Equipment Types
Peter Baker
Cranfield School of Management
Agenda
• Palletised storage and handling equipment
• Conveyors and automated guided vehicles
• Carton and small parts storage
• Carton transport and sortation equipment
Block stacking
Block stacking
Block stacking
Advantages
• High density
• Low cost
• Operated by normal
counterbalanced fork lift truck
Disadvantages
• Limited height
• possible crushing
(NB pallet collars)
• stability
• Honeycombing
• Accessibility
Drive in / through
Drive-in racking
Source:
Redirack
Drive in / through racking
Advantages
Disadvantages
• High density
• Relatively high cost
• No crushing of loads
• Limited pallet types
• Height
• Tight tolerances
• possible rack damage
• driver strain
• Honeycombing
• Accessibility
• Special sprinklers
Push back racking
Push back racking
Advantages
Disadvantages
• High density
• High cost
• Height
• Last in first out (LIFO)
• Accessibility by row (rather
than by stack)
• Limited utilisation factor
• Limited accessibility
• Maintenance
• Special sprinklers
Pallet live storage
Pallet live storage
Source: Jungenheinrich
Pallet live storage
Advantages
Disadvantages
• High density
• High cost
• Height
• Limited utilisation factor
• Accessibility by row (rather
than by stack)
• Limited accessibility
• First in first out (FIFO)
• Warehouse flow (may be
advantage or disadvantage)
• Tolerances / maintenance
• Special sprinklers
Adjustable pallet racking
Adjustable pallet racking served by
counterbalanced fork lift truck
Note: typical aisle width 3.5 metres
Adjustable pallet racking served by reach truck
Note: typical aisle width 2.7 metres
Source:
Linde
Adjustable pallet racking
served by articulated truck
Note: typical aisle width 2.0 metres
Source: Aisle-Master
Double deep racking
Source:
Link 51
Adjustable pallet racking
Advantages
• Individual pallet access
• Relatively low cost
• Relatively easy to reconfigure
Disadvantages
• Relatively poor use of floor
area
• Floor surface critical over 8
metres
• Height (typically up to 10
metres)
• Suitable for ground floor
picking
Double deep
Double deep
• Improved floor utilisation
• Reduced pallet access
Powered mobile racking
Powered mobile racking
Source: Redirack
Powered mobile racking
Advantages
Disadvantages
• Good use of floor area
• Slow in operation
• High density
• Possible queuing
• Individual pallet access
• High cost
• Floor reinforcement
• Special sprinklers
Narrow aisle racking
Note: typical aisle width 1.7 -1.8 metres
Narrow aisle racking
Typical narrow-aisle “combi” truck for pallet
movements and order picking
Narrow aisle racking
Advantages
• Height (typically up to 14
metres)
• Good use of floor area
• Individual pallet access
Disadvantages
• Floor surface critical
• Specialist (and high cost)
trucks
• Usually needs P&D stations
(for pick up and deposit)
Automated storage and retrieval system (AS/RS)
Stacker crane on a transfer car
Source: Siemens
“Curve-going” cranes
Source:
Jungheinrich.
Automated satellite crane
Source:
Jungheinrich.
Rack clad building
AS/RS systems
Advantages
• Height (typically up to 20-40
metres)
• Good use of floor area
(typically 1.5-1.8 metre aisles)
• Individual pallet access (or
deeper)
• Fast
• Reliable
• Low running costs
Disadvantages
• High capital costs
• Strong foundations
• Building / fire regulations
• Planning permission
• Inflexible (suited to pallet-in /
pallet-out operations)
• Unit load dimension
limitations
Typical location utilisations (reserve storage)
Adjustable
Doublepallet
deep
racking
Location
utilisation
90%
85%
Narrow
aisle
Block /
drive-in
90%
70%
(i.e. % of
locations that
can be filled
before
impacting on
operational
efficiency)
Note: actual figures will vary by exact nature of application.
Mobile
90%
Live
Pushback
85%
80%
By storage requirements and picking activity
Source: Phillips, E. at www.strategosinc.com/warehouse.htm, accessed 22nd August 2006.
By number of pallets stored and number of SKUs
4000
Number of SKUs
3000
To 9m
standard
selective
or power
mobile
(if slow
moving)
Free
path
narrow
aisle to
12m
Fixed
path
aisle
changing
crane
12-16m
Fixed
path
AS/RS
14-20m
2000
Two-deep free path
to 8m
1000
Drive-in racks or
block stacking or
palletflo (if fast
moving) to 9m
1000
2000
Two-deep fixed path
to 16m
Remote
recovery unit
14-18m
3000
4000
5000
Number of pallets stored
6000
Source: Hatton, G. (1990) “Materials Handling”, in Gower Handbook of Logistics & Distribution
Management, 4th Edition, edited by Gattorna, J., Gower, Vermont, pp. 194-214.
© Colby Handling Systems
11-20
6-10
2-5
1
PALLETS ON-HAND
By pallets on-hand and popularity
Off-site
floor
storage
Mobile
storage
Pallet
flow
lanes
Doubledeep
rack
Pushback
rack
Single-deep rack
POPULARITY
Source: Frazelle, E.H. (2002) World-Class Warehousing and Material Handling,
McGraw-Hill, New York.
Decision tree
How many pallets per
SKU?
1 to 4 pllts/SKU
4-12 pllts/SKU
Is throughput per
SKU greater than 5
pllts / week?
Is throughput per
SKU greater than 5
pllts / week?
No
No
Yes
Yes
Is cost of powered
mobile justified?
No
Yes
Powered
mobile
Is it possible / cost
effective for lift height
to be:
< 11 m?
Yes
APR
(reach truck)
No
11-14 m?
No
Is it possible / cost
effective for lift height
to be:
< 11 m?
Is it possible / cost
effective for lift height
to be:
Yes Double-deep,
No
Yes
Narrow aisle
No
>14 m?
>12 pllts/SKU
11-14 m?
Yes
push-back, or
live
< 11 m?
Narrow aisle
11-14 m?
No
Yes
AS/RS
single-deep
>14 m?
Yes
No
Yes
No
Yes
AS/RS
double-deep
>14 m?
Yes
Block storage,
drive-in, or live
(Consider
options above
and below)
AS/RS
high-density
Source: Rushton, A., Croucher, P. & Baker, P. (2006) The Handbook of Logistics and Distribution Management,
3rd Edition, Kogan Page, London.
% of respondents
Palletised storage equipment
100
90
80
70
60
50
40
30
20
10
0
Wide aisle
Narrow aisle
AS/RS
Equipment type
AS/RS = Automated storage and retrieval systems
Source: Baker, P. (2004) “The adoption of innovative warehouse equipment”,
Logistics Research Network Conference Proceedings, pp. 25-34.
Other
Automated palletised storage
40
% of respondents
35
30
25
20
15
10
5
0
Single deep
Double deep
> 2 deep
Equipment type
Source: Baker, P. (2004) “The adoption of innovative warehouse equipment”,
Logistics Research Network Conference Proceedings, pp. 25-34.
Any ASRS
Roller conveyor
Pallet transport
Conveyors vs. trucks
Pallet transport
Factors
• Length of movement
• Amount to be moved
• Number of pick-up points and destinations
• Nature of terrain
• Speed of movement
• Cost
• Flexibility required
Automated guided vehicles
Pallet transport
Source: Indumat
AGV route example
Pallet transport
Source: Wagner
Small parts storage
Non-pallet storage
Bins and drawers
Suitable for very small parts
Standard shelving
Can be configured within pallet racking
Longspan shelving
Fewer uprights
Cantilever shelving
No uprights. (Also cantilever racking)
Mobile shelving
Dense storage, but slow access
Live storage
FIFO. Often used in order picking
Mezzanine floors
Good use of height but access and stanchions
Horizontal carousels
Goods to picker system
Vertical carousels
Uses building height with good access
Automated systems
Mini-load (i.e. crane) systems
Bins and shelving
Non-pallet storage
Mobile shelving
Non-pallet storage
Source: Link 51
Carousels
Non-pallet storage
Source: Siemens
Source: Kardex
Miniload cranes
Non-pallet storage
• Miniload storage and
retrieval systems
• Achieve up to 150
double cycles per hour
• Products stored in tote
bins or uniform cartons
Source: Swisslog
% of respondents
Non-palletised storage equipment
100
90
80
70
60
50
40
30
20
10
0
Shelving
(pedestrian)
Shelving
(man-up)
Carousels
Miniload
Equipment type
Source: Baker, P. (2004) “The adoption of innovative warehouse equipment”,
Logistics Research Network Conference Proceedings, pp. 25-34.
Other
Carton transport
• Various trolleys and pallet trucks
• Order picking truck (e.g. PPT, free path high
level, narrow aisle high level)
• Conveyor
• Automated retrieval system (e.g. miniload,
carousel)
• Sorters
Pop-up wheel (or roller) sorter
• Achieves 2 - 2,500 sorts per
hour
• Suitable for cartons and tote
boxes with a flat base
• Integrates with conveyor
systems
• Suitable for low number of
sort destinations (<20)
Sliding shoe sorter
Source: Siemens
• Achieves 4 - 6000 sorts per hour
• Suitable for cartons or totes boxes of
regular shape and reasonable rigidity
Tilt tray sorter
• Achieves 10 - 15,000 sorts per hour
• Suitable for all types of product with non-stick base
• Care needed over range of weights carried
Cross belt sorter
Source: Siemens
• Achieves 10-15,000 sorts per hour
• Can handle all shapes of product
• More expensive than tilt tray sorters
Equipment combinations
Source: BT Systems
Top 5 lift truck companies
Global sales in 2006:
1. Toyota, Japan
$5.5 billion
2. Kion Group (Linde), Germany
$5.3 billion
3. Jungheinrich, Germany
$2.4 billion
4. NACCO (Hyster, Yale), USA
$2.3 billion
5. Crown, USA
$1.7 billion
Source: “Modern Materials Handling” July 2007
Top 10 materials handling systems suppliers
Global sales in 2007:
1. Schaefer, Germany
2. Daifuku, Japan
3. FKI, UK
4. Dematic, Germany
5. Mecalux, Spain
6. Vanderlande, Netherlands
7. Swisslog, Switzeralnd
8. Murata, Japan
9. Kardex, Switzerland
10.Columbus McKinnon, USA
Source: “Modern Materials Handling” April 2008
$2.4
$2.3
$1.6
$1.0
$0.9
$0.7
$0.7
$0.7
$0.6
$0.6
billion
billion
billion
billion
billion
billion
billion
billion
billion
billion