robdab2
Banned
Gents (and any Ladies ?),
WHAT IF the Japanese had attempted to knock out the Panama Canal on Dec.7'41 ?
I believe that they might have done so at little cost and the following is my alternative timeline (ATL) scenario as to how they might have accomplished that feat at the same time as the original timeline (OTL) historical Pearl harbor air raids were going on. It is my hope that discussion generated here will prove to be entertaining (and educational) for all involved. Sorry that its so long and that I'm not a better writer ...
One source, http://www.history.army.mil/books/wwii/ ... s/ch12.htm indicates that, "Plans for protecting the Canal against sabotage during an international crisis of this sort had been drawn up in Panama and given constant study ever since the spring of 1936. Now, steps to put them into effect were quickly taken. Three basic measures had been provided for: first, the installation and operation of special equipment in the lock chambers, designed to detect underwater mines and bombs and to prevent damage from this cause; second, the restriction of commercial traffic to one side of the dual locks; and third, the inspection of all ships before they entered the Canal and the placing of (2-25) armed guards on vessels while in transit through it. These measures were instituted between 26 August, when the President gave Secretary Harry H. Woodring the signal to go ahead, and 1 September of 1941."
Page #48 of http://books.google.ca/books?id=8WJ...=X&oi=book_result&resnum=4&ct=result#PPA48,M1 does also indicate that US ship inspectors at the Panama Canal began tossing hydrogen cyanide gas into ship's holds in order to fumigate same, in 1923. This makes it far less likely, IMO, that the Japanese or indeed anyone else, would be foolish enough to attempt any "Trojan Horse" type freighter attack on the Canal.
Thus I would expect that the chances of blockship sabotage success there would be very unlikely.
The ATL Japanese surprise air attack that I have in mind instead would see just 3 H6K 4-engined "Mavis" flyingboats trundling in the 855 nautical miles from the Galapagos Islands at 1300 in the early afternoon of Dec.7'41, timed to match with the OTL strike on Oahu at 0755.
Sneaking a pre-war IJN surface warship across the busiest shipping lanes of the wide Pacific, un-noticed a la the Kido Butai, would most likely be impossible even in peacetime so a "show-the-flag" state visit voyage by the IJN seaplane tender Chitose would have to provide a peacetime cover story to get those 3 big flyingboats within their air range of Panama.
With official permission from the governments of the countries scheduled to be visited, naturally.
Page #118 of http://books.google.ca/books?id=ehda-fB ... &ct=result details some of the 1940 trade successes that Japan achieved with Latin and South American nations. My ATL suggests that part of the OTL barter deal signed with Argentina might have included the 1941 provision by Japan of 3 long-ranged Mavis flyingboats for the Argentine military. That elongated nation had much isolated ocean coastline to patrol against Chilean incursion afterall.
A triple Mavis delivery by Chitose would thus be easily justified and would not be expected to pass anywhere near the Panama Canal as the IJN delivery vessel would be sailing southeastwards, around Cape Horn, due to the "unofficial" US ban on Japanese vessels transiting the Canal .
What world power would be greatly worried about 1 lone seaplane tender on an announced peacetime flyingboat delivery mission many miles away from it's outposts ? Completely un-announced in the newspapers would be 2 detached fast IJN crewed tankers and Chitose's close escort bodyguard of 3 long ranged IJN submarines (detached from their historical role of patrolling around Hawaii with 27 others), each capable of 21 knots on the surface and folding seaplane equipped.
Chitose's OTL war assignment at Mindanao, PI could be fulfilled by the Japanese CVL Zuiho, itself detached from the mostly idle Combined Fleet which still had a second light carrier attached (the CVL Hosho) to provide it's historically Bonin bound battleships with CAP and observation services. Please see the TROMs at http://combinedfleet.com
Much as was done historically with the Tatsuta Maru's fake voyage thru Honolulu (see Prange's "At Dawn We Slept") Chitose's schedule of South American ports of call visits would be published in various newspapers by the local Japanese consulates but she would never arrive at any of them in my ATL Panama scenario. If spotted by US/UK/Dutch ships while on her way across the still peacetime Pacific prior to Dec.7'41, she would merely be reported as being on course and schedule for those already announced port visits.
Wherever possible she would refuel at the commercial ports of the still peacetime Pacific islands that she passed so as to reduce her need for any tanker support.
She would never even cross the 300 mile boundary of the US Neutrality Patrol zone which extended out from the coasts of Latin and South America.
As she neared South America her regular radio operator would board one of her submarine escorts which would then continue on alone along Chitose's announced course towards Argentina. All the while making the same regular fake radio transmissions designed to convince the peacetime Americans that Chitose was still on her Mavis delivery mission.
On the evening of Dec.6'41 my ATL Chitose (watched over by her remaining 2 IJN submarine escorts) would quietly anchor instead in a deserted lee bay somewhere in the numerous Galapagos Islands, all 126 of them, which were/are owned by Ecuador.
That South American nation had a substantial Japanese population in 1941, many of whom were fishermen or guano miners earning their living out on the Galapagos. Both being good covers for the pre-war scouting of a suitable anchorage for my ATL Chitose and her 3 big new flyingboats.
Chitose was originally built to handle 24 single engined seaplanes with 4 catapults and 5 cranes as per the painting to be seen at http://www.combinedfleet.com/chitosesp_t.htm so in order to hoist a much heavier/larger 4 engined Mavis aboard at least one of those midship cranes would have needed to be upgraded to one similar to that installed on the stern of the much smaller Akitsushima as seen at http://www.aeronautic.dk/Warship%20Akitsushima.htm At the same time as that crane installation was done, her central "platform" would be removed to provide enough clear deck storage space for 3 Mavis.
Once anchored, all 3 Mavis flyingboats would be hoisted over the side during the night, checked out, fueled and armed with twin 800kg type 80 land bombs.
After a sheltered bay water takeoff at dawn, all three would depart at different speeds and on differing courses, for Panama's Gatun Dam, some 855 nmiles away.
The reason for those seperate but co-ordinated flight approaches to Panama being the more than passing resemblance of the Mavis to the Pan-American Airline's "China Clipper" aircraft, the Sikorsky S-42. If pre-painted in Pan-Am's minimal colors, with round windows and markings, any observer expecting to see a lone "China Clipper" pass by overhead could certainly mistake a single Mavis for one of them instead. By no coincidence at all, Pan-Am was flying a daily "China Clipper" shuttle service on the Miami - Cuba - Costa Rica - Panama - Columbia - Venezuela - Buenos Aries route at the time. As well, PanAm's subsidiary, Panagra, was busy developing a trans-Pacific route to the Galapagos Islands at the request of the American and Ecuadorian governments..
Please compare for yourself at http://www.warbirdphotographs.com/NavyJB&W/H6K-8s.jpg and http://www.flyingclippers.com/S42.html . Both with 4 engines and twin tail fins.
Each Mavis could carry a pair of torpedoes as per http://www.warbirdphotographs.com/NavyJB&W/H6K-1.jpg so the fitting of two slightly lighter big HE bombs shouldn't prove to be much of a technical challenge for my ATL Japanese.
My 3 ATL Mavis would attempt "to hide in plain sight" by fitting easily detachable sheet metal tailcones on each of their 6x800kg bombs in an attempt to disguise them as long range wing strut mounted fuel tanks
The target of the 6 bombs carried by those 3 Mavises being the Gatun Dam (not the Gatun Locks) itself which held back the water in man-made Gatun Lake and thus, allowed the operation of the entire Panama Canal.
The Gatun Dam, a stone armored earthfill structure is far too thick to be affected by a torpedo warhead but the same cannot be said wrt the concrete wingwall located immediately adjacent to the central concrete spillway. As can be seen ringed in blue at http://i73.photobucket.com/albums/i234/phylo_roadking/dam.jpg and at http://community.webshots.com/photo/fullsize/1322277285048181265JyntdB
Don't miss http://www.czimages.com/CZMemories/Photos/photoof289.htm nor
http://www.autoridaddelcanal.gob.pa/eng/plan/multimedia/photos/target32.html
Certainly the US was aware of the vulnerability of the Gatun Dam spillway to BOMBING as early as 1923 when a training exercise called Fleet Problem I, which is documented at http://en.wikipedia.org/wiki/Fleet_P..._note-Wright-1 , which pointed that out quite dramatically.
I do know that 3 US interceptor squadrons, each of 10 x P-36 fighters, were flying in Panama's rainy season cloudy skies already but AFAIK the 71 more modern P-40s which had just arrived were not combat operational there until well after Dec.7'41 due to aircraft radio shortages.
I have also found several sources which do NOT present the other OTL American defences in a good light:
For example, page #349 of http://www.history.army.mil/books/wwii/ ... s/ch13.htm summarizes the state of Dec.'41 US defences at Panama against a surprise air attack: "He did, however, call to the attention of the War Department certain deficiencies in the defenses of the Canal. In General Andrews' opinion, the commandant of the naval district did not have enough planes or vessels under his control to conduct an adequate reconnaissance. The Aircraft Warning Service in the theater, he reported, was totally inadequate in personnel to supervise the installation of detectors on hand as well as to man the equipment when installed. Only two radar detectors were installed and in operation in the Panama Canal Department. The harbor defenses had less than one complete manning detail available. The antiaircraft artillery had insufficient personnel to man the armament being installed in the Canal Zone and only enough ammunition for one minute of fire per gun for the 37-mm. guns. There were no barrage balloons. The Air Force,General Andrews continued, was totally lacking in night pursuit planes and in very-high-frequency radio equipment with which to direct pursuit in air. Only 8 modern long-range B-17C bombers and 12 modern AC-20 light bombers were available..."
Only one minutes worth of AA fire hardly inspires any confidence that a surprise IJN air attack could be prevented from reaching good positions to launch unexpected bombing attacks on the Gatun Dam's spillway. The US Army itself estimated that loss of all of the water stored in Gatun Lake would have prevented all Canal operations for a period of at least two years and possibly three, depending on the refill rates dictated solely by local rainfall amounts. This ATL attack scenario hopes to drain all of the Canal's water reserves as the Gatun Dam itself would be split open and exposed to complete destruction by erosion, thus emptying most of Gatun Lake.
Although not exactly identical, the Baldwin Hills Dam failure video to be seen at http://www.youtube.com/watch?v=kIeNM8cm6J8 aptly demonstrates the same type of quick progressive erosive failure that I predict for the earthfill Gatun Dam if those 6 big Japanese bombs can crack it's concrete upstream face open. It would take days however for the 164 square miles of Gatun Lake to drain into the Caribbean via the Chagras River.
Page #274 on http://www.ibiblio.org/hyperwar/AAF/I/AAF-I-8.html provides the assertion of: "The problems involved in providing a serviceable radar screen to alert the inner defenses of the Canal were less easily solved. Equipment in use at these stations was "inadequate" for early warning and "quite useless" for purposes of controlled interception. Sites had been selected for four British-type radars, the sets to be supplied from Canadian production, but improvement in equipment could not overcome deficiencies of operating personnel. Operators in Panama were largely untrained, had been given no indoctrination in the need for precision standards, and were frequently unenthusiastic about their assignment. Radar crews had made no effort to plot the permanent echoes in their search areas, and therefore could not discriminate between such "echoes" and "live" targets. The combination of inadequate equipment, poor site selection, and untrained operators produced such inefficiency that even the best station in Panama was "far below any acceptable standard of operational utility." The elimination of all the deficiencies noted depended on action by the War Department to provide improved equipment and better trained crews. No complete remedy was available to local commanders."
Since they had a little OTL knowledge of the American Panama radars via their spymaster there, Akiyama (please see http://www.ibiblio.org/pha/timeline/411122ax2.html ), my 3 fake ATL "China Clippers" will fly low over the Bay of Panama in an attempt to avoid it. Considering the high probability of rainy season cloud cover over Panama's mountains though, such would not be at all safe over land. Fortunately for my scenario, it seems that those same OTL radars would not likely have posed much of a detection/interception threat to my 3 ATL flyingboats anyway. Being of the same type of air warning radar as installed on Oahu, the one US radar set facing the Pacific Ocean would also have suffered from the same 20 mile minimum "blindspot" experienced by those Hawaiian radars.
Pages #424-426 of http://www.history.army.mil/books/wwii/ ... s/ch16.htm provide: "Although General Andrews recognized the U-boat campaign as "a definite menace to our war effort," he considered the canal to be "the one real enemy objective" and its protection to be his "paramount mission." Although he was somewhat concerned about the possibility of German surface raiders penetrating [from] the Caribbean, he was more than ever convinced that the principal threat was by carrier-borne aircraft from the Pacific.
The means for detecting an enemy carrier force before it launched its planes and for sighting the enemy planes before they reached the canal were the nerve center of the Panama defenses. Patrol planes, operating at about the 900-mile radius, were depended upon for the initial warning of an enemy's approach. Long-range radar (the SCR-271 and its mobile version, the SCR-270) was relied upon for the detection of enemy planes at distances up to about 150 miles. Still closer-in, the fixed antiaircraft defenses relied upon short-range, height-finding radar (SCR-268) for searchlight and fire control.
AFAIK there were only 12 PBY scouts (without RADAR) assigned to search the Pacific to the west of Panama out of the 70 (with RADAR) that were estimated to be able to provide a proper long ranged search.
At the time of the Pearl Harbor attack however, serious deficiencies existed in the warning and detection system. There were not enough planes and operating bases to carry out the search as planned. There were only two SCR-271 radars in operation, one at each end of the Canal. Although three additional sets arrived by the end of December and were being installed on the Pacific side of the Isthmus, the work was slowed down by a shortage of trained radar engineers and mechanics.
There were nevertheless certain deficiencies which were not entirely the result of a shortage of equipment and trained men. Tests in Panama repeatedly disclosed that low-flying planes approaching directly over the Bay of Panama were not detected by the radar system. Visiting British experts had noted this characteristic in American sets and attributed it to a basic defect of the equipment, but the Signal Corps insisted that, properly placed and operated by competent crews, the American equipment in this respect was just as good as, if not better than, the British radar. Whatever the cause, the blind spot remained. Furthermore, neither the SCR-270 nor the SCR-271 was designed to show the elevation of the approaching plane, and neither gave a continuous tracking plot. These qualities were indispensable for ground-controlled interception (GCI), which British experience had demonstrated to be the most successful method for conducting an air defense."
Pages #160-166 of: http://www.ibiblio.org/hyperwar/AAF/I/AAF-I-5.html detail the poor overall situation in Panama: "The vital importance of this phase of Canal defense was revealed in an estimate of enemy capabilities prepared by the Caribbean Defense Command in the latter part of November 1941. Japan was regarded in respect to the Canal itself as the primary potential enemy, and a carrier-based attack from the Pacific was considered "not an improbable feat." Other possibilities were taken into account, but it was concluded that in any event the most important defensive measure was "increasing and thorough reconnaissance and observation of the air, sea, and land approaches to the Canal Zone." Existing forces in the area were regarded as sufficient to repel any probable initial attack on the Canal provided they were given "timely warning" of the approach of hostile forces. The inability of defending naval and military air forces to perform the required amount of reconnaissance and to provide the "timely warning" constituted perhaps the chief weakness in the defenses immediately prior to American entry into the war. It was a weakness which was recognized by both Army and Navy commanders, their expressed hope lay in the postponement of attack by an enemy until the defending forces could achieve the proper degree of co-ordination and the necessary equipment for complete coverage of the vast sea frontiers."
THUS IT IS REVEALED THAT THE PRIMARY US PACIFIC DEFENSE OF THE PANAMA CANAL IN DECEMBER 1941 RELIED SOLELY ON THEIR MERE HOPE THAT THE JAPANESE WOULD NOT ATTACK THEM ANYTIME SOON !!!
Just how pathetic was that ?
Had the Japanese but known ... or dared ...
Your thoughts & constructive criticisms (with sources), please.
Veni, Vidi, Velcro. - I came, I saw, I Stuck Around
WHAT IF the Japanese had attempted to knock out the Panama Canal on Dec.7'41 ?
I believe that they might have done so at little cost and the following is my alternative timeline (ATL) scenario as to how they might have accomplished that feat at the same time as the original timeline (OTL) historical Pearl harbor air raids were going on. It is my hope that discussion generated here will prove to be entertaining (and educational) for all involved. Sorry that its so long and that I'm not a better writer ...
One source, http://www.history.army.mil/books/wwii/ ... s/ch12.htm indicates that, "Plans for protecting the Canal against sabotage during an international crisis of this sort had been drawn up in Panama and given constant study ever since the spring of 1936. Now, steps to put them into effect were quickly taken. Three basic measures had been provided for: first, the installation and operation of special equipment in the lock chambers, designed to detect underwater mines and bombs and to prevent damage from this cause; second, the restriction of commercial traffic to one side of the dual locks; and third, the inspection of all ships before they entered the Canal and the placing of (2-25) armed guards on vessels while in transit through it. These measures were instituted between 26 August, when the President gave Secretary Harry H. Woodring the signal to go ahead, and 1 September of 1941."
Page #48 of http://books.google.ca/books?id=8WJ...=X&oi=book_result&resnum=4&ct=result#PPA48,M1 does also indicate that US ship inspectors at the Panama Canal began tossing hydrogen cyanide gas into ship's holds in order to fumigate same, in 1923. This makes it far less likely, IMO, that the Japanese or indeed anyone else, would be foolish enough to attempt any "Trojan Horse" type freighter attack on the Canal.
Thus I would expect that the chances of blockship sabotage success there would be very unlikely.
The ATL Japanese surprise air attack that I have in mind instead would see just 3 H6K 4-engined "Mavis" flyingboats trundling in the 855 nautical miles from the Galapagos Islands at 1300 in the early afternoon of Dec.7'41, timed to match with the OTL strike on Oahu at 0755.
Sneaking a pre-war IJN surface warship across the busiest shipping lanes of the wide Pacific, un-noticed a la the Kido Butai, would most likely be impossible even in peacetime so a "show-the-flag" state visit voyage by the IJN seaplane tender Chitose would have to provide a peacetime cover story to get those 3 big flyingboats within their air range of Panama.
With official permission from the governments of the countries scheduled to be visited, naturally.
Page #118 of http://books.google.ca/books?id=ehda-fB ... &ct=result details some of the 1940 trade successes that Japan achieved with Latin and South American nations. My ATL suggests that part of the OTL barter deal signed with Argentina might have included the 1941 provision by Japan of 3 long-ranged Mavis flyingboats for the Argentine military. That elongated nation had much isolated ocean coastline to patrol against Chilean incursion afterall.
A triple Mavis delivery by Chitose would thus be easily justified and would not be expected to pass anywhere near the Panama Canal as the IJN delivery vessel would be sailing southeastwards, around Cape Horn, due to the "unofficial" US ban on Japanese vessels transiting the Canal .
What world power would be greatly worried about 1 lone seaplane tender on an announced peacetime flyingboat delivery mission many miles away from it's outposts ? Completely un-announced in the newspapers would be 2 detached fast IJN crewed tankers and Chitose's close escort bodyguard of 3 long ranged IJN submarines (detached from their historical role of patrolling around Hawaii with 27 others), each capable of 21 knots on the surface and folding seaplane equipped.
Chitose's OTL war assignment at Mindanao, PI could be fulfilled by the Japanese CVL Zuiho, itself detached from the mostly idle Combined Fleet which still had a second light carrier attached (the CVL Hosho) to provide it's historically Bonin bound battleships with CAP and observation services. Please see the TROMs at http://combinedfleet.com
Much as was done historically with the Tatsuta Maru's fake voyage thru Honolulu (see Prange's "At Dawn We Slept") Chitose's schedule of South American ports of call visits would be published in various newspapers by the local Japanese consulates but she would never arrive at any of them in my ATL Panama scenario. If spotted by US/UK/Dutch ships while on her way across the still peacetime Pacific prior to Dec.7'41, she would merely be reported as being on course and schedule for those already announced port visits.
Wherever possible she would refuel at the commercial ports of the still peacetime Pacific islands that she passed so as to reduce her need for any tanker support.
She would never even cross the 300 mile boundary of the US Neutrality Patrol zone which extended out from the coasts of Latin and South America.
As she neared South America her regular radio operator would board one of her submarine escorts which would then continue on alone along Chitose's announced course towards Argentina. All the while making the same regular fake radio transmissions designed to convince the peacetime Americans that Chitose was still on her Mavis delivery mission.
On the evening of Dec.6'41 my ATL Chitose (watched over by her remaining 2 IJN submarine escorts) would quietly anchor instead in a deserted lee bay somewhere in the numerous Galapagos Islands, all 126 of them, which were/are owned by Ecuador.
That South American nation had a substantial Japanese population in 1941, many of whom were fishermen or guano miners earning their living out on the Galapagos. Both being good covers for the pre-war scouting of a suitable anchorage for my ATL Chitose and her 3 big new flyingboats.
Chitose was originally built to handle 24 single engined seaplanes with 4 catapults and 5 cranes as per the painting to be seen at http://www.combinedfleet.com/chitosesp_t.htm so in order to hoist a much heavier/larger 4 engined Mavis aboard at least one of those midship cranes would have needed to be upgraded to one similar to that installed on the stern of the much smaller Akitsushima as seen at http://www.aeronautic.dk/Warship%20Akitsushima.htm At the same time as that crane installation was done, her central "platform" would be removed to provide enough clear deck storage space for 3 Mavis.
Once anchored, all 3 Mavis flyingboats would be hoisted over the side during the night, checked out, fueled and armed with twin 800kg type 80 land bombs.
After a sheltered bay water takeoff at dawn, all three would depart at different speeds and on differing courses, for Panama's Gatun Dam, some 855 nmiles away.
The reason for those seperate but co-ordinated flight approaches to Panama being the more than passing resemblance of the Mavis to the Pan-American Airline's "China Clipper" aircraft, the Sikorsky S-42. If pre-painted in Pan-Am's minimal colors, with round windows and markings, any observer expecting to see a lone "China Clipper" pass by overhead could certainly mistake a single Mavis for one of them instead. By no coincidence at all, Pan-Am was flying a daily "China Clipper" shuttle service on the Miami - Cuba - Costa Rica - Panama - Columbia - Venezuela - Buenos Aries route at the time. As well, PanAm's subsidiary, Panagra, was busy developing a trans-Pacific route to the Galapagos Islands at the request of the American and Ecuadorian governments..
Please compare for yourself at http://www.warbirdphotographs.com/NavyJB&W/H6K-8s.jpg and http://www.flyingclippers.com/S42.html . Both with 4 engines and twin tail fins.
Each Mavis could carry a pair of torpedoes as per http://www.warbirdphotographs.com/NavyJB&W/H6K-1.jpg so the fitting of two slightly lighter big HE bombs shouldn't prove to be much of a technical challenge for my ATL Japanese.
My 3 ATL Mavis would attempt "to hide in plain sight" by fitting easily detachable sheet metal tailcones on each of their 6x800kg bombs in an attempt to disguise them as long range wing strut mounted fuel tanks
The target of the 6 bombs carried by those 3 Mavises being the Gatun Dam (not the Gatun Locks) itself which held back the water in man-made Gatun Lake and thus, allowed the operation of the entire Panama Canal.
The Gatun Dam, a stone armored earthfill structure is far too thick to be affected by a torpedo warhead but the same cannot be said wrt the concrete wingwall located immediately adjacent to the central concrete spillway. As can be seen ringed in blue at http://i73.photobucket.com/albums/i234/phylo_roadking/dam.jpg and at http://community.webshots.com/photo/fullsize/1322277285048181265JyntdB
Don't miss http://www.czimages.com/CZMemories/Photos/photoof289.htm nor
http://www.autoridaddelcanal.gob.pa/eng/plan/multimedia/photos/target32.html
Certainly the US was aware of the vulnerability of the Gatun Dam spillway to BOMBING as early as 1923 when a training exercise called Fleet Problem I, which is documented at http://en.wikipedia.org/wiki/Fleet_P..._note-Wright-1 , which pointed that out quite dramatically.
I do know that 3 US interceptor squadrons, each of 10 x P-36 fighters, were flying in Panama's rainy season cloudy skies already but AFAIK the 71 more modern P-40s which had just arrived were not combat operational there until well after Dec.7'41 due to aircraft radio shortages.
I have also found several sources which do NOT present the other OTL American defences in a good light:
For example, page #349 of http://www.history.army.mil/books/wwii/ ... s/ch13.htm summarizes the state of Dec.'41 US defences at Panama against a surprise air attack: "He did, however, call to the attention of the War Department certain deficiencies in the defenses of the Canal. In General Andrews' opinion, the commandant of the naval district did not have enough planes or vessels under his control to conduct an adequate reconnaissance. The Aircraft Warning Service in the theater, he reported, was totally inadequate in personnel to supervise the installation of detectors on hand as well as to man the equipment when installed. Only two radar detectors were installed and in operation in the Panama Canal Department. The harbor defenses had less than one complete manning detail available. The antiaircraft artillery had insufficient personnel to man the armament being installed in the Canal Zone and only enough ammunition for one minute of fire per gun for the 37-mm. guns. There were no barrage balloons. The Air Force,General Andrews continued, was totally lacking in night pursuit planes and in very-high-frequency radio equipment with which to direct pursuit in air. Only 8 modern long-range B-17C bombers and 12 modern AC-20 light bombers were available..."
Only one minutes worth of AA fire hardly inspires any confidence that a surprise IJN air attack could be prevented from reaching good positions to launch unexpected bombing attacks on the Gatun Dam's spillway. The US Army itself estimated that loss of all of the water stored in Gatun Lake would have prevented all Canal operations for a period of at least two years and possibly three, depending on the refill rates dictated solely by local rainfall amounts. This ATL attack scenario hopes to drain all of the Canal's water reserves as the Gatun Dam itself would be split open and exposed to complete destruction by erosion, thus emptying most of Gatun Lake.
Although not exactly identical, the Baldwin Hills Dam failure video to be seen at http://www.youtube.com/watch?v=kIeNM8cm6J8 aptly demonstrates the same type of quick progressive erosive failure that I predict for the earthfill Gatun Dam if those 6 big Japanese bombs can crack it's concrete upstream face open. It would take days however for the 164 square miles of Gatun Lake to drain into the Caribbean via the Chagras River.
Page #274 on http://www.ibiblio.org/hyperwar/AAF/I/AAF-I-8.html provides the assertion of: "The problems involved in providing a serviceable radar screen to alert the inner defenses of the Canal were less easily solved. Equipment in use at these stations was "inadequate" for early warning and "quite useless" for purposes of controlled interception. Sites had been selected for four British-type radars, the sets to be supplied from Canadian production, but improvement in equipment could not overcome deficiencies of operating personnel. Operators in Panama were largely untrained, had been given no indoctrination in the need for precision standards, and were frequently unenthusiastic about their assignment. Radar crews had made no effort to plot the permanent echoes in their search areas, and therefore could not discriminate between such "echoes" and "live" targets. The combination of inadequate equipment, poor site selection, and untrained operators produced such inefficiency that even the best station in Panama was "far below any acceptable standard of operational utility." The elimination of all the deficiencies noted depended on action by the War Department to provide improved equipment and better trained crews. No complete remedy was available to local commanders."
Since they had a little OTL knowledge of the American Panama radars via their spymaster there, Akiyama (please see http://www.ibiblio.org/pha/timeline/411122ax2.html ), my 3 fake ATL "China Clippers" will fly low over the Bay of Panama in an attempt to avoid it. Considering the high probability of rainy season cloud cover over Panama's mountains though, such would not be at all safe over land. Fortunately for my scenario, it seems that those same OTL radars would not likely have posed much of a detection/interception threat to my 3 ATL flyingboats anyway. Being of the same type of air warning radar as installed on Oahu, the one US radar set facing the Pacific Ocean would also have suffered from the same 20 mile minimum "blindspot" experienced by those Hawaiian radars.
Pages #424-426 of http://www.history.army.mil/books/wwii/ ... s/ch16.htm provide: "Although General Andrews recognized the U-boat campaign as "a definite menace to our war effort," he considered the canal to be "the one real enemy objective" and its protection to be his "paramount mission." Although he was somewhat concerned about the possibility of German surface raiders penetrating [from] the Caribbean, he was more than ever convinced that the principal threat was by carrier-borne aircraft from the Pacific.
The means for detecting an enemy carrier force before it launched its planes and for sighting the enemy planes before they reached the canal were the nerve center of the Panama defenses. Patrol planes, operating at about the 900-mile radius, were depended upon for the initial warning of an enemy's approach. Long-range radar (the SCR-271 and its mobile version, the SCR-270) was relied upon for the detection of enemy planes at distances up to about 150 miles. Still closer-in, the fixed antiaircraft defenses relied upon short-range, height-finding radar (SCR-268) for searchlight and fire control.
AFAIK there were only 12 PBY scouts (without RADAR) assigned to search the Pacific to the west of Panama out of the 70 (with RADAR) that were estimated to be able to provide a proper long ranged search.
At the time of the Pearl Harbor attack however, serious deficiencies existed in the warning and detection system. There were not enough planes and operating bases to carry out the search as planned. There were only two SCR-271 radars in operation, one at each end of the Canal. Although three additional sets arrived by the end of December and were being installed on the Pacific side of the Isthmus, the work was slowed down by a shortage of trained radar engineers and mechanics.
There were nevertheless certain deficiencies which were not entirely the result of a shortage of equipment and trained men. Tests in Panama repeatedly disclosed that low-flying planes approaching directly over the Bay of Panama were not detected by the radar system. Visiting British experts had noted this characteristic in American sets and attributed it to a basic defect of the equipment, but the Signal Corps insisted that, properly placed and operated by competent crews, the American equipment in this respect was just as good as, if not better than, the British radar. Whatever the cause, the blind spot remained. Furthermore, neither the SCR-270 nor the SCR-271 was designed to show the elevation of the approaching plane, and neither gave a continuous tracking plot. These qualities were indispensable for ground-controlled interception (GCI), which British experience had demonstrated to be the most successful method for conducting an air defense."
Pages #160-166 of: http://www.ibiblio.org/hyperwar/AAF/I/AAF-I-5.html detail the poor overall situation in Panama: "The vital importance of this phase of Canal defense was revealed in an estimate of enemy capabilities prepared by the Caribbean Defense Command in the latter part of November 1941. Japan was regarded in respect to the Canal itself as the primary potential enemy, and a carrier-based attack from the Pacific was considered "not an improbable feat." Other possibilities were taken into account, but it was concluded that in any event the most important defensive measure was "increasing and thorough reconnaissance and observation of the air, sea, and land approaches to the Canal Zone." Existing forces in the area were regarded as sufficient to repel any probable initial attack on the Canal provided they were given "timely warning" of the approach of hostile forces. The inability of defending naval and military air forces to perform the required amount of reconnaissance and to provide the "timely warning" constituted perhaps the chief weakness in the defenses immediately prior to American entry into the war. It was a weakness which was recognized by both Army and Navy commanders, their expressed hope lay in the postponement of attack by an enemy until the defending forces could achieve the proper degree of co-ordination and the necessary equipment for complete coverage of the vast sea frontiers."
THUS IT IS REVEALED THAT THE PRIMARY US PACIFIC DEFENSE OF THE PANAMA CANAL IN DECEMBER 1941 RELIED SOLELY ON THEIR MERE HOPE THAT THE JAPANESE WOULD NOT ATTACK THEM ANYTIME SOON !!!
Just how pathetic was that ?
Had the Japanese but known ... or dared ...
Your thoughts & constructive criticisms (with sources), please.
Veni, Vidi, Velcro. - I came, I saw, I Stuck Around