GN 22 Asset Management Toolkit: Minor Structures, replaces Technical Report 22 Managing a Vital Asset: Lighting Supports as the go-to guidance for the management of lighting columns, signposts and the like. This seminal document aligns with the latest guidance for the management of highway assets; Well Managed Highway Infrastructure produced by UK Roads Liaison Group. It promotes and develops a risk-based approach to the management of highway assets including lighting and replaces previous guidance. Although developed for the management of highway lighting assets, GN22 is applicable to other sectors with responsibility for exterior lighting such as transport, retail and commercial. It develops a new methodology for the assessment of minor structures (lighting columns, signposts, CCTV poles and the like) leading to a new Column Condition Indicator (CCI) to be determined. CCI can be expressed against a single asset or assets grouped by street, district or town or at a national level. This talk is ideal for local authorities, consultants, contractors and asset managers. by Peter Harrison, ILP & Tony Parasram, Free4m Consulting

1. Guidance Note 22
Asset-management Toolkit:
Minor Structures (AToMS)
Replacement of TR22 Managing a vital asset:
Luminaire supports
Peter Harrison ILP Technical Services Manager
Tony Parasram Director, Free4m Lighting

2. GN22 AToMS
• Technical Report 22: Inspections & assessment process
• Well-Managed Highway Infrastructure
• GN22 Delivery
• Difference between TR22 & GN22
• Inspection and assessment process
• TR22 data

3. Operational Condition Assessment

4. Assessment Guidance
CRITERA VALUE
Area and
Code
Inspection GOOD
1
FAIR
2
POOR
3
BAD
4
A
BaseCompartment
a Doors Intact and in good condition
b Flange Plate Condition No indication of corrosion
on Root or Bolts
Minor internal corrosion
and signs of bolt corrosion
Layers of rust with
Parental metal or bolts
corroded
Support leaning or
structurally damaged
c Base Compartment Condition No indication of corrosion
on Base and protective
root coating intact
Minor External & internal
corrosion and protective
root coating fading
Layers of rust with
Parental metal or no root
coating or poor
foundation
Layers of rust with
Parental metal Support
leaning or structurally
damaged
d Door Opening Condition Sound Aperture Minor signs of corrosion Aperture showing signs of
stress splits
Aperture Split
e Base Compartment Shoulder Sound weld no signs of
corrosion
Minor signs of corrosion Welds showing signs of
cracks and corrosion
f Internal Compartment Condition No indication of corrosion
on Base
Minor internal corrosion Layers of rust with
Parental metal
Layers of rust with
Parental metal thin wall

5. Assessment
Inspection Results
1 2 3 4
Area A
Base
Compartment
a N/A N/A N/A N/A
b
c
d
e
f
Each area is scored based
on the worst score within
that section

6. Well-Managing Highway Infrastructure
Challenges
• Well-Managed Highway Infrastructure
October 2016
• Replaced:
– Well Managed Highways
– Well Lit Highways
– Management of Highway Structures
• Single Document, Four Parts:
– Part A: Overarching Principles
• Risk based approached
• Emphasis on performance, resilience &
lifecycle management
– Part B: Highways
– Part C: Structures
– Part D: Lighting

7. GN22 Delivery
• Funding Partners
– ILP
– HEA
– UKLB
– TfL
• Steering Group
– ILP
– HEA
– ADEPT
– UKLB
– Asset management
– LCTF
• Tender Award
– WSP/Free4m
• Consultation
– Workshops
– Test houses

8. TONY PARASRAM BEng (Hons), CEng, FICE, FIStructE
Director, Free4m Lighting
Co Author GN22/19

9. Why Change Anything?
• WHY
– Other highway codes taking a risk based approach
– Targeted maintenance vs routine maintenance
– Better use of financial resources
– Ability to track investment value through condition indicators
– Ability to predict investment against impending stock deterioration
– Ability to compare stock condition across UK
– Legal direction on issue of competence
– Determine investment levels for stead state
– Determine investment levels for improved stock condition

10. How Is It Different?
• HOW
– Migrate
• Migrate elements of TR22 that remain essentially unchanged e.g.
history
– Update
• Update elements such as asset management to reflect current
thinking
• Testing
• Inspection
– Innovate
• Introduction of new concepts such as:
– Column Condition Index
– Assumed Residual Life

11. What Is The Risk Based Approach?
• HSE Guidance
• Selection of the
minimum broadly
acceptable failure rate
to determine the ARL
• As Low As Reasonably
Possible or ALARP
Network Rail
Rural area
Where am I
on this scale?

12. GN22/TR22 – Compare
• Not just highways, all lighting and similar supports
• As Low As Reasonably Practicable or ALARP
• A new asset management approach
• Structured cost effective inspection & testing
• Visual inspections based on defect rating:
– A to E for extent
– 1 to 5 for severity
• Downloadable condition software for free
• Software calculates stock Condition Index
• Condition Index related to other Asset Managed disciplines:
– Excellent/Good/Fair/Poor
• National Condition Indicator

13. GN22 Visual Assessment
• Each element assessed
• Element Condition Score
(ECS)
A – E for extent
1 – 5 for severity
ie A1 to E5
• Results fed into model
• Element Condition Factor
(ECF) – takes account of
influence on overall
condition

14. GN22 – What Does The CCI Index Mean?

15. Considers column material
Column materials
• Aluminium
• Timber
• Concrete
• Steel
Assumed residual life model consider:
• Steel

16. Considers Protective Coating Systems

17. Considers Environment Factors
Clause:6.a,6.d
TR22
R,corr>30 µ/year
Table C1
BS EN ISO 9223:2012
ISO 9223:2012(E)
Environment R,corr( µ/year)
C1 <0.4
C2 0.4<R<8.3
C3 8.3<R<17
C4 17<R<27
C5 27<R<67
C5x 67<R<233
Environment R,corr( µ/year)
ENV01-C3 8.3<R<17
ENV02-C4 17<R<27
ENV03-C5 27<R<67
ENV04-C5x 67<R<233

18. Approach For A Deteriorating Column
Assumed residual life
Age (Years)
Applied Moments
ColumnMomentresistance
Current
age
Corrosion initiation period
Column life cycle analysis results*

19. Inspection Recording
• Inspection and
testing remain
unchanged
• Only reporting is
modified
• Training available
for inspectors

20. Convert your existing inspection data
CONVERT

21. What Do I Get Out Of It?
View by
area
Results
broken
down
Free toolkit
software

22. What Do I Get Out Of It?
1. for a given
environment
2. and a given column
height
4. and a given actual
measured base wall
thickness
5. We can
estimate the
‘assumed
residual life’
3. and a given column
diameter

23. In Summary
• A new asset management approach
• Structured cost effective inspection & testing
• Model to determine the residual life
• Risk based criteria
– Identify risk
– Analyse the risk
– Evaluate the risk
– Risk treatment
– Monitor and review

24. Final Thoughts
2017 NDT test houses report an average of 3.5% are red/critical columns
They report a growing number of amber assessed columns
(2010-11% to 2016-37%)
10% of amber columns have turned red over 3 years
PFI’s have been replacing cc 80% of their authorities stock over a five year
investment period
Understanding your asset has never been so important