38 BULLETIN 1202, U. S. DEPARTMENT OF AGRICULTURE. 
RELIABILITY OF TRACTORS. 
The reliability of a tractor has a decided effect on its profitable- 
ness. ‘To obtain definite information on this point each farmer vis- 
ited was asked how many days during the year his tractor was out of 
running order, and for how many days it was needed while out of 
order. 
On the average the 354 tractors were out of running order 10.6 
days, but were needed for an average of only 2.1 days of work during 
that time. Some of them had broken down near the end of the season 
and had not been repaired immediately, and some had been taken 
down for repairs or overhauling and allowed to remain out of run- 
ning order for considerable periods when not needed. Two hundred 
and twelve, or 60 per cent of the total, had been out of order during 
the year, but 59 of the 212 had not been needed for any work while 
out of order. The remaining 153 had been needed for an average of 
about 5 days of work while out of commission. 
No great difference in reliability was shown among the different 
sizes. About 61 per cent of the two-plow tractors, 57 per cent of 
the three-plow, and 50 per cent of the shir alo and larger machines 
were not out of order when needed at any time during the year. The 
age of the tractors likewise had no marked influence on their relia- 
bility. Of 130 machines which had been purchased new and which 
had been in use 14 months or less, 72, or 55 per cent, had not been 
out of order when needed, and the remaining 58 had been out of 
order when needed for an average of 4.6 days. Of 86 machines which 
had been purchased new and which had been used 27 months or 
more, 54, or 63 per cent, had always been ready when needed and 
the remaining 32 had been out of order when needed for 6.1 days on 
the average. 
The number of days tractors were out of order when needed in 
each area is shown in Table 45. In the southern area some time 
had been lost by about 60 per cent of the machines, in the western 
area by 40 per cent, and in the northern area by about 30 per cent. 
Considering only those which had been out of order when needed, 
the time lost by each machine amounted on the average to 5 days, 
4.7 days, and 4.5 days in the southern, western, and northern areas, 
respectively. : 
TABLE 45.—Days per year tractors were out of order when needed. 
Number out of order when needed for— Average. 
Number lapis SPT ae 
Area, of For those 
tractors. | 0 1 or 2 3 or 4 5 or 6 7 days For all | out of or- 
| days. days. days. days. or more. | tractors. | der 1 day 
or more. 
eS. a? | | 
Senter. - 5-2. - 2... 120 47 34 16 6 17 Bont 5.0 
WMOSUCIMc oto. 55 cee 107 64 12 il 11 9 1.9 4.7 
Wortern. 22-2 ..5623. 127 90 17 8 5 7 L3 4.5 
BOTA eee eS 354 201 63 35 22 | 33 2.1 4.7 
ANNUAL COST OF POWER FOR DRAWBAR WORK. 
On the average farm the cost of keeping work stock during the 
year was $541 and the cost of using the tractor for drawbar work was 
$484. Thus the total annual cost of power for drawbar work was 
ea le i, taal ee nia ee Me 
= — > a ; 
