Tuesday 26 November 2019

KNOW THE MECHANISM BEHIND EMERGENCY PULL CHAIN !!


You might have seen an Emergency pull chain in Railways. The chain is used to stop the train at the time of an Emergency. Most of us though know what the Pull chain is been used for but do not know the exact mechanism of it. Here is a brief description of what exactly happens in a Train when you pull the Emergency chain.

In a Typical Indian train, the coaches are interconnected by two pipe hoses. The alarm pull chain is in continuity with the Brake pipe (As in the Schematic diagram below) constantly maintained at specific air pressure.
Whenever the chain is been pulled some Air (earlier vacuum drop was used) escapes from the Passenger Emergency Alarm Valve ( PEAV ) vent. 

 
This drop in pressure results in the application of the brake cylinder/piston assembly in the bogie of the coach, which starts pressing the brake pads on the wheels or disc of the entire train. The loco pilot also notices the air pressure drop in the gauge and then uses his own skills to help the train stop comfortably.

As soon as there is pressure drop, the driver whistles in "two short one long" to indicate to the guard and the train TTEs that there has been Alarm chain pulling.

The guard's compartment also has the air pressure gauge which gives him an indication.



Also recently the coaches have been fitted with emergency flashers on the sidewalls of the coaches, and these flashers are also activated when the brake pipe pressure is lost for any reason other than the driver's application of the brakes.

Assistant Driver and Guard find out in which coach the ACP actually occurred and help to "put right" the concerned coach i.e. the lever needs to be manually reset that helps to release the brakes of that coach. Until this is done, the lamp and buzzer in the locomotive cab are continuously activated. The air pressure system again builds up air pressure and that releases all brakes of all coach and the train gets ready to depart.

Monday 25 November 2019

KNOW WHY BUCKETS GENERALLY HAVE FRUSTUM SHAPE !!


You might have noticed that buckets generally have a conical or frustum like shape. Have you ever wondered why is it designed so? Why not any other shape?
We will discuss the reason behind the conical shape of the bucket in this article.

The bucket is designed in conical shape due to the following reasons:


1.)A bucket is typically used to put something in, e.g. you dip a mug in it or wash something in it. This means having a large top area is useful for easy access.

2.)It makes it easy to hold or lift the bucket of such shape as any other shape like a cylinder or frustum upside down will have the chances of slipping down.

3.)The center of gravity of frustum shape is such that it provides the least effort and easy means to lift it.

4.)While pouring down the water or liquid out, the frustum of the cone-shaped bucket provides easy grabbing and balance and comfort.

5.)This shape allows multiple buckets to be stacked (nested) inside each other, providing both dense and secure storage of large numbers of buckets.

Compared to the cylinder, a frustum shape gives maximum weight distribution while lifting thus minimum effort is used while lifting bucket of frustum shape.

Wednesday 13 November 2019

KNOW WHY 10:10 IS DEFAULT TIME IN CLOCK !


You might have noticed that the watches and clocks found in product photographs and advertisements usually show the time 10:10.Have you wondered the reason behind this.We will discuss the reason for this in this article.

These are some reasons why exactly this time is chosen.According to the New York Times, the main reason is quite simple and obvious: aesthetics. There are a number of visual advantages to having the hands set at the 10:10 positions.

1.)One is that the hands are kept from overlapping at this position. Having them on both sides of the watch face ensures that the hands themselves are visible and can be appreciated.


2.)When we look at a watch at 10:10, we consider as if the watch is smiling. It is lovely to have a smiling face, rather than having a crying face when the time is at 8:20. So the form of the hands has a positive effect on the view.

 3.)The arrangement of the hands is symmetrical, which people generally find more pleasant than asymmetry, making the product more appealing to customers.

4.) The manufacturer's logo, usually is in the center of the face under the 12, is not only visible but nicely framed when the needles are positioned at 10:10.


5.) Additional elements on the face (like date windows or secondary dials), usually placed near the 3, 6, or 9, won't be obscured.

There are a number of urban legends regarding the 10:10 time floating around in the world. Many of them attribute it to a historic event (e.g. Lincoln/JFK assassinations, the dropping of the atomic bombs), but there isn’t any truth behind those explanations. 

Sunday 10 November 2019

KNOW THE DIFFERENCE BETWEEN MANUFACTURING AND FABRICATION !


Fabrication and manufacturing are industrial terms linked to the process of production or construction. Often, the two processes are confused, yet they are very different from each other. In this article we will explore the meaning of both fabrication and manufacturing in industrial processes.

Manufacturing is the process of converting raw materials into a finished product, by means of large-scale industrial operations.The manufacturing process are the steps in which the raw materials have to undergo before they are converted into the final product.Essentially, it is producing something from start to finish. The manufacturing sector involves large scale production with the use of machines, tools and chemical/biological processing. It is the course that raw materials have to undergo before being considered a final product.


Fabrication refers to the process of constructing products by combining diverse, typically standardized parts. The concept of fabrication always involves the process of assembling. An example of the process of fabrication is the fabrication of a boat by assembling standard components.

The key difference:

The key difference between manufacturing and fabrication is how much of the process a job involves. Fabrication involves the assembly of standard or specialised parts to form parts of a product to be used in the manufacture of the finished piece. Manufacturing, however, is a start to finish movement, from the creation of parts through to the final assembly to produce a finished product, often using areas of fabrication within the manufacturing process.

Friday 8 November 2019

KNOW THE PURPOSE OF HOLE IN WASHBASIN !


You all must have seen the hole in the washbasin. Have you ever wondered, what is the purpose of these holes on the side of a sink. We will discuss the purpose of the hole in the washbasin in this article.

This opening is located on the wall of the basis nearest to you, near the top of the basin. The overflow opening serves two important functions:

1.)If the water tap is left on while the drain stopper is closed, the opening will channel water down into the drain opening rather than letting is spill out of the sink onto the floor.


2.)The overflow allows the sink to drain faster by introducing air into the system.

Preventing Overflow:

If you close the drain of your bathroom sink and fill up the sink basin to the level of the overflow hole, the water will begin draining into the overflow opening and down the drain. This helps prevent the water from spilling over the top of the basin, but because sink overflow holes are usually small, they may not prevent an overflow for very long.



Improving Drainage:

The sink overflow helps the basin drain faster by allowing air into the drain pipe via the overflow channel. When there's enough water in the basin to completely cover the drain opening, the drain can't get air through the water, creating a suction effect that slows the flow of water going down the drain. But with the overflow feeding air to the drain pipe, the suction effect is reduced and the water drains much faster. By contrast, sinks that don't have overflow openings commonly send up bubbles as they drain, and they typically drain more slowly.


Different sinks have varying designs along with hole types and where they are located. Some might be on the same side of the basin, whereas others might be located under the faucet or at the sink’s opposite side. The difference in the placement of these holes is meant for aesthetic reasons only.