2 days out of the 3 production days. Danby Ridge was timed 5 days out 

 of 9 days. In both instances, the operator kept track of total hours worked, total 

 number of turns, and pieces when the study team was absent. The results of measured 

 total production variables can be seen in table 7. 



The most important production activity for which data was gathered was roundtrip 

 skidding time composed of six elements: 



1. Out -time . Time required to move the skidding unit from the landing to the 

 general area where the logs are to be hooked. Out-time starts when the skid- 

 der leaves the landing and stops when the machine arrives at the hooking site. 



2. Hook- time . Time required to get a choker around a log. Hook- time starts when 

 the operator gets off the skidder. It ends as he returns to his machine. 



3. Bunch- time . Time required for lateral movement of one or more logs prior to 

 moving towards the landing with a turn. It also includes the time necessary 

 to break pieces loose from their initial resting place and place them where 

 they can be reassembled. Bunch-time started as the machine or winch started to 

 apply pressure to the choked log. It ended when the piece was lined up to 

 start for the landing. 



4. In-time . Time required for the skidding unit to move individual pieces, and 

 the turn towards the landing. In-time started when a piece was started to- 

 wards the landing. It ended when the load was deposited on the landing and 

 the machine stopped. 



5. Unhook- time . The time required to unhook the turn and drag the chokers free. 

 Unhook-time started when the operator stopped on the landing and ended when 

 the chokers were in position for the trip out and the operator was back on 

 his machine. 



6. Landing-time . Includes all time on the landing other than out-time, in-time, 

 or unhook-time. Landing-time started when one of these three activities 

 ceased and stopped when they were resumed. 



A summary of average production elements by turn is shown in table 8. These aver- 

 ages are delay free. The effect of delays may be found by adding miscellaneous down 

 time, machine down time, and operator time out to round trip time. 



Production findings .--Tables 7 and 8 prove the value of using equipment designed 

 and built specifically for moving small pieces of wood. Neither the tractor nor the 

 rubber-tired skidder operated as efficiently as stand condition, piece size, and time 

 would indicate. This conclusion is based on the following observations: 



1. Poor tractor maintenance contributed to short work days. 



2. Lack of a winch required excessive bunching time. 



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