ABPsubm,Noise Assessment,ICAN Acousticsor,CSR,forJ&J,Oct2015.pdf

7/24/2019 ABPsubm,Noise Assessment,ICAN Acousticsor,CSR,forJ&J,Oct2015.pdf

1/40


2/40

ICAN Acoustics________________________________________________________________________________________

- i

ICAN Acoustics.

Table of Contents

EXECUTIVE SUMMARY III

1 INTRODUCTION 1

1.1 Proposed location for the NCH 1

1.2 About the Author 2

2 THE PURPOSE OF AN EIS 3

2.1 Impact from noise and vibration 3

2.2

Existing Environment 4

3 CONSTRUCTION PHASE 5

3.1

Assessment Criteria 5

3.2

Predicted Demolition/Construction Noise 6

3.3 Vibration resulting from construction activities 7

4 THE PROJECT CONSTRUCTION MANAGEMENT PLAN 9

4.1 Extract from the Outline Construction Management Plan at St. Jamess Hospital 9

4.2 Noise Limits set out in the Construction Management Plan 10

4.3 Vibration Limits set out in the Construction Management Plan 11

5 OPERATIONAL PHASE 12

5.1 Increased noise from traffic 12

5.2

Assumptions made in the AWN Consulting study 13

5.3 Measurement of an actual Medevac Hospital Landing/Take Off 17

5.4 Specialist services Health Technical Memorandum 08-01: Acoustics(2008) 26

6 CONCLUSION 31

6.1 Construction Noise Impact 31

6.2 Vibration impact during the Construction Phase. 31

6.3

The Impacts of Helicopter Noise and activity on Hospital Bedrooms 32

6.4

The Impacts of Helicopter Noise on residential amenity 32


3/40

ICAN Acoustics________________________________________________________________________________________

- ii

ICAN Acoustics.

6.5 Overall Conclusion 33

7 TERMINOLOGY 35


4/40

ICAN Acoustics________________________________________________________________________________________

- iii

ICAN Acoustics.

Executive Summary

This study examines the assessment methods used in the projects EIS and closely examines the likely impact

of demolition/construction noise on the residential properties and existing hospital buildings within vicinity of the

proposed NCH construction site. It highlights a significant short fall in the EIS, where NRA construction noise

limiting levels (for new road schemes) are being proposed in what is a long term construction project (2 to 3

years), in a constricted space arrangement unlike a moving road scheme. Our study also indentifies guidance in

BS5228 which is referenced in the EIS, yet some elements have been ignored which suggests that for the

construction noise limiting levels proposed at the site, that temporary re-housing of residents should be

considered. This assessment of noise and vibration confines itself to the St Jamess Campus. Our study shows

that the authors have been selective in the use of guidance in discussing examples of noise limits in BS 5228,

where they have only cited the most simplistic case. One is left to conclude that the criteria chosen by the

authors, the NRA criteria, have been chosen, not because they are most appropriate but because they favour

the authors argument.

We have review the projects proposed vibration assessment methodology and it is clear that no examples of

calculated vibration have been provided. It is also evident that a basic generic third party calculation method is

being considered and one that does not take account of the actual ground strata at the location. Considering

the proximity of the proposed ground works, 10m from residential properties and 7.5m from clinical areas, we

would have expected to see a rather more robust prediction method and perhaps a vibration risk assessment.

Neither of these have been provided in the submitted EIS.

The Construction Management Plan adopts the same criteria proposed in the chapter on noise and vibration

where contractors will work to limiting levels suggested by AWN Consulting which in my view are clearly not

appropriate for this site.

There are many short falls highlighted with regard to operational noise and its likely impact. Design

documentation identifies a naturally ventilated building where possible, however it would appear that noconsideration has been given to the fact that naturally ventilated building are inherently acoustically weak

structures with regard to inbound noise. It would appear that noise intrusion from external sources has not been

adequately considered and no attempt has been made to establish if the naturally ventilated hospital rooms

would be actually fit for purpose if assessed using appropriate UK guidance documents, issued by the

Department of Health (HTM-08).

Our review shows that the impact of noise arising from the proposed helipad has been grossly underestimated.

As part of our study we have investigated an actual hospital helicopter Medevac operation and timed the

duration of each element. We would be very concerned also that the project EIS considers just one aircraft type

(Augusta Westland AW-139) and does not consider the likely impact of a Sikorsky S92 and the potential impact


5/40

ICAN Acoustics________________________________________________________________________________________

- iv

ICAN Acoustics.

on both residents and hospital occupants. A fundamental shortfall in the assessment of noise impact is the fact

that noise sensitive naturally ventilated hospital bedrooms have not been assessed with regard to the likely

impact of inbound helicopter noise and the fact that it will give rise to sleep disturbance or in this case fright to

young children. The worst affected elements of the proposed NCH will be hospital bedrooms on Level 4, Level

5 and Level 6. Our predictions show that any use of the helipad will most likely give rise to sleep disturbance at

night in the hospital bedrooms and that no consideration has been given to the layout in this regard as

suggested in HTM-08. It appears also that the chapter on noise and vibration attempts to understate the likely

impact of noise on residential properties too arising from helicopter movements and goes to great lengths to cite

reports which in some cases dismiss the need for any noise assessment whatsoever. The Irish Aviation

Authority provide very clear guidance on the placement of helipads and on their likely noise impacts, however

this has been ignored. There is a serious conflict in the design strategy where it is proposed that a naturally

ventilated building would be constructed at an urban location with a proposed helipad in such close proximity,which in our view would give rise to hospital bedrooms which are unlikely to be fit for purpose.

In conclusion, the degree of noise and vibration has not been adequately considered with regard to the

proposed NCH development and these omissions seriously compromise the proposed development in our view.

An EIS should adequately consider the likely impact of noise and vibration on both the occupants of the

proposed facility and occupants of noise/vibration sensitive properties in the locality; however this has not been

satisfied for the proposed NCH development.


6/40

ICAN Acoustics________________________________________________________________________________________

www.acoustics.ie - Page 1 of 35

ICAN Acoustics.

1 Introduction

ICAN Acoustics have been engaged by the Jack and Jill Foundation, to review a noise and vibration study

submitted as part of an Environmental Impact Statement (EIS) relating to the proposed National Children's

Hospital (NCH) at St James's Hospital, James's Street, Dublin.

The noise and vibration study under review in this report has been prepared by AWN Consulting and forms a

key element to the project's Environmental Impact Assessment (EIA). The report examines the AWN

Consulting study in detail and specifically refers to Chapter 11 (Noise and Vibration) and Appendix 11.1

(Glossary of Acoustic Parameters).

This review will consider principally noise and vibration impact at the St James's site and while the AWN

Consulting study discusses a construction compound at Davitt Road, Drimnagh, Dublin 12, this will not be

considered in detail by us. The focus of this study specifically relates to the likely noise and vibration impact on

the existing St James's Hospital during the construction phase as well as considering operational noise and its

impact on the proposed National Children's Hospital and residential properties within the vicinity of the site.

1.1 Proposed location for the NCH

St James's Hospital is located in a densely populated area of Dublin 8, between St James's Street and the

LUAS Tramway. It is surrounded on four sides by residential streets, the nearest residences being

approximately 50 m from the closest part of the proposed childrens hospital. The hospital will be situated

principally where an existing car park is currently located on the hospital grounds, however it is also likely that a

number of existing buildings will also need to be demolished as part of the proposed development.

Figure 1 below shows an architectural rendered drawing of the proposed National Children's Hospital (NCH) at

St James's Hospital. Some key features are noted in the design for noise and vibration purposes including an

elevated helipad, located on the southern end of the building adjacent to the southern boundary, close to theLUAS tramway line and residential properties on St James's Walk. This figure also shows the proposed family

accommodation units proposed at the Western side of the NCH and it does give a good indication of the density

of the development and its proximity to residential dwellings within the area.

It is worth noting that the proposed NCH building will be closely bounded by residential properties on the

southern side of the site, the western side of the site and an estate of houses to the north east of the site, which

include Donnellan Avenue, O'Reilly Avenue, Owen's Avenue and Quinn Avenue. These streets are located on

the southern side of Ceannt Fort on Mount Brown and residential properties on O'Reilly Avenue will share a

rear garden boundary with the proposed NCH.


7/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

Figure 1: Photomontage of the proposed hospital building at the St James' Hospital site.

1.2 About the Author

Diarmuid Keaney of ICAN Acoustics holds a Masters of Science in Applied Acoustics from the University of

Derby, where he was awarded a distinction on completion of his studies. Following on from the completion of

his independent study (as part of the Masters programme), titled "A critical review of the assessment of traffic

noise at rural locations in Ireland", his research work was published by an independent book publishing

company. This research has since become an acoustics technical reference book which sells on Amazon today

and has been endorsed by leading experts in the field of acoustics and mathematics. Diarmuid also holds a

Diploma in Acoustics and Noise Control and was awarded a merit by the Institute of Acoustics on completion of

his studies at the University of Ulster. Diarmuid also holds an Honours (2:1) Bachelor of Engineering Degree

from the National University of Ireland.

Diarmuid Keaney has over 15 years expertise in the area of acoustics and is highly skilled and experienced in

noise and vibration measurement and assessment, noise and vibration prediction, noise contour modelling,

environmental noise, building acoustics and environmental noise control. Diarmuid is a corporate member of

the Irish Branch of the Institute of Acoustics and currently serves (for 6 years at the time of writing) on the

Committee of the Irish Branch. Diarmuid regularly presents seminars on acoustics to architects, engineers, and

members of other related professions. Diarmuid is a guest lecturer at a third level institution where he provides

seminars on environmental noise and building acoustics to undergraduates of the Masters in Environmental

Engineering and Architectural courses. He has also had formal expert witness training and regularly provides

expert testimony in Court and at Oral Hearings in the area of acoustics.

Proposed NCH

ProposedHelipad

Luas stop &James' Walk

BrookfieldRoad

Proposed familyaccommodationunits.

South CircularRoad

MountshannonRoad

Existing StJamess Hospital


8/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

2 The purpose of an EIS

2.1 Impact from noise and vibration

An EIS should adequately consider the likely impact of noise and vibration on both the occupants of the

proposed facility and occupants of noise/vibration sensitive properties in the locality. It has already been noted

that the area is densely populated and there are a large number of residences which would be potentially

impacted by the construction and operation of the proposed NCH. With the proposed NCH development, we

need to also consider the likely noise and vibration impact on the existing nearby St Jamess Hospital during

construction and operational phases of the NCH project. Operational noise and vibration should also be

evaluated with regard the proposed NCH building and any adverse impacts that operational activities could

have on that building.

Chapter 11 has addressed potential impacts of noise and vibration at both the construction and operational

stages and we shall comment on the methodology of assessment and conclusions drawn. We note that the

construction phase, i.e. prior to opening of the hospital is estimated to last until 2019, i.e. approximately 4 years.

This will involve clearance of the existing site, ground works prior to construction and the construction proper,

prior to fitting out before the proposed hospital becomes operational. It is estimated that the

clearance/construction phase will last approximately 2 to 3 years. Considering the proximity of a large

number of dwellings and the length of the project in a constricted space, it is considered that the construction

phase of the project is likely to give rise to an appreciable impact from construction activities to both local

residents and to the existing hospital.

Figure 2 below sets out the details of the AWN Consulting Noise and Vibration study and their approach with

regard to noise and vibration relating to the site.

In assessing the noise and vibration impacts the following methodology will be adopted:

1. Characterise the receiving environment through a series of baseline surveys;

2. Determine appropriate criteria for evaluating the significance of noise and vibration impactsthrough reference to local guidance documents where applicable and international best practice;

3. Calculate the potential noise & vibration impacts using industry standardised calculation

methods;

4. Assess the impact by comparing the calculated levels against the adopted criteria;

5. Where necessary specify ameliorative, remedial or reductive measures to control the impacts to be

within the adopted criteria, and;

6. Present the predicted impact of the proposed development including the ameliorative, remedial or

reductive measures.

Figure 2: An extract from the AWN Consulting Noise and Vibration study and methodology adopted(11.1.2)


9/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

We would not disagree with the methodology adopted but it will be necessary to consider the methods used for

measurement and evaluation and the criteria used in determining the likely impact of noise and vibration.

We will review the construction and operational phases separately in the light of the potential impact on the

existing environment as described in the EIS.

2.2 Existing Environment

Surveys of noise and vibration have been conducted at a relatively large number of locations in and around the

proposed site. The noise surveys indicate that the residential properties around the hospital are in what would

be described as typical urban noise environments. It is noted that the background noise levels vary between

approximately 42 - 45 dB LA90and 38 40 dB LA90during daytime periods in predominantly residential streets.

At some locations, such as N2, the background noise levels at houses close to the main road are higher, due to

the proximity of passing traffic. However as the distance from the road increases along the side streets, the

noise level will drop accordingly. In general, houses closest to the proposed site are not subjected to continuous

high levels of noise from traffic or other sources.

A number of noise and vibration measurements were made inside wards and treatment areas in close proximity

to the proposed site within the existing hospital. It was found that levels of noise within those areas was

dominated by general activity and conversation and would be typical of what might be expected in a medical

treatment room. Levels of vibration were found to be very low.


10/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

3 Construction phase

3.1 Assessment Criteria

The potential impact of noise and vibration during the construction phase is discussed in Paragraph 11.1.5.1 of

the submitted EIS. It is correctly stated that there is no published statutory Irish guidance relating to maximum

permissible noise and vibration levels during the construction phase of a development although several

publications are used to set appropriate criteria. In this case the adopted criteria are presented. It must be

presumed that the criteria have been adopted by the authors of the report, since there are no nationally adopted

criteria.

The authors briefly discuss in Appendix 11.2 a method for deriving criteria for assessing the likely impact of

noise and vibration during the construction phase of the project. Mention has been made of the National Roads

Authority (NRA) publication Guidelines for the Treatment of Noise and Vibration in National Road Schemes .

Some paragraphs from BS 5228-1:2009+A1:2014 Code of practice for noise and vibration control on

construction and open sites Noisehave been presented, principally in relation to a method of predicting noise

levels from site operations and an example of determining noise limits for construction and demolition noise.

We note however that the authors have been selective in discussing examples of noise limits in BS 5228,

where they have only cited the most simplistic case, Annex E: E2, which is described as the older and more

simplistic method. BS 5228 does in fact give a number of examples of noise limits for differing situations as

discussed in E3 Significance based on noise change. This part of the annex suggests that an alternative

and/or additional method to determine the significance of construction noise levels is to consider the

change in the ambient noise level with the construction noise. This reflects more conventional EIA

methodologies for noise.

Since an environmental impact assessment is used to determine the likely impacton the local environment, it

suggests that it would be appropriate to determine how the level of noise would change in relation to the pre-

existing or ambient environment.

Two methods are given in E.3.2 and E.3.3 (of the BS 5228 guidance) for determining appropriate limits by

considering pre-construction noise levels. When the baseline noise data shown in the EIS is considered, both

these methods would suggest a limiting noise level of 65 dB LAeqduring daytime hours, 55 dB in the evenings

and 45 dB at night-time.

Paragraph E.4 goes on to discuss the assessment of the significance of noise effect and suggests that where

the construction noise exceeds the ambient noise level by more than 10 dB and for a period of 10 days or more

in any 15 consecutive days or for a total of more than 40 days in any 6 month period, temporary re-housing

should be considered. It also suggests that buildings which are likely to be particularly sensitive to noise,

(including hospitals) will be subject to individual consideration.


11/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

It is noted that daytime and evening ambient noise levels (LAeq) at a number of the baseline monitoring sites are

below 55 dB. It is therefore surprising that no assessment against that part of the Annex E to BS 5228 relating

to relative change was included, since it is apparent that the change of impact is likely to be significant.

One is left to conclude that the criteria chosen by the authors, the NRA criteria, have been chosen, not because

they are most appropriate but because they favour the authors argument.

We must stress at this point that the demolition/construction phase will last for a period of 2 to 3 years. BS

5228 recognises that it is generally assumed that a greater difference might be tolerated, than for an industrial

source, when it is known that the operations are of short or limited duration, however it also recognises that the

longer the duration of activities on a site, the more likely it is that noise from the site will prove to be an issue.

The authors have adopted the NRA criteria, which are intended to be used for new road schemes. It should be

borne in mind that whilst a major road project may last for a period of years, the activity will not be static at any

particular location but will move along the route of the road. Hence persons affect by noise will not be

continually affected by noise however long road building occurs. However in the case of the proposed site for

the Childrens Hospital, residents will be subjected to construction noise over the entire period of construction.

We would seriously question then whether the construction noise assessment has been based on suitable

criteria for this project and this location.

3.2 Predicted Demolition/Construction Noise

The submitted EIS has predicted likely levels of demolition and construction noise on and around the site, using

typical noise levels listed in BS5228 for various operations. Models have been produced using computer

software. The model includes mitigation measures, including temporary screens around the site. Considering

that the predicted noise level models have been based on published empirical data it should be stated that the

noise levels published in Table 11.12 of the submitted EIS will not be a precise prediction. It is possible that

actual levels could be higher for a number of reasons including the degree of mitigation applied, exact location

of plant and height of emission of noise from plant.

Table11.12 indicates that the overall level of construction noise throughout the duration of such work, with

relatively few exceptions is likely to be between 60 and 68 dB LAeqat noise sensitive premises. For example at

Receiver position 24 (61 OReilly Avenue) the construction/demolition noise has been predicted to be between

64 68 dB throughout the construction period. When viewed against a measured ambient noise level of 52 dB

LAeqon an afternoon, such noise, over an extended period of several years, even during daytime hours, would

represent a considerable impact upon the residents in that locality. Similarly the predicted construction noise

level outside a number of spaces within the hospital would be high for prolonged periods. It is noted that outsidethe Trinity Health Sciences Centre the noise level has been predicted to range between 67 76 dB. It is


12/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

suggested in Table 11.13 of the EIS that the internal noise level in that space during the operations would range

from 42 51 dB, that is a reduction of 25 dB through the external faade of the building. The assumption has

been made that windows will be closed at all times but our understanding is that the rooms in the hospital are

naturally ventilated and it will therefore be necessary to open windows for ventilation. In such circumstance the

internal noise level is likely to be 10 15 dB higher, which will be between 57 66 dB. Such level would be

considered to be unacceptable in situations where good speech communication is required or where a quiet

environment is required for clinical work.

The authors have concluded that outside all noise sensitive locations around the site the construction noise

levels will be below 70 dB LAeqand hence within limits which would be considered to be acceptable. We would

argue that in many of the locations the level of construction noise would give rise to a considerable impact over

an extended period, even after mitigation measures had been employed. We do not accept that residents whowould be exposed to external noise levels of up to 70 dB LAeq day after day for a period of up to 3 years would

find the noise environment to be in any way acceptable.

It is also concluded that internal noise levels in clinical areas within the hospital will be lower than the typical

internal noise criterion of 45 dB LAeq. When windows are open for ventilation noise levels in a number of clinical

spaces would be likely to be considerably in excess of 45 dB and could materially affect clinical work. We note

that no consideration has been given to short term high levels of noise from particular operations. Such impact

type noises can give rise to shock and sleep disturbance.

3.3 Vibration resulting from construction activities

The likely impact of vibration during the construction stage of the project is discussed in chapter 11.1.5.1 of the

EIS. It is acknowledged that vibration can affect buildings and occupants, both in terms of physical effect on

buildings and human disturbance and comfort. It is acknowledged that there are concerns particularly in relation

to some residential properties which are particularly sensitive due to weak foundations and to activities within

clinical areas of the hospital.

The basis of the AWN Consulting predictions use a third party hypothesis, which we understand has been

prepared by Rupert Taylor (Document Ref. CHOI/MPH/6A dated 7 February 2011), and assumes that the work

done by an auger is proportional to pile toe area, which is proportional to the square of the radius.

We are presented with the follow hypothesis in the AWN Consulting submission

This is taken from the report prepared by Rupert Taylor (Document Ref. CHOI/MPH/6A dated 7 February 2011) on the

vibration impacts of the previously proposed Childrens Hospital Development at the Mater site where he state, Based on

the hypothesis that the work done by an auger is proportional to pile toe area, which is proportional to the square of the


13/40


14/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

4 The Project Construction Management Plan

This chapter considers a review of the Construction Management Plan prepared by O'Connor Sutton Cronin

Consulting Engineers, dated August 2015. It would appear that this document adopts the criteria for noise and

vibration which have been set out in AWN Consulting's chapter on noise and vibration.

4.1 Extract from the Outline Construction Management Plan at St. Jamess Hospital

The following text is an extract from the Outline Construction Management plan for St Jamess Hospital. This

has been reproduced below to allow us to make comment in the latter part of this chapter.

The works for the secant pile wall to the perimeter of the basement are likely to commence prior to thecompletion of, and thus overlap with, the demolition works. The piling works are estimated to continue at a rateof approx. 3-4 piles/day per piling rig. Given the plan extent of the site and the required secant pile wall, it isestimated that there would be in the order of 4-6 piling rigs on site during the peak piling works. This would giverise to a requirement for approximately 40 concrete loads per day for secant pile wall installation.

The overall plan extent of the secant pile wall is c.900 linear metres leading to a requirement for c.1000no.piles. The piles vary in length depending on their location on site and the lowest level of structure at thatlocation, with piles typically varying from c.10m to c.20m in overall length.

The proposed building is located around some sensitive receptors, namely the adjacent listed Haughton

Institute and the McDowell Avenue residential properties and boundary wall to the rear as well as 3no. maturetrees on Jamess Street. A secant pile wall is the proposed ground support system along theboundary/interfaces and has been set-back away from these in recognition of their sensitivities while protectivehoarding shall be applied to the mature trees. Throughout the build and construction process these existingbuildings and structures will be adequately protected and monitored to ensure their current condition is notstructurally impaired in any way. During the installation of the secant pile wall and basement excavationactivities, state of the art real time monitoring will be set up and carried out. A traffic light system will be put in

place consisting of:

o Green-vibrations below threshold limits-OK to proceed

o Amber-vibrations exceed first threshold limit-Stop and check

o Red-vibrations exceed second threshold limit-Stop and action

Once the secant pile wall is installed, works will commence on the excavations down to basement level. This

will involve the removal of c. 5,000m3 of material for disposal off site.

We would be concerned that the Outline Construction Management Plan appears to focus its concerns on

vibration sensitive listed buildings, some residential properties and 3 mature trees on James's Street. While the

construction management plan does make reference to allowable limits for hospital operating theatres,

precision laboratories and audiometric testing booths, it makes no specific references to vibration sensitivity of

imaging equipment such as hospital CT scans or robotic surgery systems. While it could be suggested that

precision laboratories may cover imaging and perhaps robotics medical work, we are most surprised that an

identification of vibration sensitive hospital equipment (by way of a drawing) and its exact location is not

included in the outline of the Construction management plan. In our experience, robotics work is not particularly


15/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

vibration sensitive, however it would seem prudent to carry out a risk assessment on all the potentially vibration

sensitive equipment and services that take place considering the proximity of the working St James's Hospital

to the proposed NCH construction site. This deficiency in assessment will be addressed in greater detail later

in this report.

4.2 Noise Limits set out in the Construction Management Plan

Figure 3 below is an extract from the Construction Management Plan. It is clear that the contractor is expected

to adopt the limiting levels suggested by AWN Consulting, which are in fact clearly not appropriate for this site

as shown in our Chapter 3.1 and Chapter 3.2 above.

Figure 3: Extract from the Construction Management Plan prepared by OCSC, showing prescribednoise limiting levels which have been adopted from the Chapter prepared by AWN Consulting.


16/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

4.3 Vibration Limits set out in the Construction Management Plan

It would appear also that OCSC have adopted the vibration limiting levels set out in the AWN report, which have

been discussed in our Chapter 3.3 above. In that chapter we set out our concerns relating to the methodology

which has been adopted with regard to vibration prediction and assessment.

Figure 4: Extract from the Construction Management Plan prepared by OCSC, showing prescribedvibration limiting levels which have been adopted from the Chapter prepared by AWN Consulting.


17/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

5 Operational Phase

5.1 Increased noise from traffic

It should be noted that there is a significant amount of site traffic already present at the existing St Jamess

Hospital. In terms of noise assessment and the impact of changes in the noise climate as a result of noise

arising from the proposed development, it should be noted that a doubling of traffic volume at the site would

typically result in an increase of approximately 3dB(A), therefore the resulting change would not be deemed to

be significant in terms of the overall scheme. We note that the AWN Consulting report (Table 11.16) reports a

change in traffic level which is insignificant at the year of opening, in the order of 0.1~0.6dB. Following on from

Table 11.16, Table 11.17 of the submitted EIS reports this change as being barely perceptible and minor. What

is most surprising however is that the AWN report does not give any consideration to the fact that the proposed

NCH building will be a naturally ventilated building where possible in an environment which the baseline study

describes a traffic dominated urban noise climate. Inbound noise from external sources can be a concern when

it comes to naturally ventilated buildings and the location of a naturally ventilated in high activity urban

environment would be somewhat questionable.

Architecturally rendered drawings show that it is proposed that the NCH bedrooms will be naturally ventilated

with top hinged window systems. Our Figure 15 on page 24 of this report shows an example of what we

understand to be a typical NCH bedroom. Naturally ventilated buildings are typically acoustically weak and

often are unsuitable at site locations where traffic noise and ambient noise is already likely to be high, such as

in this case.

In our view, the following guidance documents should be referenced to establish if a naturally ventilated building

is to be considered in what is already a built up urban environment, which could find the NCH proposed room

ventilation strategy to be inappropriate and unsuitable for the site.

Reference documents to be considered:

1999 WHO guidelines for community noise (sleep disturbance)

WHO Night Noise guidelines (L.O.E.L. with regard to sleep disturbance)

Health Technical Memorandum 08-01: Acoustics

The UK Department of Health issued specific guidance (HTM-08) which prescribes appropriate noise levels

relating to hospitals. The guidance provides different criteria for sleeping during the daytime and night, which

has been reproduced in Table 1 below. While it does acknowledge that Table 1 is not in full compliance with

WHO recommendations to avoid sleep disturbance, it also recognises that hospital environments can be

subject to high sporadic noise levels, including emergency vehicles and helicopters. We were unable to locate

any such assessment in relation to likely inbound noise relating to the proposed naturally ventilated NCH

hospital building being proposed at St Jamess. The applications baseline study does show that daytime noise


18/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

levels are significant at street levels, such as baseline study locations (N2, South Circular Road) with traffic

noise levels as high as 66dB(A) at the lower floor facades and (N5, St James's Walk) with distant traffic and

Luas noise as high as 62dB(A) at midnight. We note that there are parent accommodation rooms planned on

these naturally ventilated facades at Level 2 and bedroom accommodation at Level 1, which would cause

concern in relation to the proposed naturally ventilated building strategy.

Table 1: Extract from HTM-08 in relation to criteria for noise intrusion to be met inside the spaces fromexternal sources.

There is no evidence in the AWN Consulting report submitted with the application, to establish if it is appropriate

to install a naturally ventilated building at this urban location. It is worth noting also that for the construction

phase of the proposed NCH project over a 2 ~ 3 year time frame, how the noise climate in the existing St

Jamess hospital will differ from the levels described in Table 1 (HTM-08) extract above is not addressed. This

needs to be determined if the intrusive noise from construction will allow St Jamess to function and continue

as a working hospital throughout the protracted construction phase. In fact it would appear that AWN in their

review of the proposed construction noise impact, propose that Clinical areas have factored in a degree of

noise reduction afforded by a closed windows to minimise noise intrusion. This in our view should not be

proposed without the consideration of how these clinical areas will be ventilated in the absence of what appear

to be naturally ventilated rooms with openable windows.

5.2 Assumptions made in the AWN Consulting study

The AWN Consulting chapter on noise and vibration, submitted as part of the NCH EIS, suggests that the

impact of noise has been quantified using just four helicopter movements per week. The AWN Consulting

submission is clear on its assumptions that the basis of the assessment had been carried out based on the

following assumptions:

the aircraft that will be in service at the site will be an Augusta Westland AW-139 as operated by

the Irish Air Corps;

helicopter trips to the new childrens hospital will be for emergency cases only and as a result mayoccur at any time of the day and night;


19/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

the proposed helipad will service both the new childrens hospital and the wider St. Jamess Hospital

campus, and the expected number of cumulative flights (i.e. serving the new childrens hospital and St.

Jamess Hospital campus) over a week long period is 4 landings and 4 take-offs.

Following on from these assumptions, the Chapter on Noise within the EIS assumes a very basic interpretation

and limited understanding of how helicopter operations actually work in practice. In the predictions carried out,

the EIS considers:

Just one helicopter type and no consideration has been given to other helicopter types.

The prediction process has been based on measurements carried out by a third party, Commandant

Colin Roche using a Brel & Kjr Type 2260 Precision Sound Level Analyser, with no detail providedon the test arrangement, with the exception that measurements were conducted at 3m distance (from

where?). It is expected that if this relates to 3m from the aircraft fuselage, then Commandant Roche

would be directly under the main rotor.

The predictions are over simplistic in that they simply consider a landing time of 63 seconds and a take-

off time of 17 seconds.

It is clear that there is a fundamental misunderstanding of actual Medevac helicopter operational requirements

which have not been factored into the predictions carried out by the projects noise consultants. While we are

not disputing Commandant Roches measurements, there has been a fundamental misunderstanding as to how

helicopter operations function at a Hospital Helipad. When we examine the predictions, it is clear that a very

limited set of data, which are of very short duration event times (63 seconds & 17 seconds) have been

considered. Figure 5 below, extracted from the AWN Consulting report, considers a single Augusta Westland

AW-139 as the only helicopter that will use the proposed helipad.

Figure 5: Extract from the Chapter 11 (Noise and Vibration) relating to the measurement of a singleaircraft (AW-139) prepared by Commandant Colin Roche of the Irish Army.

In the submitted EIS the noise consultants have attempted to predict the impact of helicopter noise using the

benefits of averaging the noise levels over a day time 16 hour period and an 8 hour night period. In Figure 6

below we can see that the night dB(A) level is based on a single landing which has been averaged out over an


20/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

8 hour period in an attempt to minimise the apparent impact created by a landing at night. However what is

likely to be much more important in relation to assessment of helicopter noise in this particular situation is the

likely level of noise from individual events, which may give rise to sleep disturbance or in this case cause fright

to young children.

Our noise contour model shows that the actual noise level experienced at worst affected residential properties,

when the aircraft is landing or taking off at the helipad will be in the order of 72dB(A) for the Augusta Westland

AW-139 when hovering at the helipad, which in our view is a very significant impact. This has been based on

the consideration of a single helicopter type and does not represent larger aircraft such as the Sikorsky S92. It

is also worth noting that NO consideration has been given in the EIS to the likely impact of noise in relation to

the rooms in the hospital affected by noise from helicopter activity at the helipad.

Figure 6: Extract from the Chapter 11 (Noise and Vibration) of the EIS relating to the predicted noiselevels at James' Walk and South Circular Road/Mountshannon, all of which have been based onreported noise levels prepared by Commandant Colin Roche of the Irish Army

It would appear that the LAeq,T has been averaged over a 16 hour period for the daytime and an 8 hour period

for the night time, which has then been applied to noise sensitive locations at St James Walk and South

Circular/Mount Shannon.

When we examine the impact of a helicopter over shorter, more appropriate observation periods, we can see

that the impact of noise is numerically greater than what is being reported. If the noise consultants assumptions

only consider 1 landing and 1 takeoff over a 16 hour daytime period, it is likely that these two short events will

indicate a numerically lesser impact. For the night period we note also that AWN Consulting considered only a

single landing for a given night which was then averaged over an 8 hour night period. This again would indicate

a numerically lesser impact than what would have been expected if assessed using a 15 minute or 5 minute

night period, which in our view would have been wholly more appropriate.

It should be noted however that humans do not average single noise events over an eight hour period at night

and when a noise disturbance at night occurs, it is evaluated as a single event which is contrasted with the

normal noise climate expected or the noise climate before or after the event. The averaging used by AWN


21/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

Consulting, using mathematical averaging over extended periods, has clearly under-estimated the true impact

of a helicopter event during the daytime and night periods.

The Irish EPA Guidelines (NG4), used for the assessment of industrial noise in Ireland, suggest noise sample

periods should be either 15 minutes or 30 minutes in duration, which applies to day, evening and night time

periods. Other standards such as BS4142:2014 suggest a shorter period of 15 min at night from 23:00 h to

07:00 h, so the concept of averaging noise impact over extended periods (16 hour daytime, 8 hour night time)

would not be appropriate for loud infrequent noise events, such as those created by helicopter landing close to

residential properties. Table 2 below has been prepared to show how time averaging can influence the

predicted level. In this table, we have used the 16 hour and 8 hour data presented in the AWN Consulting report

and examined this as an identical helicopter noise source over 15 minute and 5 minute intervals. It should be

noted that numerically the impact is significantly greater when appropriate shorter periods of assessment areused.

AWN's

Predicted

Daytime

Level

(Averaged

over 16

hours)

AWN's

Predicted

Night time

Level

(Averaged

over 8

hours)

Predicted noise

level, for the

same source

predicted using

LAeq,15mins for

a daytime period.

Predicted

noise level, for

the same

source

predicted

using

LAeq,15min atnight.

Predicted

noise level,

for the same

source

predicted

using

LAeq,5min atnight.

James Walk 62dB 68dB 77dB 83dB 87dB

South Circular

Road/Mountshannon

62dB 72dB 77dB 87dB 91dB

Observation Period 16 hours

(57500

seconds)

8 hours

(28,800

seconds)

15mins (900

seconds)

15mins (900

seconds)

5mins (600

seconds)

Table 2: Contrasting AWN Consulting's time averaged predicted levels against typical observationperiods.

It is clearly apparent that the impact of helicopter noise on both patients and residents, assuming landing/take-

off times as reported, when assessed in relation to individual events rather than averaging over an extended

period is very much greater than would be suggested in the AWN Consulting report.


22/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

With regard to the NCH proposed helicopter landings and take-offs per week, the EIS suggests just 4 per week

which will likely underestimate the likely use for a helipad that will service the existing St Jamess adult hospital

as well as the proposed NCH. In Galway City, for a much smaller hospital facility local news reports show that

the Helipad at UCHG is currently subject to one Irish Air Corp landing and take-off per day (Augusta Westland

AW-139) and on some days the hospital can have up to seven Medevacs per day. A link to the news source

has been reproduced below for reference purposes.

http://galwaybayfm.ie/hse-justifies-upgrade-uhg-helipad/

We would be very concerned that the usage of the helipad as set out in the submitted EIS, with an expected

use of 4 times per week with a single type of helicopter, would grossly underestimate the likely noise impact on

residential properties as well as the noise impact on hospital bedrooms at the proposed NCH and the existingSt Jamess buildings. We would also suggest that Medevac operations could not be limited to just four times a

week either, simply by the fact that they are medical emergencies. Therefore in the submitted EIS, we are

unsure of the purpose of selecting just four landing/takeoffs per week was used and why some research was

not carried out at existing hospitals to determine worst case helicopter traffic, which would be then factored up

for the proposed single helipad serving the proposed NCH and the existing St Jamess hospital. This prediction

would include the likely noise impact created at the year of opening and say 15 years ahead, which would be

typical in an EIS study.

5.3 Measurement of an actual Medevac Hospital Landing/Take OffAs part of our study, we actually carried out a duration analysis for a Medevac 112 Hospital helipad landing at

UCHG Galway City. As part of this study, the aircraft evaluated was an Irish Air Corps Augusta Westland AW-

139. This study allowed us to accurately quantify the times involved, which are significantly longer than those

used in the AWN Consulting's noise predictions in relation to the proposed Helipad at the proposed NCH at St

James's.

Figure 7: Medevac 112 landing and takeoff at UCHG, Heliport Galway City (April 2015)


23/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

Action Description Duration

Approach to the helipad Helicopter noise was the dominant source of noise.

Includes the helicopter approach right up to wheel

touchdown. Engine and main rotor operating at this time.

84 seconds

Aircraft on the helipad Ramp down of main engines and main rotor, however

the APU remained running after the main rotor had been

shut down.

50 seconds

Patient/Stretcher Transfer In this study, the engine and rotor were static, therefore

we have not included this in our Medevac time analysis.

Aircraft on the helipad Engine stabilisation and pre-flight checks before takeoff.

Engine and main rotor operating at this time.

120 seconds

Aircraft takeoff, hover and

departure.

Helicopter lift from helipad and departure. 57 seconds

Total time of event 311 seconds

Table 3: Evaluation of a typical Medevac landing and departure with an Irish Air Corps AugustaWestland AW-139 at UCHG Hospital, Galway City.

It should be noted that the AWN Consulting's predictions only consider a landing event of 63 seconds and a

departure event of 17 seconds which may have been a 'touch and go' event at Baldonnel Airfield, but it is our

view that the Medevac operation has been grossly underestimated in terms of its actual duration and

consequential noise impact. In our view the impact of a Medevac landing and departure has not been

adequately considered in the AWN Consulting chapter on operational noise impacts. The duration of the noise

impact has in fact been under-estimated by a factor of almost 350~400%, possibly from the use of 'touch and

go' measurements at Baldonnel Airfield, instead of examining an actual Medevac at a hospital helipad such as

we have researched and assessed. Figures 8 & 9 below shows the proximity of the proposed Helipad to both

residential properties as well as hospital bedrooms (Level 4, Level 5 and Level 6) at the proposed NCH

building.


24/40

ICAN Acoustics____________________________

www.acoustics.ie

Figure 8: Showing the proposedat the proposed NCH. Also in thislocated at St Jamess Walk.

Figure 9: This drawing shows a sproposed proximity to residential

ProposLo

Nearest Noise Sensitive Receproposed NCH extended ov

Level 5 and Level 6

______________________________________

-

ICAN Acoustics.

CH at St Jamess with the nearest noise sen image, we can see the nearest noise sensitiv

ction through the proposed NCH and its prodwellings on James' Walk.

d Helipadcation

NearesHospital

at the

Proposed HelipadLocation

ptors at ther Level 4,.

____________________

Page 19 of 35

itive bedroom receptorse residential dwellings

osed helipad and the

Nearest Noise SensitiveResidential Receptors at

James's Walk.

t Noise Sensitiveedroom Receptorsproposed NCH

Nearest Noise SensitiveResidential Receptors at

James's Walk.


25/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

5.3.1 Location of hospital bedrooms relative to the helipad.

Figure 10 below shows a plan view of level 4 showing noise sensitive hospital bedrooms and their proximity to

the proposed helipad. It should be noted that Level 4, Level 5 and Level 6 all house noise sensitive childrensnaturally ventilated hospital bedrooms.

Figure 10: Shows a plan view of the Helipad relative to the upper levels of the NCH.

Proposed HelipadLocation

Nearest Noise Sensitive Receptors atthe proposed NCH extended over

Level 4, Level 5 and Level 6


26/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

5.3.2 Preparation of a 3D Noise Contour Model of the Helipad

Using CADNA-A by Datakustik, a 3D noise contour model has been prepared for the site to allow us to model

the likely noise levels at the nearest facades to the proposed helipad, during helicopter operations at theproposed NCH. The model allows us to accurately determine the likely noise levels during a helicopter event at

the facades of Level 4, Level 5 and Level 6 of the NCH as well as the noise sensitive residential properties

within the area, most of which are at street level and on some occasion are at 1stfloor and 2

ndfloor levels.

Figure 11: Shows a 3D view of the noise contour model with a number of noise sensitive receptorsidentified which will be shown in the 2D noise contours below.

Noise receptors were modelled at window height at Level 4 of the NCH building, to determine the likely noise

level at the naturally ventilated hospital bedroom facades of the proposed building. Receptors at street level at

locations such as St James's Walk, Mountshannon Road and South Circular Road were modelled at 4m above

the ground level to represent the likely noise levels outside a typical residential bedroom at night. However, it

should be noted that there is a three story apartment block (Glenmalure Court Apartments) on St Jamess Walk

with bedrooms windows at circa 8m high which will be exposed to still higher levels of helicopter noise than a

typical residential property within the vicinity. So our predicted NCH helicopter noise levels within the vicinity of

properties on St Jamess Walk, Mountshannon Road and South Circular Road, is conservative in its prediction

and does not include higher level residential bedrooms that would exist in apartment type buildings, such as

Glenmalure Court Apartments.

Nearest Noise SensitiveReceptors at the proposed NCHat Level 4, Level 5 and Level 6

Proposed Helipadand modeled

Augusta WestlandAW-139

Nearest residential

properties on StJames's Walk 46mfrom the Helipad

Nearest residentialproperties on

MountshannonRoad.

Nearest residentialproperties on South

Circular Road.


27/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

5.3.3 Noise contour model showing the impact on the nearest hospital bedrooms

Modelled noise source: Augusta Westland AW-139 (using Commandant Colin Roches measurement data from

Baldonnel Airfield).

A typical scenario showing the likely noise levels at the facades of Level 4, Level 5 and Level 6 during a take-off

or landing of an Augusta Westland AW-139 has been generated by us. It can been seen that noise levels

outside hospital bedrooms, during a helicopter event will be in the order of 74~76dB(A) when aircraft is located

at the proposed NCH helipad.

Figure 12: A 2D noise contour model showing the likely noise contours created by an AugustaWestland AW-139 and the predicted noise levels at the facade of bedrooms at Level 4.


28/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

5.3.4 Noise contour model showing the impact of Air-Sea rescue helicopters

The AWN Consulting assessment in the submitted EIS is based only on a short measurement of one Augusta

Westland AW29 helicopter, which we understand was measured at Baldonnel Airfield by a third party armyofficer. This consultancy has measured noise from a Sikorsky S92 helicopter at another site, and this shows

that the noise levels will be 13.5dB(A) higher for the Sikorsky S92 when compared with the proposed Augusta

Westland AW29. This 13.5dB(A) differential has been determined from the reported landing level of 101dB(A)

at 3m from the aircraft, which we understand were compiled by Commandant Colin Roche of the Irish Air

Corps. When this scenario is modelled with regard to the proposed Helipad at St Jamess Hospital, it is clear

that the noise impact will be very significant with this larger aircraft.

Figure 13: It is clear that noise levels will be greatly in excess of 85dB(A) for the most part and thatHospital Bedroom facades will be subject to noise levels in the order of 85~92dB(A) when the aircrafthas the main rotor running on the helipad as shown above.


29/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

5.3.5 The NCH Natural Ventilation Strategy on facades

An extract from NCH Energy Strategy Report 14_D110 Satellite Centres, July 2015 suggest that the majority of

the NCH building will be naturally ventilated where possible. It suggests in our Figure 14 below that the NCHbedrooms will be designed to have openable window sections which will allow these rooms to be naturally

ventilated, with the exception of an extract fan in the en suite bathroom.

Figure 14: Extract from Energy Strategy Report 14_D110 Satellite Centres, July 2015

It is well recognised that naturally ventilated buildings are acoustically weaker than their mechanically ventilated

counterparts, which would be a serious concern with regard to the likely impact of inbound noise. While

naturally ventilated buildings are typically a preferred choice from a sustainability perspective, it is questionable

if a naturally ventilated building will provide adequate resistance to the inbound noise at the proposed NCH

building for both typical environmental noise as well as helicopter movements. Typical helicopter movements at

the proposed NCH helipad will include landings and takeoffs in close proximity to the NCH bedrooms.

Figure 15: Artists impressions show large glazed windows with natural ventilation provided by large top

hinges window sashes (Source: Irish Independent, Wednesday 30thSeptember 2015).

Naturally ventilated hospital bedrooms


30/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

Our predictions show that based on the AWN reported measurement the noise from the proposed Augusta

Westland AW-139 on the helipad would be in the order of 74~76dB(A) at the worst affected bedrooms.

Based on the 1997 World Health Organisation (WHO) Guidelines on Community Noise, a partially open window

will result in approximately a 15dB(A) level difference between the external facade and noise level inside the

bedroom. This methodology allows us to estimate the likely level inside a bedroom with a window which has

been left partially open for ventilation purposes. This would indicate that during a landing (Augusta Westland

AW-139) at the helipad, internal noise levels in affected NCH bedrooms will be in the order of 59~61dB(A).

Noise contour modelling shows also that helicopter noise levels outside noise sensitive hospital bedrooms

could be as high as 88~92dB(A) with larger aircraft such as the Sikorsky S92. At a level of 88~92dB(A) outside

a naturally ventilated bedroom facade, internal noise levels at the NCH bedrooms would be in the order of73~77dB(A).

It is worth noting also that hospital bedrooms are likely to have a vinyl type of floor finish combined with minimal

furnishings, which will make the rooms slightly more reverberant than one would expect in a domestic

environment. More reverberant rooms will give rise to marginally higher noise levels inside the hospital

bedroom which may result in a still lower performance than the 15dB(A) suggested in the 1997 WHO Guidance

on Community Noise. We understand also that the NCH bedrooms will include large windows and it is accepted

that facades with larger windows perform lower acoustically than typical arrangements where the window area

is small relative to say a masonry facade. It is worth noting also that large glazed panels, as is proposed on the

facade of the NCH, could well be subject to panel resonance effects due to the proximity of their natural

frequencies to that of the helicopters main rotor blade passing frequency, which should also be considered in

the assessment process. This has also not been undertaken by the applicants.

The 1997 WHO Guidance on Community Noise also discusses noise values to limit noise which would disturb

or interfere with restful sleep as well as recommended levels in other areas within a property. These guidelines

indicate that the noise level inside a living room, due to external sources, should not exceed 35 dB(A) during

the daytime/evening to prevent moderate annoyance, and 30 dB(A) at night-time to prevent sleep disturbance.

It should be noted that these standards are based principally on relatively steady, broadband noise such as that

from traffic, machinery, plant etc. The guidance indicates that When the noise is composed of a large

proportion of low-frequency sounds a still lower guideline value is recommended. The guidance also

indicates that short term impulsive noise will disturb sleep and that itis important to limit the number of noise

events with a LAmax exceeding 45 dB

It should be noted that noise from the proposed helicopter activities at the NCH will give rise to noise levels,

inside noise sensitive bedrooms, that will be some 25dB(A) higher than would be described as the level that

would prevent moderate annoyance in a living room. As a general rule of thumb, a level difference of 20dB(A)equates to a quadrupling of perceived loudness.


31/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

With regard to the night period, the noise level from any helicopter using the helipad would greatly exceed an

LAFmax of 45 without exception inside naturally ventilated hospital bedrooms, which is a level that the World

Health Organisation in their 1997 Guidelines for Community Noise say should be avoided at night to avoid

sleep disturbance. It is also worth noting that the 30dB(A) guidance value suggested by WHO at night, would be

exceeded by 40dB(A) during larger helicopter (Sikorsky S92) activity within the vicinity of the hospital bedrooms

on the south eastern and south western end of the residential block on Level 4, Level 5 and Level 6.

5.4 Specialist services Health Technical Memorandum 08-01: Acoustics(2008)

The UK Department of Health issued specific guidance which prescribes appropriate noise levels relating to

hospitals. The guidance provides different criteria for sleeping during the daytime and night time periods and

does acknowledge that the criterion is not in full compliance with WHO recommendations. The document does

provide very clear guidance on sporadic events, such as helicopter movements. The guidance in relation to

'Sporadic Events' is as follows:

2.15 Hospitals are often affected by noisy but sporadic events such as vehicle sirens,

helicopters and aircraft. Each source has to be considered separately and an appropriate

strategy devised.

2.16 A policy of no sirens on site (unless essential) is recommended.

2.17 It is unlikely that the criteria in Table 1(Table 1 in HTM-8) will be achievable with helicopter

movements included, so helicopters may cause some disturbance. Careful planning of the

hospital layout and flight path can, however, reduce the effects of helicopter noise.

Having reviewed the AWN Consulting chapter on the potential impact of helicopter noise on the proposed NCH

building or indeed the existing St Jamess hospital facility, it is clear that no careful planning has been devised

in relation to the proposed helipad.

To locate a helipad in such close proximity to a naturally ventilated hospital bedrooms is in fact a clear

demonstration that the helipad and the buildings natural ventilation strategy of the NCH are at cross purposes.

It would appear the AWN Consulting report references many international reports, some of which suggest that

the medical helicopter services are time-critical and provide a noise-excusable public service. We would

strongly disagree with this and that it is clear that patients of the proposed NCH hospital, the existing St

Jamess hospital and residents have not been adequately considered, which in our view is a very serious

omission in the noise assessment submitted with the planning application.


32/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

5.4.1 Irish Aviation Authorities Guidelines the location of Helipads

Having examined the projects noise consultants chapter on the impacts of noise from the proposed Helipad, we

note that the authors suggest that "there are no Irish guidelines for the assessment of helicopter noise impacts".

While we are of the view that there may not be Irish guidelines for the assessment of noise impact, the Irish

Aviation Authority do provide very clear guidance on the design and placement of helipads in the interests of

protecting residential amenity of which noise and vibration can be considered a very important component. We

could not find any reference to this guidance in the EIS, which specifically refers to the siting and location of

helipads. In our view AWN Consulting have gone to great lengths to identify studies which suggest that

'helicopter noise should not be considered and that it should be noise excusable' or that 'the activity is so

infrequent that the impact of noise need not be considered'. The studies presented by AWN Consulting in

support of this have been referenced below and we have provided further comments on our interpretation of the

studies.

Study 1:A New Zealand Standard (NZS 6807:1994) where is it simply stated that their standard 'is not

intended to apply to infrequently used helicopter landing areas or emergency operations'.

This in our view is no justification or a reason to ignore the likely operational impact of such aircraft. It is also

our view that AWN Consultants are not in a position to make comment on the likely future traffic associated with

the proposed St James's Helipad. In our view 4 landings/departures per week does seem very conservative and

something which could seriously underestimate likely usage. The volume of helicopter activity does appear to

be very moderate for a helipad which is intended to service the existing St Jamess Hospital as well as the

proposed national facility, when compared with current helicopter traffic at a smaller hospital such as UCHG in

Galway City.

Study 2:A reference to US Federal Aviation Authority (FAA) document 'Non-military Helicopter Urban Noise

Study, 2004, where it states 'Emergency helicopter service should be exempt from restrictions'.

This in our view relates to wider geographical areas and does not related to a single concentrated landing sitein a densely populated residential area, which is being proposed at the NCH at St James's.

Study 3:The UK Department of Health Estates and Facilities Division publication Health Building Note 15-03:

Hospital Helipads, 2008 states The occasions when ambulance helicopters cause disturbance are likely to be

irregular, few in number and short in duration. As a result, a formal noise analysis for hospital helipads is

unlikely to draw useful or objective conclusions and will be of limited assistance to planning committees.

We welcome AWN Consultings references to UK Department of Health Documents, however we do not

understand why a well known acoustics Health Technical Memorandum 08-01: Acoustics(2008) has not been


33/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

considered in their assessment. This document specifically addresses matters pertaining helicopter noise (and

other sporadic noise events) which has been discussed above.

For clarity we have reproduced the Irish Aviation Authoritys clear guidance on the selection of suitable Helipad

locations. See Figure 16 below where we have underlined the most relevant points.

Figure 16: IAA Heliports Guidelines for Heliport Site Owners/Occupiers and for Heliport Site-keepers

In our view this Irish Aviation Authority (IAA) guidance may have been overlooked as it is not referenced in the

EIS and its guidance is detrimental to the placement of the proposed helipad in the proposed NCH site at St

James's. It clearly acknowledges that a helicopter especially when operating over a populated or congested

area, can be noisy and an irritant to persons on the ground. The IAA extend this to suggest that such

arrangements often give rise to noise disturbance/nuisance complaints from members of the public and that this

should be taken into account when planning operations.

It would appear also that the IAA are clear in their guidance that they have no responsibility for helicopter noise

and that complainants have access to the EPA Act 1992 to address noise matters. This in our view would allow

a resident to readily challenge the use of the helipad and under noise nuisance law could allow the courts to

make a ruling that helicopter operations should be restricted to open space areas within Phoenix Park with

ambulance transfers to the proposed NCH facility.

We note that in the AWN Consulting's chapter on helicopter noise, there is a final statement that does cause us

some concern. In their final comments they suggest "it is concluded that helipad activity will not be a significant

noise nuisance". In our view AWN Consulting have not demonstrated that a noise nuisance will not be caused


34/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

by the proposed NCH helipad. In fact, if we were to analysis this statement further, it could be interpreted that

AWN Consulting are actually acknowledging that there will be a 'noise nuisance' caused by the proposed NCH

helipad, but that it will not be 'a significant noise nuisance' based on their assessment.

5.4.2 Helicopter noise impact in the AWN Consulting report.

In the section on helicopter movements, the AWN Consulting report suggests that "During the night-time the

overall noise impact will be greater due to the shorter assessment period". While this is correct in terms of the

fact that that the night period (of 8 hours) is shorter than that of a daytime period (of 16 hours), the authors have

simply neglected to mention noise sensitivity at night which is a crucial part of the assessment process. It is for

this very reason that typical limiting levels used by the EPA, as an example, are some 10dB(A) lower at night

than they are during a daytime period. We would be concerned that the authors are also attempting to average

a helicopter landing period over an 8 hour night period in an effort to suggest a lesser numerical impact. We are

at a loss to know why the authors did not prepare a noise contour map for helicopter landings at the NCH to

determine the likely impact on both hospital bedrooms and residential properties within the vicinity. In our view

this has been a very serious omission in the EIS.

We do appreciate that the AWN Consulting report does recognize and acknowledge the fact that the likely

helicopter noise in the area of the proposed NCH helipad will be easily recognisable and that it will dominate the

noise environment, however it is our view that helicopter operations have been grossly under-estimated in that

it has been based on a limited number of trips, i.e. 4 per week with the use of a single aircraft type.

Figure 17: Extract from the Chapter on Noise and Vibration in the EIS prepared by AWN Consulting.

In Figure 17 above, AWN Consulting suggest that the helipad will not be a significant nuisance, however we

note that they advise that several mitigation measures are presented in section 11.2.6 in order to minimise the

impact. When we examine Section 11.2.6 refers to three specific sub headings, which have been reduced

below:

11.2.6.1 Construction Phase (Construction related noise mitigation)

11.2.6.2 Operational Phase (Building Services & Additional Traffic on Public Roads)

11.2.6.3 Do Nothing Scenario (a scenario which requires no noise mitigation)


35/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

When we review Section 11.2.6, we note that AWN Consulting have neglected to suggest any measures to

reduce the impact of helicopter noise and they have simply omitted this in their study, despite suggesting that

their chapter provides several mitigation measures.

5.4.3 Alternative Helicopters

It should be noted that the noise consultants predictions assume the exclusive use of theAugusta Westland

AW-139 which in our view is simply insufficient. The 3D noise contour modelling and measurement data from a

Sikorsky S92, indicate that the predicted noise levels will be some 13.5dB(A) higher than the data provided by

the Commandant Colin Roche, which has been the basis of the AWN Consultings predictions for the proposed

NCH helipad.


36/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

6 Conclusion

Having reviewed the noise and vibration study (Chapter 11 and Appendix 11.1), submitted in support of the

National Children's Hospital application at St James's Hospital Dublin, we are forced to conclude that the

submission fails to adequately consider the likely impact on noise and vibration for the proposed development

both at the construction phase and at the operational phase. We have a number of sub conclusions below in

relation to the proposed development to explain how we have arrived at this conclusion.

6.1 Construction Noise Impact

Having reviewed details of the baseline study, the outline construction management plan, site predictions and

noise criteria used, it is our view that the authors have selectively used guidance prepared by the National

Roads Authority with limiting levels which contradict clear guidance suggested in BS5228. It would appear that

the authors, using the NRA's guidance on construction noise (for road projects), appear to be suggesting that

residents subjected to 70 dB LAeq day after day for a period of up to 3 yearswould find the noise environment to

be acceptable. BS5228, Paragraph E.4 is very clear on the significance of noise effect and suggests that where

the construction noise exceeds the ambient noise level by more than 10 dB and for a period of 10 days or more

in any 15 consecutive days or for a total of more than 40 days in any 6 month period, temporary re-housing

should be considered. It also suggests that buildings which are likely to be particularly sensitive to noise,

(including hospitals) will be subject to individual consideration. Having reviewed the authors baseline study,

noise levels during the construction phase will be 10dB in excess of the ambient, therefore temporary re-

housing would apply if the noise consultants were to adhere to the guidance they themselves refer to in their

assessment. It is worth noting also that NRA in the guidance (Guidelines for the Treatment of Noise and

Vibration during the construction of National Road Schemes, 2004) used in the EIS suggests on page 2 that

the NRA does not accept any responsibility for loss or damage occasioned or claimed to have been

occasioned, in part or in full, as a consequence of any person acting from, or refraining from acting, as a result

of matter contained in this publication. This in our view would be a further reason to rely on more appropriate

guidance defined in British Standard BS5228, Paragraph E4.

6.2 Vibration impact during the Construction Phase.

We do not dispute the vibration threshold levels which AWN Consulting had set out in their report in relation to

vibration sensitivity within a hospital environment. This is of particular importance since it is proposed that St

Jamess will continue as a working hospital throughout the construction phase of the project. While the AWN

Consulting assessment sets out vibration thresholds that should not be exceeded, they have made no attempt

to establish if these vibration thresholds can be met at vibration sensitive locations such as theatre locations or

imaging locations where Computed Tomography (CT) scans take place. We would be very concerned however


37/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

that the AWN Consulting assessment fails to geographically identify exact vibration sensitive locations and

establish if a construction project using the proposed methods is feasible in such close proximity to these

noise/vibration sensitive places. We would be very concerned about the reliance on a single third party

hypothesis, which we understand has been prepared by Rupert Taylor (Document Ref. CHOI/MPH/6A dated 7

February 2011). In our view their approach is very simplistic and it would not be correct to rely on a hypothesis

which was in fact developed for another site which assumes the ground to be homogeneous in nature. We

would be concerned also that there is no mention of any other possible source of vibration, such as the use of

mechanical breakers and pneumatic drills which would be used for the breaking and opening of concrete and

metalled surfaces.

We are not able to make any detailed comment on the method of vibration calculation but it would appear that a

very basic generic calculation has been used rather than one which takes account of the actual ground stratain this location. Considering that piling will take place as close as 7.5 m from clinical areas and 10 m from

residential properties, we would have expected to see a rather more robust prediction method.

6.3 The Impacts of Helicopter Noise and activity on Hospital Bedrooms

It is evident that no attempt has been made by AWN Consulting to assess the likely impact of inbound

helicopter noise on the NCH building which has been designed to be naturally ventilated. In our view this is a

very significant omission on their part. Noise contour modelling shows that areas which house the NCH

bedrooms on Level 4, Level 5 and Level 6 are worst affected by the impacts of airborne helicopter noise during

the daytime and night period. Predicted levels show that with a naturally ventilated room, noise levels inside the

bedrooms during helicopter landing and takeoff events during the daytime and night period will be very high and

would be likely to cause distress to sick children. In our view, it would be wholly inappropriate to locate noise

sensitive hospital bedrooms in such close proximity to a helipad. We are concerned also about the use of third

party basic data measured at 3m from one Augusta Westland AW139 at Baldonnel Airfield which actually under

represents the time associated with a typical hospital Medevac operation.

While the AWN report neglects to consider the likely effect of inbound noise on hospital bedrooms, we havemodelled the likely noise contribution from a Sikorsky S92 which is a larger and louder aircraft than the Augusta

Westland A139. It is likely that this aircraft will have a serious adverse impact on hospital bedrooms during the

daytime periods and will most likely give rise to sleep disturbance at night in hospital bedrooms.

6.4 The Impacts of Helicopter Noise on residential amenity

While it appears that AWN Consulting have considered the residential amenity in their noise predictions, using

16 hour and 8 hour mathematical logarithmic averaging, it is our view that the actual helicopter noise impacts

have been numerically understated. The predicted levels, averaged over these longer periods are wholly


38/40

ICAN Acoustics________________________________________________________________________________________


ICAN Acoustics.

inadequate representations of the actual noise impact expected at the nearest residential properties. We would

also be very concerned that the AWN predictions assume that a Medevac landing and take-off consists of a

single 63 second landing and single 17 second takeoff period. Having quantified the duration of an actual Irish

Air Corps Medevac at UCHG at Galway City, we estimate that the AWN Consulting calculations have predicted

the noise impact which is underestimated in its duration by a factor 350~400%.

When we apply our time studies to a typical Irish Air Corps Medevac operation, combined with the shortening of

the evaluation period to 15 minutes for 1 landing during the daytime and 5 minutes at night, it is evident that

actual helicopter noise impact will be very significant at the residential properties.

It is worth notin

ABPsubm,Noise Assessment,ICAN Acousticsor,CSR,forJ&J,Oct2015.pdf

Documents

Transcript of ABPsubm,Noise Assessment,ICAN Acousticsor,CSR,forJ&J,Oct2015.pdf