LNWR Dreadnought Class explained

LNWR Dreadnought class
Powertype:Steam
Designer:Francis Webb
Builder:Crewe Works
Serialnumber:2975–2804, 2886–2905, 3012–3021
Builddate:1884–1888
Totalproduction:40
Whytetype:2-2-2-0
Uicclass:1AA n3v
Leadingdiameter:3feet + tyres
Driverdiameter:6feet + tyres
Engine Total:18feet
Leading:8feet
Drivers:9feet
Diameterinside:4feet
Lengthinside:11feet
Boilerpressure:1752NaN2
Totalsurface:1401.5square feet
Cylindercount:Three: two HP (outside), one LP (inside)
Hpcylindersize:14x
Lpcylindersize:30x
Valvegear:Joy, Slip-eccentric.
Operator:London and North Western Railway
Scrapdate:December 1903 – July 1905
Disposition:All scrapped

The LNWR Dreadnought class was a class of 40 passenger three-cylinder compound 2-2-2-0 locomotives designed by F. W. Webb for the London and North Western Railway, and manufactured by them in their Crewe Works between 1884 and 1888. The railway also commissioned the Beyer, Peacock and Company to construct an additional locomotive of the design for the Pennsylvania Railroad.[1]

Design

The design featured a boiler pressed to 1752NaN2 delivering saturated steam to two outside 140NaN0 high-pressure cylinders, which exhausted to one 300NaN0 low-pressure cylinder inside the frames. All three cylinders had a stroke of 24inches; the high-pressure cylinders drove the rear wheels, while the low-pressure drove the leading driving wheels. As the two pairs of driving wheels were not connected, the locomotives were "duplex drive" or "double-singles".

They were a development of Webb's Experiment class; they had larger boilers and smaller driving wheels, and while the Joy valve gear for the HP and LP cylinders could still be independently adjusted, it was now also possible to reverse both sets simultaneously. The inside valve gear was subsequently amended to the loose or slip-eccentric system, thus giving automatic reversal.

Decline

When George Whale become chief mechanical engineer of the LNWR in 1903, he started a programme of eliminating Webb's over-complicated duplex compound locomotives. Consequently, the class was scrapped between December 1903, and July 1905, having been replaced by Whale's Experiment class.

References

Notes and References

  1. Nock, O. S., et al. Railways at the Turn of the Century, 1895-1905. Blandford P., 1969.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "LNWR Dreadnought Class".

Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2024, A B Cryer, All Rights Reserved. Cookie policy.