Napalm for anti-shipping

[pinehilljoe]

Napalm arrived later in the War. Are there any documented uses of Napalm as an anti shipping weapon? Imagine 8 or 16 F6F or F4Us covering a cruiser or battleship with napalm. The lite AAA would be silenced and fires might turn into a conflagration on board. By the time napalm was in operational use the USN may have run out of floating targets

 

[Thumpalumpacus]

Was the teak on the battleship decks thermally treated? If so, they might be able to sustain combustion after a couple of hits. I'd be skeptical of untreated teak conflagrating.

You not only need to raise the temperature to about 450°F, you need to keep it there for a while in order for any combustion to become self-sustaining, as once the napalm burns off (about 30 seconds for the original, WWII-era formulation), any continuing combustion will have to be fueled by the pyrolysis of the wood itself -- and that requires significant, and most importantly, sustained heat.

I'd imagine that some napalm was offloaded during the Battle off Samar, but I don't have certainly knowledge. I've read that they were launching whatever was loaded, and given that one of their missions was ground support, it seems possible some napalm got lobbed at Center Force.

 

[SaparotRob]

One of the D.E.s at the Battle of Samar used star shells after using up everything else. It set the upper works of an IJN cruiser ablaze and was surprisingly effective.

 

[Thumpalumpacus]

One of the D.E.s at the Battle of Samar used star shells after using up everything else. It set the upper works of an IJN cruiser ablaze and was surprisingly effective.

White phosphorus will react with the aluminum upperworks to drive intense fires.

 

[Admiral Beez]

Napalm arrived later in the War. Are there any documented uses of Napalm as an anti shipping weapon?

Fleet oiler aside, the best target for napalm would be the IJN's matchstick aircraft carriers.

 

[Shortround6]

White phosphorus will react with the aluminum upperworks to drive intense fires.

How many WW II ships used aluminum upper works?

It did become rather popular in the 1950s.

 

[Thumpalumpacus]

How many WW II ships used aluminum upper works?

It did become rather popular in the 1950s.

I believe the Japanese did on some of their heavy cruisers, the Mogamis iirc. There were a couple present at Samar, right?

 

[tyrodtom]

Napalm bombs weren't accurate, they didn't have to be for most uses.

Most had no tail fins, they tumbled during delivery.

 

[SaparotRob]

HIJMS Suzuya was there and was a Mogami. I think some of the IJN cruisers were Tone class.

 

[GrauGeist]

Using Napalm for anti-shipping is a hit-and-miss strategy.
If you're dedicating resources to attacking surface vessels, then you want to hole the ship (torpedoes, bombs, naval shells, etc.) and send it to the bottom as quickly and efficiently as possible.

Napalm is perfect for static, land-based situations where the target has a controlled environment: pillboxes, buildings, fortresses, etc. where the need to roast the defenders will benefit the offensive.

Raining fire on a ship, especially an armored warship will not have the same results. Yes, most had decks of teak, but there was armor beneath the wood (typically calculated to protect from plunging shells) and the superstructures were designed to protect from enemy shelling (read: steel, not alloys) and shell fragments. The masting may have been comprised of alloys, but the core structure would be steel.

 

[Tkdog]

If everything goes really well dropping fire on a ship might be effective. But your odds are better if you just focus on letting water in.

 

[GrauGeist]

To be fair, Greek Fire was successful in destroying warships during the days of the Byzantine Empire - but things were a bit different in WWII...

 

[SaparotRob]

I think some of the IJN heavy cruisers did have aluminum in the construction of the upper works. This was a nod (a very small nod) to the Washington Naval Disarmament Treaty to keep the weight down somewhat on their WAY oversized cruiser displacements. I believe this, and not so good welding techniques, led to many structural failures during the 4th fleet exercises. At least I think it was the 4th Fleet exercises.

 

[pinehilljoe]

If everything goes really well dropping fire on a ship might be effective. But your odds are better if you just focus on letting water in.

In his autobiography ADM J J Clarke said to sink a ship you need to let water in. I would not want to be an AAA gunner onboard a ship hit by napalm. The 50 to 100 exposed mounts with sailors manning them would be the target

 

[Glider]

I think some of the IJN heavy cruisers did have aluminum in the construction of the upper works. This was a nod (a very small nod) to the Washington Naval Disarmament Treaty to keep the weight down somewhat on their WAY oversized cruiser displacements. I believe this, and not so good welding techniques, led to many structural failures during the 4th fleet exercises. At least I think it was the 4th Fleet exercises.

If I remember correctly the USN Cleveland Class Cruisers were designed for an Aluminium superstructure, but they were not built as such due to the need of Aluminium for aircraft production. This in turn led to them having weight issues

 

[gumbyk]

If you're wanting to burn a boat to the waterline, wouldn't Thermite be a better option?

 

[Milosh]

Didn't napalm not also consume oxygen that people needed to breathe? Many Japanese in their tunnels were not crispy after an attack but asphyxiated.

 

[gumbyk]

Didn't napalm not also consume oxygen that people needed to breathe? Many Japanese in their tunnels were not crispy after an attack but asphyxiated.

Any combustion will.

 

[Thumpalumpacus]

Any combustion will.

Not necessarily. It depends on the fuel and the heat present, and also the type of combustion. Smoldering (obviously not relevant here) is a form of combustion which will often leave some oxygen present.

Additionally, fires topside would probably be oxygenated by the atmosphere rather than the innards of a ship at general quarters, unless the deck has been opened up by a hit. As the heated air rises, the surrounding air will come in horizontally from the atmosphere -- unless there is an open hatch or damage in the flaming area.

Agreed about the AAA crews being the targets of napalming in these circumstances, and agreed that it could be deadly to them, and perhaps to any ship shorn of defenses this way.

 

[GrauGeist]

The USAAF were using a form of napalm on Japanese defenses on some of the islands.
They were literally 55 gallon drums with plywood fins - worked exceptionally well.