HomeMy WebLinkAbout780491.tiff The following is in response to the "Efficiency of Rock Crusher
Audit Report submitted by Anthony T . Jenkins , Performance Auditor ,
Weld County Council on March 21 , 1978 .
Item B. -1 . It was the decision of the Board of Weld County Commis-
sioners to accept the bid of Cox Equipment Company for the amount
of $254 , 995 . 00 with trade-in for the rock crusher at their regular-
ly scheduled meeting on July 18 , 1977. Mr. Thomas C . Dority ,
Finance Officer in his letter to Mr . Gordon Panushka of Cox Equipment
Company on July 28 , 1977 recaps the proposal regarding the terms of
final payment and trade-in . (Exhibit 1)
Item B. -2 . Frank Smith , County Engineer , Bette Rhoden , Purchasing
Director , Commissioner Norman Carlson and Commissioner Victor
Jacobucci , Coordinating Commissioner for the Department of Eng-
ineering did visit the actual site where an identical crusher as
the one purchased by the County was operating . A thorough on site
inspection of the rock crusher was made . The factory was never
visited on this on site field inspection .
Item B . -3 . The rock crusher furnished by Cox Equipment was the
lowest bid and Cox Equipment was the company selected to furnish
the rock crusher .
Item C . -1 . The Engineering Department would concur with this
statement .
Item C . -2 . In 1977, 9 , 240 Tons or average production of 107 Tons
per hour over 86 hours were produced. In 1978, 12 , 000 Tons or
average production of 231 Tons per hour over 52 hours were produced.
Item C . -3 . Crusher operated only 60% of time that old crusher did,
but average production equaled 115% more than the old crusher .
Item D . -1 . The statement that the crusher vibrates too much and
most of the vibration comes froms the jaws is in total error .
First, the cause of vibration in the plant and most of the vibration
comes from the vibrating screens in the plant which are designed
to operate at 800 ± rpms and at an average amplitude of 8 .3/8" .
All parts of the plant have been shut off with only the jaw operating
and no vibration present . This is a much larger plant than the "old
one" and it must vibrate much more than the old one. (Exhibit 2)
Item D. -2 . The bolts that were breaking on one side of the jaw
was caused by the bolts not being checked and kept tight . George
Stroh was personally told by Frank Smith to shim the space that
was in existence between the jaw frame and truck which was causing
the bolts to break . This was done by the Universal Engineering
service man on March 24, 1978 .
Item D. -3 . The plant was designed with a specified number of
troughing rolls . The belt should have been adjusted by the
crusher crew. This is routine preventative maintenance .
780491
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Item D. -4 . This is a design of the plant and not a fault in real
language . This is a personal "gripe " . The crusher foreman was
told to add additional support it he desired to do so. A point
to remember is that a conveyor is a "moving" piece of equipment
and is not totally rigid.
Item D. -5. The feed in conveyor on the plant is a 36" conveyor .
The trap conveyor is a 247 conveyor .
The plant is rated at 225-450 tons per hour in the manufacturers
"Producers Fact Book" This is compatible with competitive
equipment . The plant is capable of greater production depending
on many variables including but not limited to , finished product ,
raw material , moisture content , percent of material crushed ,
percent of free run , percent of oversize material , method of
feeding plant and number of products being produced .
The Crusher Foreman claims that he has produced at times 630 Tons/
hour with the equipment as is , based on loading 21 tons on a truck
in 2 minutes .
(21 T X 6. 0 minihr 630 Ton per hour
2 min ,
Item D . -6 . The master electrical panel is plant mounted and
since the plant does vibrate so does the panel . This again is
an item of preventative maintenance to check this item daily .
Item D . -7. The power unit was sized for a complete crusher
operation to produce more than one product while in operation .
The horsepower requirements for the rolls and jaw are 355 the
remainder is required for screening , conveyors in the plant and
external conveyors . In short you don ' t put a 5 horsepower
generator to drive a ten horsepower motor . Reference "Con-
struction Methods and Machinery" by F . H. Kellog CR 1954 , refer
to Chapter 4 Power 4-10 Internal Combustion Engines .
Deduct 10% for pumps , belts , generator and other belt driven
accessories .
Deduct 3 % for each 1000 ' above sea level-total deduct 12%
(4 X 3%)
Total available 700- (22%) = 55O HP
Total demand for electric power = 166 IIP
3 .
Demand for rolls and jaws = 355 HP
Based on above with no adjustments for temperature there is at
present a demand for 521 HP . This leaves an additional 29HP
available for additional conveyors.
Item D. -8 Weld County specified that the power unit and generator
be plant mounted for greater portability . This is not an item
that is drastic . To change all screens in the screening section
would require 3 to 5 hours depending upon crew experience .
Item D. -9 This condition is not uncommon with the type of material
now being crushed . The raw material consists primarily of elongated
flat rock . The crusher foreman was advised to order slotted or
elongated screen cloth to help or totally eliminate this problem.
These are the same recommendations of the manufacturer ' s repre-
sentative .
Item D. -10 This is incorporated in the design of the plant and
Universal sold their first plant in 1906 , I cannot critize their
engineering design .
Item D . -11 This again is in relation to design and the controls
are located in strategic areas as required by plant operation .
This type of equipment requires constant observation by the oper-
ating personnel and would require a great deal of changes and a
greatly increased cost to make it a one man "console operation" .
Item D . -12 The catwalks again are located in the areas required with
safety ever in mind. This is the first complaint ever received by
the Company in reference to catwalks being "too short" . Should a
man fall in the jaw or roll crushers he would never live to tell
about it . There is sufficient area to observe the operation to be
alerted to a malfunction.
Item D. -13 The manufacturer or the equipment company have never
failed to come to the crusher site upon request by Weld County.
It should be understood that these people have other commitments
and service requests must be scheduled. Every request from the
Engineering Department has been honored by both the manufacturer
and the equipment distributor .
Item D . -14 The service from the manufacturer has been excellent
and likewise for the distributor , as stated in Item D . -13 every
request has been honored by both if it came from the Engineering
Department . There is no record of other requests being made
either on reports from the Crusher Foreman or his Superintendent .
Item E . -1 This information is as reported on the Report to
Weld County Board of Commissioners-Crushed Rock Production Report .
Item E . -2 This information is as reported on the Report to
Weld County Board of Commissioners-Crushed Rock Production Report .
Item E . -3 An 8 hour holiday was not included in the auditing
thereby changing eleven and a half hours being accounted for
to nineteen and a half hours and making 28k hours unaccounted
for 201 hours .
Item E. -4 According to the reports this information should read
that the crusher operated for 20 hours ; 12 hours of down time ;
a total of 32 hours with S hours not accounted for .
Item E. -5 With changes in Item E. -3 and Item E . -4 the hours
not accounted for during the 4 week period would be 35 rather
than 46 . (Exhibit 3 )
Item E . -6 Any crusher employee working in County garage would
be doing work on the crusher or crusher equipment .
Item E. -7 From the employee time sheets submitted it is not
possible to determine if employee time was spent in snow removal ,
however , an excess of 11 , 000 miles of snow have been plowed through
the end of February .
Item F. -1 Information taken from the Weld County Equipment Usage
Report indicated a period usage of 156 hours for this time period .
It should be noted that at 100% production only 37 . 5 hours a week
are available . (Exhibit 4)
Item F. -2
a-d There is no basis to disagree with these statements
and there is no reason to doubt their validity. This is useful
information and, indicates that the degree of supervision is not
up to its best potential . This kind of information is needed
and appreciated and there is a solution to remedy this problem ,
providing that there was no legitimate reason for the plant not
being in operation .
•
Item G . -1 In conversation with Mr . Jenkens , Mr . Smith did not
say the employees did not put in a full day ' s work . Mr . Smith
said he knew that the crusher was not in production 8 hours per
day . At 100% production only 37 . 5 hours are available . Mr .
Smith did recognize the failure of the report sheet supplied
by the Crusher Foreman to not balance with an 8 hour day . Upon
examining employee time sheets it is verified that the employees
worked S hours per day. Mr . Jenkens said he could get into a
jobsite without people knowing who he was and "catch" people
who were not working . Mr . Smith said he could not do this because
you could spot his vehicle for a mile . In other words "when
the cat is away , the mice will play" . This is a problem in total
industry as management will readily verify . (Exhibit 5)
5 .
SUMMARY
This report is not meant to be highly technical nor is it meant
to point blame at anyone or anything . The report is meant to
point out areas where problems exist and to correct such problems
by methods which will in turn give the desired results for not
only the Crusher operation , but all operations within the Road
and Bridge Department .
A Crusher is not a simple piece of construction equipment . There
are many factors that determine the successful operation of a
crushing plant including engineering design and last but not
least the operation by the human element .
Records available from the manufacturer and distributor indicate
that some of the problems mentioned by the auditor 's report did
exist at the time the plant was placed in operation . The records
also indicate that the problems were corrected to within manufactur-
ers' tolerances . Records exist which also indicate that the
Manufacturer o-+nd Distributor did respond to the requests for
service and assistance by Weld County . In reference to the warranty
there is no evidence that it has not been honored by either the
Manufacturer or Distributor .
Based on individual employee time sheets all employees of the
Road and Bridge Department do work 40 hours per week unless they
are taking authorized time off such as vacation , sick leave ,
holidays or authorized compensatory time . There are factors
which represent production and/or "productive work" . There are
three basic production rates , peak production , normal production
and average production . Peak production is defined usually as
the manufacturer ' s rated capacity with no delays or downtime
which would result in 100% efficiency . Since there are delays
and these delays are usually called routine and can usually be
predicted, a normal production rate is considered to be 80% of
peak production with the most skillful operator . Where operators
are used of less than top skill the average production rate is
obtained which usually runs from 50 to 70%. Based on the above
and knowing that a rock crusher is a very high maintenance piece
of construction machinery it is evident that the production rate
to use is the average production rate. Using the 70% factor which
is seldom found we see that of 37 . 5 production hours available
we could expect an average of 26 . 25 hours of production per week .
This rate (average ) is used for estimating and usually a figure
less than the 70% is used .
From past records including only 1976 and 1977 , the old crusher
reached an hourly average production of 125 to 150 tons per hour .
Using the average production week of 26 . 25 hours the plant would
produce 3312 . 5 to 3975 tons per week . The latest crusher report
for 1978 shows the present crusher is producing at 338 Tons per
hour and is producing 26 . 5 X 338 = 8957 Tons per week. Should we
reduce the production by 50% the new crusher still shows ap-
proximately 4500 Tons per week. There should be little doubt as
to whether the new crusher should have been purchased. Based
on the 1978 requirement for Paving Aggregate the old crusher operating
0
at the maximum could not produce the 1978 requirements , while
the new crusher at 50% could.
In reference to County personnel being sent home when conditions
do not permit operation of the crusher , it is the responsibility
of the supervisors to assign the crew to other work .- The employees
are paid a monthly salary and there are very few people in or
outside Of the County who will take time off without pay.
The Weld County Road and Bridge Department did not know when the
crusher was purchased what was required to move the main plant .
The Road and Bridge Department does at this time have the equipment
to move the plant , and it will be moved by this equipment unless
a scheduling conflict would create an undue delay .
There is definitely a need for improvement in reporting procedures
and a need for greater accuracy . This -problem is being solved
and is the concern of many . There is no doubt that we can con-
tinually strive for greater efficiency in all areas and we should
never be satisfied. There should ever be a great effort expended
to become better . Total perfection cannot be achieved and to get
better involves time which so many fail to recognize . God , with
his infinite power , did not create the world and its contents in
\one day .
In conclusion I do not feel. that the audit performed was in error
as far as to what it accompolished. I feel that all concerned
have only one goal in mind and that is to do their very best to
have Weld County the best in all areas . I feel that effort put
forth to put the reports together has been well worth the time
and money expended . The information gained has been and is of
great value . I wish to personally thank the Commissioners , the
Council , Mr . Jenkens , and all of the Road and Bridge personnel ,
the Manufacturer and Distributor for their total cooperation and
understanding .
._;;Lan-, ./�L Sze z i A:
G . Frank Smith Jr .
Director of Engineering
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