Location: London, Ontario
Client: General Dynamics Land System Canada
General Dynamics Land Systems-Canada (“GDLS-C” is a global defence industry leader in providing land and amphibious combat vehicle solutions. The Canadian operations employ approximately 1,700 people who design, manufacture and support light and medium armoured vehicles.
Acoustic Assessment Report (“AAR”)
HGC Engineering was retained by the company to update the Acoustic Assessment Report (“AAR”) for its main Canadian facility located at 1991 Oxford Street East in in London, Ontario. The purpose of the assessment is to evaluate the overall sound emissions of the facility under a predictable worst-case operating scenario, which is defined as an hour when typically busy operation of the stationary sources under consideration could coincide with an hour of low background sound.
Computational Acoustical Model of the Facility
Sound levels were measured at the facility on numerous occasions between 2006 and 2019, near each stationary source and at neighbouring offsite points of reception. The sound power emission levels were used as input to a computational acoustical model of the facility in order to prepare a sound source inventory, and thereby determine the contribution of each individual source to the overall offsite sound levels. The Environmental Compliance Approval (“ECA”) for the facility stipulates that its sound levels comply with Ontario Ministry of the Environment, Conservation and Parks (“MECP”) Publication NPC-205, which was thus employed as the basis of this assessment.
The lands immediately surrounding the facility are a mixture of industrial and commercial zones, with residential areas further to the south and west. The most potentially impacted points of reception are single family dwellings to the southeast and west of the facility.
The background sound in the vicinity of the facility is dominated by local road traffic as well as surrounding commercial and industrial activities. The area is best characterized as a “Class 1” urban area, under MECP noise assessment guidelines.
Facility Description and Sound Source Summary
The facility can operate up to 24 hours per day, 7 days per week. The primary mechanical sound sources associated with the facility are various dust collection systems, building vents and exhausts, as well as an emergency generator and firewater pump, which are periodically tested during daytime hours.
Test Track Noise Measurements
In addition, GDLS-C tests prototype vehicles and production models on an elliptical test track at the south end of the facility. The test track is approximately 1.2 km around. HGC Engineering personnel visited the GDLS-C facility on a number of occasions between 2006 and 2015 to conduct detailed noise measurements of all documented test activities performed on the test track and in the track infield area. Independent measurements were conducted of each of the three vehicle variants produced at the facility, For each of these variants, sound level measurements were conducted of vehicle pass-bys in each transmission gear (both in the clockwise and counter-clockwise directions), as well as brake, acceleration and reverse tests. The incline test and turn test, which are completed on the infield of the test track, was also measured for each vehicle
The acoustical measurements and analysis indicated that the sound levels of the facility are within the applicable sound level limits. Given the absence of any sources of ground-borne vibration at the site, the facility also complies with the impulse vibration limits set out in NPC-207.
Service Solutions Delivered:
- Conducted detailed acoustical assessment reports and audits in accordance with provincial environmental regularly guidelines
- Performed detailed environmental noise measurements of all documented test activities performed on a vehicle test track