St. Croix Ave. Golden Valley, Minnesota 55422
you have questions, call -
Forensic and Technical Engineering Investigations for
Investor, Legal, Adjuster, and
engineering is the investigation of
structures or components that fail or do not
operate/function as intended, causing
personal injury or damage to property. The consequences of
failure are dealt by the law of
product liability. The subject is applied most commonly in
civil law cases, although may be of use in
criminal law cases. Generally the purpose of a forensic
engineering investigation is to locate cause or causes of
failure with a view to improve performance or life of a
component, or to assist a court in determining the facts of an
accident. It can also involve investigation of
intellectual property claims, especially
An experienced forensic engineer can be
expected to answer three questions - - -
1. What happened?
2. Why did it happen?
3. How could it have been prevented?
These answers can be expected in the form of a
well-written report and, if called upon, a well prepared verbal presentation.
Our specific expertise is the design, development,
and production, of products and equipment to be used by people. An interesting perspective gained from the variety of
our experience with this people-equipment interface, is how
knowledge in one area can be applied to, and bring insight into other areas.
The fundamental principles of physics do
not change, regardless of the objects to which they are applied. This
variety of experience has allowed us to quickly come up to speed on projects. It gives an added advantage in that we tend
to look at mechanical/electrical situations from a broad perspective, yet retain
the appropriate depth. This is especially characteristic of forensic
engineers with heavy experience in the actual design and production of equipment.
Mr. Berner is credited inventor for 24 U.S. patents, plus some related foreign patents.
Pro bono assistance - Suppose you, as either defendant or plaintiff, believe you have been treated unfairly by the court and would appeal a decision but for lack of funds. If upon review, we agree, we may be able and willing to help out on a no fee basis.
If you have specific questions, please contact John
M. Berner, P.E. at Applications Research, Inc. (763) 521-0217.
you need more information on any of these projects, please
CONVEYOR SYSTEM (Computer
simulation) Review and redesign of
installation where manufacturer of the system was unable to offer an explanation for
the system's non-function. Review included analysis, thorough identification
of the problem, and recommendation for correction of
inoperable conveyor system. (Peavey, Con-Agra)
REFUELING VEHICLE FIRE Investigation
for report to insurance company. Conclusions
and recommendations regarding fatal fire in manufacturers test facility for aircraft
refueling vehicles. Involved very thorough review and reconstruction of the accident.
We provided absolutely conclusive proof that the cause as failure of a
4" poppet valve subjected to hydraulic
shock. (Brown Minneapolis Tank).
RECONSTRUCTION Past (and continuing)
projects in accident reconstruction analysis involving automotive and fire mishaps. Formal
reports. (Perhaps 10-12 different situations)
PALLETIZING EQUIPMENT Review of design and structural
configuration of the complete line of palletizing equipment for soft drink
cans. The main industrial design effort was conducted by Mario
object was a redesign to streamline the general appearance of the line, yet
avoid any compromising of the structural integrity of the equipment.
Fernandez also developed a suggestion for a new logo and incorporated it
into the renderings of the equipment. This effort also involved review of OSHA issues relating to this equipment.
SUSPENSION ANALYSIS Analysis of automobile
suspension proving standard configuration of a particular U.S. passenger car that did not
meet its own specification for load capacity. Clearly identified problem(s).
Demonstrated spring design under standard load specification allowed rear axles to bottom
out as vehicle still sat in driveway.
transfer) investigation and analysis of the effect of restrictions in water flow to
various automotive heaters for various input water and air conditions. Formal report.
This was conducted for the potential manufacturer.
investigation and recommendation for potential investment and/or purchase of line. Formal
report, UL review. This was conducted for the potential purchaser and
manufacturer of the line.
BUBBLE SWITCH DESIGN
PARAMETERS This project consisted constructing
mathematical models of a number of typical bubble switch
configurations. One of our conclusions was that the sharp edge where
the bubble met the flat surface was causing very high (destructive) stresses
in the PC laminate material at that point. Also, we were able to
determine that the the problem was worse or most aggravated for the thicker
materials. This was conducted for the manufacturer.
MECHANISM DESIGN AND/OR REVIEW Paper analysis of system for
fabrication of compact disk printing system. Developed concept(s) for cost reduction and
streamlining of system and reduction of number of parts. A variety of options were
looked at. Overall effort resulted in about 30% cost reduction of the basic
system. We believe other, more radical changes will amount to even greater cost
reductions with an overall increase in performance. This was conducted
for the manufacturer.
PROCESSING FACILITY Review of cheese processing plant
equipment for problems with equipment. This effort involved a quite
detailed look at the various items provided for production. Undue wear
patterns caused foreign (metal) particles to be introduced into the finished
product. Result was the product had to be rejected with significant
financial loss to the processor. (Land O' Lakes)
SIMULATION SRMD (Seismic Response Modification
Device) Review of the safety hazards
and potential failure modes for a large ($14 million) earthquake simulation installation.
Analysis involved review of the hydraulic accumulation system, power distribution system,
and servo control system. (University of California, San Diego and MTS).
'99, UCSD AND CALTRANS California Department of Transportation officially
opened the new Caltrans Seismic Response Modification Device (SRMD)Test Facility
at the San Diego campus. The facility is the first in the world of its kind and
scale, and is designed to test new technologies to retrofit the state’s
longest span bridges.
to provide a realistic three-dimensional earthquake simulation, the facility’s
testing table is 16 ft. long by 12 ft. wide, and can move horizontally in all
directions, lift and lower, rotate, and shake at velocities of up to 70 inches
per second. Long-span bridges including the western approach to the Oakland Bay
Bridge, the San Diego-Coronado Bridge, and the Benicia Martinez Bridge are among
those targeted to be retrofitted for earthquake safety through the Caltrans Toll
Bridge Retrofit Program.
DELIVERY SYSTEM Research effort to come up with various optional
methods to pump medicinal or nutritional fluids into patient during various
hospitalization situations. Involved review of existing systems,
brainstorming of optinal systems, and presentation of best option(s) to client (Sandoz
STERILIZER UL approval
for ethylene oxide gas sterilizer for use in hospitals. Included review, summary report,
travel to Chicago (Northbrook) to review with U.L. (3M Co.)
AERATOR SIMULATION Simulation of golf course fairway aerator
system. This was a device that operated in such manner as to punch holes
in the soil as it moved down the fairway. The process involved a
tremendous load on the transmission and gears that drove the individual
spikes. The output included all the gear loads, bearing loads, some of the
other component stress loads, and a graphical representation of the system as it
cycled. Effort included a quite thorough analysis and report.
COMPUTER SIMULATION (Computer
simulation) Simulation of golf course
fairway mower system to analyze the problem(s) associated with a phenomenon referred to as
"bobbing". Bobbing is a situation where a reel mower attached to vehicle begins
to vibrate vertically at a resonant frequency which is determined, probably, by the
constants (weight, vehicle speed, tire pressure, cg's, connections, etc.) of the system
and the equivalent spring constant of the interface between the hardware and the ground -
- i.e. the grass/dirt turf pack. By way of this simulation, we were able to evaluate the
relative importance of dampening in the horizontal, vertical, and rotational directions
and the connecting point of the vehicle to the mower(s). An interesting
conceived by us and demonstrated with the computer model, was the simulation of the
apparent vehicle/mower pivot connection acting as if it was situated below the surface of
the ground. We referred to this concept as a "virtual" pivot connection since it
could not be achieved unless one devised a (very simple) linkage to create the pivot
point. The computer model was constructed in such manner as to allow changing of almost
all variables as vehicle moved along the ground up to and including drive wheel diameters.
These were variables which could not possibly be continuously modified on an operating
piece of hardware. Computer model and associated graphic was later converted to a MS
Windows-based front end.
LIFT ACCIDENT (A) Conducted investigation of fork lift
accident fatality. This involved used of a fork truck to support an
operating conveyor in a raw vegetable storage facility in southern
Minnesota. Involved a thorough review of involved mechanisms, their
functions at the time of the accident.
LIFT ACCIDENT (B) Review of the situation whereby the operator
of a lift truck was discovered (deceased) in place on the tractor with the
engine running, in a large suburban grocery distribution center. In
addition, the fatality was clearly due to head injury. Investigation
involved review of OSHA requirements, environmental situation, fork truck
configuration, measurement a re-layout of the accident site and the position
of that fork truck, as discovered at the accident scene. Client was
DAMAGE ANALYSIS BY TRUCK-TRAILER ACCIDENT
Review of damage to
approximately $800,000 worth of very sophisticated vibration simulation and control
equipment resulting from truck accident. Provided oversite review of repair activities for
insurance company and owners, Lloyd's of London and the Chinese (Mainland) Government.
TRANSMISSION ANALYSIS (Computer
simulation) Review and analysis of golf
car transmission wherein the vehicle speed tended to enter a cycling "surge"
mode when the accelerator was actuated too rapidly. Developed engine-clutch-traction relationships and clearly identified variables that affected the
natural frequency of the system. This led to development of a recommendation and
method for elimination of the problem. Additional effort involved full
stress analysis, including fatigue loading, of all components of the
ANALYSIS AND RECOMMENDATION Analysis of loads for all
positions for a vertically lifting door for an aircraft hangar. Report included full
analysis of lifting system power requirement and a general critique of system for function
CLUTCH/BRAKE Analysis and design
recommendations for high-speed clutch/brake system. Most thorough analysis of clutch/brake
interaction to that point. Formal report. Presently working on article for
national magazine concerning clutch-brake systems.
ACCIDENT ANALYSIS Review of accident
with inclined elevator on bank of St. Croix River, involving three adults who sustained serious
injury. Also involved German shepherd dog who jumped free but limped around for
about two weeks. Involved reconstruction and recommendations for prevention of
future mishaps. Formal report, photographs provided. (Client - American Family
MIXING EQUIPMENT Review, evaluation, and certification of
multiple pieces of ink mixing equipment just prior to its preparation for
shipment to India. Client was manufacturer/distributor.
PLANT FIRE Review and reconstruction of
situation leading to fire. Included site visit, photographing of site, interviews with
various individuals and recommendations to prevent future mishaps. Costs to rebuild were
reviewed for fairness and consistency with the reconstruction work performed. (St. Paul
MIXING TANK(s) Complete review and analysis of molasses mixing
tanks. This included thorough stress analysis of the main structure
and the 12 foot diameter circular perforated plates and welds. We took
into account the cyclical (fatigue) nature of the loads as the tanks were regularly
filled and emptied approximately 10 times daily (Arrow
FAILURE IN FAN-COIL COOLING UNITS This was an investigation
of the very early failure of motors in a series of fan coil
systems. This involved complete teardown and review of the various
components of the system. Our final report and certification involved description of
our investigation plus clear identification of the cause of the
problem. (City of St. Paul).
ENGINE Review of components and loads for motorcycle engine.
This included stress loads for crankshaft and recommendations for production.
Client was potential manufacturer.
OIL PURIFICATION TRANSPORT UNIT Complete review from operator
safety standpoint, of a mobile oil purification transport system
design. This include review of all electronic controls and potential
burn hazards, heat flow through unit, and final recommendations.
(Porous Media Corporation)
SWIMMING POOL Swimming pool panel stress
analysis. Involved analysis of various hydraulic load situations comparing aluminum with
fiberglass from both a strength and cost standpoint. Included fatigue analysis of
design. Investigation also involved very interesting review of the natural frequency
of the water mass in various size containers varying all the way from bath tubs to Olympic
sized pools. Recommendations for redesign were eventually incorporated.
Review, analysis, and
redesign recommendations for a high volume soft drink can palletizing machine. Work
include re-specification of components in such manner as to improve visual characteristics
of equipment without compromising the actual structure. Use of proper components
allowed actual slimming of the unit(s) while strengthening some of the critical
components. Graphiics were developed around 3D computer models of the machines.
MOTION EXERCISE DEVICE COMPUTER SIMULATION (Computer
simulation) This was a follow up, by a few
months, on work we had completed as part of our design of the original machine. Review of linkages and creation of a graphical computer
simulation of the motion of the device. Computer program was created that
not only read back the loads on all the pivot points, but the linkage loads and
the bearing lives at the expected loads and speeds. In addition it was set
up so as to allow the client to enter the applied loads and the speeds involved
in the various situations. While we had completed a number of these
calculations earlier, the program allowed the client to easily change all the
inputs and retrieve answers, by screen or printout, for the loads and lives on
all linkages and bearings in the system. (EMPI)
HANDRAIL INVESTIGATION Based upon our experience with handrail
design, we were selected to evaluate a number of different configurations for
handrails of pontoon boats. The object of this was to minimize the
potential for damage to hands and fingers of the passengers - especially young
ones. This was accompanied by a complete report.
INVESTMENT ANALYSIS This was a computerized system for
inclusion of all the company's engineering projects into an overall combined return on
investment analysis. This was done because specific
engineers recognized that, due to erroneous tax treatment, all new product
programs were being unfairly compared to alternative investments. In addition, the cost assigned to various programs
were regularly subjected to whimsical (fast and loose) estimates based more upon
USWAG figures than on factual data. This helped to put engineering
cost estimates on a more legitimate, professional, footing (Toro).
LOUVER INSPECTION - CERTIFICATION Effort involved comparison of
existing louver system with the standard for that particular building product
and to certify its compliance. Report was presented. Client was the
- RADIAL ARM A carpenter severed part of his hand while
using a radial arm saw on a job site. Although the saw was set to cut window
headers, the carpenter claimed the saw lurched rapidly toward him as he reached
for the handle. Post-accident site investigation was not possible. We were
retained because one of our strengths is the design and test of consumer grade
power equipment. Careful examination revealed that a foreseeable
distortion in the plastic motor housing unit would allow the saw to come out of
its locked vertical position. The manufacturer later incorporated the type
of restraining device recommended by us. Perhaps, the manufacturer should
have spent time with us before this happened, rather than after.
SAW SWITCH DESIGN Review of accident involving circular saw
switch wherein we clearly identified the failure mode as one whereby the
"off" contact was designed too close to the "on"
contact. This led directly to the saw's switch not cutting power to the
unit when it was switched to the "off" position.
EQUIPMENT - VARIOUS DESIGN
ANALYSIS EFFORTS Five or six various clutch,
gear, or structural analysis efforts to assist Toro engineering people with snow equipment
projects. Mr. Berner, of this office, was a major contributor to Toro's
present snow equipment design. This included the
original two-stage snow throwers, plus, origination of Toro's "Power
Curve" concept - the "star" feature of its present single stage
snow thrower lines.
STUDY AND FOR U.S. GOVERNMENT As part of
the government sponsored development of a concept for assisting the individuals to more safely climb up or down
stairs, a study was conducted, involving
the negotiation of stairways for the elderly and handicapped, The
device essentially amounts to a walker which is affixed to one side of a stairwell and
makes it possible to secure one's position all the way up and all the way down a stairway
so as to avoid the head-over-heel fall. This is presently installed in about 50 - 55
homes around the Twin Cities metropolitan area. As result of work on
this study, plus other efforts, we have gained considerable expertise in assistance technology related to
safely moving people.
EXPANDER INVESTIGATION Complete review of tissue expander
characteristics for insurance company prior to authorization for payment of
claim. This included leak testing of samples provided, observation of
pump-infusion system, and review of fabrication manual for the
expanders. Object was to identify where an obvious cut occurred in the
tissue expander surface. (St. Paul Companies).
TOY GUN MISHAP
Review of situation whereby
toy gun stuck in eye of a four year-old child by a five year-old child resulted in
destruction of the lens and iris. Demonstrated by medical photography techniques that the
incision in the surface of the eye exactly matched the configuration of the tip of the
flash suppressor of the (quite accurate) scale model of a 1967 version M-16 U.S. Army
rifle. Effort involved quite thorough investigation of the toy and the actual weapon upon
which it was based. Result based upon demonstration that all other toy guns had blunted or
rounded tips, plus observation of small children using toy guns.
VEHICLE FIRE INVESTIGATION Investigation for insurance
carrier of fire involving $550,000 track maintenance vehicle and about $350,000 repair
expense. Questions were raised concerning costs associated with level of effort required
for completion of system. Identified about $150,000 of unreasonable, expenditure.
Accounting office that missed this was not happy with us. However, the
insurance adjuster was quite pleased. (Insurance
STORE SEAT-DESK MECHANISM This project involved investigation
of, and redesign of a desk chair mechanism such as to allow a physically
handicapped individual to function in a manner that accommodated her
limitations. This involved a balance system to make it easy to lift or
lower the work surface of the work station along with all the normally
required equipment (approx 100 lbs). Work was performed as a
sub-project to overall project for the Metropolitan
ANALYSES 3 speed geared transmission
analysis - gears, bearings, shafts. Complete AGMA analysis for both stress and durability.
This was a three dimensional analysis, in that the gear and bearing forces were
analyzed in the X, Y, and Z directions, combined to determine resultants, and
applied to the appropriate gears, shafts, and bearings. This is generally
considered a fairly difficult analysis and beyond the capability (and interest)
of most engineers. Formal report. (Have performed this for Toro on multiple occasions).
INFINITELY VARIABLE This investigation involved the complete
teardown and review of each component of the mechanism of the standard Zero-Max
infinitely variable speed control. This included stress analysis, fatigue
considerations, and recommendations. (Zero-Max Industries)
TRANSMISSION ANALYSIS 3 speed geared transmission
analysis - gears, bearings, shafts. Complete AGMA analysis for both stress and durability.
3 dimensional load analysis for all shafts and bearings in all three speeds for expected
input torques. Formal report.
AUTOMATIC VALVE Analysis of high volume home
water softener system. Field failure data was analyzed, compared with lab test data, and
summarized. Summary included thorough review of components and recommendations for future
design and test procedures. Involved thorough Weibull distribution statistical
WHEELCHAIR WHEEL FABRICATION SYSTEM Analysis of wheel chair
wheel fabrication system for cost improvement and optimization of labor. Effort
included analysis of tooling costs and design changes into a return of investment
Preliminary studies, design,
and drawings and prototype construction for roof-mounted wind turbine (augmented
horizontal Darius). This effort was an investigation of the possibility of using
either man made (buildings etc.) or natural structures such as low hills, tree lines etc.
to augment the flow of air into a wind energy device. The results of this effort
look quite promising, especially in the northern climates if the power is used to directly
operate heating devices. This is because infiltration type heat loss in a structure
is closely related to wind speed. Conversely, so is heat gain if provided by the
wind energy device The match-up makes for interesting possibilities in northern
climates and/or seashore locations.
REDESIGN Redesign and recommendation
for a window frame system for apartment building windows which would reduce the problem of
young children pushing out the screen and falling through. Redesign based on
absorption of running child's kinetic energy. We were able to identify
and test at least four separate systems for accomplishing this goal.
CONCEPT Sole originators of concept for joining cord
to light for a yard light manufacturer which allowed production of lights
without infringing upon pre-existing patent(s). Project was conducted on an
emergency basis for a small electrical component manufacturer by the name of L &
L. Its manufacturing chief assigned us to this effort to overcome a patent
infringement injunction. Successful follow-up by others company led to company's
(L & L) purchase by Toro. The product line developed around this concept
eventually became the nucleus of Toro's Home Products Division.
4927 St. Croix Avenue, Golden Valley, MN 55422
If you have questions
call - (763) 521-0217
Contact Us by E-mail