KNOW WHY I-SECTION BEAMS ARE USED FOR RAILWAY TRACKS !!

Generally rail tracks are made in I Section.We might wonder many times that why any other shape is not used.We might also wonder, why solid section is not used??We will discuss the reason behind selection of I beam for railway tracks in this article.

The usual, Flat Footed rails used for Broad Gauge lines is shown below with its components below.

This is typical shape of the cross-section of a track laid with Flat-footed Rails.

The Bull headed rails resemble the 'I' shape more correctly.

These are shaped so for following purposes:

> The top portion or the HEAD of the rail is thicker to take up the impact of the fast moving wheels, and carry the load of trains preventing abrasion of the tracks.

>The WEB of the rail is to uplift the train from the ground level; and as the inner flanges of wheels are of greater area than the outer flanges as shown below, so the web mainly provides clear cover (distance) between wheel base and the sleeper/ ballast layer.

>The FLAT FOOT provides two-fold purpose. Easy clamping i.e fixing to the sleeper beneath it because of wider area as well as greater surface area due to flat foot helps in load transfer to the sleeper more efficiently which further transfers the load to ballast and later sub-base.

WHY I-SHAPED ONLY USED,WHY NOT ANY OTHER SHAPE:

• A beam is more efficient when more material is AWAY from the center. It’s has more strength as compared to solid.

• Upper half should be wide enough to support the wheel and lower half should be wide & thick enough for clamping. Taking out extra materials saves significant amount of iron without compromising over strength thus giving it the shape of what you asked.
• Rail needs to be stiff in the vertical direction to take the load of the train.
• It needs to be relatively flexible in the horizontal direction so it can easily bend around curves.So material is reduced at the center to allow a bit of flexibility.

DIFFERENCE BETWEEN COOLANT AND LUBRICANT EXPLAINED !!

We will be talking these two terms in context to engine.

COOLANT :

Coolant in engine is used to absorb the heat of the engine. It is used in radiator and circulated outside the engine(They pass through the engine through jackets provided).

Water is used as coolant but now a days chemicals are used along with water. They prevent the rusting, cool engine fast and doesn't freeze.

LUBRICANT:

Lubricants are used inside the engine. They are hydrocarbons made up of base oil and additives. Base oil is the product of refining of crude like diesel and petrol and additives are chemicals mixed with base oil for specific purposes.

They reduce friction, seals the engines, indicates service life, clean the carbon, cool the engines, preventing breaking of parts and distributes the pressure. Lubricants outside the engine are used as greases and gear oil.

KNOW WHY AUTOMATIC TRANSMISSION VEHICLE GIVES LESS MILAGE THEN MANUAL TRANSMISSION VEHICLE !!

You might have wondered why 100cc scooter gives less mileage than 100cc manual transmission bike. Think about it where a 100cc scooter returns mileage near 40-50 Kmpl, an average 100cc motorcycle provides mileage over 60 Kmpl. The answer to this question lies in the transmission used where the scooters use automatic CVT transmission, while motorcycles use a proper 4 or 5 speed manual transmission.We will discuss about the reason behind this in this article.

Lets start with the purpose of a gearbox. The engine of a vehicle runs at a certain rotary speed or revolutions per minute ( RPM ). The required speed of revolution of the wheels is usually much less than that. For example, a typical 100cc bike engine can rev upto 6000rpm, but if the wheels ( 18 inch dia ) of a typical 100cc bike move at that speed, it would reach a velocity of 518 kmph!
So basically the gearbox is the intermediate mechanism which allows the engine and wheels to run at different rpm. 

The scootys use a system called a Continuously Variable Transmission ( CVT ), which in its simplest form is just a a cone pulley system with belts which allows for automatic adjustment of speed. The 100cc bike on the other hand has a manual gearbox, which requires you to manually select an ideal gear ratio for the given speed. Usually bikes have 5 gear speed ratios to choose from nowadays and they are thus called 5 speed gearboxes. 

Fuel economy depends on your RPM. The lower the rpm, the better fuel economy. Bikes with gears allow us to shift into higher gears and by doing so, the rpms decrease.At a given speed (say 40kmph), when in higher gear (4th gear), the bike has lesser rpms as compared to it going at same speed (40kmph) in a lower gear (3rd).In a gearless scooter, the rpms just keep building up continuously. So it has lesser fuel economy. 

Also, another major contributor to this is the fact that gearless scooters have a centrifugal clutch. In such a system, as the speed is building up, the centrifugal force acting on the clutch increases. Thus, it always remains partially engaged (detached from the input shaft). This translates into power loss and thus lesser fuel economy.  

 
The clutch is not controlled by the rider, it works automatically, and the clutch is also a pretty inefficient unit which draws its power from none other than the engine. This results in more loss of power and to make that up in terms of performance, the efficiency of the scooter takes a hit.

But most consumers don't mind because of the convenience of not shifting gears manually seems a fair trade-off. However, automatic transmissions are getting more high tech as we speak, and very soon this difference in efficiency will be negligible.