Escort warship building effort in the United Kingdom & Empir

[mescal]

Hello,

I once started to compile data on escort vessels of United Kingdom, with the intent to post summary charts as I did for the destroyers.
However, there are too many ships, and the records are far less available than for bigger units.
Hence I don't think I will be able to complete this work anytime soon.

But I nonetheless have gathered a bunch of data, mainly dealing with the building process.

The first task was to plot the borders of what's under study, because the notion of "escort" is quite vague. In practice it ranged from MTB to battleships.
As I already posted a lot of data on destroyers and bigger unit, I hence focused on the 'lesser' escorts here. However, if one goes down to the smallest ships, there will be thousands of entries.
So I decided to limit the scope to the ships which had the capability to provide ASW escort to a convoy on ocean passage.
In practice, this means a displacement greater than 800 tons and Asdic, as well as a speed significantly superior to that of convoys.

Here is the list of classes I took into account
Sloops
Bridgewater, Hastings, Shoreham, Grimsby, Bittern, Egret, Black Swan and Banff* classes (total 83 ships)
Corvettes
Flower, Castle classes (total 308 ships)
Frigate
River, Loch, Bay, Captain* and Colony* classes (total 297 ships)
Escort Destroyers
Hunt and Town* (ex US DD) classes (136 ships)
Minsweepers
Halcyon, Auk*, Bathurst and Algerine classes (213 ships)

* denotes US-built ships
I did not take into account the 50+ Castle-class corvettes cancelled in late 43.
And after long considerations I decided to take the Towns into account but not the V&W classes, because the latter were not exclusively employed in trade protection.
If I'm able to have a clean categorization between the convoy escort role and other roles, I will probably reintegrate them later on.

In the end I have 1025 ships, only 53 of them were under RN (and RAN/RCN...) commission at the outbreak of war.
41 of those ships were not commissioned yet by August 1945.


You'll find below a first chart plotting the number of ships being built each month in the Empire yards during the war - US-built ships are out of the sample.

The second charts shows the number of ships by class commissionned each month - this time I included US-built ships

And finally there is the cumulative commissionning over the war. Note that losses are not taken into account and hence the last value is not the number of ships existing at the end of the war.

I know there are many loopholes and much work still to do, but that's just a first glimpse in the trade protection effort made during the war.

I'll add more data soon ...

Hope it's of interest

[LWD]

Very impressive. I assume the numerical scale on the second chart is months with Sept 39 as the start. I hate to ask this as you've already contributed so much but do you have info on losses?

[Andy H]

Hi Mescal

One of the best books ever published on this matter is Peter Elliotts Allied Escort Ships of WW2, Published by Naval Institute Press in 1973/4. It concentrates solely on the wartime builds with heaps of data.

http://www.amazon.co.uk/Allied-Escort-S ... 0356084019

Regards

Andy H

[mescal]

I assume the numerical scale on the second chart is months with Sept 39 as the start

Yes, that's it.

do you have info on losses?

Not yet double-checked, but among the ~1000 ships, there was around 120 losses, counting the ships deemd Complete Total Loss in the second part of the war.
I'll make a post on this point later, because it's quite an interesting feature : the losses among the escorts were actually low, which meant that the RN (and RCN ...) did not lose many men, leading to an increased experience, while the U-boat lost generally lost 100% of their crew (KIA, MIA or PoW) - which generated a tremendous 'experience gap' in the later part of the war.

One of the best books ever published on this matter is Peter Elliotts Allied Escort Ships of WW2

Thank you for the reference.
It's a bit on the pricey side for me right now and I don't have easy access to inter library loan, but I put it on the 'to buy' list
For the non-purely-statistical work, I used mostly Brown (Atlantic Escorts & Nelson to Vanguard). A bit short but extremely valuable.

[amcl]

Nice work, especially the first one.

There are vaguely similar tables and charts, but with a less detailed breakdown of types, showing escort and minesweeping forces in service in Eric Grove (ed), 'The Defeat of the Enemy Attack on Shipping 1939-1945' (reprinted by Ashgate for the Navy Records Society, 1997). So, if it would be useful I could try scanning them and uploading the results as the facsimile report which makes up much of the book is now in the public domain.

The introduction by Grove is still copyrighted and it is interesting enough and useful enough - it includes corrections to the original based on research since 1957 - to make it worthwhile reading the NRS reprint rather than the original history if you should happen to have the luxury of choosing between them.

Cheers,

Angus McLellan

[Jon G.]

Excellent effort, Olivier. Keep up the good work

[Polar bear]

hi, Olivier,

BRAVO ZULU = well done !

greetings, the pb

[mescal]

Hello,

You'll find below a few charts showing the building figures by country.
Of the 900+ escort ships (as defined above) commissionned during the war, slightly less than half was built in Great Britain.

Canada was the second builder of escorts for the RN/RCN/RAN..., followed by USA and Australia.
A handful of ships were built in India, but almost none were completed before the war's end, and they are not taken into account in my sample.

In the first two charts, the ships completed before the start of the war are not taken into account (Banff & Town classes for the US-built, Halcyon class and all pre-Black Swan sloops in particular)

As a summary, here are the totals of escort ships built by country

Ships_built_country.jpg (45.87 KiB) Viewed 946 times

Here is a first chart showing the number of ships under construction by month and by country

And finally, this gives the following chart of cumulative commissioning (this time, all ships are taken into account)

What's interesting is the smoothness of the GBR-built plot compared to the 'burst' delivered by USA and Canada.
If an explanation can be found for the US-built ships (the Towns & Banffs were already built and they all commissionned over a short period), I wonder what drived the delivery schedule of Canadian ships.


It is also to be noted that all the reasoning above has been made by number of ships, while there are large technical differences between ships in my sample - for example, a Flower is far less demanding to build than a Loch or a Hunt.
In rounded numbers, the GBR spent 6300 months to build ~450 ships, while the figures for Canada are 2000 months for 240 ships. For USA I have 900+ months for 121 ships (Town & Banff out of scope) and finally I found 1000+ months for 72 ships in Australia.
Comparison are quite complex, because it involves not only the complexity of the ships being built, but also the productivity of the building yards. And I do not think that such comparison have a real meaning at the country level.
I will try to go down to the dockyard level - without being too sure that it's far more relevant without data I lack as manpower comparison, supply of materials, existence of bottlenecks.
Or even priority given to a given building programm (I have in my sample some ships launched after 5 or 6 months, and not completed until the end of the war two years later - I did not check the exact reason, but I feel it's a 'disguised cancellation').

Some more to come ...