GNRI Class JT

{{Short description|Great Northern Railway of Ireland 2-4-2T tank locomotive}}

{{Use dmy dates|date=April 2017}}

{{Use British English|date=April 2017}}

{{Infobox locomotive

|name = GNR(I) class JT

|powertype = Steam

|image = JT Class In Cultra.JPG

|caption = No. 93 at the Ulster Folk and Transport Museum

|designer = J. C. Park

|builder = Dundalk Works

|ordernumber =

|serialnumber =

|buildmodel =

|builddate = 1895–1902

|totalproduction = 6

|rebuilder =

|rebuilddate =

|numberrebuilt =

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

|uicclass = 1′B1 n2t

|gauge = {{RailGauge|5ft3in}}

|leadingdiameter =

|driverdiameter = {{Convert|5|ft|7|in|mm|0|abbr=on}}

|minimumcurve =

|wheelbase =

|length =

|width =

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|axleload =

|weightondrivers =

|locoweight =

|fueltype =

|fuelcap =

|watercap =

|sandcap =

|boiler =

|boilerpressure = {{convert|140|-|175|psi|MPa|2|abbr=on}}

|feedwaterheater =

|firearea =

|tubearea =

|fluearea =

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|totalsurface =

|superheatertype =

|superheaterarea =

|cylindercount = Two, inside

|cylindersize = {{convert|16|-|17|in|mm|0|abbr=on}} bore
{{convert|22|in|mm|0|abbr=on}} stroke

|valvegear =

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|locobrakes =

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|safety =

|operator = GNR(I) → CIÉ

|operatorclass = GNR(I): JT

|powerclass =

|numinclass =

|fleetnumbers = 90, 93, 94, 95, 13 (→91), 14 (→92)

|officialname =

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|withdrawndate = 1955–1963

|preservedunits = No. 93

|restoredate =

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|disposition = One preserved, remainder scrapped

}}

The Great Northern Railway (Ireland) JT class comprised six {{whyte|2-4-2|T}} locomotives, all built between 1895 and 1902 at their Dundalk Works. These were of a J. C. Park design, but introduced following his death. They were used on Dublin suburban services; then on branch lines, including operation of the Dundalk, Newry and Greenore Railway when taken over in 1933. Most were withdrawn shortly after 1955 between 1955 and 1957 but one remained passed to Córas Iompair Éireann (CIÉ) and remained in service until 1963.