This book is a comprehensive history of all twenty-six classes of four
coupled tank engines commissioned by the Great Western Railway or built
at their Wolverhampton and Swindon Works, from the Broad Gauge 2-4-0 and
4-4-0 tanks of the 1840s and 1850s to the well known Collett 0-4-2
branch line engines of classes 48XX (later renumbered 14XX) and 58XX of
the 1930s. As well as the Broad Gauge engines, the strange looking
'Covertibles' of William Dean, a number of experimental 'one-off'
designs, the numerous Wolverhampton 0-4-2Ts of the '517' class and the
Swindon built '2-4-0 'Metro Tanks' are described with - where known -
their allocation and operation. The book includes twenty weight diagrams
and nearly 300 photographs, over 50 in color. The four-coupled tank
engines absorbed by the Great Western from other companies at or before
1923 will be featured in a separate volume to follow.