The IRY/IR20 coach was designed for a max. speed of 140km/h.
Improvements in these IRY/IR20 coaches include better ride quality, larger windows, improved noise reduction, improvements in the air-conditioning system and ducts, and modified pantry equipment including trolleys, drink dispensers, etc.
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More about IRY/IR20 coaches:
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did enter serial production in small numbers. One or two isolated examples of other RCF-built coaches with features different from the normal ICF coaches have been spotted on rare occasions (e.g., there is a report of one 3A coach used with the Grand Trunk Express in 2001), although information about these experiments (which is presumably what they were) is very sparse.
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Some of the IRY/IR20 coaches, with a ribbed or corrugated shell design for strength, were used for a while (and are still used occasionally) with the Amritsar Swarna Shatabdi. Another rake of IRY/IR20 coaches was being used for the Bareilly Shatabdi. Apart from that these coaches do not seem to be in use elsewhere. One of the IRY/IR20 rakes is no longer in service, being cannibalized as a source of spare parts for the second. The bogies for these (IR-20) will continue to be manufactured for use with MG coaches with service speeds of 100km/h, besides also being exported (Vietnam, some African countries). Meanwhile for coach bodies/shells, RCF has switched to production of the LHB
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Source: IRFCA