1. The
inside
track
steven casey, ergonomic systems design
supported
by
a
m
ethodical
process
of
analysis, design
and
testing, A
fresh
look
at
operator
ergonom
ics
and
com
fort
drove
the
design
of
the
new
Crow
n
C-5
forklift
user needs and product positioning,
create a new and exciting design
aesthetic, and verify and validate the
result of many years of work.
Reflecting the clean-sheet
approach taken for its development,
the Crown C-5 is indeed a fresh and
clean product that expresses
purposefulness, attention to every
detail, and an unmatched degree of
user-centredness in an IC forklift.
Early analysis and research
Early field research by the team at
dozens of sites identified a set of key
ergonomics and design ‘areas of
opportunity’ for the new design.
First and foremost – and based on
the premise that a comfortable
operator is a more productive
operator – a lift-truck having higher
levels of productivity and efficiency
Designing a completely new
industrial vehicle from the
ground up is an opportunity
that does not come around every
day – and that is why I jumped at
the invitation to assist Crown’s
Design Center with the development
of its revolutionary C-5 IC forklift.
The C-5’s roots can be traced
back to 2003, and even earlier, with
initial research on IC truck markets,
users, uses, and competitor product
offerings. Like any clean-sheet
product development effort should,
Crown employed ergonomics and
industrial design expertise from the
first to the last day of the programme
to help identify the functional and
performance requirements of the
overall machine, define the
objectives for the operator’s
workspace and interface, flush-out
CASE STUDY
left: Attention to
detail in the overhead
guard maximises
upward visibility
Advanced Lift-truck Technology International 2010 41Advanced Lift-truck Technology International 201040

2. CASE STUDY
Advanced Lift-truck Technology International 2010
was among the top objectives.
Second, the truck had to have best-
in-class drivability and control as
well as exceptional levels of comfort
and visibility forward as well as to
the rear, as lift-trucks are driven in
reverse for so much of the time.
Best-in-class ingress and egress
was another objective from the
outset, with particular attention
paid to step height and size, an
unobstructed and open entry path,
and high and wide overhead guard
rails and vertical support posts.
Regular maintenance activities were
also studied extensively during the
research, and maintenance
performance objectives from the
points of view of the operator and
service technician were spelled out.
At this stage of development and at
the conclusion of the initial
research, the ‘clean sheet’ of paper
still remained unmarked with no
formal design, per se, yet the team
had a clear set of objectives and
innovative concepts to be explored.
Initial workspace layouts
A first step on the ergonomics front
was to develop a set of parameters
for ‘workspace geometry’ – that is,
the basic placement of the seat,
floor, pedals, steering wheel,
controls, and ranges of adjustability
required to accommodate the range
of operator sizes. The result was
numerous seating test bucks like the
one shown in Figure 1 that illustrate
how the C-5 was truly designed
‘from the operator out’.
These seating bucks served as test
devices for numerous human factors
studies involving large samples of
lift-truck operators of all different
shapes and sizes. Required ranges of
adjustability for the seat and controls,
the height of the seat, the location of
pedals, and the ease of ingress and
egress were studied and restudied
using an evolving series of test bucks.
Early research suggested that the
general area of IC truck seating
warranted considerable attention. A
separate research, design, and
engineering team was therefore
established to develop an in-house
seat meeting a stringent set of
requirements. It had to establish
new standards of comfort and
durability, be easy to adjust, and
support the operator during forward
as well as reverse driving. It was also
felt that a seat with a larger, less
contoured and restrictive seat pan
would provide greater comfort and
seating variation for the operator.
The many research steps in the
program included the recording and
analysis of pressure maps of different
seats during high-impact driving.
Developmental performance
testing and field tests
Highly structured operator-centric
performance tests were conducted at
key points during the development of
the truck. In each, a test course and
tasks were created to simulate various
warehousing and materials handling
scenarios of interest. One or more
test truck mules were operated by
large samples of experienced drivers.
Measures of work performance,
including things like the number of
loads moved and cycle times, were
recorded and analysed.
On the subjective front, operators
provided ratings of ride quality and
comfort, visibility during different
phases of operation, control design
and functionality, ingress and egress,
and many other factors. The
objective performance measures and
subjective ratings and comments
were used to validate – as well as
refine – various aspects of the truck
during development.
‘Blind’ tests of mule trucks and
competitor IC trucks were also
conducted using disguised products
without branding, ensuring the
validity of results and the
conclusions that could be drawn.
In a major undertaking towards
the end of the program, and in
addition to other field testing tied to
machine reliability and other
engineering interests, hundreds of
pre-production trucks were placed in
private, closed facilities throughout
the USA and operated as part of each
facility’s fleet, sometimes in the
most demanding of conditions.
FIGURE 1 (ABOVE LEFT):
One of many early
seating bucks used to
test workspace geometry
and adjustability
FIGURE 2 (ABOVE RIGHT):
To evaluate seat types,
materials and structures,
pressure maps were
used – pressure map of
the Crown FlexSeat (top)
and of a competitor’s
seat (above)
43

3. Advanced Lift-truck Technology International 2010
Applications spanned low-duty,
to medium-duty, to heavy-duty
truck use in which the machines
were driven 24 hours a day, seven
days a week. Particular emphasis was
placed on understanding the success
of the machines in heavy-duty
applications – a prime target market
for the C-5 and an environment for
which the truck was designed.
Operators and service technicians
provided extensive data and ratings
to Crown’s industrial designers to
help evaluate all aspects of the
operator interface as well as the
serviceability of the truck.
Resulting design and ergonomics
Although there are dozens of
innovations on the Crown C-5
aimed at improving the comfort and
performance of the operator, a
handful of outcomes of the
preceding design and ergonomics
work are worthy of special note.
One of the first things operators
perceive about the new C-5 are its
‘clean and uncluttered lines’. From
the wide and integral first step, to
the wide entrance at the floor and
beyond to the large, unobstructed
foot space, the operator station is an
integrated, carefully planned space
where a driver can be comfortable as
well as productive.
The new Crown FlexSeat represents
a new approach to an old problem. It
provides up to 17% more width
than competitive seats, a seat pan
contoured to accommodate all driving
positions, a flexible back rest with
side shoulder cutouts to aid driving
in reverse, an easily identifiable
adjustment control, and a polymer
and Dymetrol mesh suspension
providing excellent comfort and
reduced seat pressure points.
All controls fall conveniently to
hand or foot. The wide brake pedal,
wider than that of any truck in its
class, provides for comfortable
braking from alternative foot
positions and when driving in
reverse, as well as lower brake effort
to reduce operator strain.
Steering effort has been reduced
too, and the hydraulic levers are
easily reached and operated with
light efforts. The simple-to-operate
push button electric park brake
eliminates the obstruction created
by a large hand brake lever.
The view from the operating
position surpasses that of any
competitive machine. The low front
cowl and cab-forward seating position
places the operator close to the forks
to maximise forward visibility. The
the operator
station is a
carefully
planned space
where a
driver can be
comfortable,
as well as
productive
FIGURE 4 (ABOVE
RIGHT): The open
workspace and
accommodating
controls of the
Crown C-5
FIGURE 3 (ABOVE): The
Crown FlexSeat
CASE STUDY
waterfall design of the
overhead guard and its
strategically placed cross bars
provide for clear upward views
of racks, forks, pallets, and
loads. Out the back, the lower
counterweight and lower LP bottle
position dramatically increase
rearward visibility – especially
important when driving in reverse.
The counterweight vents have
even been designed to deflect heat
and exhaust away from the operator
compartment, also important for
comfortable reverse driving. These
and many other features were the
direct result of the rigorous design-
build-test (DBT) product
development process.
The attention to detail is
particularly noticeable in the realm
of service, from the clever tilt-pivot
mechanism for switching the LP
tank, to the unprecedented degree
of access to the engine
compartment, and roomy post-to-
post clearance from the side.
The numerous operator-centric
features and innovations of the C-5
IC forklift were born out of the
dedication of the team to design the
best truck they could, but also to
their commitment to a methodical
process of analysis, design, and
testing with the future operator and
service technician in mind – which
is what ergonomics is all about. ALT
44
For further information:
Steven Casey,
5290 Overpass Rd, Suite 105,
Santa Barbara, CA 93111, USA
Tel: +1 805 683 6610
Email: scasey@
ergonomicsystemsdesign.com
Web: www.ErgonomicSystems
Design.com