A navalised P-38 Lightning?

Koopernic said:

Exactly what problem did the USN have with liquid cooled engines? The RN had no issues at all it seems. The P-40 likely would have made a good carrier fighter early in the war, possibly better than the wildcat.

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The US Navy valued low and medium altitude performance, reliability and low maintenance. Air cooled radial engines were a good fit to these criteria. Furthermore, to the extent that such engines offered high power for a given installed weight, they offered potential advantages concerning the climb rate; this was important for being able to launch and position aircraft favorably to rapidly respond to airborne attacks. The reduced vulnerability to combat damage may have been another factor - the loss of an engine over open water is a particularly unattractive proposition.

The RN seems to have been very happy to acquire and operate F4Fs and F6Fs. They appear to have been surprised by developments in aviation and military doctrine; many of their aircraft at the beginning of the war were hopelessly inferior in performance to contemporary land based types, hence the improvised adaptation of Hurricanes and Spitfires. The reputation of Rolls Royce may have been a factor in favoring the usage of liquid cooled engines in aircraft such as the Firefly and Barracuda, but neither of these types were anything special from a performance perspective. The later Sea Fury and Firebrand used the Centaurus radial in preference to the Sabre and Griffon.

rinkol said:

The US Navy valued low and medium altitude performance, reliability and low maintenance. Air cooled radial engines were a good fit to these criteria. Furthermore, to the extent that such engines offered high power for a given installed weight, they offered potential advantages concerning the climb rate; this was important for being able to launch and position aircraft favorably to rapidly respond to airborne attacks. The reduced vulnerability to combat damage may have been another factor - the loss of an engine over open water is a particularly unattractive proposition.

The RN seems to have been very happy to acquire and operate F4Fs and F6Fs. They appear to have been surprised by developments in aviation and military doctrine; many of their aircraft at the beginning of the war were hopelessly inferior in performance to contemporary land based types, hence the improvised adaptation of Hurricanes and Spitfires. The reputation of Rolls Royce may have been a factor in favoring the usage of liquid cooled engines in aircraft such as the Firefly and Barracuda, but neither of these types were anything special from a performance perspective. The later Sea Fury and Firebrand used the Centaurus radial in preference to the Sabre and Griffon.

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Which Navy, in 1939, fielded carrier aircraft that were not hopelessly inferior to to contemporary land types?

The US and Japanese navies had reasonably modern bombers (Devastator and B5N1) in service during the late 1930s and had advanced fighters and bombers in the pipeline. The British were forced into the expedient of producing a navalized version of the Spitfire (Seafire) which only became available in the second half of 1942 and was hardly an ideal carrier aircraft.

Shortround6 said:

Glycol is also flammable and the Navy used the excuse that they didn't want to store/handle hundreds of gallons of an additional flammable liquid on their carriers.

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Anything will catch fire if it gets hot enough in the right conditions but ethylene glycol is not particularly flammable. I keep seeing this cited as a reason for not storing it on US carriers. but why? Is there any evidence that the USN used this as an excuse?
It has a flash point of 111 degrees Celsius, not dissimilar to diesel fuel and a bit lower than other fuel oils you'd expect to find on such vessels. The petrol you put in your car has a flash point around -45 degrees Celsius. Ethylene glycol has an auto ignition temperature (only relevant if things around it get very hot) of 410 degrees Celsius.

There are other problems associated with storing the pure compound, but it can simply be stored in an aqueous solution.

I don't know much about the possibilities of the P-38 as a carrier aircraft, but I do have a degree in chemistry

Cheers

Steve

stona said:

Anything will catch fire if it gets hot enough in the right conditions but ethylene glycol is not particularly flammable. I keep seeing this cited as a reason for not storing it on US carriers. but why? Is there any evidence that the USN used this as an excuse?

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I've seen it written somewhere and it was spoken about when I through firefighting school while in the USNR. The word (and joke) was "If it was up to the Navy, they wouldn't have any flammable liquids on a carrier, including jet fuel."

FLYBOYJ said:

I've seen it written somewhere and it was spoken about when I through firefighting school while in the USNR. The word (and joke) was "If it was up to the Navy, they wouldn't have any flammable liquids on a carrier, including jet fuel."

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It's a nonsense reason though. WW2 carriers must have stored vast amounts of aviation fuel for their aircraft and that really is flammable. Storing a fluid with properties (as far as flammability goes) not that different from the fuel oil they ran the carrier on can't really have been a fire hazard. I'm not saying that the supposed flammability of the glycol wasn't used as a reason by people prejudiced against the use of liquid cooled engines, I simply don't know, but it is not a valid reason.
Cheers
Steve

stona said:

It's a nonsense reason though. WW2 carriers must have stored vast amounts of aviation fuel for their aircraft and that really is flammable. Storing a fluid with properties (as far as flammability goes) not that different from the fuel oil they ran the carrier on can't really have been a fire hazard. I'm not saying that the supposed flammability of the glycol wasn't used as a reason by people prejudiced against the use of liquid cooled engines, I simply don't know, but it is not a valid reason.
Cheers
Steve

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If was just one more bilge or storage locker to fill, an excuse to stay away from in lines, or just some command master chief's order, who knows, but it was policy, end of story.

rinkol said:

The US and Japanese navies had reasonably modern bombers (Devastator and B5N1) in service during the late 1930s and had advanced fighters and bombers in the pipeline. The British were forced into the expedient of producing a navalized version of the Spitfire (Seafire) which only became available in the second half of 1942 and was hardly an ideal carrier aircraft.

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And the RN had the Skua in service in Sept 39 while the Albacore, which was generally superior to the Devastator, was just completing it's trials and was awaiting volume production of the Taurus engine. The USN would not field a replacement for the TBD until mid 1942. The first production Fulmar flew in Jan 1940 and it would be almost another two years before the FAA received any folding wing fighters from Grumman and the F4U was not carrier qualified, even by the RN until late 1943 and not by the USN until early 1944. The RN planned to have the Firefly in service in 1941 and the Barracuda in late 41/early 42; those plans took a beating after France fell, as FAA production priorities took a distant 2nd to the RAF. I suspect that if Japan or the USA had a hostile army and airforce parked 20 miles offshore that their naval aircraft production plans would have also suffered numerous delays.

The FAA navalized both the Hurricane and Spitfire but then again, there was nothing available from the USA until mid 1943, that could match or exceed either aircraft's performance as naval fighters. In mid/late 1942 the USN was desperately trying to match the A6M's performance while the FAA was having to tackle the 109f and FW190, hence the need for Seafires.

RCAFson said:

And the RN had the Skua in service in Sept 39 while the Albacore, which was generally superior to the Devastator, was just completing it's trials and was awaiting volume production of the Taurus engine. The USN would not field a replacement for the TBD until mid 1942. The first production Fulmar flew in Jan 1940 and it would be almost another two years before the FAA received any folding wing fighters from Grumman and the F4U was not carrier qualified, even by the RN until late 1943 and not by the USN until early 1944. The RN planned to have the Firefly in service in 1941 and the Barracuda in late 41/early 42; those plans took a beating after France fell, as FAA production priorities took a distant 2nd to the RAF. I suspect that if Japan or the USA had a hostile army and airforce parked 20 miles offshore that their naval aircraft production plans would have also suffered numerous delays.

The FAA navalized both the Hurricane and Spitfire but then again, there was nothing available from the USA until mid 1943, that could match or exceed either aircraft's performance as naval fighters. In mid/late 1942 the USN was desperately trying to match the A6M's performance while the FAA was having to tackle the 109f and FW190, hence the need for Seafires.

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Correct. Everyone uses things like the the Italian landings (etc) to slag off the Seafire, but it was the only plane at the time (US and UK) that could hold it's own with a 109 of the era (not many 190s in that arena) . It wasn't perfect by any means and the UK had to use (because of idiotic shipbuilding decisions) escort carriers as 'real' carriers. And they were unlucky, slow ECs with zero wind.... whoops, but they did the job. Imagine a Wildcat vs a 109F or G of the time..... slaughter city.

FLYBOYJ said:

but it was policy, end of story.

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Is there any evidence for that? It seems to be one of these things that has accrued credibility by repetition whilst being based on a fallacy, the flammability of glycol. I'm genuinely interested and would love to see some evidence to back up the contention. In the absence of any evidence it should be discounted as a reason and consigned to the myth bunker (which is bulging at the seams since the internet came into being )
I can think of other perfectly valid reasons why the USN might prefer to avoid liquid cooled engines in the 1930s, but coolant storage isn't one of them.
Cheers
Steve

OldSkeptic said:

Correct. Everyone uses things like the the Italian landings (etc) to slag off the Seafire, but it was the only plane at the time (US and UK) that could hold it's own with a 109 of the era (not many 190s in that arena) . It wasn't perfect by any means and the UK had to use (because of idiotic shipbuilding decisions) escort carriers as 'real' carriers. And they were unlucky, slow ECs with zero wind.... whoops, but they did the job. Imagine a Wildcat vs a 109F or G of the time..... slaughter city.

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The Seafire received much criticism after the Salerno landings but much was unjustified.

It suffered a landing accident rate of just over 10%, but given the calm conditions in the Mediterranean at that time of year and the slow carriers this was inevitable. Mike Crossley describes it as a "mathematical certainty" given the Seafire's vertical touch down velocity (7 ft/sec) mandatory 3.5 degree descent path and 15 knots of wind over the deck.

It was described as not fast enough to fulfil its primary task, the interception of the Fw 190 fighter bombers over the beach head. This failing was more a matter of tactics. The Seafire LIIc certainly could catch a Fw 190 but not as they were deployed at Salerno. They flew about 500 sorties and only made 3 interceptions. This was entirely due to a lack of warning. The ships were inshore and the radar suffered ground clutter which led to little or no warning of the approach of enemy aircraft at low level. The Luftwaffe pilots were not stupid and had worked out that by keeping some high ground behind them, in line with their sea level approach, they were invisible to ship's radar at any range. The Seafires flew CAP at 240 knots, the maximum feasible speed to conserve fuel, and could not accelerate to the 350 knot diving approach speed of the Fw 190s in time. Combined with the poor visibility this enabled the Fw 190s to evade virtually every time. Crossley's view is that had the ships been further off shore, avoiding the clutter and giving warning of the approaching Fw 190s at about 20 miles the Seafires could easily have accelerated to their escape speed of about 300 knots and made more interceptions.

The only really irrefutable criticism of the Seafire is its lack of endurance. Even with a 45 gallon slipper tank it could not manage a two hour patrol, largely due to the faster patrol speed. Added issues were the inability of the carriers to maintain a straight course for any length of time during landing operations before they hit.....Italy. The number of accidents also led to delays. Inevitably pilots would ask for landing with fuel in hand, shortening patrol times.

The Seafire could have been used much better during these operations but Rear Admiral Vian was not a man who had a firm grasp of air operational tactics. As OldSkeptic points out, there were no viable alternatives.

Cheers

Steve

RCAFson said:

And the RN had the Skua in service in Sept 39 while the Albacore, which was generally superior to the Devastator, was just completing it's trials and was awaiting volume production of the Taurus engine. The USN would not field a replacement for the TBD until mid 1942. The first production Fulmar flew in Jan 1940 and it would be almost another two years before the FAA received any folding wing fighters from Grumman and the F4U was not carrier qualified, even by the RN until late 1943 and not by the USN until early 1944. The RN planned to have the Firefly in service in 1941 and the Barracuda in late 41/early 42; those plans took a beating after France fell, as FAA production priorities took a distant 2nd to the RAF. I suspect that if Japan or the USA had a hostile army and airforce parked 20 miles offshore that their naval aircraft production plans would have also suffered numerous delays.

The FAA navalized both the Hurricane and Spitfire but then again, there was nothing available from the USA until mid 1943, that could match or exceed either aircraft's performance as naval fighters. In mid/late 1942 the USN was desperately trying to match the A6M's performance while the FAA was having to tackle the 109f and FW190, hence the need for Seafires.

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The Albacore was about 3 years later in timing than the Devastator. Even then, with substantially less power, the Devastator was 20% faster, due at least in part to its monoplane layout. The Seafire was an unplanned improvisation - I don't doubt that it filled a real need and was the best available solution under the circumstances. Nevertheless, the RN paid a price for the fallacious belief held prior to the war that naval aircraft would operate outside the range of land based aircraft and did not need to be competitive in performance with them.

stona said:

Is there any evidence for that? It seems to be one of these things that has accrued credibility by repetition whilst being based on a fallacy, the flammability of glycol. I'm genuinely interested and would love to see some evidence to back up the contention. In the absence of any evidence it should be discounted as a reason and consigned to the myth bunker (which is bulging at the seams since the internet came into being )
I can think of other perfectly valid reasons why the USN might prefer to avoid liquid cooled engines in the 1930s, but coolant storage isn't one of them.
Cheers
Steve

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I could try to look around and find the reference but I could tell you I served in the US Navy and it was told to me on more than one occasion by guys who were around when the Skyraider was still being operated. there were other bulk liquids that were not welcomed on ships.

Well the stuff will burn, it is combustible, most things are. It seems to be a bit unlikely that this could be a genuine reason for not using liquid cooled aero engines, given some of the other materials routinely stored in large quantities on the carriers of the day
I still think that there is an element of myth about this, though obviously something that has been believed and repeated for some considerable time.

Typical storage 'instructions'.

"HANDLING AND STORAGE
Ethylene glycol is a stable, non-corrosive chemical with high flash point. Since it is hygroscopic, storage vessels must be designed to minimize moisture pickup. Other possible contaminants are iron and oxygen. For longer term storage, or where iron contamination and color are objectionable, resin linings or stainless steel and aluminium vessels are recommended. Linings based on phenolic and epoxy resins are satisfactory. Zinc or zinc alloys should not be used in glycol service. For longer-term color stability, it is recommended that the product be stored under an inert atmosphere.
Cast-iron or centrifugal pumps with stainless shafts and impellers are satisfactory. Rubber-lined or rubber-bound gaskets should be avoided. Flexible graphite filled or stainless steel double-jacketed gaskets are usually effective larger gaskets. Stainless steel winding with flexible graphite filler piping gaskets performs well. Pipe thread lubricants based on corrosion inhibiting zinc compounds or a graphite based lubricant with aluminum are generally satisfactory; however, glycols are excellent penetrants and leaks may be present where hydrostatic testing has
indicated a tight system. Therefore, the system should be rechecked after the glycol has been added. Low pressure stainless steel steam coils in storage tanks and steam tracing of transfer lines may need to be provided in cases where low environmental temperatures may make pumping of the product difficult. Flushing with water and steam can readily clean transfer or storage tanks."

There is nothing difficult or complicated about that. It's probably more difficult to store aviation fuels.

Cheers

Steve

rinkol said:

The Albacore was about 3 years later in timing than the Devastator. Even then, with substantially less power, the Devastator was 20% faster, due at least in part to its monoplane layout. The Seafire was an unplanned improvisation - I don't doubt that it filled a real need and was the best available solution under the circumstances. Nevertheless, the RN paid a price for the fallacious belief held prior to the war that naval aircraft would operate outside the range of land based aircraft and did not need to be competitive in performance with them.

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We could go back and forth on the Albacore versus TBD but it is a fact that the FAA was trying to introduce more modern aircraft that were competitive with IJN and USN aircraft (and IMHO the Albacore was, for a variety of reasons, superior to the TBD) but trying to match land based air by any countries carrier based aircraft was not achievable with existing engine technology until 1944 or so. The FAA, especially, was hampered by the short flight decks of their older carriers, and so required strike aircraft with much better STOL characteristics than the IJN or USN; the TBD, for example, would have been inoperable from any of the older RN carriers, and only marginal from the newer armoured carriers.

Neither the USN or IJN in Sept 1939 or Dec 1941 was equipped to go toe to toe with land based air. IJN carrier aircraft would have been regarded as completely outclassed by the RAF and Luftwaffe in Europe in Sept 39, April 1940 or Dec 1941 and judged unsuitable for combat due to their low performance, and lack of armour and SS tanks, ditto for USN carrier aircraft.

stona said:

Well the stuff will burn, it is combustible, most things are. It seems to be a bit unlikely that this could be a genuine reason for not using liquid cooled aero engines, given some of the other materials routinely stored in large quantities on the carriers of the day
I still think that there is an element of myth about this, though obviously something that has been believed and repeated for some considerable time.

Typical storage 'instructions'.

"HANDLING AND STORAGE
Ethylene glycol is a stable, non-corrosive chemical with high flash point. Since it is hygroscopic, storage vessels must be designed to minimize moisture pickup. Other possible contaminants are iron and oxygen. For longer term storage, or where iron contamination and color are objectionable, resin linings or stainless steel and aluminium vessels are recommended. Linings based on phenolic and epoxy resins are satisfactory. Zinc or zinc alloys should not be used in glycol service. For longer-term color stability, it is recommended that the product be stored under an inert atmosphere.
Cast-iron or centrifugal pumps with stainless shafts and impellers are satisfactory. Rubber-lined or rubber-bound gaskets should be avoided. Flexible graphite filled or stainless steel double-jacketed gaskets are usually effective larger gaskets. Stainless steel winding with flexible graphite filler piping gaskets performs well. Pipe thread lubricants based on corrosion inhibiting zinc compounds or a graphite based lubricant with aluminum are generally satisfactory; however, glycols are excellent penetrants and leaks may be present where hydrostatic testing has
indicated a tight system. Therefore, the system should be rechecked after the glycol has been added. Low pressure stainless steel steam coils in storage tanks and steam tracing of transfer lines may need to be provided in cases where low environmental temperatures may make pumping of the product difficult. Flushing with water and steam can readily clean transfer or storage tanks."

There is nothing difficult or complicated about that. It's probably more difficult to store aviation fuels.

Cheers

Steve

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I think this comes more from the fact that if there were large amounts of a liquid aboard a carrier, it would have to be stored in a bilge and that's probably the reason why there was a resistance of this extra "bulk liquid."

As stated, if it wasn't necessary, folks running a carrier wouldn't even want aviation fuel on board!

Something interesting on this out of Wiki - a reference from a written by Tommy Thomason on his book about the Bell XFL-1 Airabonita.

"As a possible further reason for the rejection it is often stated that the Navy's position during that era was that all its aircraft should use air-cooled engines (while the Allison was liquid-cooled). This appears unfounded speculation. The U.S. Navy "would consider a liquid-cooled engine installation provided a material increase in performance over air-cooled engine can be shown."

In addition to this "story or myth" on glycol on US Carriers, I was also told that one of the reasons why the Skyraider went away immediately after Vietnam was because of the storage of high octane Avgas. These comments were made by Chiefs, and those of us who were in the Navy knows you never argue with a Chief!!!!

FLYBOYJ said:

I think this comes more from the fact that if there were large amounts of a liquid aboard a carrier, it would have to be stored in a bilge and that's probably the reason why there was a resistance of this extra "bulk liquid."

As stated, if it wasn't necessary, folks running a carrier wouldn't even want aviation fuel on board!

Something interesting on this out of Wiki - a reference from a written by Tommy Thomason on his book about the Bell XFL-1 Airabonita.

"As a possible further reason for the rejection it is often stated that the Navy's position during that era was that all its aircraft should use air-cooled engines (while the Allison was liquid-cooled). This appears unfounded speculation. The U.S. Navy "would consider a liquid-cooled engine installation provided a material increase in performance over air-cooled engine can be shown."

In addition to this "story or myth" on glycol on US Carriers, I was also told that one of the reasons why the Skyraider went away immediately after Vietnam was because of the storage of high octane Avgas. These comments were made by Chiefs, and those of us who were in the Navy knows you never argue with a Chief!!!!

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The Navy did sponsor a high powered liquid cooled engine, the P&W XH-3130, during the late 1930's. This was later abandoned in favor of the R-4360. Nevertheless, it does indicate that, while the Navy may have had definite preferences, it was willing to consider other approaches if necessary.

The Navy tested a P-51 and P-51D, so they were definately open to options as far as liquid-cooled aircraft are concerned.

These comments were made by Chiefs, and those of us who were in the Navy knows you never argue with a Chief!!!!

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Try having two retired career USN Chiefs (who were also WWII/Korea combat vets) as Uncles!

Hi Steve,

If anything is flammable, a direct hit from a 14 - 16 inch Naval gun will set it off rather instantly, or at least ignite it since armor-piercing rounds went through many layers of walls and decks before they detonated. I think they were open to a liquid-cooled aircraft if it showed itself to be clearly superior to the air-cooled variety. Not many could do that at the time (early WWII for the USA).

There was NO force likely to be encountered that could ruin your day like an accurate Naval gun salvo.

I'm not saying I agree with them, but I heard that too when in the service ... even in the Air Force, since we had Navy exchange fliers who were WWII aviation fans like we were, so it got discussed. Another factor was the pilots. If they had their choice, none of them wanted to fly liquid-cooled planes. It was said the some aviators said if they were ordered to do so on operations, they's hand in their wings. I have no reference for that since it was conversation over a meal. Possible mutiny among the aircrews is enough to make deploying a liquid-cooled unit something to consider before some were introduced at land bases where they could be proven to be OK before being deployed.

The Navy had had a lot of bad experiences with water cooled engines in the 1920s. A lot of which had very little to do with the engine itself and a lot to do with broken waterlines/piping and leaking radiators. Pure Ethylene Glycol leaks worse than plain water. It has the ability to seep through joints that are actually water tight.
Piping, joints, couplings and radiators all got better during the late 20s and 30s but the Officers making the decisions in the late 30s early 40s may have been the same guys ( or from the same class) as the guys who had to ditch and be fished out of the water (hopefully) due to water leaks back in the 20s.
The storage "problem" may have been the final straw or nail in the coffin in the argument. I doubt it was the only reason for staying away from liquid cooled planes. By about 1940 Both the Merlin and Allison had moved back from pure Ethylene Glycol to mixes of Ethylene Glycol and water which were much easier to seal up.