What if japan hit the fuel stores at pearl harbour?

I've read a few of the threads regarding a Japanese invasion of hawaii and the concensus seems to be that it's impossible mainly due to logistics.
But it's definitely possible for them to have launched a third wave of attacks and blown up the giant fuel stores and damaged the dry docks, and I think this was the plan at one point.
I'm wondering how much of an affect this would have had on the Pacific war overall.
Could the difference have been made up with tankers, or would it have hamstrung the us fleet for a time?
Any thoughts?
 
I've read a few of the threads regarding a Japanese invasion of hawaii and the concensus seems to be that it's impossible mainly due to logistics.
But it's definitely possible for them to have launched a third wave of attacks and blown up the giant fuel stores and damaged the dry docks, and I think this was the plan at one point.
I'm wondering how much of an affect this would have had on the Pacific war overall.
Could the difference have been made up with tankers, or would it have hamstrung the us fleet for a time?
Any thoughts?
One of the issues is that hitting the fuel storage is very nearly impossible to actually _do_. Bunker C doesn't burn, not like gasoline or the like. It has to be heated a lot before it will even burn at all, so hitting a tank of it is more likely to result in an oil slick than a burning fireball. There's about 40 tanks at Pearl, divided from each other by berms to prevent blast damage. With smoke and flak, a 50% hit rate would be pretty good, so you need about 80 bombers to have a decent shot at even puncturing every tank. Either you have to divert a lot of the bombers from the early waves, or you have to rearm and refuel one of the first two waves and send it into the teeth of thickening US flack, with bombers hanging around to make sure they don't lob their bombs into the same tanks, so they need to loiter and see the results of sequential attacks to ensure things are destroyed, but not "overkilled" with wasted bombs. The Japanese lost 20 aircraft in the second wave--a third wave will take several hours to arrive, meaning that long of a time for the US to sort out additional AA ammunition, get fire control dialed in properly, and repair what planes can fly with a few hour's patchwork. Losses in a third wave could approach....30, 40 additional aircraft? To be honest, the effect of that--especially on any chance of CarDiv2 being sent to Wake, might be well worth having to patch and refill a few fuel tanks from US tankers after Japan withdraws.

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Apart from the above mentioned points, the lingering of the Kido Butai for several more hours, possibly about half a day, means that the chances of being spotted and counterattacked in that timeframe increase.
 
But it's definitely possible for them to have launched a third wave of attacks and blown up the giant fuel stores and damaged the dry docks, and I think this was the plan at one point.
A Japanese third wave has been calculated (see Alan Zimm), under impossibly perfect operating conditions, to destroy merely anywhere between 6 and 12 percent of the dock facilities - imagine what the number would be like under normal operating conditions.

They simply did not have the firepower to inflict any significant degree of damage on the Navy Yard.

Multi-engined bombers would have had a difficult enough job doing so, to say nothing of carrier planes.
 
Pembroke in 1940 showed that aircraft could successfully bomb fuel tanks and Darwin in 1942 showed that even the Japanese could do this. The third attack would probably be at dawn the next morning and from a different direction. Smoke over the target would probably be the biggest obstacle to hitting the fuel tanks. CV6 had replenished and refueled and cleared the channel by 6am. If spotted then she's the target for the 4th strike.
 
Pembroke in 1940 showed that aircraft could successfully bomb fuel tanks and Darwin in 1942 showed that even the Japanese could do this. The third attack would probably be at dawn the next morning and from a different direction. Smoke over the target would probably be the biggest obstacle to hitting the fuel tanks. CV6 had replenished and refueled and cleared the channel by 6am. If spotted then she's the target for the 4th strike.
Darwin saw destruction of only seven oil tanks, using twice as many bombers as either the first or second waves over Pearl. The fact that the Japanese have 140 planes lost or damaged - nearly a third of their total - and the fact that the aviators have to be exhausted put further downward pressure on Japanese abilities to hit the tanks.

As for Pembroke, averting that catastrophe is precisely why the tanks are widely separated and have earthen berms between them.
 
Apart from the above mentioned points, the lingering of the Kido Butai for several more hours, possibly about half a day, means that the chances of being spotted and counterattacked in that timeframe increase.
Maybe halsey get correct info and send his strike north.
 
The third attack would probably be at dawn the next morning and from a different direction. Smoke over the target would probably be the biggest obstacle to hitting the fuel tanks. CV6 had replenished and refueled and cleared the channel by 6am. If spotted then she's the target for the 4th strike.
Giving the US 24 hours to react turns it into an incredibly thorny problem, worse than attacking at 3-4 PM the same day--there will have been hours for basic damage assessment, getting every single AA gun war-ready and stocked, and in 12 hours, some of the strafed fighters and such put out of action at the various Army and Navy fields will be back serviceable, so there may be CAP up too. Losing "merely" 50 planes would start sounding optimistic. What's the benefit of destroying 25% or so of Pearl's fuel storage if it costs the entire combat power of the Kido Butai for six months to do it? It's not a war game, you don't tally your victory points at the end of the battle and see who won, you have to sail home with the survivors, and figure out how to keep fighting the rest of the war.
 
Darwin saw destruction of only seven oil tanks, using twice as many bombers as either the first or second waves over Pearl. The fact that the Japanese have 140 planes lost or damaged - nearly a third of their total - and the fact that the aviators have to be exhausted put further downward pressure on Japanese abilities to hit the tanks.

As for Pembroke, averting that catastrophe is precisely why the tanks are widely separated and have earthen berms between them.
What fuel was contained in the seven tanks destroyed at Darwin? Gasoline or bunker fuel? Did all seven tanks catch fire?

As has been covered in several previous PH threads, for the Japanese to have been anywhere near successful in destroying the PH naval fuel stores would require:
- Destruction of the fuel farm would need to have been a primary objective, not an ad hoc target of opportunity.
- Intensive prior planning, targeting, and method of attack training would be needed, similar to what was done when the primary objective was the destruction of the fleet.
- Special munitions would be required to breach the tanks and set the thick nearly inflammable fuel alight.
-The special incendiary munitions would need to be part of the Kido Butai's ammunition load out and would come at the expense of being able to carry sufficient quantities of ship killing and general purpose munitions. Shipboard ammunition magazine space was limited.
- There would need to be total air superiority and suppression of AA.
 
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The other challenge is that another set of launches and recoveries and a bit more hanging around consumes fuel, which was already a serious challenge OTL.
The possibility of running out part way home or - more likely - diverting tankers and destroyers with barrels on deck to provide a top up is not appealing. Being out of fuel or refuelling at sea and found by subs or by the remaining carriers would result in a bad day.
 
What fuel was contained in the seven tanks destroyed at Darwin? Gasoline or bunker fuel? Did all seven tanks catch fire?

As has been covered in several previous PH threads, for the Japanese to have been anywhere near successful in destroying the PH naval fuel stores would require:
- Destruction of the fuel farm would need to have been a primary objective, not an ad hoc target of opportunity.
- Intensive prior planning, targeting, and method of attack training would be needed, similar to what was done when the primary objective was the destruction of the fleet.
- Special munitions would be required to breach the tanks and set the thick nearly inflammable fuel alight.
-The special incendiary munitions would need to be part of the Kido Butai's ammunition load out and would come at the expense of being able to carry sufficient quantities of ship killing and general purpose munitions. Shipboard ammunition magazine space was limited.
- There would need to be total air superiority and suppression of AA.
Most likely bunker fuel for ships; the Pembroke tanks were definitely storing bunker fuel.
 
Also, an obligatory reminder every time anyone suggests the Japanese sticking around (especially for another full day)

Destroyers. They were already at the very ragged edge of their range. If the Kido Butai sticks around much longer, especially that much longer, you're starting to run some serious risks of some of the DDs just plain running out of fuel on the way back.
 
A Japanese third wave has been calculated (see Alan Zimm), under impossibly perfect operating conditions, to destroy merely anywhere between 6 and 12 percent of the dock facilities - imagine what the number would be like under normal operating conditions.
I have Zimm. He talks about possible results of attacking the oil tanks. His verdict was that an attack could have destroyed a significant slice of the stored fuel, but that US tankers could have rectified the imbalance in subsequent months, making such a gesture strategically of little significance.
 
Giving the US 24 hours to react turns it into an incredibly thorny problem, worse than attacking at 3-4 PM the same day--there will have been hours for basic damage assessment, getting every single AA gun war-ready and stocked, and in 12 hours, some of the strafed fighters and such put out of action at the various Army and Navy fields will be back serviceable, so there may be CAP up too. Losing "merely" 50 planes would start sounding optimistic. What's the benefit of destroying 25% or so of Pearl's fuel storage if it costs the entire combat power of the Kido Butai for six months to do it? It's not a war game, you don't tally your victory points at the end of the battle and see who won, you have to sail home with the survivors, and figure out how to keep fighting the rest of the war.

I agree with your broad conclusion - I think Zimm was generally correct to conclude that an attack on the oil tanks, even if largely successful, would not mean that much to the war within the context of the Japanese strategy of a Southern Operation in which Hawaii would be subjected to no major pressure until the 2nd half of 1942.

On the question of exact losses of another assault, it all depends on the tactics used. To hit the tanks, the presumed method would be to use level bombers at around 20,000 feet. If so, then US AA and aerial defenses would probably have proven quite useless. The IJN would achieve little of strategic value in such an attack, the IJN would probably lose far fewer planes than imagined. (The IJN may have lost 29 aircraft in the attack, but not even one bomber making a level bombing attack was shot down in either wave, so bad was US higher altitude AA).
 
Destroyers. They were already at the very ragged edge of their range. If the Kido Butai sticks around much longer, especially that much longer, you're starting to run some serious risks of some of the DDs just plain running out of fuel on the way back.

IJN DD fuel levels were not a factor in the decision to withdraw. The IJN fuel tanker train provided was quite strong, (KB was usually operating with 5 tankers, but assigned 8 (actually 7) for the Hawaii Op). On the way over, IJN destroyers appear to have refueled to full daily. At the point when the 24 hour final run commenced, the destroyers had again just topped up. Judging from the fuel records of one of the destroyers published after the war, the 48 hours of high-speed running had reduced fuel levels to about 60%, or about 20% per day. Another day off Hawaii was therefore perfectly possible, another 2 days could be done provided that the planned provision of using the capital ships to refuel the destroyers had been implemented.

Nagumo gave a number of reasons on his decision to retreat including residual US airpower, the uncertainty of the location of the US carriers, the mission objectives having been accomplished. These were all true to a certain extent, but another factor was that Nagumo had failed to scout properly during the morning of the attack, and at the time when a decision had to be made, this oversight left him with zero tactical information of the seas to 250nm around him.
 
Honestly anyone thinking high level bombing it getting very high hit rates with WWII era tech even against non moving targets is probably being way to generous. Given the likely opposition and smoky as hell conditions if even 20% of bombs dropped hit the target accurately enough to matter I'll be amazed.
 
I've read a few of the threads regarding a Japanese invasion of hawaii and the concensus seems to be that it's impossible mainly due to logistics.
But it's definitely possible for them to have launched a third wave of attacks and blown up the giant fuel stores and damaged the dry docks, and I think this was the plan at one point.
I'm wondering how much of an affect this would have had on the Pacific war overall.
Could the difference have been made up with tankers, or would it have hamstrung the us fleet for a time?
Any thoughts?
I used to wonder this myself

The answer however is that ships fuel or number 5 fuel or Bunker B oil used then for warship fuels is like treacle and it has to be preheated to about 77–104 °C before it can be pumped into a ship from shore or sprayed into a boiler from the ships tanks

So a bomb hitting a tank or holing it is unlikely to cause a fire

The Avgas tanks on the other hand would more easily catch fire so there might be something gained from such an attack on the aircraft fuel

I have come to the conclusion that a third wave intended to destroy the fuel tanks would lead to far heavier losses than the first 2 waves combined and expose the fleet to a counter attack

Also the 3rd wave would be obliged to make a night landing - the sun setting at about 18.00 hrs at that time of year - with exhausted pilots

Also the IJN fleet particularly the escorting destroyers were at the very limit of their fuel and hanging around for another 6 hours might have made the difference to some of them not making it back
 
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