What if Japan attack both Pearl Habor and Panama canal at the same time

[Rubicon]

The Japanese submarines built to carry seaplanes where not commissioned until 1944/1945 genius.

Sometimes it is wiser never to open your mouth

Type A1 completed 1941-42, capable of carrying a seaplane
Type B1 completed 1940-43, capable of carrying a seaplane
Type J1M, completed 1932, capable of carrying a seaplane

 

[David S Poepoe]

But if I could get a merchant ship through security that was poorly searched, i would just have 30,000 lbs of explosives deep in the cargo hold that I would explode. There is no reason to get cute, if the security is that poor.

Finally someone channels Hector Bywater. I would consider that the attack on the Panama Canal does not have to be mounted simutaneously with that of Pearl Harbor, but at least within a week before it. The object is not to permanently block the canel, since you can't, but to more pound American morale and try to convince them to reconsider their ways.

Tho of course, with the US practically reading IJN dispatches it might just come to naught.

 

[Rubicon]

Tho of course, with the US practically reading IJN dispatches it might just come to naught.

Japan had switched naval codes on December 1st, it took quite a while before the code breakers of the USA could regain the main naval code, and they actually never broke the new highest Japanese naval code only the common one.

 

[tchizek]

Finally someone channels Hector Bywater. I would consider that the attack on the Panama Canal does not have to be mounted simutaneously with that of Pearl Harbor, but at least within a week before it. The object is not to permanently block the canel, since you can't, but to more pound American morale and try to convince them to reconsider their ways.

Tho of course, with the US practically reading IJN dispatches it might just come to naught.

The problem with this is that

1) It will be (I was going to put almost here but no it would be impossible) impossible to get this through the security around the Canal after 1939. About the same odds of getting a Japanese agent into the Magazine of a USN Capitol ship and setting it off.
2) If it goes off a week before Pearl the US goes absolutely apesh*t crazy and is ready when the IJN tries to attack Pearl so they walk into a completely alerted air-defense system.
3) All the other things I said above about the odds of this happening.

 

[tchizek]

Sometimes it is wiser never to open your mouth

Type A1 completed 1941-42, capable of carrying a seaplane
Type B1 completed 1940-43, capable of carrying a seaplane
Type J1M, completed 1932, capable of carrying a seaplane

Well yes he shouldn't have said the Japanese didn't have any seaplane carrying subs before 1944, that was silly, on the other hand... they were carrying mostly the Watanabe E9W1 Type 96 in 1941

which had a total armament of 2 7.7mm mg (one fixed forward firing, one rear flexible firing) and 2 66 pound bombs. So the whole argument of how much damage the are going to do is kind of moot.

Even if they had been upgraded to the better Japanese sub launched plane you are talking about the Yokosuka E14Y1 Type 0 with one rear firing 7.7 mm mg and 2 132 pound bombs.

None of the sub launched aircraft are going to even scratch the locks - even if they can get to them through the canal air defenses.

 

[BlondieBC]

BlondieBC, how about offering some evidence that the Japanese assumptions, which the IJN was never able/willing to put to the test, were correct?

I notice you did not provide evidence. So I will take your statement as simple opinion.

I did if you read the earlier post. The Japanese had detailed technical drawings (i.e. blueprints) for the gate and had 3 engineers review them, who came up with the attack plan. I find it unlikely that engineers with blueprints miscalculate the amount of explosive required to blow through the steel.

The Japanese believed 4 800KG bombs per gate was enough.

 

[tchizek]

I notice you did not provide evidence. So I will take your statement as simple opinion.

I did if you read the earlier post. The Japanese had detailed technical drawings (i.e. blueprints) for the gate and had 3 engineers review them, who came up with the attack plan. I find it unlikely that engineers with blueprints miscalculate the amount of explosive required to blow through the steel.

The Japanese believed 4 800KG bombs per gate was enough.

Which sounds about right, but a bit more than 1 torpedo, or the available air power if attacked with sub-launched aircraft.

If you figure 20% hit rate, 25% attrition from anti-aircraft and fighter cover.

1 800KG bomb per aircraft, you are talking 25 strike aircraft minimum to knock out a single gate. Add escort and wanting to take out two or more gates and you are talking a carrier strike force. That doesn't have the range to reach the Canal without more logistical support than the Japanese have.

 

[Johnrankins]

The problem with this is that

1) It will be (I was going to put almost here but no it would be impossible) impossible to get this through the security around the Canal after 1939. About the same odds of getting a Japanese agent into the Magazine of a USN Capitol ship and setting it off.
2) If it goes off a week before Pearl the US goes absolutely apesh*t crazy and is ready when the IJN tries to attack Pearl so they walk into a completely alerted air-defense system.
3) All the other things I said above about the odds of this happening.

Yeah, you just started a war without doing any real damage. The canal is blocked for a while but he US fleet at Pearl is untouched and is probably headed east.

 

[elkarlo]

Where exactly are they going to board the merchant vessel? And what small boat are they going to steal? They US kept very close watch over everything that moved in and around the Canal.

So they land somewhere in Panama, move through the jungle avoiding all of the locals because well they look like a Japanese Special Forces Team. Carrying enough explosives to sink a large freighter quickly (because a small freighter will not do any good). They come to the edge of the canal zone and find - barbed wire and patrols. Because frankly the US doesn't trust the locals at this point. They find a weak point in the defenses and work their way past - but now they are several days past schedule. They start working their way toward Gatun Lake, which is the only real place to get a small boat and intercept a freighter. They avoid the US patrols and reach the lake to find, US PT boats patrolling and locals that all know each other and who owns what boat. They have to either find a local they can bribe (not really the Japanese style) or steal a boat and make it past the patrols on the lake, get on a freighter that has escorts on board, get rid of the escorts and pilot, successfully pilot the ship correctly through the canal to a vulnerable location without anyone noticing that the ship is being piloted by a non-canal pilot. or they have to try to keep control of the pilot and crew long enough to have them get the ship to the right spot, when all it takes is a 1 or 2 degree miss and the ship is aground in the middle of the Lake and the SF force is stranded waiting for the US Navy to show up...

This would make a great book or movie, real life would not work so well...

I didn't think the entire length of the canal was guarded. I thought it was mostly the locks and other key choke points.

But a team could easily roll through Panama. The only place to be sure to catch a well trained group would be at the canal. In the jungle, esp since our jungle school didn't exist then, would be unlikely.

 

[warlock]

Hi guys ,I'm going to take a stab at this so let me know what you think.A Japanese cargo ship ,crewed by naval personnel, load with thousands of tons of high explosives enters the locks, the ship explodes .(THINK OF THE HALIFAX EXPLOSION 1917)I think that might do the trick .Well guys what do you think . Regards Warlock

 

[SAVORYapple]

Hi guys ,I'm going to take a stab at this so let me know what you think.A Japanese cargo ship ,crewed by naval personnel, load with thousands of tons of high explosives enters the locks, the ship explodes .(THINK OF THE HALIFAX EXPLOSION 1917)I think that might do the trick .Well guys what do you think . Regards Warlock

that would DEFINITELY work. the same thing can happen to San Francisco

 

[David S Poepoe]

Hi guys ,I'm going to take a stab at this so let me know what you think.A Japanese cargo ship ,crewed by naval personnel, load with thousands of tons of high explosives enters the locks, the ship explodes .(THINK OF THE HALIFAX EXPLOSION 1917)I think that might do the trick .Well guys what do you think . Regards Warlock

I had to consult Bywater's Great Pacific War, but perhaps it would be easier to employ geological forces by blowing up the ship in the Gaillard or Culebra Cut. That portion of the canal is historically subjected to landslides.

 

[RamscoopRaider]

Hi guys ,I'm going to take a stab at this so let me know what you think.A Japanese cargo ship ,crewed by naval personnel, load with thousands of tons of high explosives enters the locks, the ship explodes .(THINK OF THE HALIFAX EXPLOSION 1917)I think that might do the trick .Well guys what do you think . Regards Warlock

Uh, the US would turn away the ship in all probability, what is JAPAN of all countries doing sending several thousand tons of HE through the canal, nope not suspicious at all and as another poster mentioned the US turned away ships from the canal for far less and searched down to individual cameras and pistols

 

[BlondieBC]

I think I figure out how they planned to blow the dams, it was not the gates, it was the land itself. Evidently, a battleship shell can create a 15m wide, 6m deep crater. With the bottom of the lock missing, the water would flow under the gate, and due to the great amount of the water, it would erode the land underneath even more, much like a dam break.

 

[warlock]

Ram doesn't need to be high explosives it could be ammonia nitrite ( a fertilizer) Which is highly explosive !!(check out Texas city 1947) As for passage thru the canal Japan still had the rite of passage ,because we weren't at war with Japan at that time.As for Turing ships away I'll get back to you on that my brother was stationed in canal zone back in th 70's he ounce told me they never turn a ship away . But who knows I could be wrong .

 

[RamscoopRaider]

Ram doesn't need to be high explosives it could be ammonia nitrite ( a fertilizer) Which is highly explosive !!(check out Texas city 1947) As for passage thru the canal Japan still had the rite of passage ,because we weren't at war with Japan at that time.As for Turing ships away I'll get back to you on that my brother was stationed in canal zone back in th 70's he ounce told me they never turn a ship away . But who knows I could be wrong .

He was right about the 70's, except this is the late 30's/early 40's, they were turning away ships then even from nations we were not at war with

And Ammonium Nitrate is still a suspicious cargo, and not something Japan has an abundance of or any reason to be sending through the Panama Canal, though in this case they may just give the Japanese crew a free train ride across the Isthmus while an American crew pilots the ship through

 

[Mike Stearns]

I think I figure out how they planned to blow the dams, it was not the gates, it was the land itself. Evidently, a battleship shell can create a 15m wide, 6m deep crater. With the bottom of the lock missing, the water would flow under the gate, and due to the great amount of the water, it would erode the land underneath even more, much like a dam break.

Except that battleship rounds weigh something like three tons. I think that they will be found at the inspection check point and the ship will be held.

I think the best way for the Japanese to disrupt the Canal would be to slip a commando team into Panama with the objective of going after the motors and gearing systems for the lock gates.

A secondary objective might be to blow the flood control gates on the Gatun Dam and flood the Canal.

 

[BlondieBC]

Which sounds about right, but a bit more than 1 torpedo, or the available air power if attacked with sub-launched aircraft.

If you figure 20% hit rate, 25% attrition from anti-aircraft and fighter cover.

1 800KG bomb per aircraft, you are talking 25 strike aircraft minimum to knock out a single gate. Add escort and wanting to take out two or more gates and you are talking a carrier strike force. That doesn't have the range to reach the Canal without more logistical support than the Japanese have.

The whole plan was two torpedoes and 8 bombs, maybe they assumed kamikaze, which if the most elite pilots were used should be a majority hits, maybe, if everything, just everything goes just perfect. Japanese intel told the Japanese by late 1945 the airplanes and AA were gone. Now even if not air defenses and total surprise, I give 10 planes a 1 in 3 chance of working.

Except that battleship rounds weigh something like three tons. I think that they will be found at the inspection check point and the ship will be held.

I think the best way for the Japanese to disrupt the Canal would be to slip a commando team into Panama with the objective of going after the motors and gearing systems for the lock gates.

A secondary objective might be to blow the flood control gates on the Gatun Dam and flood the Canal.

http://www.usstexasbb35.com/14_naval_gun.htm

Looks like 578 KG on 14", 45 Caliber. The Japanese bombs were 800KG, so they are battleship class rounds, probably the same type of weapons used on the Arizona.

I do like the commando option better too, because at such a high risk operation, cheapness (not using 3 custom built subs) has huge advantages.

 

[Mike Stearns]

I do like the commando option better too, because at such a high risk operation, cheapness (not using 3 custom built subs) has huge advantages.

When it comes down to it, a brute force frontal assault won't work. While packing a ship full of explosives would destroy the locks, the Americans would be expecting that and know what to look for. Sub-based seaplanes can't lift the ordinance needed, there aren't enough of them and the Canal has a very strong AA defence system, and the Japanese can't spare the ships or the pilots for a dedicated carrier strikeforce. The only way for the Japanese to disrupt the Canal is by sabotage.

 

[RamscoopRaider]

The whole plan was two torpedoes and 8 bombs, maybe they assumed kamikaze, which if the most elite pilots were used should be a majority hits, maybe, if everything, just everything goes just perfect. Japanese intel told the Japanese by late 1945 the airplanes and AA were gone. Now even if not air defenses and total surprise, I give 10 planes a 1 in 3 chance of working.

http://www.usstexasbb35.com/14_naval_gun.htm

Looks like 578 KG on 14", 45 Caliber. The Japanese bombs were 800KG, so they are battleship class rounds, probably the same type of weapons used on the Arizona.

I do like the commando option better too, because at such a high risk operation, cheapness (not using 3 custom built subs) has huge advantages.

The Arizona attack used a modified version of a 40.6cm Shell weighing 1020 kg, carrying less than 25kg of HE, good enough to set off a magazine, you would need something completely different for this attack