Midland Railway 6 Class

{{Use dmy dates|date=April 2022}}

{{Infobox locomotive

| name = Midland Railway 6 class

| image =

| alt =

| caption =

| powertype = Steam

| designer = S. W. Johnson

| builder = Derby Works

| ordernumber = 1

| serialnumber =

| buildmodel =

| builddate = 1875

| totalproduction = 10

| rebuilder =

| rebuilddate =

| numberrebuilt =

| whytetype = 0-4-4T

| uicclass = B2′ n2t

| driver =

| gauge = {{track gauge|ussg}}

| driverdiameter = {{convert|5|ft|3|in|m|3|abbr=on}}

| trailingdiameter = {{convert|3|ft|0|in|m|3|abbr=on}}

| minimumcurve =

| wheelbase =

| engine total = {{ubl|{{convert|8|ft|9|in|m|3}} +|{{convert|9|ft|9|in|m|3}} +|{{convert|5|ft|0|in|m|3}}}}

| drivers =

| coupled =

| trailing =

| wheelspacing =

| length =

| over couplers =

| over bufferbeams=

| width =

| height =

| frametype =

| axleload =

| coupled all =

| coupled 1 =

| coupled 2 =

| trail bogie/pony=

| weightondrivers =

| locoweight = {{convert|43|LT|6|Lcwt|abbr=on}}

| fueltype = Coal

| fuelcap =

| watercap =

| sandcap =

| fireboxtype =

| firearea =

| boiler = Midland Railway Class C

| boilertype =

| pitch =

| diameterinside = {{convert|4|ft|1|in|m|3|abbr=on}}

| lengthinside = {{convert|10|ft|6|in|m|3|abbr=on}}

| smalltubediameter=

| largetubediameter=

| boilerpressure = {{convert|160|lbf/in2|MPa|2|abbr=on}}

| safetyvalvetype =

| feedwaterheater =

| totalsurface = {{convert|1254|sqft|m2|abbr=on}}

| tubearea =

| archarea =

| fluearea =

| tubesandflues =

| fireboxarea =

| superheatertype =

| superheaterarea =

| cylindercount = Two, inside

| cylindersize = {{convert|17|x|24|in|mm|0|abbr=on}}

| valvegear =

| valvetype =

| valvetravel =

| valvelap =

| valvelead =

| transmission =

| trainheating =

| locobrakes =

| locobrakeforce =

| trainbrakes =

| safety =

| coupling =

| maxspeed =

| poweroutput =

| tractiveeffort =

| factorofadhesion =

| operator = {{ubl|Midland Railway|London, Midland and Scottish Railway}}

| operatorclass =

| powerclass =

| numinclass =

| fleetnumbers =

| officialname =

| nicknames =

| axleloadclass =

| locale =

| deliverydate =

| firstrundate =

| lastrundate =

| withdrawndate = 1925–1935

| preservedunits =

| restoredate =

| scrapdate =

| currentowner =

| disposition =

| notes =

}}

The Midland Railway 6 Class was a class of ten 0-4-4T steam locomotives. They were built at Derby Works in 1875. A development of the earlier 0-4-4WT of the 690 and 780 classes, the first Johnson engines had side tanks instead of back tanks.

The original Midland Railway (MR) numbers were 6, 15, 18, 137, 140–144, and 147. The 1907 numbers were 1226–1235. All passed to the LMS in 1923, but they were all withdrawn and scrapped by 1935.

An abortive attempt was made to preserve the first of the class (No. 1226, which was withdrawn in 1930) and repainted back into its original livery and renumbered it as 6. However, the new Chief Mechanical Engineer, William Stanier, ordered it scrapped in 1932.

class="wikitable collapsible collapsed" style=text-align:center |+ class="nowrap" | Table of withdrawals{{sfn|Baxter|1982|p=136}} ! Year !! Quantity in service at start of year !! Quantity withdrawn !! Locomotive numbers !! Notes
1925	10	1	align=left | 1233	align=left |
1926	9	1	align=left | 1232	align=left |
1927	8	1	align=left | 1231	align=left |
1928	7	3	align=left | 1227, 1228, 1230	align=left |
1930	4	3	align=left | 1226, 1229, 1234	align=left |
1935	1	1	align=left | 1235	align=left |