Originally introduced by the Midland Railway, it says a lot that the LMS continued to produce this class of locomotive until 1941.   It was intended to be an attempt to reduce the need for the Midland Railway for double-heading their freight trains; whether or not it was successful in this is debatable as compared to later LMS designs it wasn't all that powerful.   It also suffered the typical Midland design weaknesses in the front end design and the axlebox bearings.   However they were of a robust and simple construction and so it is perhaps not too surprising that the LMS continued with their construction, even after class
Technical Data
 

Introduced : 1911
Number built : 772
Wheel arrangement : 0-6-0

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Class 4F Freight Locomotive

Class 4F no. 44422 on Wansford Turntable, Nene Valley Railway, 25th April, 2010

Preservation
4 of the class survive in preservation
3924 - Located at the Keighley and Worth Valley Railway, operational
4027 - Located at the Gloucestershire Warwickshire Railway, under overhaul
4123 - Located at the Avon Valley Railway, undergoing restoration
4422 - Undergoing overhaul. 
 
44422_50274ai.jpg
5F and 8F locomotives were introduced.  It was only the post-war Ivatt designs that finally removed the need for any more of this class to be constructed.  
 Numbers  Location Built Year Built 
 3835-3826  Derby  1911
 3837-3851  Derby  1917
 3852-3901  Derby  1918 - 1919
 3902-3936  Derby  1920 - 1921
 3937-3986  Armstrong Whitworth  1921 -1922
 3987-4026  Derby   1921 -1922
 SDJR 57-61  Armstrong Whitworth  1921 -1922
Midland Railway-built Locomotives
 Numbers  Location Built Year Built 
 4027-4034  Derby  1924-1925
 4057-4081  North British  1925
 4082-4106  Kerr, Stuart  1925-1926
 4107-4176  Crewe  1924 -1926
 4177-4178  St Rollox  1924
 4179-4206  St Rollox  1926
 4207-4301  Derby  1925-1927
 4302-4311  Crewe  1926
 4312-4331  St Rollox  1927-1928
 4332-4356  Kerr, Stuart  1926-1927
 4357-4381  Andrew Barclay  1926-1927
 4382-4406  North British  1926-1927
 4470-4436  Derby  1927
 4437-4456  Crewe  1927-1928
 4457-4466  Horwich  1928
 4467-4476  St Rollox  1928
 4477-4506  North British  1927
 4507-4556  Crewe  1928 
 4562-4576  Crewe  1937
 4577-4606  Derby  1939-1941
LMS-built Locomotives
Note: The locomotives built for the Somerset and Dorset Railway in the above table were taken into LMS stock in 1930 and renumbered 4557-4561 (hence the gap in the table on the right).