I've long found a almost forgotten conversion, and one that is not even mentioned here, to be quite fascinating - that being the WWII 'British Merchant Aircraft Carrier' or MAC Ship. What may seem at first sight to be an absurdity austere aircraft carrier - they make proper escort carriers look over-engineered - are I would argue not only well suited to their intended task but also brilliantly economical designs for a nation that lacked the near limitless resources of the USA. These mini carriers were in effect merchant vessels fitted with a simple flight deck over their cargo holds sufficient to operate a handful of FAA Swordfish biplanes. The true brilliance of the MAC Ship concept is that while doing that they also retained a large part of the original merchant vessel design's cargo carrying capacity. Obviously the aircraft number was small but they still provided their convoy with a potentially useful evel of ASW air cover. Furthermore, these eminently simple ships did not even require scarce RN trained crew as many non flight functions were still performed by Merchant Navy personal. I think the real drawback with the MAC Ship concept was that they appeared only after the U Boat threat had been largely defeated and at a time when land based VLR aircraft and far more capable CVE types were readily available to cover the dreaded 'Mid Atlantic Gap'. Had the MAC been put into service in 1940 however then one suspects they would have proved to be very useful ships indeed. By the way the earlier CAM ships were also a interesting emergency wartime conversation in many ways.
Oh,son of a gun. A true naval statement there. Just what I needed. Another interesting channel to add to my already unwieldy subscription list. Oh,well. Well done.
"Built over a 100 of the things" when referring to the US construction of escort carriers. Between those & the swarms of Fletcher-class DDs...AND let's not forget the Liberty ships which were almost like a printer being jammed that just keeps spitting out sheets. For the AXIS those are quite literally scenes right out of countless tech-horror novels. All are great examples of the industrial complex that was roused.
The ship 'Fairsky', that my parents immigrated to Australia on in 1965, was once an Aircraft carrier built in San Francisco in 1942. Leased to the British during ww2, and was named 'Attack'.
The Independence class was cramped but still very effective. Their Achilles heel was the ammunition storage. It was not as well protected as it would be on a full-size. This fact was clearly demonstrated with a loss of the USS Princeton.
Also consider USS Langley, first US carrier, converted from collier Jupiter, then later converted to what could be considered the best seaplane tender. Her original cargo holds also provided ample storage and working spaces, but her speed (or lack thereof) did hinder her usage.
@ElijKarma No real indication Langley ever intended to be "fleet carrier" (not even sure that concept had been fully developed in 1922 and note derrigible/carrier experiments) due to her limited speed, etc. She seemed to be an experimental ship/concept during a period of budget constraints and as such was primarily a learning tool for the US Navy first real fleet carriers Lexington and Saratoga.
It's a great and entertaining overview of various conversions and what drove their respective navies to undertake them. My favorite part was the shade you threw at Kaga the floating space heater hahaha.
There is one Japanese carrier from the interwar period, the Ryujo, that LOOKS like a conversion, (and a kludge), but was actually a purpose built carrier.
The best class of escort carriers was the Sagamone's. Not only were they a little bit larger but they still had their oil tanks and could fuel their escorts. Being conversions from tanker hulls their engineering spaces were at the stern of the ship. This created turbulence from the exhaust gases. Still if I had to choose that is the class I would choose for my Navy. I wonder if you took a similar design if you could convert it to an arsenal in addition to the tanker role. How many VLS launchers could be put on that deck? 🤔
You also forgot two important conversions, the USNS Mercy (T-AH 19) and the USNS Comfort (T-AH 20), both of which were laid down as tanker hulls in the early 70's and converted to Hospital Ships in the late 80's.
One thing about conversions. The Allies had the aircraft to put on all those merchant hulled aircraft carriers - but the Japanese didn't. They couldn't even field enough aircraft for their fleet carriers - and used them as decoy's at Leyte Gulf. .
Yea, those escort carriers could be pretty weak. USS Gambier Bay was lost to an armor piercing shell from Yamato to the engine room from 20,000 yards. While the shell over penetrated Gambier Bay, it badly cracked the hull, and did admiringly leave two 18.1-inch holes under the waterline. This caused horrible flooding that sank the ship, despite Yamato's shell not even exploding. USS Saint Lo was also lost to a single kamikaze following the surface engagement. However, they could also be pretty resilient with a little bit of luck. In the same battle Yamato sank Gambier Bay, USS Kalinin Bay survived heavy fire. She was first hit by a battleship caliber shell to the hanger bay from an unknown battleship (though we can narrow it down to either Haruna or Nagato, due to Yamato and Kongo not recording targeting Kalinin Bay) that crippled the ship by destroying it's ability to launch aircraft. After that, she was hit by over a dozen 8-inch shells from the heavy cruisers Tone and Haguro, while hitting Haguro with gunfire. After that, she was hit by two Kamikazes and survived.
@@bkjeong4302 I think Yamato scored one-two hits on her. As stated, she scored a hit from 20,000 yards that sank the ship. She also claimed another main battery hit, a hit also claimed by the battlecruiser Kongo, though It's far more likely Yamato landed the hit due to having the shorter range and the superior firing angle, and indeed credit was given to Yamato for the hit post battle.
The US 4 stack destroyers were probably the most numerous and varied in their repurposing (minesweeper, mine layer, fast transport, seaplane tender, convoy escort, and even experimental ship-see USS Turner DD-259/ USS Moosehead)!
There was a third battleship conversion, the French aircraft carrier Bearn. This ship was more convoluted than Kaga or Eagle dreamed of being. It was so poorly designed, it didn't even make a good aircraft ferry.
Enjoyed your video but was surprised to see that you didn't mention conversions such as USS Jupiter (into USS Langley) and SS Seeandbee (into USS Wolverine) and SS Greater Buffalo (into USS Sable.) These three ships are well worth covering.
You missed an opportunity or two or three with the U.S.S. Sable, the U.S.S. Wolverine, and the U.S.S. Wilmette, Great Lakes passenger ships converted to Navy training ships. The first two were coal-fired sidewheel steamers converted for use in WWII teaching Naval aviators how to land on a ship and the third was converted even earlier for gun crew training, particularly merchant seamen who were about to find themselves in the middle of a shooting war.
Something more modern might be the practice of parking small aircraft or STOL on cargo ship hulls, either the improvised (like the UK Falklands Atlantic Conveyor) or the yard-converted (recent Iranian drone carrier conversion). Not particularly fast, well armored, or well-armed, but in the realm of "better than nothing, maybe".
The Independence class and others like the Block Island were desperately needed. It was all about getting aircraft into the air and worry about the danger later and hope for the best until the Essex class could kick in.
A class of ships that saw a variety of conversions was the Barnegat-class small seaplane tenders of the United States. Several would be converted as PT-boat tenders. One would be used for catapult training. One was in the process of being converted into a Public Relations platform for the media when Japan surrendered. Post war a number were transferred to the Coast Guard as patrol ships, some as scientific research vessels for the US Government, while others would see service in foreign countries in various duties including a special warfare platform.
Hey, Skynea, there are a few you forgot. Alongside Kaga, the Japanese converted the battlecruiser Akagi into a carrier. She was pretty much the best carrier in the world until the arrival of the Shokaku class an…arguably the Yorktown class. She was fairly fast, capable of 31.5 knots, and fairly maneuverable. She could carried up to 91 aircraft, and carried some of the best aircraft available. Somewhat famously, the four Kongo class battlecruisers were…..allegedly converted into fast battleships. Their deck was made much thicker, and their 6-8-inch belt was ungraded to a uniform 8-inch belt. That being said, an 8-inch belt was no where near battleship levels of protection, so many people (including myself) still call them battlecruisers, despite the reclassification. I also disagree on the Mogamis being poorly made heavy cruisers. Their light weight was fixed when they were converted, meaning they were the fastest heavy cruisers in history (besides the Myoko class), the carried heavy armor, a 3.9-5.5-inch belt and 1.6-inch deck, they carried a heavy armament of ten 8-inch gun and sixteen 24-inch long lance torpedo tubes, and they were fairly accurate as well. Hiyo and Junyo were also not escort carries, they were fleet carriers. They each carried 54 top of the line aircraft, and carried a heavy armament. They are only sometimes called light carries due to their speed of 25 knots.
In order: Mentioned Akagi with Kaga, focused more on the latter because of her issues. The Kongous are refits, not conversions. Even if you insist on calling them battleships, it’s still not a conversion in the sense this video is using. They really only had a slight armor reworking and more typical refit (if more along Italian lines) things. The Mogamis cracked welds on gunnery trials. were incredibly top heavy, and required multiple corrective refits. Including fitting hull bulges that dropped their speed by a couple knots. It’s not that they’re terrible ships, it’s that they sacrificed a lot to get the ability to take those bigger guns. And I called the Hiyos light fleet carriers here. I explicitly said ‘more light fleet carriers than escort carriers’. And that’s what they basically were, considering their design and aircraft capacity.
A more recent (and quite successful) conversion has been the conversion of the container ship MS Asterix to the RCN-leased (but privately-owned) replenishment ship MV Asterix. She is filling the gap caused by the retirement of RCN’s Protecteur class of replenishment/oilers and the long-delayed construction of the new Protecteur class of auxiliary ships. (The RCN does like to reuse names, doesn’t it?)
You could have included HMS Audacity, converted here in the UK in my home town Blyth, Northumberland. We also built the very first purpose built aircraft 'carrier' HMS Ark Royal in 1914, also the only aircraft carrier to have a sail!
well many navys still convert their old FFG into patrol boats by removing missiles and only retaining guns. That's a conversion very cheap and easy (despite a propper patrol ship should burn quite less fuel since it is designed for around 20knt, while a frigate sits around 30knt speed and has a faster more fuel-hungry power plant)
A razee or razée /rəˈziː/ is a sailing ship that has been cut down (razeed) to reduce the number of decks. The word is derived from the French vaisseau rasé, meaning a razed (in the sense of shaved down) ship.
Vasco da Gama had a long life, from sail to full motor ship, being completely transformed in Italy and serving the Portuguese Royal Navy for many years, finishing unfortunately scrapped. pt.wikipedia.org/wiki/Vasco_da_Gama_(couraçado)
Thanks for the FRAM I& FRAM II pictures.
I've long found a almost forgotten conversion, and one that is not even mentioned here, to be quite fascinating - that being the WWII 'British Merchant Aircraft Carrier' or MAC Ship. What may seem at first sight to be an absurdity austere aircraft carrier - they make proper escort carriers look over-engineered - are I would argue not only well suited to their intended task but also brilliantly economical designs for a nation that lacked the near limitless resources of the USA.
These mini carriers were in effect merchant vessels fitted with a simple flight deck over their cargo holds sufficient to operate a handful of FAA Swordfish biplanes. The true brilliance of the MAC Ship concept is that while doing that they also retained a large part of the original merchant vessel design's cargo carrying capacity. Obviously the aircraft number was small but they still provided their convoy with a potentially useful evel of ASW air cover. Furthermore, these eminently simple ships did not even require scarce RN trained crew as many non flight functions were still performed by Merchant Navy personal.
I think the real drawback with the MAC Ship concept was that they appeared only after the U Boat threat had been largely defeated and at a time when land based VLR aircraft and far more capable CVE types were readily available to cover the dreaded 'Mid Atlantic Gap'. Had the MAC been put into service in 1940 however then one suspects they would have proved to be very useful ships indeed.
By the way the earlier CAM ships were also a interesting emergency wartime conversation in many ways.
Roosevelt 'pushing them'.... Military Industrial Complex and back room deals comes to mind 😬
Oh,son of a gun. A true naval statement there. Just what I needed. Another interesting channel to add to my already unwieldy subscription list. Oh,well.
Well done.
"Built over a 100 of the things" when referring to the US construction of escort carriers. Between those & the swarms of Fletcher-class DDs...AND let's not forget the Liberty ships which were almost like a printer being jammed that just keeps spitting out sheets. For the AXIS those are quite literally scenes right out of countless tech-horror novels. All are great examples of the industrial complex that was roused.
The ship 'Fairsky', that my parents immigrated to Australia on in 1965, was once an Aircraft carrier built in San Francisco in 1942. Leased to the British during ww2, and was named 'Attack'.
0:52 Royal Navy Raze Frigates have entered the chat.
Exceptions to the rule are purpose-built CV4 Ranger and CV7 Wasp being inferior to the two cruiser conversions CV2 Lexington and CV3 Saratoga.
The Independence class was cramped but still very effective. Their Achilles heel was the ammunition storage. It was not as well protected as it would be on a full-size. This fact was clearly demonstrated with a loss of the USS Princeton.
Then again, they Jinxed Princeton by changing her name after she went into service. She was originally Midway.
@@kdrapertrucker that was the uss st lo
@@davidsmallwood1663 I stand corrected, somehow I got those 2 mixed up. I guess since both of them were lost about the same time.
Love your channel. Excellent work.
Also consider USS Langley, first US carrier, converted from collier Jupiter, then later converted to what could be considered the best seaplane tender. Her original cargo holds also provided ample storage and working spaces, but her speed (or lack thereof) did hinder her usage.
Langley is considered the worst fleet carrier ever built.
A failure compared to Hosho and Argus.
@ElijKarma No real indication Langley ever intended to be "fleet carrier" (not even sure that concept had been fully developed in 1922 and note derrigible/carrier experiments) due to her limited speed, etc.
She seemed to be an experimental ship/concept during a period of budget constraints and as such was primarily a learning tool for the US Navy first real fleet carriers Lexington and Saratoga.
The Jupiter later Langley was the sister of the USS cyclops that disappeared in the Bermuda triangle.
It's a great and entertaining overview of various conversions and what drove their respective navies to undertake them. My favorite part was the shade you threw at Kaga the floating space heater hahaha.
There is one Japanese carrier from the interwar period, the Ryujo, that LOOKS like a conversion, (and a kludge), but was actually a purpose built carrier.
You not many people use that term these days. Are you an old programmer or some other IT professional?
@@JohnRodriguesPhotographer I am. I worked as a computer technician in the '80s.
She was based on a heavy cruiser hull. You can feel the Aoba vibes on her
Lexingtons, the best conversion. Drach himslef also agrees.
Sail ~ row vessel conversions became either~oar... depending on the weather
The best class of escort carriers was the Sagamone's. Not only were they a little bit larger but they still had their oil tanks and could fuel their escorts. Being conversions from tanker hulls their engineering spaces were at the stern of the ship. This created turbulence from the exhaust gases. Still if I had to choose that is the class I would choose for my Navy. I wonder if you took a similar design if you could convert it to an arsenal in addition to the tanker role. How many VLS launchers could be put on that deck? 🤔
Very good video. I really liked it. Very informative. Thanks for the time and effort required to put your videos together and online.
As far as Razee, don't forget the USS Independence. She was fast as hell, an excellent sailer, and very well armed.
I've always been fascinated by the evolution of the _Chiyoda_ and _Chitose._
You also forgot two important conversions, the USNS Mercy (T-AH 19) and the USNS Comfort (T-AH 20), both of which were laid down as tanker hulls in the early 70's and converted to Hospital Ships in the late 80's.
You left put my favorite gun boat conversion. The Scarnhorst class.
One thing about conversions. The Allies had the aircraft to put on all those merchant hulled aircraft carriers - but the Japanese didn't. They couldn't even field enough aircraft for their fleet carriers - and used them as decoy's at Leyte Gulf.
.
Yea, those escort carriers could be pretty weak. USS Gambier Bay was lost to an armor piercing shell from Yamato to the engine room from 20,000 yards. While the shell over penetrated Gambier Bay, it badly cracked the hull, and did admiringly leave two 18.1-inch holes under the waterline. This caused horrible flooding that sank the ship, despite Yamato's shell not even exploding. USS Saint Lo was also lost to a single kamikaze following the surface engagement.
However, they could also be pretty resilient with a little bit of luck. In the same battle Yamato sank Gambier Bay, USS Kalinin Bay survived heavy fire. She was first hit by a battleship caliber shell to the hanger bay from an unknown battleship (though we can narrow it down to either Haruna or Nagato, due to Yamato and Kongo not recording targeting Kalinin Bay) that crippled the ship by destroying it's ability to launch aircraft. After that, she was hit by over a dozen 8-inch shells from the heavy cruisers Tone and Haguro, while hitting Haguro with gunfire. After that, she was hit by two Kamikazes and survived.
It’s not clear if Yamato hit Gambier Bay, actually, due to ambiguity over where that shell came from). She did get a straddle on her, however.
@@bkjeong4302 I think Yamato scored one-two hits on her. As stated, she scored a hit from 20,000 yards that sank the ship. She also claimed another main battery hit, a hit also claimed by the battlecruiser Kongo, though It's far more likely Yamato landed the hit due to having the shorter range and the superior firing angle, and indeed credit was given to Yamato for the hit post battle.
CVE: 'Combustible, Vulnerable, Expendable'.
Great stuff
The US 4 stack destroyers were probably the most numerous and varied in their repurposing (minesweeper, mine layer, fast transport, seaplane tender, convoy escort, and even experimental ship-see USS Turner DD-259/ USS Moosehead)!
There was a third battleship conversion, the French aircraft carrier Bearn. This ship was more convoluted than Kaga or Eagle dreamed of being. It was so poorly designed, it didn't even make a good aircraft ferry.
Enjoyed your video but was surprised to see that you didn't mention conversions such as USS Jupiter (into USS Langley) and SS Seeandbee (into USS Wolverine) and SS Greater Buffalo (into USS Sable.) These three ships are well worth covering.
Yes! Two carriers built for freshwater and with paddle wheels!
Great work. Just found your channel and I like what I've seen so far.
Escort carriers also had providing CAP as one of their primary functions.
As always, very well done. I do have one small nitpick: it's "from the *keel* up" not the 'ground'. 😉
My brain had the same reflex.
You missed an opportunity or two or three with the U.S.S. Sable, the U.S.S. Wolverine, and the U.S.S. Wilmette, Great Lakes passenger ships converted to Navy training ships. The first two were coal-fired sidewheel steamers converted for use in WWII teaching Naval aviators how to land on a ship and the third was converted even earlier for gun crew training, particularly merchant seamen who were about to find themselves in the middle of a shooting war.
You missed a "to another level" pun at 8:48
I was in tiers...
Something more modern might be the practice of parking small aircraft or STOL on cargo ship hulls, either the improvised (like the UK Falklands Atlantic Conveyor) or the yard-converted (recent Iranian drone carrier conversion). Not particularly fast, well armored, or well-armed, but in the realm of "better than nothing, maybe".
The Independence class and others like the Block Island were desperately needed. It was all about getting aircraft into the air and worry about the danger later and hope for the best until the Essex class could kick in.
A class of ships that saw a variety of conversions was the Barnegat-class small seaplane tenders of the United States. Several would be converted as PT-boat tenders. One would be used for catapult training. One was in the process of being converted into a Public Relations platform for the media when Japan surrendered. Post war a number were transferred to the Coast Guard as patrol ships, some as scientific research vessels for the US Government, while others would see service in foreign countries in various duties including a special warfare platform.
The HMS Eagle sure looked good though.🍻
It looks like it is better to convert downward in class than upward. :)
Hey, Skynea, there are a few you forgot.
Alongside Kaga, the Japanese converted the battlecruiser Akagi into a carrier. She was pretty much the best carrier in the world until the arrival of the Shokaku class an…arguably the Yorktown class. She was fairly fast, capable of 31.5 knots, and fairly maneuverable. She could carried up to 91 aircraft, and carried some of the best aircraft available.
Somewhat famously, the four Kongo class battlecruisers were…..allegedly converted into fast battleships. Their deck was made much thicker, and their 6-8-inch belt was ungraded to a uniform 8-inch belt. That being said, an 8-inch belt was no where near battleship levels of protection, so many people (including myself) still call them battlecruisers, despite the reclassification.
I also disagree on the Mogamis being poorly made heavy cruisers. Their light weight was fixed when they were converted, meaning they were the fastest heavy cruisers in history (besides the Myoko class), the carried heavy armor, a 3.9-5.5-inch belt and 1.6-inch deck, they carried a heavy armament of ten 8-inch gun and sixteen 24-inch long lance torpedo tubes, and they were fairly accurate as well.
Hiyo and Junyo were also not escort carries, they were fleet carriers. They each carried 54 top of the line aircraft, and carried a heavy armament. They are only sometimes called light carries due to their speed of 25 knots.
In order:
Mentioned Akagi with Kaga, focused more on the latter because of her issues.
The Kongous are refits, not conversions. Even if you insist on calling them battleships, it’s still not a conversion in the sense this video is using. They really only had a slight armor reworking and more typical refit (if more along Italian lines) things.
The Mogamis cracked welds on gunnery trials. were incredibly top heavy, and required multiple corrective refits. Including fitting hull bulges that dropped their speed by a couple knots.
It’s not that they’re terrible ships, it’s that they sacrificed a lot to get the ability to take those bigger guns.
And I called the Hiyos light fleet carriers here. I explicitly said ‘more light fleet carriers than escort carriers’.
And that’s what they basically were, considering their design and aircraft capacity.
A more recent (and quite successful) conversion has been the conversion of the container ship MS Asterix to the RCN-leased (but privately-owned) replenishment ship MV Asterix. She is filling the gap caused by the retirement of RCN’s Protecteur class of replenishment/oilers and the long-delayed construction of the new Protecteur class of auxiliary ships. (The RCN does like to reuse names, doesn’t it?)
You could have included HMS Audacity, converted here in the UK in my home town Blyth, Northumberland. We also built the very first purpose built aircraft 'carrier' HMS Ark Royal in 1914, also the only aircraft carrier to have a sail!
I had to look that up. Definitely an oddity, but it makes sense!
Well…the USS Intrepid did use a makeshift sail to get back to port once. Definitely wasn’t intended to have one though. 😅
@@aceofspadesattorney now, I've got another story to look up. Thanks! :)
well many navys still convert their old FFG into patrol boats by removing missiles and only retaining guns.
That's a conversion very cheap and easy (despite a propper patrol ship should burn quite less fuel since it is designed for around 20knt, while a frigate sits around 30knt speed and has a faster more fuel-hungry power plant)
You could have added USS Kearsarge BB-5 conversion to crane ship for something different.
Could the littoral combat ships (both versions) be converted to be drone carriers?
I just saw Iran convert box panamax ships to UAV carrier's, make a video of that please
Does commenting help the algorithm or whatever?
Common superstition says yes, but the algorithm is truly beyond our ken, inscrutable and unknowable.
Merrymac and monitor was only guardships around a harbour nothing to project naval power with.
Or you're running out of the required ship! Cough cough IJN COUGH!
Real model kit bashing.
A razee or razée /rəˈziː/ is a sailing ship that has been cut down (razeed) to reduce the number of decks. The word is derived from the French vaisseau rasé, meaning a razed (in the sense of shaved down) ship.
Vasco da Gama had a long life, from sail to full motor ship, being completely transformed in Italy and serving the Portuguese Royal Navy for many years, finishing unfortunately scrapped. pt.wikipedia.org/wiki/Vasco_da_Gama_(couraçado)