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.Nock, O. S., et al. Railways at the Turn of the Century, 1895-1905. Blandford P., 1969.
Design The design featured a boiler pressed to delivering saturated steam to two outside high-pressure cylinders, which exhausted to one low-pressure cylinder inside the frames. All three cylinders had a stroke of ; 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 Consequently, the class was scrapped between December 1903, and July 1905, having been replaced by Whale's Experiment class.
+ Table of locomotives LNWR No. LNWR Name CreweWorksNo. Date built Date scrapped Notes 503 Dreadnought 2795 508 Titan 2796 504 Thunderer 2797 507 Marchioness of Stafford 2798 509 Ajax 2799 510 Leviathan 2800 511 Achilles 2801 513 Mammoth 2802 515 Niagara 2803 685 Himalaya 2804 2055 Dunrobin 2886 2056 Argus 2887 2057 Euphrates 2888 2058 Medusa 2889 2059 Greyhound 2890 2060 Vandal 2891 2061 Harpy 2892 2062 Herald 2893 2063 Huskisson 2894 2064 Autocrat 2895 173 City of Manchester 2896 2 City of Carlisle 2897 1539 City of Chester 2898 Renumbered 437 in November 1886 410 City of Liverpool 2899 1353 City of Edinburgh 2900 1370 City of Glasgow 2901 1395 Archimedes 2902 1379 Stork 2903 545 Tamerlane 2904 659 Rowland Hill 2905 637 City of New York 3012 638 City of Paris 3013 639 City of London 3014 640 City of Dublin 3015 641 City of Lichfield 3016 643 Raven 3017 644 Vesuvius 3018 645 Alchymist 3019 647 Ambassador 3020 648 Swiftsure 3021
References
Morandière, Jules (1885). "Locomotive compound de M. Webb, modèle de 1884 pour trains rapides et lourds", Revue Générale des Chemins de fer et des Tramways, VII. Dunod éditeur, pp.75-79, fig. VI.