Bank Station Capacity Upgrade

Background 

The Bank Station Capacity Upgrade project was a comprehensive initiative aimed at enhancing the station’s capacity and improving passenger experience.  

What we did 

We were commissioned by Dragados SA to undertake several key components, including baseline noise and vibration monitoring, groundborne noise and vibration assessment prior to the commencement of the works and then a decade later fixed plant atmospheric noise impact assessment, internal noise commissioning, internal plant operational noise assessment, and EDNE (Emergency Do Not Enter) audibility measurements.  

This case study provides an overview of the methodologies, findings, and outcomes of these assessments. 

Baseline Noise and Vibration Monitoring 

The baseline noise and vibration monitoring were conducted to assess the existing environmental conditions before the commencement of the upgrade works. The monitoring was carried out between October and December 2013 at various locations around the proposed upgrade site. The primary objectives were to evaluate potential construction noise and vibration impacts, identify appropriate mitigation measures, and assess the suitability of the site for over-site development 

• Noise levels were measured using indices such as L,_Aeq,T, L,_Amax,F, and L,_A90,T
• Vibration levels were assessed using Peak Particle Velocity (PPV) and Vibration Dose Value (VDV)
• Long-term noise monitoring was conducted at several locations for periods ranging from 7 to 14 days
• Vibration monitoring focused on measuring train pass-bys over a sample period of two hours 

 Groundborne Noise and Vibration Assessment 

The groundborne noise and vibration assessment was conducted between November and December 2013 at two locations near the proposed upgrade site. The primary focus was on evaluating the impact of London Underground train movements on groundborne noise and vibration levels 

• Vibration and sound pressure measurements were carried out in 100ms intervals
• The main sources of groundborne noise and vibration were identified as train pass-bys
• Measurement locations included sensitive buildings that might be affected by the upgrade works 

Fixed Plant Atmospheric Noise Impact Assessment 

The fixed plant atmospheric noise impact assessment aimed to evaluate the effect of noise emissions from operational fixed plant at Bank Station following the capacity upgrade works. The assessment involved attended and unattended noise measurements, acoustic modeling, and comparison with design noise level criteria. 

• Noise levels from operational plant were measured at various locations around the station
• Acoustic modeling was used to predict noise levels at nearby receptors
• The assessment demonstrated compliance with both London Underground and City of London noise emission limits

Internal Noise Commissioning 

The internal noise commissioning assessment in 2023, following the works, focused on measuring noise levels within specific internal spaces at Bank Station. The objective was to ensure that noise levels met the design criteria for various room types, including ticket offices, station computer rooms, and plant areas. 

• Measurements were conducted during both day and night to capture typical operational conditions
• Noise levels were compared against criteria specified in the Bank Station Capacity Upgrade Project Mechanical Services Specification
• In most cases, the measured noise levels were within the acceptable limits

Internal Plant Operational Noise Assessment 

The internal plant operational noise assessment aimed to evaluated the noise emissions from fixed plant within the station building. The assessment involved measuring noise levels in various internal spaces and comparing them against the design criteria. 

• Measurements were conducted in both occupied and unoccupied spaces
• The assessment demonstrated that the noise levels from operational plant were within the acceptable limits for most spaces

EDNE Audibility Measurements 

The EDNE (Emergency Do Not Enter) audibility measurements were conducted to assess the audibility of new emergency signage installed as part of the Bank Station Capacity Upgrade works. The assessment aimed to ensure compliance with Transport for London (TfL) Standard S1087 Fire Prevention and Protection – Emergency Do Not Enter Signs. 

• Acoustic measurements were conducted during a night-time survey to minimize the influence of ambient noise sources
• Measurements of daytime ambient noise levels during peak travel times were also taken for comparison
• We recommended further adjustments to improve the sound emission levels from the signage so to meet the required standards and to ensure audibility

 Conclusion 

Our involvement in the Bank Station Capacity Upgrade project ensured the team successfully addressed the challenges of noise and vibration management through undertaking comprehensive assessments and recommending mitigation measures.  

The project demonstrated compliance with relevant noise and vibration standards, ensuring minimal impact on the surrounding environment and enhancing the overall passenger experience.