Indian locomotive class YM

{{Infobox locomotive

| name = Indian locomotive class YM

| image = YM 5757 at Secunderabad 1976.jpg

| caption = YM 5757 at Secunderabad, 1976

| powertype = Steam

| builder = Nippon Sharyo

| builddate = 1956

| totalproduction = 12

| whytetype = {{whyte|2-6-4|T}}

| gauge = {{track gauge|1000 mm}}

| coupleddiameter = {{convert|1219|mm|ftin|abbr=on}}

| axleload = {{convert|9|t|abbr=on}}

| weightondrivers = {{convert|27|t|abbr=on}}

| serviceweight = {{convert|53.5|t|abbr=on}}

| firearea = {{convert|1.11|m2|sqft|abbr=on}}

| boilerpressure = {{convert|14.5|bar|psi|abbr=on}}

| totalsurface = {{convert|51.75|m2|sqft|abbr=on}}

| cylindercount = Two, outside

| cylindersize = {{convert|330|x|560|mm|in|abbr=on}}

| operator = Indian Railways

| fleetnumbers = Pre-1957: 6001–6012
Post-1957: 5750–5761

| notes = {{Cite web |url=https://jdhsmith.math.iastate.edu/term/slinigr.htm |title=Indian Government Railways steam locomotives |last=Smith |first=Jonathan |date=2009 |website=The terminal: Standard steam locomotives |publisher=Iowa State University |access-date=30 November 2024 |quote=}}{{sfn|Hughes|1977|page=24}}{{sfn|Hughes|1977|page=92}}

}}

The Indian locomotive class YM were {{whyte|2-6-4|T}} tank locomotives built for Indian Railways' metre-gauge network, as one of the post-partition designs evolved from the Indian Railway Standard locomotives.

History

In 1954, the Indian Railways ordered twelve tank locomotives from Nippon Sharyo for use on suburban trains,{{Cite report |title=Report by the Railway Board of Indian Railways 1954-55 |date=1955 |publisher=Indian Railway Board |issue=1|page=59}} and were delivered in 1956 to the Central Railway zone. Three examples initially went to the Southern Railway zone, but were soon transferred to Lallaguda depot of Central Railways, near Secunderabad. The YM class were mainly used to haul trains on the line between Bolarum via Secunderabad to Hyderabad.{{Sfn|Hughes|1977|p=27}}

With the formation of the South Central Railway zone and the associated reorganization of the surrounding regional zones in October 1966, all 12 members went to the South Central Railways, where they were in service as of 1975.{{cite web|access-date=31 January 2024 |title=History of the Railway Zones |url=https://www.irfca.org/faq/faq-geog.html#history |website=IRFCA website |publisher= Indian Railways Fan Club (IRFCA)}}{{Sfn|Hughes|1977|p=27}}

Technically, the YM class were similar to the broad-gauge WM class, although the former is smaller than the latter.{{Sfn|Hughes|1977|p=23}}

Proposed variants

Indian Railways drew up plans for the Class YS {{whyte|2-10-6|T}} heavy tank locomotive.{{Sfn|Atkins|1999|p=82}}{{Sfn|Hughes|1979|p=23}}{{Failed verification|date=November 2024}} In 1957, however, these plans were dropped, in favour of a larger, heavier version of the YM class, with an axle load of 10.5 tons and a service weight of 73 tons. A requirement of 89 locomotives was determined for both suburban and shunting duties. However, in light of both dieselisation and electrification, the plan ultimately never came to fruition, and surplus class YL locomotives were deployed for these roles.{{Cite report |url=https://archive.org/details/dli.csl.1651/mode/1up |title=Report of the Thirty-Seventh Meeting of the Locomotive Standards Committee March |date=1957 |publisher=Ministry of Railways |location=New Delhi |page=15}}{{Sfn|Hughes|1979|p=23}}

References

Bibliography

  • {{Cite book |last=Hughes |first=Hugh |title=Steam Locomotives in India, Part 2 – Metre Gauge |publisher=The Continental Railway Circle |year=1977 |isbn=0-9503469-3-4}}
  • {{Cite book |last=Hughes |first=Hugh |url=https://archive.org/details/steamlocomotives0000hugh/mode/2up |title=Steam Locomotives of India, Part 3 – Broad Gauge |publisher=The Continental Railway Circle |year=1979 |isbn=0-9503469-4-2 |url-access=registration}}
  • {{Cite book |last=Atkins |first=Philip |title=Dropping the Fire - The Decline and Fall of the Steam Locomotive |publisher=Irwell Press |year=1999 |isbn=1-871608-89-9}}