18 
BULLETIN 660, U. S. DEPARTMENT OF AGRICULTURE. 
operation "mixing" is taken from the operation code (p. 17) and 
found to be 38. Joining the two together with a dash produces 
the full code symbol 27-38. The letter "C" prefixed would indicate 
construction work, while the letter "M" would indicate a maintenance 
operation. 
Usually no classification letter will be used, but instead the capital 
letter "C", "M", or "R" will be shown on the recording form. If 
it be desired to know what code symbol to use in order to indicate 
properly the time of a man spreading bituminous material on a road 
for maintenance purposes, the letter "M" is set down first to show 
that the work is that of maintenance. From the class code (p. 15) 
the number for a surface is found to be 28. Preceding this number 
with a capital letter "M" gives M-28, which shows that maintenance 
work has been done on a road surface. Then there is selected from 
the operation code (p. 17) the number for spreading bitumen, 
which is found to be 60. The code symbol for maintenance work 
of spreading bitumen on a road surface then will be M-28-60. 
USE OF CODE IN OPERATIONS. 
In actual use the cost keeper generally would obtain his data from 
the timekeeper, who would be charged with keeping time and costs. 
A code for use of the timekeeper would be prepared from the class 
and operation codes, which would have the advantage of being abbre- 
viated and also properly arranged for the cost keeper's needs. ' Below 
is shown such a code, which was used on work where costs of the 
principal operations were desired, and also the expanded code, which 
was used where it was desired to make a more detailed study of 
operations for the purposes of efficiency. 
TIMEKEEPER'S CODE. 
ABBREVIATED. 
(1) 
19-17 Grading — rough. 
EXPANDED. 
Grade and roadside. 
11 Shoulders: 
-56 Rolling. 
-58 Shaping. 
19 Miscellaneous: 
-07 Clearing. 
-16 Excavating borrow. 
-17 Excavating common. 
-19 Excavating loose rock. 
-20 Excavating solid rock. 
-28 Grubbing. 
-31 Hauling. 
-35 Loading. 
