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.

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.

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.