Asia Noise News

Upgrade to Hong Kong’s tram tracks is music to the ears of residents

Hong Kong’s double-decker trams will tiptoe through busy neighbourhoods and spare residents the usual screeching when upgrades to the tracks are completed over the next three years.

Affectionately nicknamed “ding dings” by locals for their bell sound, the trams generate a less desirable noise when they negotiate sharp bends or junctions.

Operator Hong Kong Tramways said work was now under way to replace the noisiest sections of the tracks with a design that was 16 decibels quieter.

“Don’t underestimate this number – for every two decibels we reduce, it translates to a 50 per cent noise reduction to the human ear,” senior engineering manager Steven Chan Si-yiu said.

The new design, featuring a rubber coating made up of recycled tyres, was successfully tested along a 100-metre stretch near the Shau Kei Wan terminus in 2016.

“Some residents nearby asked if services had been suspended because they could not hear the trams pass through anymore,” Chan said.

Additional benefits over the traditional concrete-lined tracks include better durability and shortened repaving time. But the upgrades come at a hefty price – each metre can cost up to HK$18,000, 40 per cent more than the current method.

Chief Executive Leung Chun-ying offered a much-needed financial boost in his policy address on Wednesday, promising subsidies to cover 2.4km of track.

Managing director Emmanuel Vivant estimated this grant would help them save HK$20 million. He revealed that four 90-degree bends around the Kennedy Town loop would be the first section to be upgraded, with other busy junctions in the pipeline.

In a separate development, the operator confirmed that more 10 air-conditioned trams would join the fleet next year after a pilot scheme last summer received overwhelmingly positive feedback.

A “cooler tram” has been in operation since June, picking up around 300,000 passengers and receiving a 98 per cent satisfaction rate.

The goal is to retrofit air-conditioning systems into 30 to 40 trams, subject to government approval as well as the capacity of the electricity grid.

The fares would be “different” from normal trams, but the management would not reveal details at this stage.Source

Asia Noise News

Road Noise: rolling noise

A noisy cabin can be irritating, especially if you want some peace and quiet after a stressful day at work. There are many reasons why they happen, but surprisingly, one of the most common culprits is your tires. Generally, when your moving tire’s rubber meets head-on with the road’s surface, it creates friction and noise that transfer inside your car.

Types of Tire Noise

There are many kinds of tire noise. These sounds may be caused by:

  • Tire tread in contact with the road.
  • Air getting compressed inside the tread grooves.
  • Air chamber inside the tire that causes a low-frequency hum when tires roll.

You can significantly lessen the level of road noise inside your car by choosing the right tire. Make sure to look for the following factors:

Tire’s Weight and Speed

You probably already know that different tires cater to different speed and weight limits.

You can see this in a car’s aspect ratio, which basically says that the higher load your tire can handle, the noisier it will be because they’re harder and stronger. Similarly, the faster speed your tire can handle, the more noise it’s going to generate.

Tire’s Wheel Size

The size of the wheel matters. This is because the thicker the height of a tire’s rubber that rolls on the road, the noisier it gets. So an 18-inch tire is quieter on the road compared to a 20-inch tire.

Tire’s Width

The narrower your tire’s width, the quieter it is because there’s only a small portion of rubber that comes in contact with the road.

Tread Design (Pitch Pattern)

Believe it or not, even the grooves in your tire–or tread style–can create different noise levels. Short, repetitive tread pitch patterns like the lug or block type patterns can create a “whining” sound, while those with rib tread patterns are often the quietest. Those with variations, such as the rib-lug lug tread patterns, stand in the middle when it comes to noise levels.

Tread Rubber

Tires perform better depending on how they’re made. When you match them to the right specifications, you’ll find that they don’t generate too much noise.

For instance, tread rubber (or compound) determines how much traction can be made on the road when it’s wet. The softer tread rubber gives the car a tighter grip during slippery conditions. It also helps create more heat in the tire, making it stick better on the surface. When used for this purpose, there is less noise generated, since the tires are working efficiently.

Materials (Road and Tires)

The road’s surface can also affect noise, especially when taken together with your tire’s composition. Rough roads that come in contact with tires will generate more noise compared to those with smoother surfaces.

On the other hand, softer rubber compositions are quieter, while the harder ones can generate more noise. Nevertheless, it’s important to consider your needs and priorities first. Yes, the softer ones can lessen road noise, but you might spend a lot on fuel each month if you drive huge distances or drive on bumpy roads daily. In this case, you should choose which matters to you more: saving money or a quieter, more comfortable ride.

Tire Pressure

Tire pressure matters.  Over- or under- inflated tires will greatly diminish your tire’s efficiency, even if you’re using the right tread rubber and tire pattern. For instance, the level of noise that goes inside your cabin may be louder if your tire’s under-inflated. Not only is this bad for your tire, but it can also waste a lot of fuel in the process.

Choosing the right tires is often a trial-and-error process, and it may take a bit of time to find out what works best for you. The good news is there are many tires to choose from these days, and technology has manufactured innovative ones that create less noise than the traditional tires. They’re certainly worth every penny, if peace and comfort are what you’re looking for in a vehicle.

Source link Carmundi