❓ A WA parliamentary question on notice regarding traffic volume in the Northbridge Tunnel and air quality monitoring in the new William Street railway tunnel. The response details traffic figures and explains why air quality monitoring isn't required for electric rail tunnels.
AnsweredQoN 2948Legislative Council
QuestionView source ↗
(1) Further to question No. 722 regarding the Northbridge Tunnel, will the Minister provide details of the numbers of vehicles using the tunnel each year for the past five years?
(2) Which agency or contractor will monitor the air quality in the railway tunnel under William Street, Perth once it is in operation?
(3) What pollutants will be monitored in the William Street tunnel and what standards will be applied to air quality?
(2) Which agency or contractor will monitor the air quality in the railway tunnel under William Street, Perth once it is in operation?
(3) What pollutants will be monitored in the William Street tunnel and what standards will be applied to air quality?
AnswerView source ↗
Answered
16 March 2006
Responded by
Parliamentary Secretary representing the Minister for Planning and Infrastructure
Response time
120 days
2001 - 25 500 000 2002 - 26 500 000 2003 - 27 250 000 2004 - 28 750 000 2005 - 30 000 000 (2) Air quality will not be monitored. In road tunnels it is necessary to monitor the level of pollutants that are emitted from vehicles as a result of the combustion of hydrocarbon fuel. In the normal course of tunnel operation the pollutants are carried to the portals through the "piston effect" of traffic movement, where they escape to atmosphere. When the traffic in the tunnel is slow, congested or stalled for a length of time the piston effect does not work and ventilation fans are switched on to clear the build up of pollutants. The fans operate in response to devices in the tunnel that measure particulates (carbon particles from diesel motors) and carbon monoxide; other pollutants such as oxides of nitrogen and sulphur cannot be easily measured and in any case do not get to critical levels before the measurable pollutants noted above. Tunnels that convey electric railcars are entirely different in that there are no combustion emissions to pollute the air and therefore no requirement for devices to measure levels of either carbon monoxide or particulates that would trigger the operation of ventilation equipment. Consequently, no monitoring equipment is required for this purpose and accordingly, none will be installed in the City Project tunnels. This is standard practice for tunnels running electric railcars; for example, air quality is not monitored in any of the existing rail tunnels in Perth (Subiaco, Claisebrook and Roe Street) or on the underground systems in Singapore and Hong Kong. Notwithstanding the above, the air in the tunnels will be subject to constant change with every passage of train and through the ventilation systems in the stations, which will create air movement. If a train is stationary in the tunnel for an extended period of time there will be a build up of heat above the trains that will be measured and trigger the operation of the tunnel ventilation system to remove the heat from around the train's air conditioning units and change the air. There will be infrequent times during maintenance of the railway and with breakdowns that a diesel locomotive will pass through the tunnels; these will be planned occurrences and the tunnel exhaust system will be in operation to remove the particulates and diesel emissions. (3) Not applicable.
(2) Air quality will not be monitored. In road tunnels it is necessary to monitor the level of pollutants that are emitted from vehicles as a result of the combustion of hydrocarbon fuel. In the normal course of tunnel operation the pollutants are carried to the portals through the "piston effect" of traffic movement, where they escape to atmosphere. When the traffic in the tunnel is slow, congested or stalled for a length of time the piston effect does not work and ventilation fans are switched on to clear the build up of pollutants. The fans operate in response to devices in the tunnel that measure particulates (carbon particles from diesel motors) and carbon monoxide; other pollutants such as oxides of nitrogen and sulphur cannot be easily measured and in any case do not get to critical levels before the measurable pollutants noted above. Tunnels that convey electric railcars are entirely different in that there are no combustion emissions to pollute the air and therefore no requirement for devices to measure levels of either carbon monoxide or particulates that would trigger the operation of ventilation equipment. Consequently, no monitoring equipment is required for this purpose and accordingly, none will be installed in the City Project tunnels. This is standard practice for tunnels running electric railcars; for example, air quality is not monitored in any of the existing rail tunnels in Perth (Subiaco, Claisebrook and Roe Street) or on the underground systems in Singapore and Hong Kong. Notwithstanding the above, the air in the tunnels will be subject to constant change with every passage of train and through the ventilation systems in the stations, which will create air movement. If a train is stationary in the tunnel for an extended period of time there will be a build up of heat above the trains that will be measured and trigger the operation of the tunnel ventilation system to remove the heat from around the train's air conditioning units and change the air. There will be infrequent times during maintenance of the railway and with breakdowns that a diesel locomotive will pass through the tunnels; these will be planned occurrences and the tunnel exhaust system will be in operation to remove the particulates and diesel emissions. (3) Not applicable.
Tunnels that convey electric railcars are entirely different in that there are no combustion emissions to pollute the air and therefore no requirement for devices to measure levels of either carbon monoxide or particulates that would trigger the operation of ventilation equipment. Consequently, no monitoring equipment is required for this purpose and accordingly, none will be installed in the City Project tunnels. This is standard practice for tunnels running electric railcars; for example, air quality is not monitored in any of the existing rail tunnels in Perth (Subiaco, Claisebrook and Roe Street) or on the underground systems in Singapore and Hong Kong. Notwithstanding the above, the air in the tunnels will be subject to constant change with every passage of train and through the ventilation systems in the stations, which will create air movement. If a train is stationary in the tunnel for an extended period of time there will be a build up of heat above the trains that will be measured and trigger the operation of the tunnel ventilation system to remove the heat from around the train's air conditioning units and change the air. There will be infrequent times during maintenance of the railway and with breakdowns that a diesel locomotive will pass through the tunnels; these will be planned occurrences and the tunnel exhaust system will be in operation to remove the particulates and diesel emissions. (3) Not applicable.
Notwithstanding the above, the air in the tunnels will be subject to constant change with every passage of train and through the ventilation systems in the stations, which will create air movement. If a train is stationary in the tunnel for an extended period of time there will be a build up of heat above the trains that will be measured and trigger the operation of the tunnel ventilation system to remove the heat from around the train's air conditioning units and change the air. There will be infrequent times during maintenance of the railway and with breakdowns that a diesel locomotive will pass through the tunnels; these will be planned occurrences and the tunnel exhaust system will be in operation to remove the particulates and diesel emissions. (3) Not applicable.
There will be infrequent times during maintenance of the railway and with breakdowns that a diesel locomotive will pass through the tunnels; these will be planned occurrences and the tunnel exhaust system will be in operation to remove the particulates and diesel emissions. (3) Not applicable.
(3) Not applicable.
(2) Air quality will not be monitored. In road tunnels it is necessary to monitor the level of pollutants that are emitted from vehicles as a result of the combustion of hydrocarbon fuel. In the normal course of tunnel operation the pollutants are carried to the portals through the "piston effect" of traffic movement, where they escape to atmosphere. When the traffic in the tunnel is slow, congested or stalled for a length of time the piston effect does not work and ventilation fans are switched on to clear the build up of pollutants. The fans operate in response to devices in the tunnel that measure particulates (carbon particles from diesel motors) and carbon monoxide; other pollutants such as oxides of nitrogen and sulphur cannot be easily measured and in any case do not get to critical levels before the measurable pollutants noted above. Tunnels that convey electric railcars are entirely different in that there are no combustion emissions to pollute the air and therefore no requirement for devices to measure levels of either carbon monoxide or particulates that would trigger the operation of ventilation equipment. Consequently, no monitoring equipment is required for this purpose and accordingly, none will be installed in the City Project tunnels. This is standard practice for tunnels running electric railcars; for example, air quality is not monitored in any of the existing rail tunnels in Perth (Subiaco, Claisebrook and Roe Street) or on the underground systems in Singapore and Hong Kong. Notwithstanding the above, the air in the tunnels will be subject to constant change with every passage of train and through the ventilation systems in the stations, which will create air movement. If a train is stationary in the tunnel for an extended period of time there will be a build up of heat above the trains that will be measured and trigger the operation of the tunnel ventilation system to remove the heat from around the train's air conditioning units and change the air. There will be infrequent times during maintenance of the railway and with breakdowns that a diesel locomotive will pass through the tunnels; these will be planned occurrences and the tunnel exhaust system will be in operation to remove the particulates and diesel emissions. (3) Not applicable.
Tunnels that convey electric railcars are entirely different in that there are no combustion emissions to pollute the air and therefore no requirement for devices to measure levels of either carbon monoxide or particulates that would trigger the operation of ventilation equipment. Consequently, no monitoring equipment is required for this purpose and accordingly, none will be installed in the City Project tunnels. This is standard practice for tunnels running electric railcars; for example, air quality is not monitored in any of the existing rail tunnels in Perth (Subiaco, Claisebrook and Roe Street) or on the underground systems in Singapore and Hong Kong. Notwithstanding the above, the air in the tunnels will be subject to constant change with every passage of train and through the ventilation systems in the stations, which will create air movement. If a train is stationary in the tunnel for an extended period of time there will be a build up of heat above the trains that will be measured and trigger the operation of the tunnel ventilation system to remove the heat from around the train's air conditioning units and change the air. There will be infrequent times during maintenance of the railway and with breakdowns that a diesel locomotive will pass through the tunnels; these will be planned occurrences and the tunnel exhaust system will be in operation to remove the particulates and diesel emissions. (3) Not applicable.
Notwithstanding the above, the air in the tunnels will be subject to constant change with every passage of train and through the ventilation systems in the stations, which will create air movement. If a train is stationary in the tunnel for an extended period of time there will be a build up of heat above the trains that will be measured and trigger the operation of the tunnel ventilation system to remove the heat from around the train's air conditioning units and change the air. There will be infrequent times during maintenance of the railway and with breakdowns that a diesel locomotive will pass through the tunnels; these will be planned occurrences and the tunnel exhaust system will be in operation to remove the particulates and diesel emissions. (3) Not applicable.
There will be infrequent times during maintenance of the railway and with breakdowns that a diesel locomotive will pass through the tunnels; these will be planned occurrences and the tunnel exhaust system will be in operation to remove the particulates and diesel emissions. (3) Not applicable.
(3) Not applicable.
Explore WA Government Data
Search the full archive in the free dashboard, or query programmatically via API.
Explore more
Government Gazette
Appointments, regulatory notices, planning changes.
Hansard
Debates, questions, speeches and sentiment.
Tabled Papers
Reports and documents tabled in Parliament.
Committees
Committee profiles and recent reports.
Regulations
Subsidiary legislation with filters and summaries.
Bills
Proposed laws and parliamentary progress.
Acts
Current WA legislation and summaries.
Explanatory Memoranda
Bills with EMs (text/PDF) available.
Members
MP profiles, party breakdown and rankings.
Pollie Rankings
Data-driven rankings across 19 categories.
Amendment Chains
Track how schemes and regulations evolve over time.