LMS Turbomotive

Infobox Locomotive
name=LMS Turbomotive
powertype=Steam Turbine-mechanical

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caption=Diagram of the LMS Turbomotive to show the relative size of the turbine
designer=William Stanier
builder=LMS Crewe Works
built = 1935
gauge=RailGauge|ussg
whytetype = 4-6-2
uicclass = 2'C1'turb.h
leadingsize= convert|36|in|m|3|abbr=on
drivingsize= convert|78|in|m|3|abbr=on
trailingsize = convert|45|in|m|3|abbr=on
boilerpressure=convert|250|psi|MPa|abbr=on|lk=on
boiler=LMS type 1
weight=convert|110.55|LT|t|1 (orig.)
convert|105.20|LT|t|1 (rebuilt)
length=74 ft 4¼ in (orig.)
74 ft 0¼ in (rebuilt)
firearea=convert|45|sqft|abbr=on
fireboxarea=convert|217|sqft|abbr=on
fueltype=Coal
fuelc
convert|9|LT|t|1
waterc
convert|4000|impgal|l|abbr=on|lk=on
railroad=London, Midland & Scottish
British Railways
railroadcalss=LMS: 7P
BR: 8P
roadnumber:LMS 6202
BR: 46202
disposition=Rebuilt as conventional reciprocating-steam locomotive in 1952, wrecked same year, scrapped.

The Turbomotive was a modified Princess Royal Class steam locomotive designed by William Stanier and built by the London, Midland and Scottish Railway in 1935. It used turbines instead of cylinders. It was later rebuilt as a conventional locomotive 46202 "Princess Anne".

This was one of the few experimental steam turbine locomotives which really did beat conventional engines on thermal efficiency, despite having no condenser. The main reason for its high thermal efficiency was that it had six separate steam nozzles and they were controlled individually as on or off and not throttled. It has to be called an engineering success; it covered over convert|300000|mi|km between 1936 and 1945, and was finally taken out of turbine service in 1949. These were war years of extra heavy demands and little tolerance of waste. It was taken out of turbine service due to a failed forward turbine, and the turbine was not repaired because Stanier was no longer in charge in the nationalized system.

The forward turbine had 18 rows of blading. Output was convert|2400|hp|abbr=on at 7060 rpm, corresponding to running at convert|62|mi/h|km/h|abbr=on. Boiler pressure was 250 lbf/in² (1.7 MPa). The turbine was designed to operate into a maximum back-pressure of 2 lbf/in² (14 kPa), allowing a conventional double blast-pipe to provide the boiler draught, and eliminating draught fans, which always seemed to give a disproportionate amount of trouble.

The reverse turbine had 4 rows of blades. It was engaged by a dog clutch, activated when the reverser lever being set to "0". This was originally steam-operated by a small piston and cylinder.

46202 Princess Anne

46202 was rebuilt as a conventional locomotive in 1952 and named "Princess Anne". On 8th October 1952, after only two months in service, it was involved in the Harrow and Wealdstone railway accident. It was the train engine of the double headed Liverpool and Manchester express which ran into the wreckage of the first collision which had happened moments before. The locomotive was taken to Crewe where it was decided it was beyond economical repair and scrapped. The destruction of No. 46202 led to the construction of BR Standard Class 8 number 71000, Duke of Gloucester.

See also

* Steam turbine locomotive

External links

* [http://www.dself.dsl.pipex.com/MUSEUM/LOCOLOCO/turbom/turbom.htm Pictures]
* [http://www.skyrocket.de/locomotive/data/lms_turbomotive.htm Technical specifications]