Environmental Statement Appendix 9 E (6.3.9.5 ...

Environmental Statement Appendix 9 E (6.3.9.5)

Arboricultural Impact Assessment

April 2016

Silvertown Tunnel

Appendix 9.E Arboricultural Impact Assessment

Document Reference: 6.3.9.5

THIS PAGE HAS INTENTIONALLY BEEN LEFT BLANK

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Contents Contents .................................................................................................................... 3

List of Abbreviations ................................................................................................ 5

1. INTRODUCTION ......................................................................................... 11

1.1 Background ................................................................................................. 11

1.2 Site Location and Setting ............................................................................ 11

1.3 Report Limitations ....................................................................................... 11

1.4 Summary of Tree Survey Report ................................................................. 12

1.5 Statutory Tree Protection ............................................................................ 12

2. ARBORICULTURAL IMPACT ASSESSMENT METHOD .......................... 13

2.2 Desk Top Study ........................................................................................... 13

3. ARBORICULTURAL IMPACTS .................................................................. 13

3.2 Tree Removals ............................................................................................ 13

3.3 Incursions within Root Protection Areas ...................................................... 16

3.4 Facilitation Pruning ...................................................................................... 16

3.5 Site Storage ................................................................................................ 16

3.6 Retained Trees ............................................................................................ 17

3.7 Bus Services ............................................................................................... 17

3.8 Shading and Seasonal Nuisance Issues ..................................................... 17

3.9 Mitigation ..................................................................................................... 17

4. FURTHER WORK ....................................................................................... 19

5. CONCLUSIONS .......................................................................................... 21

6. REFERENCES ............................................................................................ 22

Appendix A. Explanation of Terms ................................................................... 29

Appendix B. Tree Schedules............................................................................. 33

Appendix C. Protective Fencing Specification ................................................ 43

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List of Tables

Table 3-1: Trees to be removed ............................................................................... 14

Table 3-2: Groups of trees requiring part removed .................................................. 16

Table 6-1: Catergorisation of Trees .......................................................................... 30

Table 6-2: Tree Schedule ......................................................................................... 33

Table 6-3: Root Protection Area ............................................................................... 39

Table 6-4: Key to Categories .................................................................................... 41

List of Figures Figure 6-1 Tree Protection Plan ............................................................................... 23

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List of Abbreviations

AIA Arboricultural Impact Assessment

DCO Development Consent Order

EIA Environmental Impact Assessment

RPA Root Protection Area

TfL Transport for London

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Glossary of Terms

Blackwall Tunnel An existing road tunnel underneath the River Thames in east London, linking the London Borough of Tower Hamlets with the Royal Borough of Greenwich, comprising two bores each with two lanes of traffic.

Counterweight A weight used as a counterbalance

Desk top study A data collection exercise using existing sources of data. The purpose is to identify relevant known resources. The London Boroughs of Tower Hamlets, Greenwich and Newham.

Facilitation Pruning Pruning to reduce or raise the crown of a tree (according to good practice) to allow vehicular access for site works.

Jib The projecting arm of a crane

Mitigation Measures including any process, activity, or design to avoid, reduce, remedy or compensate for negative environmental impact or effects of a development. Indicative user charges for the scheme.

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Silvertown Tunnel Proposed new twin-bore road tunnels under the River Thames from the A1020 in Silvertown to the A102 on Greenwich Peninsula, East London.

Tree Preservation Order A TPO is made by a Local Planning Authority (usually a local council) to protect specific trees or a particular area, group or woodland from deliberate damage and destruction.

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https://en.wikipedia.org/wiki/Local_Planning_Authority

https://en.wikipedia.org/wiki/Local_Planning_Authority

https://en.wikipedia.org/wiki/Local_government_in_the_United_Kingdom

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SUMMARY

S.1.1 This Arboricultural Impact Assessment (AIA) presents the results of a desk top study in line with BS 5837:2012. This report should be read in conjunction with Appendix 9.D - Arboricultural Survey Report (Document Reference: 6.3.9.4).

S.1.2 The findings of this assessment are presented in a format intended to identify any impacts on existing trees from the proposed development and where existing and potential arboricultural constraints exist, thus informing appropriate provision for the integration of existing trees and mitigation measures.

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1. INTRODUCTION

1.1 Background

1.1.1 Arcadis was commissioned by Transport for London (TfL) to undertake an Arboricultural Impact Assessment in line with British Standard BS 5837:2012 Trees in relation to design, demolition and construction – Recommendations, henceforth referred to as BS 5837:2012, to inform an Environmental Impact Assessment (EIA) for the Silvertown Tunnel proposal.

1.2 Site Location and Setting

1.2.1 The proposed site is located in Silvertown on the north side of the Thames and Greenwich on the south side of the Thames. The site comprises of existing highways, carparks and parkland. The site has a mixture of trees of varying age, species and quality listed in the tree survey schedule, in Appendix B - Tree Schedules.

1.3 Report Limitations

1.3.1 Base mapping was provided without full locations of any site trees. As such Site trees and groups of trees were plotted using local land based features as reference points. For the purposes of BS 5837:2012, only trees with a stem diameter greater than 75mm, (measured at 1.5m above ground level), have been included within the survey; however, it should be noted that a number of individual trees and shrubs with a stem diameter of less than 75mm were present within the site.

1.3.2 Only trees within the likely influence of the proposed development have been included within this report. Any additional trees in the vicinity of the site have been deemed to not be affected by the proposals and have not been included.

1.3.3 The Root Protection Areas (RPAs) are based on a given tree’s stem diameter taken at 1.5 metres above ground level with each RPA (see Appendix B- Tree Schedules) being calculated from the above ground portions of the tree. It should be recognized that the RPA may not entirely encompass all of the trees rooting material.

1.3.4 Trees are living organisms and as such their health and condition are naturally subject to change over time. Unforeseen future circumstances such as neglect, wilful damage or severe/extreme weather conditions may affect the future health and condition of the trees included in this report.

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1.4 Summary of Tree Survey Report

1.4.1 A total of 35 arboricultural items were recorded within the site and are listed in Appendix B - Tree Schedules. They have been identified and assessed in accordance with BS 5837:2012 and categorised as 6 single ‘B’ grade trees, 4 ‘B’ grade groups, 11 single ‘C’ grade trees, 13 ‘C’ grade groups and 1 single ‘U’ grade tree.

1.4.2 All ‘B’ grade trees are of moderate quality and value and should be considered for retention where possible. The ‘C’ grade trees are of low quality and value and should not place a constraint on the proposals. From an arboricultural point of view the ‘U’ grade trees, with a life expectancy of less than 10 years due to their poor condition, cannot realistically be considered for retention as a living tree in the context of the current land use.

1.5 Statutory Tree Protection

1.5.1 None of the trees on site are subject to a Tree Preservation Order or within a Conservation Area.

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2. ARBORICULTURAL IMPACT ASSESSMENT METHOD

2.1.1 This is a desk based study, undertaken by an arboriculturist, to identify, and evaluate the extent of direct and indirect impacts on existing trees that may arise as a result of the implementation of proposed development. The AIA may also include identification of mitigation measures.

2.1.2 As yet the potential impacts do not include those associated with the construction footprint.

2.2 Desk Top Study

2.2.1 A review of field data and design drawings was undertaken in order to assess the arboricultural impacts of the proposed development. Including the Silvertown Tree Constraints Plan, Arboricultural Survey Report (Appendix 9.D (Document Reference: 6.3.9.4)), Land Plans and Potential Landscaping Areas.

3. ARBORICULTURAL IMPACTS

3.1.1 Development can have an adverse impact on trees and other woody vegetation within a site. This can result in: (1) immediate vegetation removal to facilitate the footprint of a new development; (2) potential future tree loss through the early decline of trees due to soil compaction; and (3) root disturbance and damage within a trees rooting area.

3.2 Tree Removals

3.2.1 A total of 11 individual trees and 12 groups of trees are within, or immediately adjacent to the footprint of the proposed development and will need to be removed (listed in Table 3-1).

3.2.2 One group of trees detailed in Table 3-2 will be directly impacted and will need to be partially removed.

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Table 3-1: Trees to be removed

Tree No. Species Grade

G4 Flowering pear (Pyrus calleryana) x 12

C2

T5 Sycamore (Acer pseudoplatanus) C1

G6 Flowering pear (Pyrus calleryana) x 18, Cherry (Prunus sp.) x 3, Blackthorn (Prunus spinosa) x 8

C2


C2

T8 Cherry (Prunus sp.) C1

G9 Silver birch (Betula pendula) x 50, Sycamore (Acer pseudoplatanus) x4

C2

G10 Silver birch (Betula pendula) x 80 C2

G13 London plane (Platanus × hispanica) x 12, Black locust (Robinia pseudoacacia) x 24, Ash (Farxinus excelsior) x 12, Willow (Salix spp.) x 8

C2

G16 London plane (Platanus x hispanica) x 7

B2

T17 False acacia (Robinia pseudoacacia)

C1

T18 Cockspur thorn (Crataegus crus-galli)

C1

T19 Silver birch (Beltula pendula) C1

T20 Cherry (Prunus sp.) C1

G22 Silver birch (Beltula pendula) x 3 U

T23 London plane (Platanus x B1

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Tree No. Species Grade

hispanica)

T24 Elder (Sambucus nigra) C1

T25 Common walnut (Juglans regia) B1

T26 Sycamore (Acer pseudoplatanus) C1

G27 Sycamore (Acer pseudoplatanus) x 12, Silver birch (Belula pendula) x 3, Elder (Sambucus nigra) x 6

C2

G29 Sycamore (Acer pseudoplatanus) x 4

C2

G32 Willow (Salix spp) x 3 oak (Quercus spp) x 15

C2


C2

T34 London plane (Platanus x hispanica)

B1

T35 River birch (Betula nigra) B1

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Table 3-2: Groups of trees requiring part removed

(All percentages and tree numbers shown for removal are approximate)

Tree No.

Species Number / % requiring Removal

Grade


72% C2

3.3 Incursions within Root Protection Areas

3.3.1 There will be some incursions/excavations within the RPA of group G14 (percentages to be confirmed), however the new hard surface should not exceed 20% of any existing unsurfaced ground within the RPA. To mitigate any potential impact on the trees, a method statement should be provided by the contractor to demonstrate that all operations proposed within the RPAs can be undertaken to ensure their safe protection and retention. Where trees are to be retained the works should be supervised by a competent arboriculturist, and hand digging should be undertaken if any excavations are to be undertaken within the RPA, particularly where there is potentially a greater risk of root damage occurring to trees by virtue of their age/size and close proximity to the development. No roots over 25mm in diameter should be severed without prior consultation with a competent arboriculturist.

3.4 Facilitation Pruning

3.4.1 Based on the information currently available, it is not possible to predict the requirement for access facilitation pruning. Any requirements for access facilitation pruning should be discussed at a pre-commencement meeting with the project arboriculturalist.

3.4.2 Site operations involving plant with booms, jibs and counterweights should be planned in advance to prevent contact with retained trees. All operations involving such plant in close proximity to trees should be conducted under the supervision of a banksman to ensure that adequate clearance from the retained trees is maintained.

3.5 Site Storage

3.5.1 The exact locations of site compounds and storage areas are not known at the time of writing this report. Adequate allowance for and the planning of

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such items should be made to avoid encroachment with the RPAs of, or prevent direct contact with, all retained trees on site.

3.6 Retained Trees

3.6.1 The remaining trees are to be incorporated into a new landscaping Scheme, as described in Chapter 4 – Scheme Description (Document Reference: 6.1.4). The existing ground levels within the RPAs of the retained trees are to be maintained. If a change in ground levels cannot be avoided then early consultation with an Arboricultural Consultant should be sought.

3.6.2 All retained trees on site will require adequate protective fencing as detailed in Appendix C- Protective Fencing Specification and will need to be installed before any materials and machinery are brought on site. The alignment of the protective fencing is shown on Figure 6-1.The fencing should remain intact throughout the duration of the scheme and only be removed upon completion. All weather notices should be placed on the fences that clearly indicate ‘NO ACCESS’(See examples in Appendix C - Protective Fencing Specification).

3.7 Bus Services

3.7.1 Details of the routing of bus services for the proposed development are not currently available. Once details of the routing of new services become available, prior to commencement, these should be reviewed by the project arboriculturalist.

3.8 Shading and Seasonal Nuisance Issues

3.8.1 The proposed development is non-residential and as such there would be no future pressures placed on the retained tree stock resulting from excessive shading of dwellings or gardens or other pressures associated with residential developments and future tree growth. The design is expected to withstand any impacts from any future root growth or secondary thickening within its operational life time. However it is likely that tree produced debris such as leaf fall and the dropping of fruit and seeds would have a limited influence on the end use of the proposed development but as this is a natural phenomenon it should be treated as a regular maintenance issue.

3.9 Mitigation

3.9.1 The trees listed in Table 3-1 and Table 3-2 are located within or directly adjacent to the proposed development footprint and will need to be removed. The loss of these trees can be mitigated by appropriate replacement tree

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planting as part of the scheme. An arboriculturist should be involved in deciding on the suitability of replacement species, their location, potential ultimate size, life span, shade tolerance and growth habits.

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4. FURTHER WORK

4.1.1 It is recommended that the final landscape design has input from an arboriculturalist. When construction access and storage and compounds have been resolved additional AIA will be undertaken and a finalised Tree Protection Plan. Supervision and monitoring of works will be carried out by a competent arboriculturist at an interval agreed at a pre-commencement site meeting. The interval should be sufficiently flexible to allow the supervision of key works as they occur. The arboriculturist’s role would be to monitor compliance with arboricultural conditions and advising on any tree problems that arise or modifications that become necessary.

4.1.2 The key stages requiring supervision should be agreed at a pre-commencement site meeting, but will usually include:

• installation of tree protection barriers;

• installation of ground protection; and

• regular monitoring of compliance.

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5. CONCLUSIONS

5.1.1 Consideration has been given to retaining trees, where appropriate, across the scheme depending on their general condition and value. However, ultimately their removal is dependent on their close proximity to the footprint of the proposed development and a final Tree Protection Plan should be provided when details of the Scheme construction footprint and permanent footprint are evolved.

5.1.2 A total of 35 trees and groups of trees are located within or directly adjacent to the proposed development footprint. Of these 11 trees and 13 groups of trees will need to be removed or partly removed (listed in Table 3-1and Table 3-2) 5 of these arboricultural items to be removed are B Grade. The loss of these trees can be mitigated by appropriate replacement tree planting as part of the scheme. A tree replacement strategy should be implemented with consideration given to species selection (in relation to form and potential size) and planting locations to ensure their successful integration into the new development.

5.1.3 It is recommended that adequate protective fencing as detailed in Appendix C - Protective Fencing Specification is installed around all retained trees before any materials and machinery are brought on site. Site operations involving plant with booms, jibs and counterweights should be planned in advance to prevent contact with retained trees. All operations involving such plant in close proximity to trees should be conducted under the supervision of a banksman to ensure that adequate clearance from the retained trees is maintained.

5.1.4 All tree works must be carried out by a qualified contractor in accordance with BS3998:2010: Tree Work – Recommendations.

5.1.5 Prior to undertaking any tree works recommended in this report, it is essential that the trees are assessed by a suitably competent ecologist for the presence of nesting birds and protected species such as bats. See Chapter 9 – Terrestrial Ecology (Document Reference: 6.1.9) for legislative compliance requirements.

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6. REFERENCES

British Standards Institution (2012) BS 5837: 2012 ‘Trees in relation to design, demolition and construction – Recommendations’. BSI, London, UK.

British Standards Institution (2010) BS 3998:2010, Tree Work Recommendations. BSI, London, UK.

Mattheck, C. and Broeler, H. (1994) The Body Language of Trees: A Handbook for Failure Analysis Research for Amenity Trees No.4. DETR, London, UK.

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Figure 6-1 Tree Protection Plan

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Appendix A. Explanation of Terms

A.1 Age Class

Young – Trees in the first fifth of full life expectancy

Semi-mature – Trees in the second fifth of full life expectancy

Early-mature – Trees in the third fifth of full life expectancy

Mature – Trees in the fourth fifth of full life expectancy

Over Mature – Trees having reached full life expectancy and trees in natural decline

Veteran – Trees of interest biologically, culturally and aesthetically because of their age

A.2 Stem Diameter

The diameter of the stem measured in millimetres (mm) at a height of 1.5m above ground level

A.3 Crown Spread

Average measured in metres using a ground tape where possible.

A.4 Physiological Condition

Good – Healthy tree with no signs of ill health and signs of good extension growth for species

Fair – Trees with signs of disease, minor defects and decreased life expectancy due to physical damage

Poor – Trees with significant disease, significantly reduced life expectancy and/or under major physiological stress

Dead – Dead tree or trees with over 70% crown dieback

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A.5 Structural Condition

Good – Trees with no significant defects

Fair – Trees with remedial defects which require minor tree surgery works

Poor – Trees with remedial defects which require significant tree surgery works or felling

Dead – Trees which require felling

A.6 BS 5837:2012 Retention Category

Each tree, group of trees or hedge is assigned to a retention category where:

Table 6-1: Catergorisation of Trees

Category Description

A Trees of high quality and value, retention is highly desirable

B Trees of moderate quality and value where retention is desirable

C

Trees of low quality and value, or young trees with a stem diameter <150mm. Category C trees may be retained, replaced or in the case of younger trees, relocated

U Trees unsuitable for retention or trees which should be removed

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In addition, each tree, group of trees or hedge is assigned to a retention sub-category where categorisation is for:

Sub-category Reason for Categorisation

1 Mainly arboricultural qualities

2 Mainly landscape qualities

3 Mainly cultural values, including conservation

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Appendix B. Tree Schedules

Table 6-2: Tree Schedule

Tree reference number

Species Height (m)

Stem diameter

(mm)

Branch spread (m)

Height of crown

clearance (m)

Age class

Physiological condition

Structural condition

Preliminary management

recommendations

Estimated remaining

contribution (years)

Category grading

N E S W

T1 Cherry (Prunus sp.)

8 300 4 4 4 4 2 EM Fair Fair None 10+ C1

G2 Elder (Sambucas nigra) x 2

5 250 av 2 2 2 2 0 M Fair Fair None <10 C3


8 200 2 2 2 2 2 Y Fair Fair None 10+ C1


5 100 av 1 1 1 1 2 Y Fair Fair None 20+ C2

T5 Sycamore (Acer pseudoplatanus)

8 300 4 4 4 4 1 SM Fair Fair None 20+ C1

G6 Flowering pear (Pyrus calleryana) x 18, Cherry (Prunus sp.) x 3, Blackthorn

4 100 av 1 1 1 1 1 Y Good Good None 20+ C2

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Species Height (m)

Stem diameter

(mm)

Branch spread (m)

Height of crown

clearance (m)

Age class




recommendations

Estimated remaining


Category grading

(Prunus spinosa) x 8


5 100 av 1 1 1 1 1 Y Good Good None 20+ C2


4 150 3 3 3 3 0 SM Good Fair None 20+ C1

G9 Silver birch (Betula pendula) x 50, Sycamore (Acer pseudoplatanus) x4

6 120 av 1 1 1 1 1 Y Good Fair – Amenity planting with poor stem taper

None 20+ C2

G10 Silver birch (Betula pendula) x 80

7 120 av 1 1 1 1 1 Y Good Fair – Amenity planting with poor stem taper

None 20+ C2

G11 London plane (Platanus × hispanica) x 5

14 400 av 5 5 5 5 3 EM Good Fair None 40+ B2

G12 White polar (Populus alba) x6, Ash (Fraxinus

18 270 av 4 4 4 4 2 EM Fair Fair None 10+ C2

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Species Height (m)

Stem diameter

(mm)

Branch spread (m)

Height of crown

clearance (m)

Age class




recommendations

Estimated remaining


Category grading

excelsior) x 3

G13 London plane (Platanus × hispanica) x 12, Black locust (Robinia pseudoacacia) x 24, Ash (Farxinus excelsior) x 12, Willow (Salix spp.) x 8

16 200 av 4 4 4 4 1 SM Fair Fair - Amenity planting with poor stem taper

None 20+ C2


14 650 av 4 4 4 4 4 EM Fair Fair - Trees within pollard regime

None 40+ B2


5 140 2 2 2 2 2 Y Fair Fair None 20+ C1


16 650 av 5 5 5 5 3 EM Fair Fair None 40+ B2



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Species Height (m)

Stem diameter

(mm)

Branch spread (m)

Height of crown

clearance (m)

Age class




recommendations

Estimated remaining


Category grading


5 180 2 2 2 2 2 EM Fair Fair None 10+ C1

T19 Silver birch (Beltula pendula)

5 210 2 2 2 2 3 SM Fair Fair - Suppressed by G16

None 10+ C1

T20 Cherry (Prunus sp)

8 430 5 5 5 5 3 M Fair Fair None 10+ C1


10 300 3 3 3 3 3 SM Fair Fair - In contact with CCTV

None 40+ B1

G22 Silver birch (Beltula pendula) x 3

3 90 av 1 1 1 1 1 Y Poor Poor - 50% crown dieback

None <10 U


14 680 3 3 3 3 5 EM Fair Fair – Tree within pollard regime

None 40+ B1

T24 Elder (Sambucus nigra)

6 250 est 3 3 3 3 3 M Fair Fair None 10+ C1

T25 Common walnut (Juglans regia)

13 400 est 6 6 6 6 3 EM Fair Good None 40+ B1

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Species Height (m)

Stem diameter

(mm)

Branch spread (m)

Height of crown

clearance (m)

Age class




recommendations

Estimated remaining


Category grading



G27 Sycamore (Acer pseudoplatanus) x 12, Silver birch (Belula pendula) x 3, Elder (Sambucus nigra) x 6

12 250 av 3 3 3 3 2 SM Fair Fair None 20+ C2

T28 Elm (Ulmus sp.) 12 430 4 4 4 4 2 EM Fair Good None 40+ B1




17 600 av 6 6 6 6 3 EM Fair Fair – Ivy covering main stems and lower crown

None 40+ B2



G32 Willow (Salix spp) x 3 oak (Quercus spp.) x

15max 250 av 3 3 3 3 2 SM Fair Fair None 20+ C2

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Species Height (m)

Stem diameter

(mm)

Branch spread (m)

Height of crown

clearance (m)

Age class




recommendations

Estimated remaining


Category grading

15




10 400 5 5 5 5 2 EM Fair Good None 40+ B1

T35 River birch (Betula nigra)

6 200 3 3 3 3 2 SM Fair Good None 20+ B1

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Table 6-3: Root Protection Area

Tree reference number Species Stem diameter

(mm)

Radius of nominal circle (m)

RPA (m2)

T1 Cherry (Prunus sp) 300 3.6 40.7

G2 Elder (Sambucas nigra) x 2 250 av 3.0 28.3

T3 Cherry (Prunus sp.) 200 2.4 18.1


100 av 1.2 4.5

T5 Sycamore (Acer pseudoplatanus) 300 3.6 40.7

G6

Flowering pear (Pyrus calleryana) x 18, Cherry (Prunus sp.) x3, Blackthorn (Prunus spinosa) x8

100 av 1.2 4.5


100 av 1.2 4.5

T8 Cherry (Prunus sp) 150 1.8 10.2

G9

Silver birch (Betula pendula) x 50, Sycamore (Acer pseudoplatanus) x4

120 av 1.44 6.5

G10 Silver birch (Betula pendula) x 80 120 av 1.44 6.5

G11 London plane (Platanus × hispanica) x 5

400 av 4.8 72.4

G12

White polar (Populus alba) x6, Ash (Fraxinus excelsior) x3

270 av 3.24 33.0

G13

London plane (Platanus × hispanica) x 12, Black locust (Robinia

200 av 2.4 18.1

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(mm)


RPA (m2)

pseudoacacia) x 24, Ash (Farxinus excelsior) x12, Willow (Salix spp.) x8


650 av 7.8 191.1


140 1.68 8.9


650 av 7.8 191.1


370 4.44 61.9


180 2.16 14.7

T19 Silver birch (Beltula pendula)

210 2.52 20.0


430 5.16 83.6


300 3.6 40.7

G22 Silver birch (Beltula pendula) x 3

90 av 1.08 3.7


680 8.16 209.2

T24 Elder (Sambucus nigra)

250 est 3.0 28.3

T25 Common walnut (Juglans regia)

400 est 4.8 72.4


360 4.32 58.6

G27 Sycamore (Acer 250 av 3.0 28.3

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(mm)


RPA (m2)

pseudoplatanus) x 12, Silver birch (Belula pendula) x 3, Elder (Sambucus nigra) x 6

T28 Elm (Ulmus sp.) 430 5.16 83.6


120 av 1.44 6.5


600 av 7.2 162.9


150 av 1.8 10.2

G32 Willow (Salix spp) x 3 oak (Quercus spp) x 15

250 av 3.0 28.3


150 av 1.8 10.2


400 4.8 72.4

T35 River birch (Betula nigra)

200 2.4 18.1

Table 6-4: Key to Categories

Tree Reference Number Category

T/GXX Category A

T/GXX Category B

T/GXX Category C

T/GXX Category U

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Appendix C. Protective Fencing Specification

Default specification for protective barrier – (Figure 2 BS 5837 2012 Trees in relation to design, demolition and construction recommendations).

Key

1 Standard scaffold poles

2 Heavy gauge 2 m tall galvanized tube and welded mesh infill panels

3 Panels secured to uprights and cross-members with wire ties

4 Ground level

5 Uprights driven into the ground until secure (minimum depth 0.6m)

6 Standard scaffold clamps

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Stabilizer Strut – (Figure 3 BS 5837 2012 Trees in relation to design, demolition and construction recommendations).

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C.1 Example of Protective Fencing Signs

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