LMS Fowler Class 4F

Infobox Locomotive
powertype=Steam
name = LMS Fowler Class 4F

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caption = 44252 at Coalville MPD, June 1955. It is in unlined BR black livery with the early crest on its tender.
designer = Henry Fowler
builder = LMS Derby Works
LMS Crewe Works
LMS St. Rollox Works
LMS Horwich Works
North British Locomotive
Kerr, Stuart & Co.
Andrew Barclay & Sons Co.
builddate = 1924–1941
totalproduction = 575
whytetype = 0-6-0
uicclass=Ch
gauge = RailGauge|ussg
driversize = convert|63|in|m|3|abbr=on
length = 52 ft 0 1/8 in
weight = convert|48.75|LT|t|1
fueltype = Coal
fuelc
convert|4|LT|t|1
waterc
convert|3500|impgal|l|abbr=on|lk=on
cylindercount = Two, inside
cylindersize = 20×26 in (508×660 mm)
valvegear=Stephenson, piston valves
boiler=LMS type G7S
tubearea=convert|1034|sqft|abbr=on
superheaterarea=convert|252|sqft|abbr=on later convert|246|sqft|abbr=on
fireboxarea=convert|124|sqft|abbr=on
firearea = convert|21|sqft|abbr=on
boilerpressure = convert|175|psi|MPa|2|abbr=on|lk=on
tractiveeffort = convert|24555|lbf|kN|2|abbr=on
railroadclass=4F
retiredate=1959–1966

The London Midland and Scottish Railway (LMS) Fowler 4F is a class of 0-6-0 steam locomotive designed for medium freight work. They represent the ultimate development of Midland Railway's six coupled tender engines.

Background

The 4F was based on the 197-strong Midland Railway 3835 Class of 1911, with only a few modifications, primarily the adoption of left-hand drive in favour of right-hand drive. They originally had been designed by Henry Fowler, who from 1925 became CME of the LMS.

Midland Railway locomotives were notorious for their short axle-box bearings, which were prone to overheating. Why this poor design feature was perpetuated is a complete mystery but, unfortunately, the LMS 4F inherited it.

Construction

The LMS constructed 530 of the locomotives between 1923 and 1928, numbered sequentially from where the Midland engines left off from 4027. A further 45 examples were reluctantly authorised by William Stanier in 1937 at the behest of the operating department.

The missing numbers 44557-44561 relate to five locomotives built for the Somerset and Dorset Joint Railway to the Midland Railway 3835 Class design in 1922, and taken into LMS stock in 1930.

All entered British Railways stock in 1948. BR added 40000 to their numbers. They were all withdrawn between 1959 and 1966.

Preservation

Three LMS-built 4Fs survive. The first-built LMS 4F No. (4)4027 is part of the National Railway Collection. Classmates (4)4123 and (4)4422 have also escaped the cutter's torch. In addition, one of the Midland-built 4Fs, (4)3924 also survives.

Dimensions

* LMS/BR Power classification, 4F
* Locomotive weight, 48 tons 15 cwt
** Tender weight, 41 tons 4 cwt
* Boiler pressure, 175 psi
* Superheater, Yes
* Cylinders, 20"x26"
* Driving wheel diameter, 5' 3"
* Tractive effort, convert|24555|lb|abbr=on
* Valve gear, Stephenson (piston valves)

For terminology, see Steam locomotive components

4F models

The 4F has been modelled by Lima ( O, OO and N Gauge), Graham Farish (N Gauge, still produced under the Bachmann label). Also Hornby and Airfix 00 gauge.

References

*

External links

* [http://www.railuk.co.uk/steam/getsteamclass.php?item=4F-C Railuk database]
* [http://www.44422.co.uk/ The 44422 Locomotive Fund]
* [http://www.4123.co.uk The London Midland Society]