BNR class N

{{one source|date=January 2015}}

{{Infobox locomotive

| name = BNR class N

| powertype = Steam

| image = Beyer Garratt 6594.jpg

| alt =

| caption = Preserved class member 815 (BP 6594/1930) at the National Rail Museum, New Delhi

| builder = Beyer, Peacock & Company

| serialnumber = 6583–6598

| builddate = 1929

| totalproduction = 16

| whytetype = 4-8-0+0-8-4

| uicclass = (2′D)(D2′) h4t

| gauge = {{track gauge|5ft6in}}

| driverdiameter = {{convert|4|ft|8|in|m|3|abbr=on}}

| axleload = {{convert|20.25|LT|t ST}}

| weightondrivers = {{convert|159.4|LT|t ST}}

| locoweight = {{convert|234|LT|t ST|1}}

| fueltype = Coal

| fuelcap = {{convert|14|LT|t ST|1}}

| watercap = {{convert|10000|impgal|abbr=on}}

| boilerpressure = {{convert|210|psi|MPa|2|abbr=on}}

| firearea = {{convert|69.8|sqft|m2|abbr=on}}

| superheaterarea = {{convert|642|sqft|m2|abbr=on}}

| cylindercount = Four, outside

| cylindersize = {{convert|20+1/2|x|26|in|mm|0|abbr=on}}

| valvegear = Walschaerts

| valvetype = Piston valves

| maxspeed = {{convert|45|mph|abbr=on}}

| tractiveeffort = {{convert|69655|lbf|kN|2|abbr=on}}

| operator = {{ubl|Bengal Nagpur Railway|→Indian Railways}}

| fleetnumbers = {{ubl|BNR: 810–825|→IR: 38810–38825}}

| locale = South Eastern Railway zone

| firstrundate = 1929

| lastrundate = 1970

| retiredate = 1970

| withdrawndate = 1970

| preservedunits = No. 811 and 815

| currentowner = National Rail Museum, New Delhi and Kharagpur Workshops

}}

The Bengal Nagpur Railway class N was a class of 4-8-0+0-8-4 Garratt steam locomotives built by Beyer, Peacock & Company in England in 1929. At the time of their construction, they had the largest water capacity of any Garratt, in addition to being the largest locomotives in India. The class N Garratts were introduced following successful performance results from the earlier HSG Garratts. Due to their heavy weight, they were restricted to {{cvt|90|lb/yard}} rails. They had straight-ported cylinders; it is not known if this was suitable for slow, heavy coal traffic. Like the earlier HSG Garratts, they worked on the Chakradharpur-Jharsuguda and the Anara-Tatanagar sections. After electrification, they were used at Rourkela. They could haul {{cvt|2400|t|LT ST|0}} on a 1 in 100 gradient.{{cite web|title=5Brinkster |url=http://sundar.brinkster.net/Garratt.htm |url-status=dead |archiveurl=https://web.archive.org/web/20131023060832/http://sundar.brinkster.net/Garratt.htm |archivedate=2013-10-23 }}

In 2006, class member 811 at Kharagpur workshop was returned to working order and used on a few runs{{cite web |url=https://www.internationalsteam.co.uk/beyergarrattlocos/active2023.htm |title=List of active Garratt locomotives for 2023/24. |last=Heath |first=Trevor |date=2024-01-09 |website=International Steam Pages|access-date=2024-08-25}} before being stored again. Many parts were borrowed from class member 815 at the National Rail Museum of India in order to achieve this. The parts were later returned and refitted to 815, which was given a cosmetic overhaul. In 2018 a second attempt to return 811 to working order was made; this time all missing parts were fabricated in a US$400,000 refurbishment that was put out to public tender. The locomotive had one test run in late 2019, and has remained on static display as of 2024.