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MONITORING AND MAPPING OF ENVIRONMENTAL NOISE

CHAPTER THREE AQUIRED DATA

STUDY AREA

3.1 The study lies within Renfrew and is a 9 km ² area which runs east and south from Glasgow Airport. This area was selected as it contained all of the main elements to be assessed with respect to transportation noise and also at least one industrial process likely to be covered by IPPC. It was also deemed necessary to extend the area of concern to 500m outwith each 500m square 'tile' to ensure that all contributors to the noise climate within the area to be mapped would be included. The total area (16m ²) can be identified in terms of OS reference points as follows; British National Grid X coordinates 248500 to 252500 and Y coordinates 663500 to 667500.

Mapping Data

3.2 Mr Stuart Gardner of SEGIS supplied the Ordnance Survey products listed in Table 3.1 on CD to STANGER under licence (Scottish Executive Licence number: GD031135G001 2002).

Table 3.1: Ordnance Survey Map Products Obtained from SEGIS (Scottish Executive Licence No. GD031135G001 2002).

3.3 Mr Gardner was not able to provide building height data, which is understood not to be available commercially. These data were therefore obtained through a one day site survey. A further day was required to collate this information. Where road and railway levels varied from the surrounding contours the required input data was estimated from the bitmaps, site survey and aerial photographs. Railtrack also supplied a chart indicating line ground levels. It was not possible to obtain road level data from Amey within the timescales of the project for the elevated sections of the M8 or the road levels for bridges and so road levels were estimated on site. Between junctions 27 and 28, as the road travels west the M8 passes under the A741 (Renfrew Road) and becomes a flyover passing Glasgow International Airport until the road drops towards junction 29 where the M8 turns north towards the coast and the slip road to the A737 turns south west.

3.4 To examine the feasibility of mapping using the data provided the dxf tiles supplied were assembled within one file using Autocad and a separate building layer was created. The compiled dxf file was imported into the noise modelling package and building heights were input. The bitmap files were also imported to provide a basemap used to interpret the object lines. The contour and Oscar shape files (road centre lines) were then imported. The map at this stage assumed that all objects 'sat' on the contours therefore further editing was required to include road and railway cuttings, bridges, road widths, and railway tracks.

3.5 Areas of soft and hard ground were identified from local knowledge as the land use file was not helpful in this case. It may be possible to convert the land use files to facilitate the identification of soft and hard ground, this possibility is considered in Chapter 6.

3.6 Building height data and road level data were collected on site.

Road Traffic Attribute Data

3.7 Mr Stuart Hay (Scottish Executive RNMM) supplied traffic flow data for the M8 from junctions 27 to 28. Although the traffic data was requested in the format outlined in chapter 2, it was not supplied in this format and there was no speed data supplied for the M8.

3.8 Hourly data was supplied with vehicle length classes, N1 to N3 (short, medium and long). These classes were used to determine the percentage of heavy goods vehicles (HGV). It is acknowledged that this method is likely to underestimate the percentage HGV as defined in CRTN88.

3.9 As an alternative to using average traffic speeds STANGER requested road speed limit data however there is no such database held by the Scottish Executive RNMM. Consequently the input data was obtained by driving around the site. Travelling east to west the M8 has a 70mph (113kph) limit to junction 27 which is then reduced to 60mph (97kph) until junction 29, where the speed limit is further reduced to 50mph (80kph) before returning to 70mph (113kph).

3.10 Mr Willie Grant (Scottish Executive RNMM) supplied road surface texture depth data for junctions 27 to 28.

3.11 Mr Stuart Rankin (Renfrewshire Council Roads Department) supplied non trunk road flow data which he had and road surface texture depth data. Mr Rankin provided a list of major roads however he did not have counts available for all roads requiring consideration and so the data were incomplete. Where data was unavailable Mr Rankin provided estimates.

3.12 The traffic data supplied is summarised in Table 3.2.

Table 3.2: Road Traffic Input Data for Project Area

Railway Attribute Data for Project Area

3.13 STANGER met with Ms Young on 15 January 2002 at Buchanan House. At the meeting Ms Young gave STANGER the result of her initial search for data. She explained that Railtrack uses three databases Trust, Tops and Gemini. The Tops database is an overall stock control system which is a live view of traffic on the line, collected at 'Trust' points. The Trust database mainly deals with freight traffic and Gemini with passenger traffic. The data is archived for the previous 7 days.

3.14 Within the study area two services operate. The Glasgow Central to Ayrshire Line and the Glasgow Central to Wemyss Bay line. Data was provided for 'up' and 'down' lines for each route for Monday to Fridays, Saturdays and Sundays. The Glasgow to Wemyss Bay service is passenger traffic. While the Glasgow to Ayrshire service has both passenger and freight traffic. Coal trains run between Glasgow and Hunterston and Falklands Yards. There are occasional specialist freight trains.

3.15 Ms Young provided train data for the periods Monday to Friday, Saturday and Sunday in the time periods 07.00 to 19.00 hours, 19.00 to 23.00 hours and 23.00 to 07.00 hours. The train timetable supplied for the study area included both passenger and freight trains and provided the time of the train and the origin/destination. Ms Young had annotated the table with the engine type, the number of carriages or wagons for each train, the nature of the freight trains (cargo and whether loaded or unloaded) and the 'Rules' regarding the speed applicable for each train.

3.16 Also provided were a schematic diagram of the railway lines indicating the direction of travel on each track, tunnel and bridge locations, and train speed through junctions, a cross section of the line indicating the track gradient and the type of track, whether continuously welded or jointed. Most tracks are continuously welded.

3.17 CRN95 requires corrections to be made for different track and track support structures. Information on the bridge types and ballast and was not available, therefore it would be necessary to obtain this information through a site survey at this time.

3.18 All EMU's/DMU's run fast between Paisley and Glasgow at 75mph (non-stop) and visa versa. Class 66 (Diesel) and 29 and 36 HAA loaded coal wagons on the up line run at 45mph. Class 66 (Diesel) and 29 and 36 HAA empty coal wagons on down line run at 60 mph. The speed for freight trains varies between 45 and 60mph. Noise from trains leaving stations is not specifically addressed within CRN95, however it was agreed that an average speed would be used for sections of the line passing through stations. The average speed is taken to be 30 mph.

3.19 There are also loops in the system which are use for shunting operations and for trains to wait e.g. freight to allow passenger trains to pass. As discussed in chapter 2 the treatment of this activity was not specifically referred to within the Directive. It may be worth noting however that in terms of Scottish Office Development Department Planning Advice Note PAN 56, this area would be classed as industrial.

3.20 The data supplied is summarised in Tables 3.3 and 3.4. It was necessary to manipulate the data into a format for input into the model.

Table 3.3: Railway Input Data for Project Area (Down Tracks)

Table 3.4: Railway Input Data for Project Area (Up Tracks)

Aircraft Attribute Data CAA - Noise Model Output

3.21 Mr Lee at CAA agreed to provide the raw contour output.. This data is not however in a format suitable for direct input into the GIS model. As discussed in chapter 2, STANGER required to map the aircraft noise onto a 4 km by 4 km rectangular grid , with 10m spacing, aligned with the National Grid coordinate system, i.e. for eastings 210000, 210010, 210020, etc. The noise contours CAA produced for Glasgow Airport on behalf of BAA were based on a rectangular grid (100m spacing), rotated to be in line with the airport runway, and so the two grids will not match as demonstrated by the sample data presented in Table 3.5.

Table 3.5: ANCON Noise Model Output

3.22 In this case it will be necessary to interpolate the data levels for discreet receptor points on a 10m x 10m grid. CAA are able to do this for an additional cost. Casella Stanger are also able to convert the data for use in noise mapping, due to the costs involved, interpolation was not carried out.

Industrial Source Attribute Data

3.23 The SEPA officer dealing with the study area is Mr Jim McIntyre, who explained that over the next six years SEPA estimates there will be between 600 and 800 IPPC applications made in Scotland overall under the registration procedure, although at the time of writing this report only thirty five such permits have been issued. For the study area SEPA hold little noise data at this time. Mr McIntyre advised contacting the East Kilbride SEPA Registrar in order to obtain information from the existing register of Part A and Part B processes..

3.24 Peter Birrell, SEPA Information Technology Department Edinburgh is currently developing a GIS system which will incorporate the permitted processes register information. At this stage it is understood that there is no plan to include the noise producing sites to be identified according to some form of specified criteria. Reference is made to this in Chapter 6.

3.25 STANGER also contacted Mr David Paris at Renfrewshire Council Environmental Health Department regarding industrial sources in the study area which would not be included in the SEPA register. The Council have complied their own register of complaints. STANGER did not request information from the register.

Sea Ports Attribute Data

3.26 Mr Peter Sommerville at Clydeport Operations Greenock and Mr Andrew Hemphill at Clydeport Glasgow were contacted, however they were unable to provide information within the timescales of the project.

3.27 From previous port assessments it is possible to identify the potentially significant noise sources to consider: vessels docking, vessel and dockside cranes, cargo unloading, forklifts on dockside, straddle carriers operating within container yard, HGVs moving containers from/to yard, refrigerated containers operating within yard. Consideration of this detail is outwith the scope of this project, however with a knowledge of the timetable of activities within the port it would have been possible to model port noise using information contained within the Stanger database.

Preliminary Restricted Noise Map

3.28 STANGER has constructed a preliminary restricted noise map of the selected area using the available detailed information received on the trunk and principle roads, and railway lines.

3.29 The modelling software used for the noise map was ' Cadna'.

3.30 The mapping products were in a form which were readily input into the model although additional data was required to be collected through a site survey, e.g. building heights and road level and speed limits, railway cuttings. Editing of the files was therefore required - specifically joining together the dxf files, putting heights onto buildings, 'cleaning' the roads data (identifying road segments), inputting bridges flyovers and cuttings.

3.31 STANGER have requested a level of data detail from the attribute data providers determined by the accepted UK prediction methodologies as discussed in Chapter 2.

3.32 Both the Scottish Executive and the Local Authority were able to provide traffic flow data (although some data is still to be collated by the local authority). Percentage HGV were derived from vehicle length classes in the case of the M8 which is probably underestimating the percentage HGV. For local authority data the percentage HGV was derived from count data. Protocol for describing HGV requires to be produced to ensure consistency of approach. Average traffic flow speeds were not available and this information was obtained through site survey. The Scottish Executive was able to provide texture depth information but not surface type. Renfrewshire Council were able to provide both road surface type and texture depth information as they had undertaken a site survey. It may be possible to obtain road level information from the road maintenance 'operating companies'.

3.33 It was possible to model road traffic noise with the data available.

3.34 Railtrack were able to provide all information requested except data on the various different track and track support structures, e.g. bridges. This would require a site survey. It was possible to model railway noise with the data available.

3.35 The aircraft data was not readily useable in the noise model. It required conversion to the grid locations used in the model. This work was outwith the scope of the project and so this aircraft noise has not been included in the restricted noise model.

3.36 Limited data on the location of Part A and Part B processes was available from SEPA however no noise data was available. This would require development of a noise protocol. Both development of a protocol and site measurement were outwith the scope of the project. Consequently industrial noise has not been included in the restricted noise model.

3.37 Similarly assessment of Sea Ports operations would also require a site survey to identify noise sources and subsequent modelling using on site measurements or database sources noise levels. This was outwith the scope of the project and so port noise has not been included in the restricted noise model.

3.38 Therefore there are limitations in the data currently available, e.g. industrial sources, seaports, road traffic speed, building heights, road levels, information on structures such as bridges cuttings, flyovers.

3.39 The accuracy of the data is not necessarily a reflection of the accuracy of the prediction model. For example CRTN88 claims that extrapolation outwith the 300m radius can lead to progressive and significant error. If assumptions have to be made in relation to the input data e.g. speed then the significance of error within 300m of the source may be a consideration.

3.40 The validity and relevance of the model produced should be considered in terms of strategic use. Extrapolation of the model for use in a very localised scale is not advisable.

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