What if japan attacked/destroyed the panama canal at the same time as pearl harbour?

[Ross789]

What if japan had attacked the panama canal at the same time as it attacked pearl harbour?
It did launch attacks on Singapore and other targets across southeast Asia on the same day, and I wondered if this was feasible.
I was picturing some kind of giant kamikaze style thing where a merchant ship loaded with explosives was sailed into the locks and detonated.
I'm not sure what security was like at the time, or how long it would have taken to fix.
If they could have done it, it would surely have given them at least some advantage, with the delays getting allied warships and supplies transported.
Any thoughts?

 

[Garrison]

What if japan had attacked the panama canal at the same time as it attacked pearl harbour?
It did launch attacks on Singapore and other targets across southeast Asia on the same day, and I wondered if this was feasible.
I was picturing some kind of giant kamikaze style thing where a merchant ship loaded with explosives was sailed into the locks and detonated.
I'm not sure what security was like at the time, or how long it would have taken to fix.
If they could have done it, it would surely have given them at least some advantage, with the delays getting allied warships and supplies transported.
Any thoughts?

It took a massive effort to attack Pearl Harbor, mounting a major attack against the Panama Canal is probably out of the question.

 

[Fatt Shea]

Too far I think

 

[Catspoke]

Its peacetime until it isn't. Is it feasible to load up a Japanese merchant with explosives' and blow up a lock at same time as Pearl, timing would have to be perfect and the Japanese crew would have to be clued in and bail at the right time.

 

[Ian Henderson]

Its peacetime until it isn't. Is it feasible to load up a Japanese merchant with explosives' and blow up a lock at same time as Pearl, timing would have to be perfect and the Japanese crew would have to be clued in and bail at the right time.

The US was actually better prepared for this exact scenario than it was for the attack on Pearl Harbor. They were stopping and inspecting cargo ships before they entered the canal.

 

[Mad Bad Rabbit]

They had a very sketchy plan to attack the Canal locks using kamikaze floatplanes (painted with US insignia to fool us) launched from a submarine carrier, but by the time all the pieces were finally ready, the war was over. There's no way they could've had them ready for a one-two punch in 1941.

Japan's Panama Canal Buster

Japan's I-400 class special submarines, known as Sen-Toku, weren't just the largest subs of their time. They were the world's first underwater aircraft carriers, intended to attack the Panama Canal with Seiran bombers.

www.historynet.com

 

[Deleted member 2186]

What if japan had attacked the panama canal at the same time as it attacked pearl harbour?
It did launch attacks on Singapore and other targets across southeast Asia on the same day, and I wondered if this was feasible.
I was picturing some kind of giant kamikaze style thing where a merchant ship loaded with explosives was sailed into the locks and detonated.
I'm not sure what security was like at the time, or how long it would have taken to fix.
If they could have done it, it would surely have given them at least some advantage, with the delays getting allied warships and supplies transported.
Any thoughts?

Well a couple of Type B1 submarines carying each a float plane could do the trick, having pilots flying them do a kamikaze attack on the locks.

 

[Ross789]

They had a very sketchy plan to attack the Canal locks using kamikaze floatplanes (painted with US insignia to fool us) launched from a submarine carrier, but by the time all the pieces were finally ready, the war was over. There's no way they could've had them ready for a one-two punch in 1941.

Japan's Panama Canal Buster

Japan's I-400 class special submarines, known as Sen-Toku, weren't just the largest subs of their time. They were the world's first underwater aircraft carriers, intended to attack the Panama Canal with Seiran bombers.

www.historynet.com

I knew I'd read this somewhere! Couldn't remember if it was real or in a book or timeline

 

[wcv215]

Its peacetime until it isn't. Is it feasible to load up a Japanese merchant with explosives' and blow up a lock at same time as Pearl, timing would have to be perfect and the Japanese crew would have to be clued in and bail at the right time.

The US banned Japanese shipping through the Panama Canal before Warl Harbor. So no, it isn’t feasible.

 

[Draconis]

Its peacetime until it isn't. Is it feasible to load up a Japanese merchant with explosives' and blow up a lock at same time as Pearl, timing would have to be perfect and the Japanese crew would have to be clued in and bail at the right time.

Who says the Japanese crew would bail? These scenarios always remind me of this fine old 1950s Cold War melodrama. Courtesy of Youtube here it is.

 

[marathag]

Its peacetime until it isn't. Is it feasible to load up a Japanese merchant with explosives' and blow up a lock at same time as Pearl, timing would have to be perfect and the Japanese crew would have to be clued in and bail at the right time.

No, the US officials weren't drinking lead paint and eating paint chips since 1914.
Sure, let a Maru freighter, packed to the gills with High Explosive, thru the locks after a War Warning had been sent out on the 22nd of the previous Month

 

[marathag]

Well a couple of Type B1 submarines carying each a float plane could do the trick, having pilots flying them do a kamikaze attack on the locks.

Look at the size of the locks.
Unless they had a Nuke, there wouldn't be enough to do the job

 

[Deleted member 2186]

Look at the size of the locks.
Unless they had a Nuke, there wouldn't be enough to do the job

Not to destroy them, but to put them out of action for some time.

 

[Mad Bad Rabbit]

It boils down to: how much explosive would it take to breach the lock gates, could the Japanese floatplanes carry such a bomb, and how much water would escape Lake Gatun before crews dammed that lock by dumping rocks into it.

 

[nbcman]

It boils down to: how much explosive would it take to breach the lock gates, could the Japanese floatplanes carry such a bomb, and how much water would escape Lake Gatun before crews dammed that lock by dumping rocks into it.

The size / durability of the Gatun Dam is considerable per the below post by CalBear:

Consequences of Operation Pelikan going Through?

Operation Pelikan was basically Germany's 1943 version of Japan's planned 1945 strike on the Panama Canal. This thread will discuss some things surrounding the operation, and the consequences of it happening. I have a few questions about it happening: 1. What was the "betrayal" that prevented...

www.alternatehistory.com

In short, the estimate was it would take 5 hits by Upkeep bombs that each had a 6000 pound explosive filling. The Glen / E14Y float planes that the B1 submarines used had a bomb capacity of 2 x 76 kg. Pretty big difference between ~150 kg load of a Glen and the 2,700+ kg bomb X5 requirement to potentially breach the dam.

EDIT: A 1941 attack on Panama was extensively discussed in this thread as well:

Japan attacks somewhere else other than Pearl Harbor?

Lets say that in this timeline, Japan still attacks the US. But they attack somewhere else than Pearl harbor, where would they likely attack, and how will the USA react to this?

www.alternatehistory.com

 

[gatordad699]

Starting during WW1, but getting really paranoid in the 1930s, the US took security there seriously. Once the war started in 1939 they put armed guards on almost all civilian ships. They only let civilian ships use one side of the lock system. In case one did damage a lock, they still had the other side. They put up minefields and torpedo nets. They had installed radar on each coast and expanded airfields and AAA to deal with airborne threats. Even with not taking the distance from Japan into account, it would have been a tough nut to crack.
Went through them on an SSN in the 80s. Marathg is right, the lock doors are larger than you think.

 

[Carl Schwamberger]

It boils down to: how much explosive would it take to breach the lock gates, could the Japanese floatplanes carry such a bomb, and how much water would escape Lake Gatun before crews dammed that lock by dumping rocks into it.

The two obvious models are the Halifax explosion & the Texas City explosion. Both of cargo ships loaded with explosive material. In the latter case the cargo ship docked ahead of the detonated ship was shoved up onto dry land. In both cases the damage to the surrounding industrial sites and cities were significant.

The US banned Japanese shipping through the Panama Canal before Warl Harbor. So no, it isn’t feasible.

Even before the ban any ships transiting the canal underwent a safety inspection of the engineering and cargo. They were commanded thru the canal by a canal pilot & assistant. No one wanted to think of a drunk crew of a third rate tramp cargo hauler banging its way thru the channels and locks. Banning Japanese flagged or crewed ships simplified a already in place security system.

 

[Lucius Verus]

This would also go against Kentai Kassen, the focus on destroying warships so that the weak and cowardly Americans sue for peace after a short war. It's the same reason they didn't focus subs on shipping or oilers despite the heavy American shortage of the later.

If the war lasts, they'd lose regardless; so why bother planning for that?

 

[Father Maryland]

The two obvious models are the Halifax explosion & the Texas City explosion. Both of cargo ships loaded with explosive material. In the latter case the cargo ship docked ahead of the detonated ship was shoved up onto dry land. In both cases the damage to the surrounding industrial sites and cities were significant.



Even before the ban any ships transiting the canal underwent a safety inspection of the engineering and cargo. They were commanded thru the canal by a canal pilot & assistant. No one wanted to think of a drunk crew of a third rate tramp cargo hauler banging its way thru the channels and locks. Banning Japanese flagged or crewed ships simplified a already in place security system.

Yep security started getting real tight I think as far back as the German invasion of Poland. Thorough inspection of pretty much every ship and a Detachment of armed guards on board for the entire transit. The actual piloting was done by a Panama canal pilot and not a member of the ships crew.

Arguably Panama was by a margin the single most heavily secure area in North America with heavily tightened security. And for the time a pretty massive chunk of the US Army ( Before the early expansion I think the Panama Canal division was one of five in the entire US Army and was the one with the highest readiness and best equipped of all of them.) was stationed there well before Pearl Harbor. And since the US pre PH had banned Japanese owned or manned ships transiting it trying to sneak a Maru filled with explosives through would be difficult. Even if the Japanese tried using a non Japanese owned vessel manned by IJN pretending to be from some other Asian nation the bigotries of the era would result in even more intense suspicion and searching.

Basically its impossible. The closest thing to a viable way would be to send say half a dozen subs each carrying one or two Kaiten like suicide minisubs. Release them at night at a distance from the Canal and then try and get enough of the mini subs to the closest lock and detonate as close as possible. I'm not sure if they had anti submarine/ anti torpedo nets in place. Even if they didn't the odds of success are really low. As shown by the attempted usage of mini subs in PH there is a lot of risk involved of them just sinking. If they're extremely lucky they might get one or at most two close enough to matter. Not sure if one or even two Kaiten sized warheads detonating pretty close to the lock would be enough to badly damage it.

Honestly theres a pretty decent chance all the minisubs accidentally sink before they get close to the lock.

Be really ironic if after all that effort the US doesn't even notice the sunken minisubs immediately.

 

[Carl Schwamberger]

Submarines, including mini subs might sink some ships in the channel, blocking it for a few weeks. Or they might be all driven off and sunk. The group deployed at PH managed to get off one possible torpedo hit inside the harbor and hit a few cargo and warships at sea around the Hawaiian islands in December and January.