GNRI Class RT

{{short description|Class of 4 Irish 0-6-4T locomotives}}

{{Use dmy dates|date=October 2018}}

{{Use British English|date=October 2018}}

{{Infobox locomotive

| name = Great Northern Railway class RT

| powertype = Steam

| image =

| alt =

| caption = GNR (I) Class RT No. 22 at Belfast Adelaide in March 1959 following withdrawal the previous year

| designer = C. Clifford

| builder = Beyer, Peacock and Company

| ordernumber =

| serialnumber =

| buildmodel =

| builddate = 1908 (2), 1911 (2)

| totalproduction = 4

| rebuilder =

| rebuilddate =

| numberrebuilt =

| whytetype = 0-6-4T

| uicclass =

| gauge = {{track gauge|5ft3in|lk=on}}

| driverdiameter = {{convert|4|ft|3|in|mm|0|abbr=on}}

| minimumcurve =

| wheelbase =

| length =

| width =

| height =

| axleload =

| weightondrivers =

| locoweight = {{long ton|56|0}}

| tenderweight =

| locotenderweight =

| tendertype =

| fueltype =

| fuelcap =

| watercap =

| tendercap =

| sandcap =

| boiler =

| boilerpressure = {{convert|175|lbf/in2|kPa|2|abbr=on}}

| feedwaterheater =

| firearea =

| tubearea =

| fluearea =

| tubesandflues =

| fireboxarea =

| totalsurface =

| superheatertype =

| superheaterarea =

| cylindercount = Two, inside

| cylindersize = {{convert|17x24|in|mm|0|abbr=on}}

| valvegear =

| valvetype =

| valvetravel =

| valvelap =

| valvelead =

| transmission =

| maxspeed =

| poweroutput =

| tractiveeffort = {{convert|18075|lbf|kN|2|abbr=on}}

| factorofadhesion =

| trainheating = Steam

| locobrakes =

| locobrakeforce =

| trainbrakes =

| safety =

| operator = GNR(I) → UTA

| operatorclass =

| powerclass =

| numinclass = 4

| fleetnumbers = {{ubl|GNRI: 22, 23, 166, 167|UTA: 22–25}}

| officialname =

| nicknames =

| axleloadclass =

| locale =

| deliverydate =

| firstrundate =

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| retiredate =

| withdrawndate = 1958—1963

| preservedunits =

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| currentowner =

| disposition = All scrapped

| notes =

}}

Great Northern Railway (Ireland) Class RT were set of set of four 0-6-4T tank locomotives designed by Charles Clifford. The success of the first two in 1908 led to the order for two more in 1911. They were used for shunting and transfer work around the docks and railways of Belfast.