December 7, 1941. The Day Japan Attacked the Panama Canal

[rascal1225]

Boom! Another huge column of water rose into the air, this one right at the top of the spillway, behind a closed gate. Two things now happened simultaneously. A closed spillway gate burst open in the center and a hole big enough to admit a steam locomotive appeared, allowing a great stream of water to jet through. As if that was not enough, a torpedo leaped like a dolphin out of one of the water streams pouring through an open spillway gate. The torpedo, just like one he had seen in Life magazine, flew through the air, and struck the concrete side wall of the spillway channel, at wa

As he pondered this question, he watched the giant spillway gate that had been punctured by the torpedo’s explosion slowly begin to lose its shape, until it folded in the middle and leaped out of its track, admitting another 45 foot wide by 16 foot deep deluge of water into the spillway channel. Now there were five open gates. The roaring of the discharge became even louder. He felt a hand on his shoulder.

Just when Daniel was sure the flying boat had been atomized by the exploding shells so that no trace remained, it burst out of a wall of drifting black smoke, utterly engulfed in flames. One of the wings broke off and the plane fell to one side, struck the water with a wingtip, and cartwheeled across the lake surface, throwing bits and pieces high in the air. The wreckage sank. All that was left was a burning slick of gasoline on th

You missed a golden opportunity to have that 3rd (fake) S-42 deliberately crash into another Gatun Spillway gate, suicide dive style, while still hauling it's 2nd torpedo ... all that would be needed was some mechanism of allowing it's tail propeller to begin spinning in the airstream so that it would have been armed as it hit another spillway gate...

I also note that you mentioned the two earthen saddle dams which also helped to historically enclose Gatun Lake ... also possible targets for IJN torpedo hits but both were armored with concrete faces and rose up from rock ridges running between adjacent hilltops ... an erosive water flow thru either/both saddle dams would have reduced the level of Gatun Lake by some 14' eventually but the rock ridge bases of both would also have prevented the complete draining of Gatun Lake ... as was the historical case for the Gatun Spillway (16' waterlevel drop)... yes, a slowed down Panama Canal but NOT a knocked out of action Panama Canal for an estimated 2 years ...

EDIT: My mistake ... dropping the Cano saddle dam would have lowered the level of Gatun Lake by 15', not the 14' that I typed above ... sorry for the error. According to the report provided by YYJ here in a later posting.

 

[rascal1225]

Any junior US officer responsible for a Panama AA battery would no doubt be aware that long range ocean searches were CRITICAL to allowing him to have as much warning time as was possible to prepare for any attack on the Panama targets that he was assigned to protect and would NOT be expecting to see 2 x PBYs over Gatun Lake ...

While it might only buy them moments, the flight crews of those 2 x (fake) S-42s would no doubt be hoping that any and all US AA gunners might hold off for just a bit as they flew by on what might appear to be Gatun Lake water landing runs, rather than what would appear to be higher altitude level bombing runs, on the Gatun Lake Spillway structure.

American confusion might provide those by surprise AH IJN fliers with time to line up their 2 x 2 torpedo runs on those spillway gates, without enduring incoming US AA fire, Steadier hands ...

Sorry to quote myself but I present further evidence that the American defenders of the Panama Canal would NOT be expecting to see American PBYs over Gatun Lake .

Historicaly those PBYs had real Axis threats to search for elsewhere ...

For example, the German auxiliary cruiser Komet attacked and sank 3 Allied merchant vessels in the area of the Galapagos Islands as follows:

Operations in the Atlantic Ocean and Galapagos Islands​

The hunt for allied ships in the Indian Ocean had no success; after some months, Eyssen sailed towards the Panama Canal, hoping to find more convoys in the Pan-American Security Zone, recently opened to military actions from the Kriegsmarine high command. From 14 July 1941 until 25 July the Komet was resupplied by the German freighter Anneliese Essberger near the Tuamotu Archipelago.[21] At this time, the Komet was disguised as the Osaka Shosen Kaisha line Ryoku Maru.

On 14 August the ship met near the Galápagos Islands the British freighter Australind and sunk it.[22][23] Three days later the German cruiser met the Dutch 7,300 ton freighter Kota Nopan, loading more than 2,000 tons of tin and manganese.[24] Due to her precious load, the supply ship was spared from sinking and captured. On 19 August Komet met the freighter Devon and sank it.[1] Except for some casualties, the German sailors saved the crew members of the enemy ships, who became prisoners of war.[25]

comes from https://en.wikipedia.org/wiki/German_auxiliary_cruiser_Komet

 

[YYJ]

Sorry to quote myself but I present further evidence that the American defenders of the Panama Canal would NOT be expecting to see American PBYs over Gatun Lake .

Historicaly those PBYs had real Axis threats to search for elsewhere ...

For example, the German auxiliary cruiser Komet attacked and sank 3 Allied merchant vessels in the area of the Galapagos Islands as follows:



comes from https://en.wikipedia.org/wiki/German_auxiliary_cruiser_Komet

As far as I can tell the PBYs from VP-32 based in the Canal Zone all flew from NAS Coco Solo which was on the Caribbean coast. So the Pacific patrols would overfly the lake as they went south and west. But they would be still climbing from takeoff at the naval seadrome area in Limon Bay or returning, not doing something weird like landing on the lake.

Komet was already back in Hamburg at the time of this story, although the threat of German raiders was still considered to be real. It may be that the temporary staging of PBYs out of the Galapagos up until November 1941 had to do with looking for these raiders.

 

[njslim]

I also note that you mentioned the two earthen saddle dams which also helped to historically enclose Gatun Lake ... also possible targets for IJN torpedo hits but both were armored with concrete faces and rose up from rock ridges running between adjacent hilltops ... an erosive water flow thru either/both saddle dams would have reduced the level of Gatun Lake by some 14' eventually but the rock ridge bases of both would also have prevented the complete draining of Gatun Lake ... as was the historical case for the Gatun Spillway (16' waterlevel drop)... yes, a slowed down Panama Canal but NOT a knocked out of action Panama Canal for an estimated 2 years ,,,

The British made several attacks against the SORPE Dam in the Ruhr, the Sorpe was a concrete core covered with dirt resisted a hit with a bouncing bomb and later by several Tallboy bombs

Sorpe Dam - Wikipedia

en.wikipedia.org

 

[NHBL]

The British made several attacks against the SORPE Dam in the Ruhr, the Sorpe was a concrete core covered with dirt resisted a hit with a bouncing bomb and later by several Tallboy bombs

Sorpe Dam - Wikipedia

en.wikipedia.org

IIRC, torpedoes were not used, not because tehy couldn't do the job, but because there were torpedo nets in place

 

[Gudestein]

Damn that was intense. Sounds like the AA batteries were still firing after the third H6K crashed- quite believable that the gunners would be seeing ghosts. Man the tension is at an all-time high, I expect more " Great Los Angeles Air Raid" mishaps will happen in the future. Still, that's a maximum of two spillways crippled when four were open already- so the lake is not gone it seems.

Poor Daniel. Were the local workers really so mistreated that he is right to be surprised when the Americans don't expect him to just keep working after he nearly became collateral damage to the raid?

I look forward to the damage report. A torpedo blast is large and could destroy two gates in one blast and a collapsed gate may/will have a bigger whole. Also there are 4 open gates, but it is at a high water point. They need to be able to close when it’s not high waters. Do we even no if they are normally fully opened?

 

[YYJ]

I look forward to the damage report. A torpedo blast is large and could destroy two gates in one blast and a collapsed gate may/will have a bigger whole. Also there are 4 open gates, but it is at a high water point. They need to be able to close when it’s not high waters. Do we even no if they are normally fully opened?

Patience. All will be revealed.

Regarding the spillway Stoney gates, they are at least sometimes opened all the way, one at a time or multiples. In fact I usually see each gate either closed or wide open. It is extraordinary for all 14 gates to be open at the same time, but I have seen lots of photos taken over the years when this is the case . Each gate when fully open allows the passage of 10,000 cubic feet per second of water, although I have also seen figures as high as 12,500 cfs. This may depend on the lake level at the time of discharge. Normal lake full pool is 86 feet above sea level, but it has risen significantly higher in major storm events.

 

[YYJ]

The British made several attacks against the SORPE Dam in the Ruhr, the Sorpe was a concrete core covered with dirt resisted a hit with a bouncing bomb and later by several Tallboy bombs

Sorpe Dam - Wikipedia

en.wikipedia.org

IIRC, torpedoes were not used, not because tehy couldn't do the job, but because there were torpedo nets in place

A study was done on the Cano saddle dam, the one the US military thought was most vulnerable. They figured in the case of sabotage, 6000 pounds of TNT would have to be employed to breach the saddle dam enough to initiate a progressive failure.

Security and defense of the Panama Canal, 1903-2000

original-ufdc.uflib.ufl.edu

 

[GTStinger]

Patience. All will be revealed.

Regarding the spillway Stoney gates, they are at least sometimes opened all the way, one at a time or multiples. In fact I usually see each gate either closed or wide open. It is extraordinary for all 14 gates to be open at the same time, but I have seen lots of photos taken over the years when this is the case . Each gate when fully open allows the passage of 10,000 cubic feet per second of water, although I have also seen figures as high as 12,500 cfs. This may depend on the lake level at the time of discharge. Normal lake full pool is 86 feet above sea level, but it has risen significantly higher in major storm events.

Do photos taken with all the gates open look more impressive? There may be a tendency for those photos to be more common than expected because official photos were more likely scheduled when they knew it would look “cooler”.

 

[YYJ]

Dec 7, 1941. 1242 local time. Naval Intelligence Office, 15th Naval District Headquarters, Balboa, Panama Canal Zone.

“I thought you should see this sir,” said the message runner. The young private was red in the face, breathing hard, and looked alarmed. “You are the ranking officer in the department here now.” Cooper held out his hand and was given a Radiogram slip.

AIR RAID PEARL HARBOUR THIS IS NO DRILL, read the slip. He read it again. Then he whistled.

“Oh boy!” Cooper said. “War.”

“What?” responded Reyes, incredulous. He rolled over from his desk in his swivel chair. Cooper handed him the piece of paper. Reyes swore, and jumped to his feet. “I’m going to transfer to some branch where they’ll give me a gun. I…”

“Keep your cool,” said Cooper. “We have work to do here.” Phones started ringing, many of them siting on empty desks. Only a few of the intelligence analysts were in the office on the Sunday.

Reyes picked up the nearest phone. “Yeah,” he said flatly, then his eyes opened wide and he motioned for Cooper to pick up too. He toggled the phone to the same line.

“…I didn’t know who to call,” said the young voice on the line. “I’m a Coastal Artillery officer 4th Regiment, at Battery Birney, Fort Amador. I was on a civilian flight to… oh it doesn’t matter. Our plane was shot down over the Republic. West of Santiago. We crash landed. We were shot down by a flying boat. Four engines. It looked like a Pan Am clipper at first, but it wasn’t.”

Cooper put his hand over the mic end of the Bakelite handset. “Report this to Albrook Field Operations,” he said to Reyes in a stage whisper. “Where are you?” he asked the officer on the phone.

“Some one-horse town called San Bartolo, in the Republic, in a police station,” the officer answered.

Reyes made his call to pass the warning on to the Army Air Force on another line.

“Did the plane that shot you down have markings?” Cooper asked.

“It was painted like a Pan Am clipper,” the officer insisted. Then air raid sirens began to sound, and the men had to shout to be heard. Cooper covered his free ear with his hand.

“Did the plane have the Japanese rondel, that big red meatball?” Cooper yelled into the mouthpiece.

“Oh jeez!” said the officer, “That’s what it was! It had a circle painted on the side, but just an outline, like a big O.”

Cooper told the young officer to call his own regiment. Even more phones were ringing now. The noise of airplane engines rose from nearby Albrook Field, over top of the sirens.

He answered several other calls, and began to make his own, to order his absent men into the office. At the same time Reyes was having an increasingly animated conversation on another line. Finally, Reyes hung up.

“Do they have these sirens on because Pearl Harbor is under attack?” Cooper yelled. “I can’t hear myself think!”

“No!” answered Reyes, wide eyed. “We are under attack! Here! The Canal! Over on the Caribbean side!”

“Wow!” yelled Cooper. “You and I are going to be asked by some brass really soon – what the hell is going on? We better have some answers for them!” Both men got back on the phones. They had to contend with jammed lines. Everyone in the Canal Zone was on the telephone asking the same question. Airplanes were taking off from Albrook Field now pretty much constantly.

Cooper got ahold of a supervisor at the Gatun Lock Control House. “Aerial torpedo attack on the spillway,” he called out to Reyes. “The supervisor had a great vantage point to witness the whole thing from the lock control room. The attackers got four hits. At least one of their aircraft was shot down.”

Reyes was talking to a major in the 72nd Coastal Artillery Antiaircraft Regiment. “You’re sure about that?” he said. Cooper only heard the last part of the conversation. Reyes put down the phone.

“Three Mavis flying boats just attacked the Gatun Dam spillway,” said Reyes, as if he felt a headache coming on.

“Three Mavis flying boats,” repeated Cooper. “God damn it!”

File:Ww2-pearl-harbor-attack-radiogram-xl.jpg - Wikimedia Commons

commons.wikimedia.org

 

[Ramontxo]

And the proverbial brown matter has hit the revolving apparatus...

 

[Amon34]

very good chapter but don't forget threadmark

 

[rascal1225]

Cooper got a hold of a supervisor at the Gatun Lock Control House. “Aerial torpedo attack on the spillway,” he called out to Reyes. “The supervisor had a great vantage point to witness the whole thing from the lock control room. The attackers got four hits. At least one of their aircraft was shot down.”

Reyes was talking to a major in the 72nd Coastal Artillery Antiaircraft Regiment. “You’re sure about that?” he said. Cooper only heard the last part of the conversation. Reyes put down the phone.

“Three Mavis flying boats just attacked the Gatun Dam spillway,” said Reyes, as if he felt a headache coming on.

“Three Mavis flying boats,” repeated Cooper. “God damn it!”

Just a few questions if I might ?

Would not the (likely experienced) Supervisor at the Gatun Lock Control House have specified just three torpedo hits on the Gatun Spillway gates since the first IJN torpedo in your AH scenario actually hit the protective SIP-9 trestle structure just upstream of the spillways ?

Perhaps that Gatun Lock Control House (some distance away with the part of the higher Gatun Dam structure in between) did not have an unobstructed view of the Gatun Dam Spillway structure ?? How would the Supervisior know from that lower vantage point that those were torpedo explosions, rather than bomb explosions ? Granted that multiple large explosions are still multiple large explosions ...

In fact just two torpedo hits on the spillway gates since you seem to have your third torpedo punching thru a spillway gate without exploding ... ?

You seem to be ignoring the multiple layers of torpedo nets historicaly hung between the 14 spillway gate arch and that newly built railway trestle protective structure just upstream of them ? Since the nets would be easier and faster to install than building that trestle would be, would those nets not have been installed first, in order to provide some almost instant anti-torpedo protection to those spillway gates ? My understanding is that the railway trestle was built primarily to enable the quicker placement, via railway cars, of emergency replacement spillway plugs should some gates be destroyed by enemy attack, making the trestle only a second level priority ...

 

[rascal1225]

I look forward to the damage report. A torpedo blast is large and could destroy two gates in one blast and a collapsed gate may/will have a bigger whole. Also there are 4 open gates, but it is at a high water point. They need to be able to close when it’s not high waters. Do we even no if they are normally fully opened?

IIRC each spillway gate was separated from its neighbors by a thick reinforced concrete pier (clearly visible in the numerous spillway photos posted here) on which were mounted the steel tracks which held the gate's steel wheels in place as it was raised or lowered by electric motors mounted above.

Yes IJN aerial torpedoes of the day were powerful but I think it unlikely that one could take down one of those reinforced concrete piers which were designed to resist the immense sideways pressure exerted by some 16' of water overflowing two adjacent spillway gates during Panama's rainy season storm water runoff events ...

 

[rascal1225]

Patience. All will be revealed.

Regarding the spillway Stoney gates, they are at least sometimes opened all the way, one at a time or multiples.

If opened at times of high water flow those Gatun Spillway gates would usually be opened in pairs, on opposite sides of the spillway arch, so that the high speed errosive water flows would impact each other in the center of the lower pool and thus largely cancel out that erosive scour power ... not even reinforced concrete can stand up to that amount of rushing water (carrying abrasive debris within it) forever without some help ...

 

[Major Major]

And everyone searches libraries for a copy of The Great Pacific War.

 

[YYJ]

Perhaps that Gatun Lock Control House (some distance away with the part of the higher Gatun Dam structure in between) did not have an unobstructed view of the Gatun Dam Spillway structure ?? How would the Supervisior know from that lower vantage point that those were torpedo explosions, rather than bomb explosions ? Granted that multiple large explosions are still multiple large explosions ...

This is basically the view from the Gatun Lock control house in the direction of the spillway. The aerial photo from 1942 shows a lot of buildings on the top of the dam, so the view would have been more obscured at ground level. The Google photo may be from a newer, taller structure, but I don't think so, because the locks look like they would from the 1913 control house.

Panama Canal Gatun Locks Control House Stock Photo - Alamy

Download this stock image: Panama Canal Gatun Locks Control House - P89RDD from Alamy's library of millions of high resolution stock photos, illustrations and vectors.

www.alamy.com

I think that the first plane attack might have been missed by a lot of observers, but, like on 9/11, by the time the second plane came in, the commotion would have everyones attention.

Anyone watching the run-in of the second plane, even a 15 year old janitor, would be able to describe it as looking like a torpedo attack.

Google Maps

Find local businesses, view maps and get driving directions in Google Maps.

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[nbcman]

With all of the confusion in the aftermath of the attack, it seems strange that they called out the specific airplane designation of the Japanese aircraft as opposed to just calling them a flying boat plus the precise number of planes.

Reyes was talking to a major in the 72nd Coastal Artillery Antiaircraft Regiment. “You’re sure about that?” he said. Cooper only heard the last part of the conversation. Reyes put down the phone.

“Three Mavis flying boats just attacked the Gatun Dam spillway,” said Reyes, as if he felt a headache coming on.

“Three Mavis flying boats,” repeated Cooper. “God damn it!”

 

[YYJ]

You seem to be ignoring the multiple layers of torpedo nets historicaly hung between the 14 spillway gate arch and that newly built railway trestle protective structure just upstream of them ? Since the nets would be easier and faster to install than building that trestle would be, would those nets not have been installed first, in order to provide some almost instant anti-torpedo protection to those spillway gates ? My understanding is that the railway trestle was built primarily to enable the quicker placement, via railway cars, of emergency replacement spillway plugs should some gates be destroyed by enemy attack, making the trestle only a second level priority ...

The General led them to a better vantage point to look out over Gatun Lake. The lakeward face of the earth fill dam curved inward where it met the spillway. “This is the SIP-9 defensive project Senator, and it is nearly completed.” He yelled to be heard. The inlet on the lake side of the spillway was closed off with a curved section of railway line, appearing to sit on the lake surface. Construction barges floated on the lake, tied up to the rail trestle. “When the European war broke out, we placed torpedo nets in front of the vulnerable structures. You can see the floats supporting the nets there.” He pointed to four rows of white buoys out in the lake. “The problem is, conventional torpedo nets do not work well when suspended in a high flow current. When a torpedo net was rigged on the Miraflores dam, it went over top of the spillway the next day. This structure is more durable. Concrete caissons were built in sections, complete with the framework for a rail trestle on top, floated here, and then sunk in place to make an underwater barrier. A rock and concrete berm was built around the caissons. This berm is completely invulnerable to torpedoes and would stop a ship trying to ram the spillway gates. There is even a plan for a net to be hung in the air between the trestle and the spillway towers to catch bombs, although as an airman I am skeptical about how that would work. The best feature of this project is that the railway trestle framework will allow temporary gates to be lowered in tracks, as a back-up should the original gates be damaged.”

General Andrews mentioned the problem with torpedo nets in a strong current in the chapter entitled Redundancies, but I am sure we will come back to that later. In the photo above the 4 rows of white dots in front of the trestle must be supporting torpedo nets, but we can also see that the spillway gates are all closed, so there would be no current except for the intakes for the hydro-electric plant.

 

[YYJ]

With all of the confusion in the aftermath of the attack, it seems strange that they called out the specific airplane designation of the Japanese aircraft as opposed to just calling them a flying boat plus the precise number of planes.

The report on the aircraft type was from a major in the Coastal Artillery AA. He would have his aircraft recognition silhouettes pretty well memorized, or the junior officers who passed the report up to him would. Once the gunners saw "Japanese navy flying boat" there would not be a lot of types to mistake one for the other. I imagine if he was talking to the Office of Naval Intelligence he would try to be as precise as possible.