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Transport for London
London Underground
Category 1 Standard
1-026 Topographical Surveys and Mapping
Issue No.: A2 MAYOR OF LONDON
Issue date: Review date:
March 2011 March 2016
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
Contents
1 Purpose ______________________________________________________________________ 3 2 Scope _______________________________________________________________________ 3 3 Requirements _________________________________________________________________ 3
3.1 London Survey Grid and datum ______________________________________________ 3 3.2 Ordnance Survey mapping _________________________________________________ 6 3.3 Topographical surveys _____________________________________________________ 7 3.4 Digital tunnel outline maps __________________________________________________ 9 3.5 Information management __________________________________________________ 11 3.6 Evidence of compliance ___________________________________________________ 11 4 Responsibilities _______________________________________________________________ 11 5 Supporting information _________________________________________________________ 12 5.1 Background ____________________________________________________________ 12 5.2 Safety considerations_____________________________________________________ 12 6 Reference Section_____________________________________________________________ 12 6.1 References_____________________________________________________________ 12 6.2 Abbreviations ___________________________________________________________ 12 6.3 Definitions _____________________________________________________________ 13 6.4 Technical content manager ________________________________________________ 14 6.5 Document history ________________________________________________________ 14 7 Attachments _________________________________________________________________ 15 7.1 London Survey Grid Scale Factors __________________________________________ 15 7.2 British National Grid (OSGB36) to London Survey Grid transformation blocks _________ 16 7.3 Factors for conversion between London Survey Grid and British National Grid ________ 17 7.4 London Survey Grid to JLE grid transformation block ____________________________ 18 7.5 Factors for conversion between London Survey Grid and JLE grids _________________ 19 7.6 Primary Control Survey Stations ____________________________________________ 20 7.7 Form to request the supply of Ordnance Survey digital data _______________________ 21 7.8 Typical items for inclusion in a model survey specification ________________________ 22 7.9 Survey station records ____________________________________________________ 24 7.10 Sample survey reference box ______________________________________________ 26 7.11 The Ordnance Survey Contractor Licence Agreement ___________________________ 27
Reference: 1-026 A2
Page 2 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
1 Purpose
1.1
The purpose of this standard is to define the requirements for and the procedures for
performing and recording topographical surveys and to define the controls on the use
of Ordnance Survey (OS) mapping.
2 Scope
2.1
The scope of this standard is to define:
a) the requirements for topographical surveys and mapping performed by LU and its Suppliers surveying LU fixed assets;
b) the requirements for topographical surveys and mapping for projects promoted by LU or its Suppliers on land and assets not currently owned by LU and;
c) the procedures to control the use of OS mapping and other OS survey products that are licensed to LU.
2.2
This standard replaces 1-026 A1
3 Requirements
3.1 London Survey Grid and datum
3.1.1 3.1.1.1
London Survey Grid (LSG) definition
All topographical survey and mapping work shall be reported on the London Survey Grid.
Note:
The London Survey Grid is a Transverse Mercator Projection with parameters chosen to minimise grid distortion caused by the Earth’s curvature over the LU area. The distortion is such that for large portions of the area projection corrections can be ignored. The Grid was formerly known as the LU Grid, the LUL Grid or the Crossrail Grid
A network of primary survey stations with London Survey Grid co-ordinates has been established across London.
3.1.1.2 LSG height datum shall be used. The LSG height datum level is set at approximately 100m below OS Datum at Newlyn.
Note:
The LSG height datum is an orthometric height datum chosen to provide positive values for areas of interest to LU. This datum is realised by the network of OS benchmarks that have been connected by spirit levelling to LU survey control points. . In areas that will interface with Crossrail projects the Crossrail First Order benchmarks should be used. Trials in 2009 indicated that GPS survey heights can be transformed using the Ordnance Survey Geoid Model 2002 (OSGM02), plus the 100m shift, to produce acceptable LSG Height Datum values
Reference: 1-026 A2
Page 3 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
The London Survey Grid is defined by the following parameters:
Parameter
Value
Spheroid
WGS 84
Semi major axis
6,378,137.000m
Semi minor axis
6,356,752.3142m
1/f (f = earth’s flattening)
298.25722356300
e
0.00669437999013
Datum
Xrail84 *
Projection
Transverse Mercator
Central meridian
W000°-09’-30”
Latitude of true origin
N051°-10’-00”
Easting of true origin/ central meridian
78,250.000m
Northing of true origin
-2,800.000m
Central meridian scale factor
0.9999999

Xrail84 * = Datum as derived by the Crossrail project in 1984.
3.1.2 Grid computation 3.1.2.1 Distances shall be reduced to the WGS 84 spheroid. 3.1.2.2 The London Survey Grid scale factors given in Attachment 7.1 shall be used.
3.1.3 Relationships between London Survey Grid and other grids
3.1.3.1 Ordnance Survey grid (also known as the British National Grid or OSGB36) 3.1.3.1.1 The formulae in Tables 1 and 2 in Attachment 7.3 shall be used for conversion of OS
mapping to and from London Survey Grid within the areas shown in Attachment 7.2. These formulae are accurate to a commensurate standard as the OS mapping ie +/400mm.
3.1.3.1.2 To obtain more precise conversions of existing survey information held on the OS grid a local best fit formula shall be derived from the nearest primary or other common survey control stations.
3.1.3.2 JLE grid
The formulae in Tables 3 and 4 in Attachment 7.5 shall be used for conversion of JLE digital data to and from London Survey Grid within the areas shown in Attachment 7.4.
Note:
Automation of conversion. LU holds a grid converter utility designed to convert MicroStation 2D and 3D design files from one co-ordinate system to another. It will change a file’s scale, rotation, location, working units and global origin.
3.1.4 3.1.4.1
Control surveys
Primary Control stations consist of the original control points that were used as a basis for the Crossrail and Earth Structures Projects and were confirmed by the 2002 reobservation programme. These are considered to be permanent points in long term stable locations. The co-ordinate values shall not be changed without an amendment to this standard. These surveys have been computed as a single coherent system known as the London Survey Grid based on WGS84. Transformation parameters have been established to the National Grid (OSGB36). In 2002 a re-observation program was carried out by LU which proved the consistency of the original work and established transformation parameters to ETRS89. Further analysis by Prof Marek
Reference: 1-026 A2
Page 4 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
Ziebart of University College London in April 2009 confirmed the transformation parameters. The list of Primary control points is included as Attachment 7.6
Note: Primary Control Surveys have been carried out for the Crossrail Project and the LU Earth Structures Project.
3.1.4.2
Secondary control points consist of control schemes that are based on Primary control and have been adjusted by a rigorous method. These control points shall be permanent points in long term stable locations. The co-ordinate values may be varied as a result of re-observation and re-computation. Such variations shall only be introduced after the LU Land Survey Manager has notified all parties that have received a controlled issue of this information and no objections have been raised. Secondary control points shall be the minimum requirement for surveys in project interface areas.
3.1.4.3
Third order control points consist of control schemes that are based on any combination of Primary, Secondary or Third Order control and have been adjusted by a rigorous method. The control points shall be established to be durable and stable for the duration of the project. The project surveyor may only vary the co-ordinate values as a result of re-observation and re-computation in which case the point will be renumbered. The LU Land Survey Manager shall distribute revised values to parties that have received a controlled issue of this information.
3.1.4.4
Fourth order control points consist of control schemes that are based on any combination of Primary, Secondary or Third Order control. The control points may be in situation where the durability or stability is doubtful or where conditions have prevented a rigorous regime of observation and computation. The project surveyor may vary the co-ordinate values as a result of re-observation and re-computation. The LU Land Survey Manager shall not further distribute this information.
3.1.5
GPS and ETRS89 The following Seven Parameter Transformation shall be used when converting ETRS89 data onto the London Survey Grid based on the Geoid model OSGM02
Method Rotation about x axis Rotation about y axis Rotation about z axis Translation along x axis Translation along y axis Translation along z axis Scale factor (PPM)
Seven Parameter -0°00'03.577824" 0°00'03.484437" 0°00'02.767646"
19.019m 115.122m -97.287m 18.60847540
Note: Note:
The convention used for the rotations is that a positive rotation acts in a clockwise sense as viewed along the rotation axis looking towards the origin. Checks should be made to ensure that this notation is used correctly.
GPS has been used to establish the entire primary control network, and is now routinely used for survey work. The transformation parameters between London Survey Grid and ETRS89 allow the use of recorded base station data from the National GPS Network service.
Reference: 1-026 A2
Page 5 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
3.2 Ordnance Survey mapping
3.2.1 3.2.1.1
Supply of data
LU shall supply OS data for use on projects related to LU infrastructure and operations.
3.2.1.2 LU departments and suppliers wishing to obtain OS digital data and copyright licensing shall contact the LU Land Survey Data Manager.
3.2.1.3 Requests shall be submitted in the form given in Attachment 7.7
3.2.1.4
Suppliers shall enter into a Contractor Licence Agreement with the LU Land Survey Data Manager and abide by the copyright conditions as described in the Appendix 1 Licensed Use of the Public Sector Mapping Agreement (PSMA) Member Licence. The current form of Contractor Licence Agreement and copyright conditions are to be found in Attachment 7.11.
3.2.1.5 The recipient of data issued by LU shall acknowledge receipt within 10 working days.
3.2.1.6 The LU Land Survey Data Manager shall maintain records of requests for OS data and issue data in a controlled manner.
Note:
LU has a licence for the business use of OS digital data, which falls under the Copyright, Designs and Patents Act. Failure to comply with this procedure could lead to an infringement of Crown copyright which is a criminal offence under the Act, and would also lead to the loss of LU’s licence and expose the company to civil proceedings for damages.
3.2.2 3.2.2.1
Copyright requirements
LU is a party to the TfL member licence to use OS data under the PSMA for the supply and use of digital data and licensing of copyright works.
3.2.2.2 Users of OS data shall abide by the terms of the agreement which shall be for Internal Business Use (including display and promotion) and limited internet applications only.
Note:
There is a Public Sector Mapping Agreement between the DCLG and OS for the supply of OS mapping data to all public bodies. LU receives data licensed under this agreement through TfL. The Public Sector Mapping Agreement, which may be varied from time to time, at present, includes the provision of the products listed in table below. Additional products are now made available free to use known as OS Open Data. All products are available free of charge and can be supplied as national coverage.
The Public Sector Mapping Agreement, which may be varied from time to time, at present, covers the provision of the following:
PSMA data Product MasterMap; Topography
MasterMap; Integrated Transport Network inc. Road Routing Information 1:10,000 Raster 1:50,000 Raster
Update Cycle On Line, Change only update On Line, Change only update
Annual, Change only update Annual, Change only update
Notes To be withdrawn in 2013
Reference: 1-026 A2
Page 6 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
PSMA data Product Address-Point
Code Point Code Point with Polygons 1:25,000- Raster Vector Map Local OpenData Product 1:50,000 Scale Gazetteer 1:250,000 Colour Raster Boundary-Line Code-Point Open Land-Form Panorama Meridian 2 MiniScale OS Locator Strategi Vector Map District Street View
Update Cycle Quarterly
Quarterly 6 Monthly
Annual Annual Update Cycle Annual, Change only update
Annual 6 Monthly Quarterly Not Maintained 6 Monthly Annual 6 Monthly Annual Not specified 6 Monthly, Change only update
Notes To be replaced by National Address Gazetteer in 2011
Notes
3.3
3.3.1 3.3.2
3.3.3
Note:    
  
Topographical surveys
The Supplier shall appoint a Survey Co-ordinator / Project Manager
The Supplier shall advise the LU Land Survey Manager of the nominated Survey Coordinator/Project Manager.
The Supplier’s Survey Co-ordinator shall prepare and promote model specifications for the various types of survey carried out.
The following surveys are typically used:
Land surveys;
Building surveys:
Un-connected survey – Using simple methods which do not enable one part of the survey to be related to another, this would not normally be acceptable for LU work;
Semi-connected survey – One floor (normally the ground floor) is surveyed with all parts connected by instrumental control. Other floors are matched by assuming verticality of common features;
Fully connected survey – All floors are instrumentally related to a common survey control framework.
Buried utilities surveys:
Record information – Underground service information to be taken from statutory or other authorities' record drawings and plotted to agree as closely as possible with surveyed surface features;
Direct visual surveys – Accessible inspection chamber covers should be lifted where permissible and services positively identified;
Reference: 1-026 A2
Page 7 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
       3.3.4
3.3.5
Direct visual surveys supplemented by record drawings – Accessible inspection chamber covers should be lifted where permissible and services positively identified. Routes of services between access points to be taken from record drawings and plotted to agree as closely as possible with surveyed surface features and trench scars where obvious;
Full investigation including electronic tracing – Services to be fully investigated by visual survey supplemented by electronic, or other tracing of inaccessible routes.
Track Surveys
Detailed surveys of track alignment for track design purposes
Clearance surveys to establish the clearance between line side objects and rolling stock
Scanned Surveys
Track trolley mounted scan surveys
Tripod mounted static scan surveys
The items listed in Attachment 7.8 are typical items for inclusion in the model specifications.
The Supplier shall establish procedures to record and monitor survey activities.
3.3.6 3.3.6.1
Survey control
The Supplier’s Survey Co-ordinator shall obtain a list of relevant LU survey stations from the LU Land Survey Data Manager.
3.3.6.2 The Suppliers Survey Co-ordinator shall advise the LU Survey Manager in writing of any inconsistencies or inaccuracies found in the information supplied by the LU Survey Data Manager.
3.3.7
Survey requirements
The survey requirements will be defined in the site specific survey specification. The following should be used as guidance for minimum standards:
3.3.7.1 The maximum planimetric error between permanent survey control stations shall not exceed 1 part in 20,000 for distances exceeding 200 metres. For shorter distances the maximum error shall not be greater than 10mm.
3.3.7.2 The height difference between any two points used as permanent bench marks shall not be in error by more than ± 12 x k mm, where k is the square root of the distance in kilometres between the points being considered, or ± 5mm, whichever is the greater.
3.3.7.3
For Land Surveys:
a) The accuracy of planimetric detail shall be such that the plan position of any well defined point of detail shall be correct to within 0.3mm r.m.s.e. at the plan scale when checked from the nearest permanent control station;
b) Ground survey spot levels on hard surfaces shall be correct to ± 10mm r.m.s.e. and elsewhere to ± 50mm r.m.s.e., except on ploughed or otherwise broken surfaces;
c) At least 90% of all contours shall be correct to within one half of the specified contour interval;
d) Any contour which can be brought within this vertical tolerance by moving its plotted position in any direction by an amount equal to 1/10th of the horizontal
Reference: 1-026 A2
Page 8 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
3.3.7.4
distance between contours, or 0.5mm at plan scale, whichever is the greater, shall be considered as correct.
For Building Surveys:
a) The maximum error between permanent survey control stations shall not exceed ± 5mm or 1 part in 10,000 for distances exceeding 50 metres;
b) The height difference between any two points used as permanent bench marks shall not be in error by more than ± 3mm on any floor or by more than ± 1.5mm per metre of height between floors;
c) In fully-controlled surveys the absolute plan position of well defined detail shall be accurate to ± 15mm at 1:50 scale or ± 30mm at 1:100 scale, when checked from the nearest survey control station on that floor;
d) Directly measured figured dimensions shall be quoted to the nearest 0.01 metre;
e) The quoted level of any feature relative to the nearest bench mark on that floor shall be to ± 5mm.
3.3.8 Survey report 3.3.8.1 The Supplier shall ensure a technical report is prepared for each survey.
3.3.8.2 The technical report shall confirm that the survey meets the requirements as laid down in the site specific survey specification.
Note: The technical report is intended to assist future users in making a judgement about the suitability, quality and accuracy of the survey.
3.3.8.3 The report shall contain details of control points established during the survey.
3.3.8.4 A Survey Station record sheet shall be prepared for each control point which shall contain the information highlighted in Appendix 7.9 and may also contain additional information and photographs.
3.3.8.5 Survey Control point details shall be delivered as a spreadsheet in the form given in Attachment 7.9.
3.3.9 3.3.9.1
Retention of survey information
Survey information shall be retained in a form compliant with the LU Standard 1-691 (Information).
3.3.9.2 CAD information shall comply with LU Standard 1-037 (Computer Aided Design Data).
3.3.9.3 The Supplier’s Survey Co-ordinator shall be the custodian of the survey information, and shall supply a copy of the information to the LU Land Survey Manager within one month of completion of the survey.
Note:
The LU Land Survey Manager may release this information, without reference to the Supplier, or their Surveyor, subject to such rules and conditions as may be determined by LU and the requirements of the Freedom of Information Act and the Environmental Information Regulations. Surveys shall be procured so that the IPR in the survey information is vested in LU and IPR issues are not an inhibitor to the free use of survey information within LU..
3.4 Digital tunnel outline maps
Note:
The LU Land Survey Manager is required to maintain maps to show the outline of the London Underground tunnels to supply to internal and external bodies legitimately requiring information about the location of LU infrastructure.
Reference: 1-026 A2
Page 9 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
3.4.1 3.4.1.1
Preparation of digital tunnel outline maps
Tunnel outline map files shall be prepared as digital files in Bentley MicroStation Design file (.dgn) format.
3.4.1.2 Individual files shall represent a single line of the Underground network.
3.4.1.3 Separate tunnel outline map files shall be held in two dimensional and three dimensional design file format.
3.4.1.4 Filenames shall use the three letter abbreviation for the line followed by a 2 or 3 to indicate a 2D or 3D file followed by TNL to indicate a Tunnel file, followed by the extension .dgn to indicate a MicroStation design file, e.g. BAK2TNL.dgn
3.4.1.5 The running tunnels and cross passages shall be represented by separate lines showing:
a) intrados at horizontal axis; b) extrados at horizontal axis; c) extrados at tunnel crown; d) intrados at tunnel crown; e) running edge of rails.
3.4.1.6 Tunnel crown levels related to LU Datum shall be recorded at significant points on the tunnel maps, e.g. changes in section.
3.4.1.7 The following shall be recorded for tunnel linings at change of section and at no greater than 200m intervals:
a) construction material; b) bolted or expanded; c) nominal internal diameter; d) nominal external diameter.
3.4.1.8 A survey reference box shall be displayed adjacent to the survey area, summarising relevant survey reference information.
Note: This information should include: a) survey drawing numbers, dates, authors; b) revision and approval dates; c) general notes and remarks.
A sample survey reference box is shown in Attachment 7.10.
3.4.1.9 The extent of each survey shall be shown with survey flags, annotated where necessary to identify overlapping surveys.
3.4.2
Updating tunnel outline map The Supplier shall notify LU of updates of the tunnel maps produced from information from measured surveys within one month following their preparation.
Reference: 1-026 A2
Page 10 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
3.5 Information management
3.5.1 3.5.1.1
Survey data
The Supplier shall deliver a copy of all completed survey reports, survey drawings and the relevant method statement and specification to the LU Land Survey Manager.
3.5.1.2 All land, utility and building surveys shall be delivered in digital form as two or three dimensional Bentley MicroStation Design File (.dgn) format and include details of how the drawing is structured (levels, colours, style, etc.).
3.5.1.3 Survey information shall include metadata to enable the data to be held in the LU CAD Document Management System conforming to ISO 19115:2003 Geographic information – Metadata.
3.5.2 3.5.2.1
Survey control information
The LU Land Survey Data Manager shall hold and maintain the information as listed in Attachment 7.9 about the LU survey stations.
3.5.2.2 The LU Land Survey Data Manager shall prepare and maintain a network diagram of the LU survey stations.
3.5.2.3 The LU Land Survey Data Manager shall make available details of relevant LU survey stations and the relevant part of the network diagram to surveyors who have been commissioned to carry out survey work for LU.
3.5.2.4 The LU Land Survey Data Manager will assign an accuracy classification to each survey control point, which will be issued to users on request.
3.5.2.5 The Supplier shall advise the LU Land Survey Data Manager in writing of any inconsistencies or inaccuracies in the information supplied by the LU Land Survey Coordinator.
3.6 Evidence of compliance
Compliance with the requirements of this standard shall be demonstrated to LU by each party contracted to LU. Additionally LU may audit compliance as part of its surveillance regime.
4 Responsibilities
4.1
The LU Land Survey Manager is the custodian of LU survey information. He shall
also be responsible for ensuring that the digital tunnel outline maps are updated to
include new information from each survey completed.
4.2
The Supplier is responsible for appointing a competent Survey Co-ordinator/Project
Manager.
4.3
The Supplier’s Survey Co-ordinator/Project Manager is responsible for preparing
specifications for survey work, approving Surveyor’s Method Statements and the
design of survey ground marks. He shall receive data from the Supplier, retain for his
record and pass on to the LU Land Survey Manager. He shall update the digital tunnel
outline maps and inform LU of the update.
Reference: 1-026 A2
Page 11 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
5 Supporting information
5.1
5.1.1 5.1.2
5.2
5.2.1
Background
This standard is one of a suite of standards produced by the LU Project Directorate, Engineering Information Manager.
The suite consists of standards as follows:
Standard Number Title
1-026
Topographical Surveys and Mapping
Safety considerations
The correct use of survey information and the London Survey Grid is important in establishing the position of the LU Infrastructure especially where this is underground. The use of the incorrect survey grid has been established as a contributory factor involving asset damage and service disruption.
6 Reference Section
6.1 References
6.1.1 National standards
Document no. Title
ISO 19115
Geographic Information - Metadata
6.1.2 LU company documents
Document no. 1-037 1-622
Title Computer Aided Design Data Glossary of terms and abbreviations
6.2 Abbreviations
The following abbreviations are created:
a)
within London Underground’s Glossary of Terms (1-622) (a Category 1 Standard);
b)
from published sources that are clearly identified.
Abbreviation CAD DGN ETRS89 GPS IPR JLE LU OS OSGM02
Definition Computer Aided Design Intergraph MicroStation Design Format European Terrestrial Reference System 1989 Global Positioning System Intellectual Property Rights Jubilee Line Extension London Underground Ordnance Survey Ordnance Survey Geoid Model 2002
www.ordnancesurvey.co.uk/gps/docs/osgm_report.doc
Source a a a a a a a a b
Reference: 1-026 A2
Page 12 of 27
Abbreviation r.m.s.e. WGS 84
Definition Root mean square error World Geodetic System 1984
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
Source a a
6.3 Definitions
The following topic specific definitions are created:
a)
within London Underground’s Glossary of Terms (1-622) (a Category 1 Standard);
b)
from published sources that are clearly identified.
Term
Definition
Source
Bench mark
a fixed point used for levelling whose height above datum is
a
known
Custodian
- a person nominated to be responsible for nominated
a
documents and for their maintenance and update
Design file
Computer generated data file containing constituent CAD data
a
file elements of the drawing
Easting
distance in metres in the east or west direction from the false
a
origin of the grid
ETRS89
The European Terrestrial Reference System 1989 is the
a
standard precise GPS co-ordinate system throughout Europe.
In 2000, the difference between the WGS84 and ETRS89 co-
ordinates was about 25 cm, and increasing by about 2.5 cm per year. ETRS89 has been officially adopted as a standard
co-ordinate system for precise GPS surveying by most national
mapping agencies in Europe.
JLE Grid
a ‘flat earth’ projection. With an extent of 11 kilometres the
a
maximum distortion due to ignoring effects of the earth’s
curvature is 1 part in a million. Original observation and
computations were made in 1990. Additional observations
were taken in 1992 and the primary network re-computed. Coordinates were linked to the OS values at Cheviot House.
London Survey a transverse Mercator projection with parameters chosen to
a
Grid
minimise grid distortion caused by curvature of the earth over
the LU area
LU Land Survey the person appointed by LU to be the custodian of land survey
a
Manager
information for LU.
LU survey station a permanent ground mark co-ordinated to the London Survey
a
Grid and contained on the LU Land Survey Co-ordinator’s
controlled list of survey stations
MicroStation
proprietary two and three dimensional CAD drafting software
a
package supplied by Bentley Systems, Inc.
Network diagram a diagram, not necessarily to scale, showing the relationship
a
between survey stations
Northing
distance in metres in the north or south direction from the false
a
origin of the grid
OS grid
is the national grid co-ordinate system for Great Britain. The
a
co-ordinate system is based on the transverse Mercator
projection, with parameters chosen to cover the whole of Great
Britain. More correctly known as British National Grid (BNG) or
OSGB36
Scale factor
ratio of a distance on the spheroid to that on the grid
a
Reference: 1-026 A2
Page 13 of 27
Term Supplier
Surveyor True origin
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
Definition
Source
Supplier to London Underground, the primary organisation or
a
individual that is selected to deliver a product, service or facility
to London Underground and contracting directly to London
Underground. This includes Consultants, Contractors and PFI
Contractors and excludes organisations or individuals selected
by and contracting directly to them.
an external company or LU manager appropriately qualified
a
and experienced to undertake land survey work
the point where the spheroid and grid are coincident, hence
a
grid north equals true north
6.4 Technical content manager
Paragraph number Technical content manager
All
LU, Project Directorate, Engineering Information Manager
6.5 Document history
Issue no R9
Date July 2007
Changes
Standard 2-01030-004 re formatted and renumbered to 1-026, no technical changes have been made to the content other than changing references to other Standards where their numbers have changed.
Author
A1
October
Authorised for use. Previous authorisation is
2007
valid
A2
March
Reviewed and revised to change from the term Richard Barrett
2011
LU Grid to London Survey Grid as per
DRACCT No. 0329. Also, Incorporate G-026
into this standard to reflect current best
practise in this specialist field and withdraw
G-026.
Reference: 1-026 A2
Page 14 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
7 Attachments
7.1 London Survey Grid Scale Factors
London Survey Grid eastings 48,000 49,000 50,000 51,000 52,000 53,000 54,000 55,000 56,000 57,000 58,000 59,000 60,000 61,000 62,000 63,000 64,000 65,000 66,000 67,000 68,000 69,000 70,000 71,000 72,000 73,000 74,000 75,000 76,000 77,000
London Survey Grid scale factor 1.0000111 1.0000104 1.0000097 1.0000090 1.0000084 1.0000077 1.0000071 1.0000065 1.0000060 1.0000055 1.0000049 1.0000045 1.0000040 1.0000036 1.0000031 1.0000028 1.0000024 1.0000021 1.0000017 1.0000015 1.0000012 1.0000010 1.0000007 1.0000005 1.0000004 1.0000002 1.0000001 1.0000000 1.0000000 0.9999999
Correction mm per km
11 10 10 9 8 8 7 7 6 5 5 4 4 4 3 3 2 2 2 1 1 1 1 1 0 0 0 0 0 0
London Survey Grid eastings 78,000 79,000 80,000 81,000 82,000 83,000 84,000 85,000 86,000 87,000 88,000 89,000 90,000 91,000 92,000 93,000 94,000 95,000 96,000 97,000 98,000 99,000 100,000 101,000 102,000 103,000 104,000 105,000 106,000 107,000
London Survey Grid scale factor 0.9999999 0.9999999 0.9999999 1.0000000 1.0000001 1.0000002 1.0000003 1.0000005 1.0000006 1.0000008 1.0000011 1.0000013 1.0000016 1.0000019 1.0000022 1.0000026 1.0000029 1.0000033 1.0000038 1.0000042 1.0000047 1.0000052 1.0000057 1.0000063 1.0000068 1.0000074 1.0000080 1.0000087 1.0000094 1.0000101
Correction mm per km
0 0 0 0 0 0 0 0 1 1 1 1 2 2 2 3 3 3 4 4 5 5 6 6 7 7 8 9 9 10
Reference: 1-026 A2
Page 15 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
7.2 British National Grid (OSGB36) to London Survey Grid transformation blocks
NOTE: This map contains coloured lines marking the boundaries of the transformation blocks. These may be obscured if this page is reproduced in black and white.
Point A B C D E F G H I J K L M N O P Q
Easting 538,000 517,000 517,000 518,000 518,000 519,500 519,500 522,000 522,000 523,000 523,000 529,000 529,000 540,000 540,000 539,500 539,500
British National Grid Co-ordinates Northing Point Easting Northing Point 197,000 R 538,000 185,000 II 197,000 S 538,000 205,000 JJ 185,000 T 556,500 205,000 KK 185,000 U 556,500 187,500 LL 184,000 V 557,500 187,500 MM 184,000 W 557,500 186,500 NN 182,500 X 556,500 186,500 OO 182,500 Y 556,500 178,000 PP 178,500 Z 540,000 178,000 QQ 178,500 AA 530,000 175,000 RR 177,500 BB 530,000 167,500 SS 177,500 CC 515,000 167,500 TT 175,000 DD 515,000 173,500 UU 175,000 EE 522,000 173,500 VV 182,500 FF 505,000 173,500 WW 182,500 GG 505,000 188,500 185,000 HH 513,500 188,500
Easting 513,500 517,000 517,000 495,000 495,000 493,500 493,500 495,000 495,000 550,000 550,000 505,000 504,500 504,500 505,000
Northing 187,500 187,500 202,500 202,500 199,250 199,250 198,250 198,250 188,500 167,500 178,000 174,500 174,500 177,000 177,000
Reference: 1-026 A2
Page 16 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
7.3 Factors for conversion between London Survey Grid and British National Grid
North West area
South West area
Central area East area South area
Rotation (Rot)
358°.55579884 358°.55810730
358°.55752333
358°.557282 358°.5600609
50
8
Scale factor (SF) 1.000254411
1.000243743
1.000192479
1.000146053 1.000217914
Shift Eastings
-454195.142
-454182.581
-454157.420
-454133.105 -454163.487
Shift Northings
-131867.340
-131886.233
-131872.044
-131861.837 -131899.767
P=SFxCos(Rot) 0.999936674
0.999927024
0.999875520
0.999829003 0.999902061
Q=SFxSin(Rot) -0.025209808 -0.025169252
-0.025178154
-
-0.025134508
0.025181187
Note: Rotation is a conventional anticlockwise angle
For converting British National Grid to London Survey Grid the conversion equations are:
E.London Survey Grid = (E.British National Grid x P) - (N. British National Grid x Q) + shift Eastings N.London Survey Grid = (N. British National Grid x P) + (E. British National Grid x Q) + shift Northings
South East area
358°.55962194
1.000152383 -454129.735 -131885.180 0.9999836358 -0.025140520
Table 1 Factors for conversion of British National Grid to London Survey Grid
North West area
South West area
Central area East area
Rotation (Rot)
01°.44420116 01°.44189270 01°.44247667 01°.44271751
Scale factor (SF) 0.999745653
0.999756316
0.999807558
0.999853968
Shift Eastings
450612.718
450610.266
450607.111
450603.379
Shift Northings
143236.271
143238.209
143235.329
143233.058
P=SFxCos(Rot)
0.999428078
0.999439752
0.999490721
0.999537011
Q=SFxSin(Rot)
0.025196986
0.025156987
0.025168464
0.025173833
Note: Rotation is a conventional anticlockwise angle
For converting London Survey Grid to British National Grid the equations are:
E. British National Grid = (E.London Survey Grid x P) - (N.London Survey Grid x Q) + shift Eastings N. British National Grid = (N.London Survey Grid x P) + (E.London Survey Grid x Q) + shift Northings
South area
01°.439938901 0.999782133 450607.363 143239.590 0.999466418 0.025123557
South East area
01°.44037806 0.99984764 450602.420 143236.998 0.999531712 0.025132860
Table 2 Factors for conversion from London Survey Grid to British National Grid
Note:
Transformation blocks given in tables 1 and 2 have been created such that the differences along the boundary edges when using adjacent sets of conversion parameters is within the 1:1,250 mapping accuracy of 400mm, equivalent to 0.3mm at map scale.
Reference: 1-026 A2
Page 17 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
7.4 London Survey Grid to JLE grid transformation block
Reference: 1-026 A2
Page 18 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
7.5 Factors for conversion between London Survey Grid and JLE grids
Rotation (Rot) Scale factor (SF) Shift Eastings Shift Northings P=SFxCos(Rot) Q=SFxSin(Rot)
358°.55814059 0.99999717553 66,231.840 m -7,897.815 m 0.9996805496 -0.0251624670
For converting JLE Grid to London Survey Grid the conversion equations are: E.London Survey Grid = (E.JLE grid x P) - (N.JLE survey grid x Q) + shift Eastings N.London Survey Grid = (N.JLE grid x P) + (E.JLE survey grid x Q) + shift Northings
Table 3 Factors for conversion from JLE grid to London Survey Grid.
Rotation (Rot) Scale factor (SF) Shift Eastings Shift Northings P=SFxCos(Rot) Q=SFxSin(Rot)
01°.44185941 1.00000282446 -66,409.786 m 6,228.771 m 0.9996861968 0.0251626091
For converting London Survey Grid to JLE Grid the conversion equations are: E.JLE grid = (E.London Survey Grid x P) - (N. London Survey Grid x Q) + shift Eastings N. JLE grid = (N. London Survey Grid x P) + (E. London Survey Grid x Q) + shift Northings
Table 4 Factors for conversion from London Survey Grid to JLE grid.
Note:
The transformation parameters listed were produced from a survey linking 13 common survey control stations in March 1998. Checks at platform level were made between the London Survey Grid and JLE grid survey stations at Waterloo, London Bridge and Canada Water; the worst linear agreement being 20mm.
Reference: 1-026 A2
Page 19 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
7.6 Primary Control Survey Stations
Primary
ID.
Coldharbour Farm Woodoak Farm Northwood Potters Crouch Belmont Northwick Park Richmond Park Arkley Reservoir Parsonage Farm Pollards Hill CRP08 CRP09 Pole Hill Monkhams Hall London Cemetery Garland Hill Dog Kennel Hill Little Tawney Hall Romford Common Little Tomkyns Farm North Ockendon
Primary
ID.
Coldharbour Farm Woodoak Farm Northwood Potters Crouch Belmont Northwick Park Richmond Park Arkley Reservoir Parsonage Farm Pollards Hill CRP08 CRP09 Pole Hill Monkhams Hall London Cemetery Garland Hill Dog Kennel Hill Little Tawney Hall Romford Common Little Tomkyns Farm North Ockendon
London Survey Grid
Easting
Northing Level
46361.463
51436.772 269.250
53381.506
48723.612 181.780
59856.174
46617.755 172.620
62699.360
60269.761 218.110
66880.348
46173.863 205.120
67132.785
43064.558 159.280
68789.410
28207.392 156.040
72798.176
50771.145 244.790
73391.128
60967.109 210.250
80377.022
23572.176 164.900
85139.159
35988.862 138.710
89078.330
38845.733 121.470
89084.473
49493.790 191.350
89435.862
56969.529 182.990
92293.548
40746.816 113.570
97913.484
23544.634 180.510
98574.848
46845.271 184.500
101119.124
53502.584 171.720
103125.267
46081.679 171.540
107520.335
43599.754 174.690
110084.438
39449.241
British National Grid
(OSGB36)
140.930
Easting
Northing Level
495651.749
195811.887 169.250
502736.180
193277.140 81.780
509260.020
191335.609 72.620
511757.480
205051.440 118.110
516291.420
191068.930 105.120
516622.066
187967.597 59.280
518651.426
173160.233 56.040
522090.190
195812.700 144.790
522425.970
206018.180 110.250
530349.360
168818.410 64.900
534797.127
181348.683 38.710
538662.387
184303.243 21.470
538400.586
194946.428 91.350
538563.362
202427.410 82.990
541828.530
186284.370 13.570
547878.520
169231.370 80.510
547953.500
192538.250 84.500
550328.900
199256.600 71.720
552521.150
191889.650 71.540
556976.930
189519.450 74.690
559644.340
185435.160 40.930
ETRS89
Latitude
Longitude
51o39'10.70333"N 51o37'44.19131"N 51o36'36.94875"N 51o43'58.97747"N
0 o37'07.46043"W 0 o31'01.61567"W 0o25'24.60943"W 0o22'59.03900"W
51o36'23.25284"N 0o19'19.52792"W
51o34'42.66530"N 0o19'06.05689"W
51o26'42.04359"N 51o38'52.32048"N 51o44'22.23903"N 51o24'12.32820"N
0o17'38.59546"W 0o14'12.27308"W 0o13'41.94128"W 0o07'38.68851"W
51o30'53.95951"N 0o03'31.45489"W
51o32'26.17548"N 0o00'06.85567"W
51o38'10.70718"N 51o42'12.56647"N 51o33'27.43244"N 51o24'10.22224"N
0o00'05.35162"W 0o00'13.78286"E 0o02'40.24986"E 0o07'28.51579"E
51o36'44.06493"N 0o08'07.56697"E
51o40'19.11488"N 0o10'21.35841"E
51o36'18.70046"N 51o34'57.63555"N 51o32'42.84291"N
0o12'03.85359"E 0o15'51.47932"E 0o18'03.29210"E
Height
214.518 127.050 117.890 163.379 150.389 104.550 101.310 190.059 155.519 110.169
83.980 66.740 136.619 128.259 58.840 125.778 129.769 116.989 116.809 119.958 86.199
DESCRIPTION
O.S. Pillar 2nd.Order. Height to bracket O.S. Pillar 3rd.Order. Height to bracket
Brass Rivet O.S. Pillar 3rd.Order. Height to bracket O.S. Pillar 3rd.Order. Height to bracket
Brass Rivet O.S. Pillar 2nd.Order. Height to bracket O.S. Pillar 3rd.Order. Height to bracket O.S. Pillar 3rd.Order. Height to bracket O.S. Pillar 3rd.Order. Height to bracket
Bolt Bolt O.S. Pillar 2nd.Order. Height to bracket O.S. Pillar 2nd.Order. Height to bracket Survey Bolt O.S. Pillar 3rd.Order. Height to bracket O.S. Pillar 3rd.Order. Height to bracket O.S. Pillar 3rd.Order. Height to bracket O.S. Pillar 3rd.Order. Height to bracket O.S. Pillar 3rd.Order. Height to bracket O.S. Pillar 3rd.Order. Height to bracket
Reference: 1-026 A2
Page 20 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
7.7 Form to request the supply of Ordnance Survey digital data
Project Name …………………………………………..
Contact Name Organisation Name E-mail address PO Box Building Name / No. Street Post Town County Postcode Phone / Fax
Originator / Authoriser
Please complete details below of person in TfL requesting the data for their use or use by their contractors
Contractor
If data is requested for distribution to an external contractor complete their details below.
OS Product
MasterMap, Topography MasterMap, ITN
MasterMap CAD version 1:10,000 Scale Raster 1:25,000 Scale Raster 1:50,000 Scale Raster 1:250,000 Scale Raster
Address-Point Code Point with Polygons
Code Point Boundary-Line
Street View VectorMap Local
Meridian 2
GZ GZ DGN TIF TIF TIF TIF CSV MID-MIF CSV NTF TIF GZ NTF
Tick Formats Required DWG
NTF NTF DGN
Extent
e.g. A tile list TQ3181 or London Borough Brent etc
Special Requirements Grid System Updates Required Project End Date Other Requirements
London Survey Grid Yes
British National Grid No
Note, all products are available in BNG, MasterMap CAD DGN is also available in LSG
Reference: 1-026 A2
Page 21 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
7.8 Typical items for inclusion in a model survey specification
Survey title Summary of requirements
Description of the site to be surveyed Site hazards and access arrangements
Survey control Survey grid and height datum to be used Horizontal control network, design and accuracy Vertical control network, design and accuracy Details of LU survey stations to be used
Mapping Detail to be surveyed Accuracy Additional information required - e.g. names, type
Digital data Data file structure Data standards Data transfer format Graphical definition requirement
Presentation of final drawings Size Colour Number Material
Programme Works programme Progress reports
Method statement Survey title Survey organisation Project or job name Job Manager name Brief description and purpose of the survey Location of the survey Brief scope of work Personnel to be employed Equipment and resources to be used Detailed technical methodology Delivery schedule Quality checks to be applied Safety arrangements
Reference: 1-026 A2
Page 22 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
Information and materials to be delivered Sample, proof and final data Return of information supplied by LU
Technical report Survey registration number Survey title Survey organisation Project or job name Brief description and purpose of the survey Technical specifications for the work Agreed amendments and variations Variations to the accepted method statement The actual delivery schedule Quality management procedures employed with the results of tests carried out Horizontal and vertical network diagrams Abstracts of adjustments to observations carried out showing accuracy of data List and details of LU survey station and bench marks used List, details and description of all survey control points and bench marks established
Bill of quantities
Reference: 1-026 A2
Page 23 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
7.9 Survey station records
Records should be submitted in a spreadsheet format with the column headings and field formats as shown below. Diagrams to be included in the survey station record should be in Bentley MicroStation Design file (.dgn) format, photographs may be from digital cameras or a scanned graphical image in TIF or JPEG format. All the fields listed should be included in the spreadsheet, the fields shown in bold must include data, the remaining columns are optional or may be completed subsequently.
Column Name
Format
Description Example
Field
Obligation
Length
PGM ORG_EST_MARK
Text Text
ESTABLISHED_DATE MARK_DESCRIPTION
Date YYYY_MM_ DD
Text
Easting Northing Height Grid
Number (Double)
Number (Double)
Number (Double)
Text
Datum
Text
Location_Description Text
DIAGRAM
Logical
Survey Station name
Organisation establishing and checking the survey station Date survey station established Description of the ground mark Easting
Northing
Level
Information to describe the spatial reference system Information to describe the vertical reference system Information to describe the location Yes / No
CRP08 CROSSRAIL
1996_11_05
OS 3rd Order Roof Bolt 85139.159 35988.862 138.71 JLE
ODN
Lambeth North Station
Concourse Y
32 Mandatory 50 Mandatory
10 Mandatory 50 Mandatory 10 Mandatory 10 Mandatory
8 Mandatory 12 Mandatory
12 Mandatory
100 Mandatory 1 Mandatory
LCS
Text
Location Code
M154
5 Mandatory
ALIAS
Text
Project Description
Text
Alternate name or number
Information to describe project
Cheviot House
Station Modernisation
Project
32 Optional additional information
50 Optional additional information
Reference: 1-026 A2
Page 24 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
Column Name
Format
Description Example
Line_Owner
LAST_VISIT_DATE STATUS
Text
Date YYYY_MM_ DD Text
London Underground Line operating trains in location Date of last known visit
Condition at last visit
Jubilee
1996 ok
Field
Obligation
Length
Optional additional 25 information
10 Optional additional information
80 Optional additional information
NOTES ACCESS_INST
Text Text
Details of any special condition
Access instructions
24 hours notice required
Tel Security office 0207 790 1818
80 Optional additional information
250 Optional additional information
Diagram_Drawn_By Text
Diagram_Drawn_Date
Diagram_Verification_ By
Date YYYY_MM_ DD
Text
Diagram_Verification_ Date
Diagram_Rev
Date YYYY_MM_ DD
Text
Author of witness diagram
Date of drawing completion
Authorising authority of witness diagram
Date witness diagram was checked
Revision of drawing
CD 2010_12_25
AEL
2010_10 A
16 Optional additional information
10 Optional additional information
16 Optional additional information
10 Optional additional information
2 Optional additional information
SIN CONTROL_ORDER HEIGHT_ORDER Grade
Text Text Text Text
PHOTO_Link Drawing_Link
URL URL
Code for LU job
1st Order, 2nd Order etc
1st Order, 2nd Order etc
Confidence level in information A, B, C, D, N, S, P Link to digital photographs
Link to Drawing file of station record sheet
W124 2nd Order 3rd Order
A
http://intranet.mr.i nt
http://intranet.mr.i nt
5 LU use only 9 LU use only 9 LU use only 1 LU use only
250 LU use only 250 LU use only
Note: Confidence levels are selected from the lookup table in the Survey Control Database
Reference: 1-026 A2
Page 25 of 27
7.10 Sample survey reference box
No. AUTHOR DATE
SURVEY/SOURCE DATA
TUNNEL UPDATE INFORMATION
REV
DESCRIPTION
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
REF No.
DATE AUTH.
APP.
COMMENTS
Plan accuracy Level Accuracy File transfer format
Reference: 1-026 A2
Page 26 of 27
Title: Topographical Surveys and Mapping Number: 1-026 Issue no: A2
Issue date: March 2011
7.11
The Ordnance Survey Contractor Licence Agreement
Introduction
Transport for London is a member of the Public Sector Mapping Agreement which licenses a range of Ordnance Survey data products for use within London Underground. This licence extends to use by London Underground’s contractors carrying out work for LU when the contractor enters into an OS Contractor Licence Agreement with LU. The contractor licence agreement may be downloaded from the Ordnance Survey website together with additional information. http://www.ordnancesurvey.co.uk/oswebsite/business/sectors/government/psma/index. html
Reference: 1-026 A2
Page 27 of 27
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