If you are traveling via train in India & you are trying to pick what to choose. Here are your options.
SL - Sleeper class: The sleeper class is the most common coach, and usually ten or more coaches could be attached. These are regular sleeping coaches with three berths vertically stacked. In broad gauge, it carries 72 passengers per coach in regular ICF coaches and 78 berths in the new LHB coaches manufactured (present in Durontos).
1A - The First class AC: This is the most expensive class, where the fares are on par with airlines. Bedding is included with the fare in IR. This air conditioned coach is present only on popular routes between metropolitan cities and can carry 18 passengers in ICF coaches whereas accommodates 24 passengers in LHB coach (present in some Rajdhanis, Durontos and AC Expresses). The coaches are carpeted, have sleeping accommodation and have privacy features like personal couples.
2A - AC-Two tier: Air conditioned coaches with sleeping berths, ample leg room, curtains and individual reading lamps. Berths are usually arranged in two tiers in bays of six, four across the width of the coach then the gangway then two berths longways, with curtains provided to give some privacy from those walking up and down. Bedding is included with the fare. A broad gauge coach can carry 46 passengers in case of ICF coach whereas 52 in the new wagon.
3A - AC three tier: Air conditioned coaches with sleeping berths. Berths are usually arranged as in 2A but with three tiers across the width and two longways as before giving eight bays of eight. They are slightly less well-appointed, usually no reading lights, but recently the trend has been to furnish the 3A coaches better. Bedding is included with fare. It carries 64 passengers in broad gauge in the old Integral Coach Factory rakes and 72 in the new LHB coach rakes manufactured by Rail Coach Factory owing to longer coaches.
2S - Seater class: same as AC Chair car, but with bench style seats and without the air-conditioning.108 seats per coach and not very comfortable. Suitable for short travel
CC - AC chair car: An air-conditioned seater coach with a total of five seats in a row used for day travel between cities.
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