23-05-2014, 10:53 AM
Railways
History of Railways
In the earlier stage of 17th century coaches were built and it was drawn by the horses only.
After that in the year of 1769, Nicholas Joseph Cugnot invent & construct a steam locomotive, at that time it was tractive work on roads only.
In year 1784 timber blocks were laid and coaches drawned, and in the year of 1789 the timber was get replaced by Cast-iron plates.
In the year of 1804 Trevithick designed & constructed the locomotive for railways, on feb 24, 1804 it started its journey to a small town of Merthyr in wales.
Five heavy Carts full of irons & 10 men's were traveled in that coach, it takes 2 hours to reach 14.5 km.
Indian Railway – (IR)
In the year of 1832 construction of railway line b/w Madras & Bangalore was stopped though non-materialised.
In 1844, the first proposal for the construction of railways in were submitted by East India company by R.M.Stephenson.
In 1853, the first railway line b/w Bombay to Thane was opened. It has 14 coaches & 3 engines.
In the year of 1855-60, 8 Railway companies were established.
India had total of 14,920 km of railway lines in the year of 1879, and new contracts were also signed in 1881-97.
1920 Indian Railway Committee was appointed under Sir William Acworth.
General Introduction - IR
Service : Passenger Railway, Freight Services, Parcel Carrier, Catering, Tourism Services.
Controlled by Ministry of Railways India.
Net income Rs. 145 billion
Employees 1.4 million
Division 17 zones.
Route passing 65000 km & 7500 stations.
25 million of peoples were using daily.
2.5 million tons of goods were transport daily.
It covers 24 states & 3 territories.
International services to Pakistan, Bangladesh & Nepal.
Gauges Board Gauge(1.676 m), Meter Gauge(1.000m) & Narrow Gauge(0.762 & 0.610m).
Railway Track – (The Permanent Way)
The combinations of Rails, fitted on Sleepers and resting on Ballast & Subgrade is called The Railway Track or The Permanent way.
In railway tracks, the rails are joined in series by Fish Plates & Bolts.
Then they are fixed to sleepers by different Types of Fastenings.
The sleepers were properly spaced, resting on ballast are suitably packed & boxed with ballast.
The ballast rest on the prepared subgrade called Formation.
Min. ballast cushion is maintained at the inner rail, while the outer rail gets more ballast cushion.
Theory of Coning
On a railway level track, the moment the hinge loco motes towards one rail, the wheel tread width above the rail steps-up but reduces over the other rail. This forbids the auxiliary movement and hinge pulls back to its original position. This is possible only if the diameters on both rails are equal and the pressure on both the rails is also equal.
On a coiled path, because of rigidity of the wheel bottom either of the wheels has to slip by a measure equal to the differentiation of length or else the axle has to move outward a bit so that a tread with longer diameter is formed over the outer rail whereas a slighter diameter tread is formed over the inner rail.
Curves
Transitional Curves
It is defined as a curve of parabolic nature which is introduced b/w a straight & circular curve or b/w two branches of a compound curve.
It’s radius varies from infinity to a selected min in order to attach full super elevation & curvature gradually.
Types of Transition Curve
Spiral curve -> Radius of curvature = (l / length of curvature)
Cubic parabola -> Decrease of radius of curvature from 4o to 9o
Bernoulli’s lemniscate -> acceleration fall without uniform beyond 30o defelection