British Introduce MACs Early On

[Tyg]

Suppose that a year or two before the outbreak of WWII, a British shipbuilder/designer takes inspiration from aircraft carriers, and ambitiously develops a design for a MAC that they think might make them more relevant in the next war. Once the war does begin, the design gets dusted off and presented as a vital supplement to merchant shipping protection or convoy escort against surface, submarine, or aerial raids.

Presuming that this finds some backing, and more importantly the pilots and aircraft can be found, what are the effects of increasingly numerous MACs protecting British convoys by 1940? This obviously isn't a replacement for actual convoy escorts, but even a little air cover or scouting could certainly improve the efficiency of protection in the Atlantic.

Could this have much effect on shipping losses, or is it just an interesting gimmick without substantial impact on the Battle of the Atlantic?

[Astrodragon]

Suppose that a year or two before the outbreak of WWII, a British shipbuilder/designer takes inspiration from aircraft carriers, and ambitiously develops a design for a MAC that they think might make them more relevant in the next war. Once the war does begin, the design gets dusted off and presented as a vital supplement to merchant shipping protection or convoy escort against surface, submarine, or aerial raids.

Presuming that this finds some backing, and more importantly the pilots and aircraft can be found, what are the effects of increasingly numerous MACs protecting British convoys by 1940? This obviously isn't a replacement for actual convoy escorts, but even a little air cover or scouting could certainly improve the efficiency of protection in the Atlantic.

Could this have much effect on shipping losses, or is it just an interesting gimmick without substantial impact on the Battle of the Atlantic?

They actually had plans for MAC ships in the late 20's. The problem with building them in OTL was that thanks to the RAF they didnt actually have enough planes to put on them, so they never got any attention until later in the war, although they did underestimate how fast aircraft production could ramp up.

[Tyg]

They actually had plans for MAC ships in the late 20's. The problem with building them in OTL was that thanks to the RAF they didnt actually have enough planes to put on them, so they never got any attention until later in the war, although they did underestimate how fast aircraft production could ramp up.

It was actually from reading the latest few pages of your TL's thread that I was thinking of this.

So either we have to have a competent Air Ministry, a strong(er) RN Fleet Air Arm, or significantly greater British planes available in 1939-40 for this to work? Those are all rather significant in their own right, to put it mildly.

If I understand the implications, MACs might not be a gimmick, but rather the conditions necessary for them to exist in number involve a substantial deviation from OTL at least several years earlier anyway?

[Astrodragon]

It was actually from reading the latest few pages of your TL's thread that I was thinking of this.

So either we have to have a competent Air Ministry, a strong(er) RN Fleet Air Arm, or significantly greater British planes available in 1939-40 for this to work? Those are all rather significant in their own right, to put it mildly.

If I understand the implications, MACs might not be a gimmick, but rather the conditions necessary for them to exist in number involve a substantial deviation from OTL at least several years earlier anyway?

Not a huge deviation, but you need some way of getting the available aircraft up.
That was why, in my TL, giving the Navy control early leads to so many changes - in OTL, there were bottlenecks that made it pointless to do some things, in fact one of the reasons they went to armoured carriers with small air groups was that they couldnt get the aircraft for bigger air groups anyway!
The Swordfish was produced early on, so as long as you have someone getting some more aircraft early, and deciding to implement the MAC concept, its technically easy enough.

Having the IRA bomb the Air Ministry might be a good start as well...:D:D

[PMN1]

The Aircraft Carrier Story 1908 – 1945, Guy Robbins

Page 86

In 1923 the DNC suggested ‘Mercantile Aircraft Carriers’ using grain ships and oil tankers. The Ten Year Programme of 1924 had recommend small 10,000 tons carriers for commerce protection (the emphasis was against air attack, not submarines), but this was seen as a ‘luxury’. The Admiralty intended to build four MAC ships and equip Armed Merchant Cruisers with aircraft when war began, but funds were not available.


Air Power and the Royal Navy 1914 – 1045, Geoffrey Till

Page 77

There were three methods of producing carriers for this purpose. The first, also suggested in the First World War, was “for merchant vessels to be fitted and equipped for carrying machines of suitable type.” Shortly after the war the idea was taken up by DNC, who prophetically suggested “Mercantile Aircraft Carriers,” even to the extent of using grain ships and oil tankers for the purpose. In correspondence with the Chief of the Air Staff, he also outlined proposals for Mail Steamer Carriers capable of operating between 25 and 50 aircraft, which he thought would be “very valuable in convoys.” But little was done about this idea, largely for reasons of cost. It was nonetheless the Admiralty’s declared intention to build and equip four Merchant Ship Carriers and a force of Armed Merchant Cruisers (AMC), with aircraft, once war had begun.

[Tyg]

Not a huge deviation, but you need some way of getting the available aircraft up.
That was why, in my TL, giving the Navy control early leads to so many changes - in OTL, there were bottlenecks that made it pointless to do some things, in fact one of the reasons they went to armoured carriers with small air groups was that they couldnt get the aircraft for bigger air groups anyway!

Hmm... There are probably quite a few ways to deal with (or entirely avoid) those bottlenecks without substantially changing the nature of British aviation in general, but I'm also thinking of the industry itself.

The Swordfish was produced early on, so as long as you have someone getting some more aircraft early, and deciding to implement the MAC concept, its technically easy enough.

It seems logical that MACs would be equipped with older aircraft that aren't capable of matching combat performance of the latest front line aircraft. If the swordfish are being replaced, they could have somewhere to go in this case.

Having the IRA bomb the Air Ministry might be a good start as well...:D:D

I still need to read the Competent Air Ministry timeline, though the search function has failed me. :(

The Aircraft Carrier Story 1908 – 1945, Guy Robbins

Page 86

In 1923 the DNC suggested ‘Mercantile Aircraft Carriers’ using grain ships and oil tankers. The Ten Year Programme of 1924 had recommend small 10,000 tons carriers for commerce protection (the emphasis was against air attack, not submarines), but this was seen as a ‘luxury’. The Admiralty intended to build four MAC ships and equip Armed Merchant Cruisers with aircraft when war began, but funds were not available.

The dates in question here are extraordinarily timely and useful for a TL project I'm working on. Thanks for these references!


Air Power and the Royal Navy 1914 – 1045, Geoffrey Till

Page 77

There were three methods of producing carriers for this purpose. The first, also suggested in the First World War, was “for merchant vessels to be fitted and equipped for carrying machines of suitable type.” Shortly after the war the idea was taken up by DNC, who prophetically suggested “Mercantile Aircraft Carriers,” even to the extent of using grain ships and oil tankers for the purpose. In correspondence with the Chief of the Air Staff, he also outlined proposals for Mail Steamer Carriers capable of operating between 25 and 50 aircraft, which he thought would be “very valuable in convoys.” But little was done about this idea, largely for reasons of cost. It was nonetheless the Admiralty’s declared intention to build and equip four Merchant Ship Carriers and a force of Armed Merchant Cruisers (AMC), with aircraft, once war had begun.

25 to 50 aircraft!? That's a complement approaching or rivaling interwar CVs right there. I suppose realistically speaking expense and need would dictate a lower-end of that range, but its interesting to see a proposal made that was so ambitious.

One thing that does occur to me, wouldn't having numerous MACs allow them to be used more extensively as aircraft ferries? The capacity for aircraft shipping would be higher at least, and they could be delivered off the deck rather than in pieces.

[PMN1]

25 to 50 aircraft!? That's a complement approaching or rivaling interwar CVs right there. I suppose realistically speaking expense and need would dictate a lower-end of that range, but its interesting to see a proposal made that was so ambitious.



The Mail Steamer carrier could be this

http://img.photobucket.com/albums/v136/paul1/1923UKmailcarrier1.jpg

http://img.photobucket.com/albums/v136/paul1/1923UKmailcarrier.jpg

Notes copied form another poster on another board

This originally is suppose to have come from the publication “Transactions of the Institution of Naval Architects” Mar 1923 and was proposed by Eustace d’Eyncourt who was the British “Director of Naval Construction” from 1912 to 1923. According to Friedman’s “US Aircraft Carriers” there was a somewhat similar US proposal in 1928 for a 980-foot high speed North Atlantic liner.

The British proposal was for a 600/80/28 foot, 24 knot mail packet capable of carrying 80% of the first and second class and 40% of the third class passengers of the Mauritania for such routes as the

GB to NY with aircraft delivering mail to Canada on route

GB to Australia with aircraft delivering mail to Egypt and India on route

Vancouver to Hong Kong or Australia.

No armament was mentioned though it did say it could carry either 18 Sopwith Cuckoos or 21 Parnall Panthers or 21 Nieuport Night Hawks.

The mast was said to be not a problem because aircraft took off quickly but if it did become a problem an alternate folding mast and derrick was proposed. Bulges were fitted to protect against “icebergs”. The boilers being exhausted out the stern would probably be a problem since it ran right above the First Class lounge and I doubt that people would pay to get overheated. If you notice the B deck amidships is dedicated to lifeboats so I am wondering if during war time the deck could be removed and combined with C deck to create a midship hanger to double the amount of aircraft carried?

I am guessing that as long as the British did not put any armament on them in peacetime they would not legally be considered warships and would not come under the Washington limits.

[Simon]

I still need to read the Competent Air Ministry timeline, though the search function has failed me. :(
Ask and ye shall receive, For Want of a... Competent Air Ministry (http://www.alternatehistory.com/discussion/showthread.php?t=122468).

[Tyg]

The Mail Steamer carrier could be this [schematics snipped]

Notes copied form another poster on another board

This originally is suppose to have come from the publication “Transactions of the Institution of Naval Architects” Mar 1923 and was proposed by Eustace d’Eyncourt who was the British “Director of Naval Construction” from 1912 to 1923. According to Friedman’s “US Aircraft Carriers” there was a somewhat similar US proposal in 1928 for a 980-foot high speed North Atlantic liner.

Now this is most interesting, and warrants more exploration.

The British proposal was for a 600/80/28 foot, 24 knot mail packet capable of carrying 80% of the first and second class and 40% of the third class passengers of the Mauritania for such routes as the

GB to NY with aircraft delivering mail to Canada on route

GB to Australia with aircraft delivering mail to Egypt and India on route

Vancouver to Hong Kong or Australia.

That's an intriguing idea in its own right as an efficient and relatively fast mail delivery system. Maybe not cost effective without the military applications though.

No armament was mentioned though it did say it could carry either 18 Sopwith Cuckoos or 21 Parnall Panthers or 21 Nieuport Night Hawks.

The mast was said to be not a problem because aircraft took off quickly but if it did become a problem an alternate folding mast and derrick was proposed. Bulges were fitted to protect against “icebergs”. The boilers being exhausted out the stern would probably be a problem since it ran right above the First Class lounge and I doubt that people would pay to get overheated. If you notice the B deck amidships is dedicated to lifeboats so I am wondering if during war time the deck could be removed and combined with C deck to create a midship hanger to double the amount of aircraft carried?

I'd imagine if that modification was originally in the minds of builders/designers, it'd be a fairly quick transition from passenger and mail liner to merchant escort carrier. Would they have considered the value of that hanger space enough to justify making that modification easier?

I'm no engineer though, so I couldn't say whether it'd be feasible to begin with.

I am guessing that as long as the British did not put any armament on them in peacetime they would not legally be considered warships and would not come under the Washington limits.

Now THAT is the kind of cleverness I like to see in AH--Britain effectively having several light/escort carriers on ready reserve that 'pay for themselves', or at least the Royal Mail does. That loophole abuse seems unlikely to be ignored by everyone else for very long, but imitating it could be more difficult.

[Dathi THorfinnsson]

If Britain is producing MACs, does that mean the US has to one up them and produce Big Macs?:p

[Garrison]

Notes copied form another poster on another board

This originally is suppose to have come from the publication “Transactions of the Institution of Naval Architects” Mar 1923 and was proposed by Eustace d’Eyncourt who was the British “Director of Naval Construction” from 1912 to 1923. According to Friedman’s “US Aircraft Carriers” there was a somewhat similar US proposal in 1928 for a 980-foot high speed North Atlantic liner.

The British proposal was for a 600/80/28 foot, 24 knot mail packet capable of carrying 80% of the first and second class and 40% of the third class passengers of the Mauritania for such routes as the

GB to NY with aircraft delivering mail to Canada on route

GB to Australia with aircraft delivering mail to Egypt and India on route

Vancouver to Hong Kong or Australia.

No armament was mentioned though it did say it could carry either 18 Sopwith Cuckoos or 21 Parnall Panthers or 21 Nieuport Night Hawks.

The mast was said to be not a problem because aircraft took off quickly but if it did become a problem an alternate folding mast and derrick was proposed. Bulges were fitted to protect against “icebergs”. The boilers being exhausted out the stern would probably be a problem since it ran right above the First Class lounge and I doubt that people would pay to get overheated. If you notice the B deck amidships is dedicated to lifeboats so I am wondering if during war time the deck could be removed and combined with C deck to create a midship hanger to double the amount of aircraft carried?

I am guessing that as long as the British did not put any armament on them in peacetime they would not legally be considered warships and would not come under the Washington limits.

Wow in another thread I proposed the German's building a 'civilian' carrier to develop experience and dodge treaty restrictions; I had no idea it was a real thing. :eek:

[Just Leo]

Wow in another thread I proposed the German's building a 'civilian' carrier to develop experience and dodge treaty restrictions; I had no idea it was a real thing. :eek:

Germany had lots of civilian experience with flying boat carriers, and were fully adept at taking off. They never landed on a deck, ever, that I've heard.

[Garrison]

Germany had lots of civilian experience with flying boat carriers, and were fully adept at taking off. They never landed on a deck, ever, that I've heard.

Very interesting but I've probably threadjacked this far enough, thanks!

[BlondieBC]

How much would one of these ships cost?

How long to build?

[StevoJH]

How much would one of these ships cost?

Not much, they are basically a cargo ship with a steel deck bolted on top and presumably a lift to the hanger deck.

It also depends on what facilities there are to *support* the aircraft carried.

How long to build?

Not sure, but it shouldn't take to much longer then normal if designed in from the start of construction.

[Peg Leg Pom]

Could the government offer a subsidy to help pay for ships designed to be readily convertable into MACs or CVEs? Even without admiting the military aspect of the ships the subsidy could be justified as a way of reducing unemployment in the shipbuilding areas. If some of the ships could be contracted to supply the fleet then the navy gets a double benefit, a source of easily convertable ships and merchant crews accustomed to meeting the demands of the fleet.

[BlondieBC]

Now THAT is the kind of cleverness I like to see in AH--Britain effectively having several light/escort carriers on ready reserve that 'pay for themselves', or at least the Royal Mail does. That loophole abuse seems unlikely to be ignored by everyone else for very long, but imitating it could be more difficult.

The risk is someone like Japan or Italy will use it as a loop hole. What prevents the Japanese from building a CVL, labeling it a mail ship, and claiming it delivers mail to Taiwan? If Britain pushes the rules this much, Japan could probably go ahead and just build a fully functional CVL, just keep the AA guns in storage. After all, couldn't the airplane hanger deck hold a lot of mail. It just happens the Japanese like their mail shipped with advance fire fighting capability, armored decks and a top speed of 35 knots. ;) I am not so sure cheating on a naval treaty designed to lower ship building costs is such a wise idea.

[tchizek]

Not much, they are basically a cargo ship with a steel deck bolted on top and presumably a lift to the hanger deck.

It also depends on what facilities there are to *support* the aircraft carried.



Not sure, but it shouldn't take to much longer then normal if designed in from the start of construction.

The most basic didn't even have a hanger deck, just carried their 4-6 aircraft as a deck load with a basic elevator to lift ammunition. All refueling/rearming was done on deck with those.

I think the total extra time for the most basic MAC was on the order of an extra month.

[Tyg]

Could the government offer a subsidy to help pay for ships designed to be readily convertable into MACs or CVEs? Even without admiting the military aspect of the ships the subsidy could be justified as a way of reducing unemployment in the shipbuilding areas. If some of the ships could be contracted to supply the fleet then the navy gets a double benefit, a source of easily convertable ships and merchant crews accustomed to meeting the demands of the fleet.

MACs were bulk cargo vessels, and I could see oilers/tankers being especially logical targets for that sort of plan. The subsidies might not even need to be all that extensive operationally, the MACs still carried 80+% of their original loads IIRC. All this sounds vaguely similar to US merchant marine planning, actually.

The risk is someone like Japan or Italy will use it as a loop hole. What prevents the Japanese from building a CVL, labeling it a mail ship, and claiming it delivers mail to Taiwan? If Britain pushes the rules this much, Japan could probably go ahead and just build a fully functional CVL, just keep the AA guns in storage. After all, couldn't the airplane hanger deck hold a lot of mail.

This is an excellent point, but what serves to limit the British in doing this after 1936 or so, once treaty concerns are no longer relevant? The Mail Carriers or bulk cargo MACs would be quick to build, and would be cheaper to maintain than any fully military vessel.

And besides, if Italy and Japan want to get into a race to build what are effectively merchant ships, Britain has more than enough spare capacity to match them there. Such a race would be far cheaper for the British as well. Then there's the question of what the Japanese/Italians/Germans wouldn't be building because they were building MACs with their limited capacity.

Still, it'd be surprising if they didn't respond in like fashion. Presumably the Germans mainly use them for commerce raiding, and in support of their operations in Norway. The Japanese though... How would they use imitation MACs?

It just happens the Japanese like their mail shipped with advance fire fighting capability, armored decks and a top speed of 35 knots. ;) I am not so sure cheating on a naval treaty designed to lower ship building costs is such a wise idea.

Let's at least be serious, here.:mad: :rolleyes:

The Japanese wouldn't use advanced firefighting systems. ;)

[BlondieBC]

MACs were bulk cargo vessels, and I could see oilers/tankers being especially logical targets for that sort of plan. The subsidies might not even need to be all that extensive operationally, the MACs still carried 80+% of their original loads IIRC. All this sounds vaguely similar to US merchant marine planning, actually.



This is an excellent point, but what serves to limit the British in doing this after 1936 or so, once treaty concerns are no longer relevant? The Mail Carriers or bulk cargo MACs would be quick to build, and would be cheaper to maintain than any fully military vessel.

And besides, if Italy and Japan want to get into a race to build what are effectively merchant ships, Britain has more than enough spare capacity to match them there. Such a race would be far cheaper for the British as well. Then there's the question of what the Japanese/Italians/Germans wouldn't be building because they were building MACs with their limited capacity.

Still, it'd be surprising if they didn't respond in like fashion. Presumably the Germans mainly use them for commerce raiding, and in support of their operations in Norway. The Japanese though... How would they use imitation MACs?



Let's at least be serious, here.:mad: :rolleyes:

The Japanese wouldn't use advanced firefighting systems. ;)

Some of the quotes in this time frame are talking in the 1920's. What I am saying is cheating during this time frame does not make sense. If Britain cheated say in 1928, they others might also cheat but more. By the time the Naval treaty is over, why not just build CVE or CVL. The only time the MAC makes sense is once the war starts, and ship are needed in months.

[Tyg]

Some of the quotes in this time frame are talking in the 1920's. What I am saying is cheating during this time frame does not make sense.

I agree with you. The references and discussion upthread just show these are not new ideas, and could have had time to percolate more deeply into British planning for the next war.

By the time the Naval treaty is over, why not just build CVE or CVL. The only time the MAC makes sense is once the war starts, and ship are needed in months.

If you start planning for ships you need only right when you need them, it's going to be a very sore gap of time before they're ready.

As for not just build a CVE/CVL, it's simple: Time, capacity, and expense. The British in 1936-7 have no idea when or even if war is certain, merely that their readiness appears poor compared to their potential adversaries. The Germans in the last war did a great deal of damage with u-boats far inferior to what they're building now, and Britain herself is no less dependent on her Empire overseas and on American trade to sustain any prolonged war effort. But, for a relatively small investment compared to the cost of a true CV(L), trade protection can be markedly improved when and if the war arrives. Better, this construction can absorb underutilized (cheap) domestic capacity, preserving and developing strategic industries necessary to support the war later.