The introduction of high-speed trains on Indian Railways has necessitated some changes in the design of the rolling stock. The important design features of modern coaches and goods wagons are described in the following sections.
The need for increasing the number of passengers in every coach along with providing them with greater comfort, introducing having more coaches in every train, and running trains at progressively increasing speeds has necessitated the modernization of the rolling stock.
The coaches manufactured by the Integral Coach Factory, Chennai are of the latest design. The body of the coach is made of a lightweight metal and has a tubular structure. The trough under-flooring, the sides, and the roof are welded together to form an integral unit. The floor consists of cross-beams, specially designed head stocks, sole bars, etc., all of which are welded together. The steel trough flooring run under the cross-beams and is welded to the head stocks and the sole bars. The advantage in this is that a trough section can withstand greater longitudinal loads and still help in keeping a check on the weight of the coach. The curved body of the coach reduces wind resistance and helps stability. The ends are also specially designed to absorb heavy impact shocks. Further, at the ends, the under-flooring is designed to be collapsible so that in the case of an accident, it absorbs the maximum force of the impact. The tubular structure ensures that the coach does not collapse inwards and thus ensures maximum passenger safety against heavy impacts. ICF coaches are, therefore, called 'anti-telescopic' coaches.
Like the coach body, the rest of the ICF bogie is also of a welded, lightweight design with a 9' 6” rigid wheel base running on roller bearings and mounted on pendulum-type axle boxes. The axle box guides are fitted with dash pots for absorbing the effects of the lateral bumps. Lateral shock absorbers prevent or absorb lateral shocks. All these fittings and the coiled spring design of the bogies ensure that they provide a very smooth side.
The BOX-type open wagon is the most significant of all the new wagons. It has a tare weight of 25 t and a haulage capacity of about 55 t. It has a robust structure and is fitted with centre buffer couplers at the ends that provide have automatic coupling. It runs on two bogies fitted with roller-bearing axle boxes. These wagons are most suited for long block rakes (consisting of 35 to 45 box wagons per train) carrying bulk commodities at high speeds.
The covered version of this type of wagon is the BCX wagon measuring 14.5 m in length, about 3 m in width, and about 2.5 m in height from the inside and with a haulage capacity of 52 to 78 t. It has two wing-cum-flap doors on each side and is provided with centre-buffer couplers.
The effort behind the design of these wagons has been directed towards increasing their size. The average haulage capacity of a wagon has progressively increased in a bid to absorb the growth in traffic as much possible without increasing the line capacity, which is costly in terms of both money and time.
There are three types of traction on Indian Railways, namely, steam traction, diesel traction, and electric traction. Steam traction has gradually been replaced by diesel and electric traction. Electric traction has many advantages over diesel and stream traction and is most suitable for high-speed and super-high-speed tracks. Locomotives, coaches, and wagons are the three components of rolling stock. Rolling stock for the modern tracks on Indian Railways are designed and manufactured by the Integral Coach Factory, Chennai. Special attention is paid to the maintenance of these coaches, which have been modified to suit the growing needs of the Railways.
1. With the help of a neat sketch, describe a vacuum brake and its working principle.
2. Explain slipping and skidding of wheels.
3. What are the requirements of a locomotive? Briefly the describe merits of the different type of tractions commonly in use in India.
4. What is a locomotive? What do you understand by a locomotive with a nomenclature 4-6-2? Describe the various components of a steam locomotive.
5. What do you understand by the preventive maintenance of locomotives? What are the various schedules prescribed for the maintenance of steam and diesel locomotives?
6. Where are the coaches for Indian Railways manufactured? Compare the structural design of coaches manufactured at different sources. What do you understand by anti-telescopic coaches?
7. Describe the salient features of the vacuum brakes and compressed air brakes used on Indian Railways. Discuss their relative advantages/disadvantages.
8. What are the special design features of the modem coaching and goods stock on Indian Railways?
9. Write short notes on following.
(a) Railway traction
(b) Compressed air brake
(c) Preventive maintenance
(d) Breakdown maintenance