The document summarizes a town hall meeting about planned works on a clay embankment in Cromwell Road. It discusses resident concerns over vegetation management and potential geotechnical issues. An engineering expert presents on the geological context and how tree roots can impact embankments by changing soil moisture. Track maintenance issues linked to vegetation are also reviewed. Environmental mitigation strategies are outlined. Lessons are shared on improving notification of nearby residents for future works. Representatives were available for questions afterward.

1. Whitstable Town Hall Meeting -
Cromwell Road Embankment Works
Thursday 3rd May 2012 – St Marys Hall, Whitstable – 18:30
Rev Paul Wilson and John Burrows

2. Before We Start…….
• Fire Evacuation Procedure
• Fire Exits
• Mobile Phones
• Any Members of the Press ?
• Filming

3. Agenda
• Residents Concerns – Julie Wassmer
• Geotechnics Report – Simon Abbott
• Track Geometry – Jordan Faulkner
• Environmental Issues – Glen Brown
• Work Scope and Method – Martin Pope
• Notification Policy & Lessons Learnt – Glen Brown
• Summary
• Questions Session

4. Resident’s Concerns and
Objections

5. Clay Embankments and the
Problems Associated with
Vegetation
Simon Abbott (BEng), CGeol, FGS, – Senior Asset Engineer (Geotechnics)

6. Earthwork Assets
Three principal geotechnical asset types we are responsible for;
Soil Emb R oc
Cutt ank k Cu
ings men tting
ts s
Continued process of examination, maintenance, investigation, assessment and remediation

7. Geological Context & Construction
Sensitivity to Moisture Change
•Gault
•London Clay
•Weald Clay
BGS Swell-Shrink Potential Map

8. 1960’s compared to 2012
Historically little vegetation aside from grass and low scrub on embankments and cuttings

9. 1960’s compared to 2012
Car parks highlighted for point of reference

10. Trees – good or bad?
Cuttings – bad

11. Trees – good or bad?
Chelsfield Cutting

12. Trees – good or bad? Embankments..
It is misunderstood that mature vegetation only has
positive impacts on slopes.
High water demand trees have a detrimental effect on
the condition of particular embankments (next slide)
Tall trees impose high loads as a result of wind
loading.
Leaf fall
Signal Sighting

13. Modern Understanding of Geotechnics
Land take pressures during railway
construction mean assets are typically
over steep
Settlement & Heave up to 50mm
between summer and winter.
Permanent outward spreading of embankment

14. Leading industry research

15. Soil Moisture Deficit (SMD)
Ashford’s Square 174
Faversham’s Squares 163 & 164
SMD = Amount of
rainfall (mm) that the
ground can absorb
before reaching
saturation.
SMD of 0 = saturated
SMD of 200 = dry
15

16. SMD Chart 163 VIR
Gillingham to Herne Bay
Rate of SMD rise in Morec Square 163 2009
2010
350 2011
2012
300
250
200
150
100
50
0
01-Jan 01-Feb 01-Mar 01-Apr 01-May 01-Jun 01-Jul 01-Aug 01-Sep 01-Oct 01-Nov 01-Dec 01-Jan
16

17. How the line side vegetation should be
We always endeavour to
leave trees at the toe
Remedial scheme
necessitated removal of
trees on inner verge.

18. What Happens if we don’t manage the
vegetation on our clay embankments?

19. Serviceability and Delayed Failure
Delayed failure is associated with long
term shrink-swell induced by vegetation

20. References:
• Briggs, K (2010). Charing Embankment: Climate Change
Impacts on Embankment Hydrology. Cooling Prize 2010 Winning
Submission.
• Loveridge, F.A et al (2010). The impact of climate and climate
change on UK Infrastructure slopes.
• Smethurst, J.A etc al (2005). Seasonal changes in pore water
pressure in a grass covered cut slope in London Clay.
• O’Brien, A.S.O et al (2004). Old Railway Embankment Clay Fill –
Laboratory Experiments, Numerical Modelling and Field
Behaviour.
• CIRIA Special Publication C592 (2003). Infrastructure
Embankments – condition appraisal and remedial techniques.

21. Track Geometry
Jordan Faulkner – Track Maintenance Engineer (Faversham)

22. Network Rail Standards – Track Maintenance
Working to Network Rail standards
that are applied nationally for
inspection and maintenance of track.
The standard specifies:
• Minimum frequencies for
inspections.
• Processes for carrying out
inspections.
• Details those track geometry faults
which require action.

23. Good track geometry

24. Whitstable track geometry
• Shows vertical and
lateral rail alignment.
• Super Red eighth =
eighth within in
maximum SD band.
• Eighths within
maximum SD band
pose an increased
risk of an incident.

25. Whitstable track geometry
Standards state:
•Engineers must use other
asset information and/or
arrange more detailed
examinations where needed
to identify root causes.
• Standards require that we
take appropriate action to
improve track geometry
quality by tackling the
underlying causes.
• Also faults shall be repaired
before they affect the safe
performance of the track.

26. Track Geometry
Photos from 2011

27. Clay Bank Vegetation Management

28. Ashford to Maidstone line - Hollingbourne
Station

29. Ashford to Maidstone line - Charing Station

30. Evidence of TQ affected by trees on
Ashford to Hastings line.
Individual Trees

31. Track - Summary
Repeat maximum SD (Super Red) track geometry
• Increased safety risk.
• Increased inspection frequencies.
• Condition of track speed restriction for 13+ weeks in
summer 2011.
• There is a limit to work that can be completed in
summer due to the risk of track buckles.
• Already undertaking maintenance work 3 times more
frequent than similar track.
• Large number of speeds across East Kent in 2011.
• Component deterioration – increased maintenance –
component deterioration.

32. Environmental Concerns and Summary of
Vegetation Management
Angela Cruickshanks – Infrastructure Maintenance Environmental Specialist
(BSc/MSc Environmental Consultancy, AIEMA)
Martin Pope – Infrastructure Maintenance Programme Manager
Date 00.00.00 32

33. Environmental Concerns
• Pre-work survey completed by Network Rail to identify if any
protected areas in the vicinity or any protected trees are present
• Daily site inspection recorded by the contractor to identify any
nesting birds in the area of work
• Risk of nesting birds identified by Network Rail in the work
package plan and provided to the contractor
• Consultation with Natural England to advise on the scope of the
works
• Site walkouts completed to identify nests by the Network Rail
Environment Specialist, Lineside Engineer and Programme
Manager
Presentation title to go here 33

34. Environmental Legislation/Mitigation
• Under the Wildlife and Countryside Act 1981, all wild birds, their
eggs and nests are protected
• It is an offence to intentionally take, damage or destroy the nest
of any bird while in use or being built.
• There is no reference in the Wildlife and Countryside Act 1981 to
specific dates when vegetation work cannot be carried out as
birds potentially nest all year round and is dependant on climate
• Contractor advised to create an exclusion zone of 2m
surrounding any potential nests identified as per the company
corporate guidance

35. Proposed Plan
• Phase 1 - Remove all younger Sycamore re-growth close to the
lineside first and any dense shrubbery which restricts access to
larger trees
• Phase 2 – Re-Survey the large Sycamore trees for nest which
may be covered by the ivy. NB The ivy indicates poor health of
the trees and some trees identified as decaying
• Any larger trees where birds are not nesting shall be removed in
accordance with the specifications discussed.
• A proposal to use other Network Rail land to create a dense
woodland to compensate for the woodland habitat removed at
Whitstable in a habitat trading scheme

36. Network Rail’s ongoing Vegetation Management
• In addition to the specifications already discussed there are a number of other
specifications where Network Rail are required, in accordance with Company
Standards, to proactively manage vegetation on Network Rail controlled
infrastructure. One such specification is to clear, up to 5 metres laterally from
the running line, maintain clear of all woody vegetation. The area vertically
above shall also be maintained clear of all vegetation. This excludes general
ground and scrub clearance for the safe removal of trees on embankments.

37. The Network Rail
Pre Notification Policy
Glen Brown – Maintenance Protection Co-ordinator

38. Pre Notification of Works Policy
• Maintenance is the general day-to-day upkeep of the railway which keeps the
trains running, for instance looking after tracks, signals, power supply and
vegetation. Engineering is the larger scale infrastructure work, for example
track replacement and upgrade works.
• When we are planning engineering works near residential areas, we aim to
send letters to local people 10 days before the work begins. The letters explain
what we plan to do and when we expect the works to start and finish.
• For maintenance work (such as emergency repairs or general up-keep), it is not
possible for us to tell the people who live nearby. This is because maintenance
work takes place every day and night of the year on the railway all over the
country which makes it impractical to give advance notice to all the people
affected by every job.

39. Pre Notification of Works Policy
• The vegetation works carried out in the Whitstable area are classified
as maintenance works. Due to the timescales involved, letter drops
were done in good will at Cromwell Road several days before work was
due to start on this side of the railway.
• If we can, we will work on the plants and trees near the railway during
the day between Monday and Friday, but sometimes we have to work
at nights or weekends so that we can keep our staff safe and the trains
running.
• If we are working in an area for a prolonged period, we try to let our
neighbours know through letter drops. We will also contact the
appropriate local authority informally and if necessary submit a formal
activity and noise application to obtain consent.

40. Lessons Learnt –
Cromwell Road Tree Clearance
Glen Brown – Maintenance Protection Co-ordinator

41. What we could have done much better…
• Network Rail standard letter templates were not used as the contractor was
asked to manage this process without full guide lines on our process being
provided.
• Our contractors have been fully re-briefed on the NR pre-
notification policy and the new updated templates to use.
• Letters should have been more descriptive of the works being carried out so
as to avoid confusion that all trees were being removed from the embankment.
• The words “Vegetation Clearance” are open to interpretation and very rarely mean
all vegetation. These have been changed to be more descriptive on our new
template.

42. and how we are making it better?
• Letters should have been distributed to affected residents 10 days in advance
of the works through our postal service – Via post.
• All larger scale vegetation works are to be notified to the MPC so that letters
can be sent out 14 days in advance as we do with all engineering projects or
road closures etc.
• Managing the publics expectations when stopping works was not handled
well.
• Information given to the public was reactive and did not explain that the site
must by law be left safe and that this may require a bit more time of noise to
achieve.

43. Questions & Answers

44. • THANK YOU FOR ATTENDING AND GOODNIGHT.