John Jordan - Warships After London

W ARSHIPS A FTER L ONDON

J OHN J ORDAN

Frontispiece: Honolulu (CL-48), one of seven 10,000-ton light cruisers armed with fifteen 6in guns in triple turrets built for the US Navy as a response to the Japanese Mogami class during the mid-1930s. The photo was taken on the occasion of the ships visit to the port after which she was named, Honolulu,Territory of Hawaii, on 14 July 1939. Note the 45ft flower garland ( lei ) suspended from the eyes of the ship. (NHHC, NH 80-G-451204)

Copyright John Jordan 2021

First published in Great Britain in 2021 by

Seaforth Publishing

An imprint of Pen & Sword Books Ltd

47 Church Street, Barnsley

S Yorkshire S70 2AS

www.seaforthpublishing.com

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British Library Cataloguing in Publication Data

A CIP data record for this book is available from the British Library

ISBN 978-1-5267-7749-2 (Hardback)

ISBN 978-1-5267-7750-8 (ePub)

ISBN 978-1-5267-7751-5 (Kindle)

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W ARSHIPS AFTER WASHINGTON , covering naval developments in the five major fleets during the eight-year period that followed the signing of the Washington Treaty on 6 February 1922, was first published in late 2011. It was generally well received, and a second, corrected edition was published two years later, followed by a paperback edition in 2015. A number of reviewers of the book stated that they looked forward to a sequel covering the period 193036, following the signing of the London Treaty of 22 April 1930, which modified the Treaty provisions and extended the quantitative limitations imposed on capital ships and aircraft carriers to other categories of warship. Warships After London is that sequel.

My aim in writing the original book was to attempt to bridge the gap between the political and the technical. I also wanted to look at the very different ways in which the five major navies responded to the new limitations imposed by the Washington Treaty. The classification of all surface units outside the closely defined capital ship and aircraft carrier categories as auxiliary vessels allowed considerable flexibility in the types of ship built, with heavily armed treaty cruisers increasingly complemented by super-destroyers and numbers limited only by national budgets. This had led to something of a free-for-all, which on the one hand promoted inventive solutions to problems of national security but which by the late 1920s was causing increasing concern. The London Treaty was an attempt impose order on chaos by defining three new categories of warship, cruisers, destroyers and submarines, which could then be kept in check by imposing qualitative and quantitative limitations similar in conception to those placed on capital ships and aircraft carriers at Washington.

This was to have a major impact on naval programmes. In the years that followed the signing of the Washington Treaty the five major navies did not have to concern themselves with the construction and financing of new capital ships due to the ten-year battleship holiday, and during the period 192230 not one of the high contracting powers opted to build up to its tonnage allocation for aircraft carriers; construction of lesser vessels continued unabated, without regard for unit displacement or numbers. However, the strict quantitative limits agreed at London instituted a completely different ball game. When reviewing the implications for the new categories, each of the major navies needed to look closely at its current inventory, assess how many of the ships could be replaced before the Washington Treaty expired on 31 December 1936, and calculate how to use the available tonnage to best advantage. It is these deliberations and their outcomes that constitute the primary focus of the present book .

Warships After London follows the same basic format as its predecessor. The fifty or so schematics have been specially prepared for this book, and are drawn and labelled in a uniform style to enable the reader to make an informed comparison between the different designs developed by the five navies within the parameters laid down by the Treaty. This has not been an easy task given the disparity in the quality of published material; where possible the author has used either official plans or drawings published in reliable secondary sources.

The tabulated data that accompanies the drawings and the text has been simplified for the purpose of making meaningful comparisons, with figures for dimensions rounded up or down to the nearest foot or metre and displacement figures which often varied even between ships of the same class to the nearest five tons. The British and American navies of the period used imperial units, the other three navies the metric system. Even within the metric system there were anomalies: the Italians and the French at least in the post-Washington period expressed gun calibre and torpedo diameter in millimetres, whereas the Japanese used centimetres and often rounded the figures up or down. Despite the authors wish to facilitate comparisons, there was an issue here of authenticity and respect for the non-Anglo-Saxon navies. The solution adopted was inevitably a compromise: displacements, which are generally Washington standard for all ships and all navies, are given in long tons (tW); dimensions are in imperial units for Britain and the USA (with metric equivalents in parentheses), and in metric for Japan, France and Italy; for guns, torpedoes, armour thickness, boiler pressure, etc, the appropriate units for the navy concerned are used and conversion tables provided at the front of the book. Readers looking for more accurate and comprehensive data about a particular class of ship are referred to the specialist works cited in the bibliography.

There was a similar issue to resolve with regard to the different practices in programming and authorising construction. In all the countries concerned naval construction, together with the necessary funding, had to be authorised before ships could be ordered; in most cases there then followed a short interval before the ship was laid down. Naval estimates were generally voted by the respective parliaments annually. However, in Japan construction programmes generally ran over several years. During the period covered by this book there were only two naval replenishment programmes, dated 1931 and 1934. Ships approved in each of these programmes would be laid down to a schedule determined by the Navy, taking into account capacity in the naval dockyards, and some of the units within a single programme would be of improved design. The author has endeavoured to respect these cultural differences in drawing up the authorisation tables in .