light rail wheel/rail noise mitigation ashmont station ... rail wheel/rail noise mitigation ashmont...

Light Rail Wheel/Rail Noise Mitigation

Ashmont Station Noise Reduction John Grenier

Deputy Director Light Rail Maintenance, MBTA

Christopher Pacher

New England Regional Manager, LTK

June 14, 2011

June 14, 2011 | Leading the Nation in Transportation Excellence | www.mbta.com2 June 14, 201122

Ashmont-Mattapan High Speed Line Facts

Operating since 1929

8 Passenger Stations

9 PCC Cars in-service

2.6 miles

Connects to Red Line at Ashmont Station

Operating Rush Hour Headway of 5 mins

June 14, 2011 | Leading the Nation in Transportation Excellence | www.mbta.com3

Issue: Excessive Wheel Rail NoiseNew Ashmont MBTA Station required new turnaround

Direct Fixation track approx. 65 ft radius

Noise complaints from the surrounding community


MBTA ActionMBTA Subway Operations – vehicle maintenance department was tasked with developing a vehicle based solution for reducing wheel squeal of the PCC cars.

Measurements were taken by HMMH in June 2010 at 5 locations which allowed the MBTA to analyze the sound and develop a “Wheel Squeal Spectra”.

The MBTA immediately began investigating multiple short and long term corrective actions.

85 87

99

84 90

0

20

40

60

80

100

120

Radford Lane Beale Street Center of Loop Dorchester Ave Station Platform

Ma

xim

um

A-w

eig

hte

d S

ou

nd

Le

ve

l (d

BA

)

Prior to Mitigation

*Lmax - The highest noise level which occurs during approach to or departure

from the station


Wheel Squeal Spectra The analysis showed that the primary frequency source of the wheel squeal is 4,100 Hz. This analysis was used to develop corrective actions and was provided to potential solution providers.

Measurements taken by HMMH June 2010

Wheel "Squeal" Without Mitigation

at Center of Loop (65 feet), Car #3087

-140

-120

-100

-80

-60

-40

-20

0

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000 24000

Rela

tive S

ound P

ressure

Level

[dB

re: 20 m

Pa]

4,101 Hz

8,201 Hz

12,300 Hz

16,409 Hz 20,507 Hz

630 Hz

1,258 Hz

1,891 Hz


MBTA Solution Plan

Two Phases

Short Term

Ashmont Loop Water Spray System

Wheel Hubs

Vehicle Based Spray System

Long Term

Schrey & Veit (S&V) GMBH Wheel Absorbers

“A Vehicle Based Solution Benefits the Whole Line”


Short-Term Solutions


Ashmont Loop Water Spray SystemThe spray system is located adjacent to rail

A proven mitigation method

Lubricates the rail as the train traverses the curve

Impractical for the long term and in cold weather

16 1923

14 12

0

20

40

60

80

100

120

Radford Lane Beale Street Center of Loop Dorchester Ave Station

Platform

Maxim

um

A-w

eig

hte

d S

ound L

evel (d

BA

)

Prior to Mitigation With Mitigation Noise Reduction

Measurements taken by HMMH June 2010


Rubber HubMultiple configurations were evaluated, one selected

The hub works to mitigate the sound radiating from the wheels

Great short-term solution. Uncertainty remains about how long the rubber material will continue to be effective given constant service and environmental conditions.


Vehicle Spray SystemMBTA developed an onboard water spray systemThe system provides fluid directly onto the wheels of the lead truck The fluid changes the wheel to rail friction which reduces generated noiseThe flow of the water is initiated by the operator through a momentary switch


Long-Term Solutions


Tuned Vibration AbsorberSchrey & Veit GMBH (S&V)

Tuned vibration absorber affixed to the face of the wheel

Laboratory testing showing frequency response correction


Schrey & Veit Tuned Vibration Absorber Design


PCC Car Equipped With Tuned Vibration Absorber


Comparison of June 2010 & May 2011 Measurement Results

Prior to Mitigation Efforts

(June 2010)

Water Spraying System

(June 2010)

Rubber Hub

(May 2011)

Tuned Vibration Absorbers

(May 2011)

60

70

80

90

100

Radford Lane Beale Street Center of Loop Dorchester Ave Station Platform

Ma

xim

um

A-w

eig

hte

d S

ou

nd

Le

ve

l (d

BA

)


Wheel Squeal Spectra at Beale Street

20

30

40

50

60

70

80

90

100

110

12.5 25 50 100 200 400 800 1600 3150 6300 12500

1/3-Octave Band Center Frequency [Hz]

Max

imum

Sou

nd L

evel

[dB

]

Beale Street No Mitigation

Beale Street w/ Water Spray

Beale Street Damping Panels onWheel Web

Beale Street Tuned VibrationAbsorbers


Wheels with Tuned Vibration Absorbers


-140

-120

-100

-80

-60

-40

-20

0

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000 24000

Rela

tive S

ound P

ressure

Level

[dB

re: 20 m

Pa]

630 Hz

1,258 Hz

1,891 Hz

Wheels with Rubber Damping Panels


-140

-120

-100

-80

-60

-40

-20

0

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000 24000

Rela

tive S

ound P

ressure

Level

[dB

re: 20 m

Pa]

630 Hz

1,258 Hz

1,891 Hz

Comparisons of Corrective ActionsWheel "Squeal" Without Mitigation


-140

-120

-100

-80

-60

-40

-20

0

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000 24000

Rela

tive S

ound P

ressure

Level

[dB

re: 20 m

Pa]

4,101 Hz

8,201 Hz

12,300 Hz

16,409 Hz 20,507 Hz

630 Hz

1,258 Hz

1,891 Hz


Long Term – Vehicle Based Noise Reduction

Final Configuration

Schrey & Veit GMBH (S&V) Tuned Vibration

Absorbers

On board Water Spray System

Back of Flange Lubrication


Acknowledgments

3M

The Rubber Group

Schrey & Veit GMBH

HMMH

MBTA Everett Shops &

Mattapan Car House

http://www.rubber-group.com/index.html

http://solutions.3m.com/wps/portal/3M/en_WW/Worldwide/WW/

http://www.hmmh.com/index.html


Thank You

Go hear the results for yourselves - take the Red

line to Ashmont!

light rail wheel/rail noise mitigation ashmont station ... rail wheel/rail noise mitigation ashmont...

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