WWII aircraft with four or more torpedoes...

[Avimimus]

For torpedo attacks on ships one wants sufficient range and endurance to increase the likelihood of encountering a target (which favours a large aircraft) and the ability to maximise the likelihood of a hit once a target has been detected.


There is no obvious reason why air-forces wouldn't favour long range aircraft with larger torpedo loads:

1) Most countries didn't field systems for programming torpedoes once airborne there is no reason to avoid increasing the number of torpedoes fired.

2) Most submarines carried multiple ready-to-fire torpedo tubes and often fired spreads to increase the likelihood of scoring a hit

3) An aircraft could make multiple attack runs on a target dropping one torpedo each time (although surprise would suffer).

4) Aircraft are much more manoeuvrable than ships


Now there are some less obvious reasons:

1) Few air-forces in the 1930s used large enough aircraft to carry more than two torpedoes

2) Larger aircraft are larger targets for anti-aircraft gunners. While dropping a spread of torpedoes allows release of the weapons further away from the target (as you can accept a reduced probability of hit for each shot), it likely doesn't provide adequate compensation.

3) The probability of scoring a hit with a torpedo may have been massively over-estimated in the interwar years

That said - I'm surprised there isn't more evidence of aircraft proposals carrying five, six, or seven torpedoes.

Does anyone know of such a project?

 

[Rickshaw]

Torpedoes are not small nor light weight. Multiple torpedoes severely affect range of aircraft.

Then there is the problem, torpedoes are used to attack ships. They are generally reserved to the nations that need to do that. The Luftwaffe did not have a reliable airborne torpedo until 1941 (and it was a copy of an Italian design) having relied until then on Dive Bombers and level bombers for ship killing. The Russians developed unreliable torpedoes. The British. Americans, Italians and Japanese are the main developers of and users of aerial torpedoes between the wars, having the largest navies and air forces. Their reliability varied, considerably. All initially relied on contact pistols (fuses) for their warheads to be detonated. Magnet and acoustic pistols were later developments and were unreliable until about mid-war.

 

[Avimimus]

Torpedoes are not small nor light weight. Multiple torpedoes severely affect range of aircraft.

Then there is the problem, torpedoes are used to attack ships. They are generally reserved to the nations that need to do that. The Luftwaffe did not have a reliable airborne torpedo until 1941 (and it was a copy of an Italian design) having relied until then on Dive Bombers and level bombers for ship killing. The Russians developed unreliable torpedoes. The British. Americans, Italians and Japanese are the main developers of and users of aerial torpedoes between the wars, having the largest navies and air forces. Their reliability varied, considerably. All initially relied on contact pistols (fuses) for their warheads to be detonated. Magnet and acoustic pistols were later developments and were unreliable until about mid-war.

The reliability argument would encourage multiple shots.

But you are absolutely right! I was looking at range to payload charts for heavy bombers - and the ability to carry more than two torpedoes would very much limit range. Despite this many designs did attempt to carry three or four torpedoes!

I suspect a Short Stirling or Avro Lancaster could've been modified to carry more (as could a B-29)... but they had other roles to fill.

 

[GTX]

There were a few examples of 4 torpedoes being carried (whether fully operational or not though I cannot say):

He-177:

Do-217:

For the most part, I believe you don't see too many examples for the following reasons:

• The Allies didn't have as great a need since there weren't as great a number of targets
• The existing platforms (carrying either 1 or 2 torpedoes were satisfying the need
• The additional weight and reduced manoeuvrability resulting from carrying 4 - especially down low - made it unattractive
• Doing so would be 'putting too many eggs in a basket' - i.e. torpedoes were not simple or cheap things - why put 4 on a single platform which could get shot down (thus loosing all) when you could put 2 each on a pair or even 1 each on 4 with a better loss ratio

 

[Hood]

The Douglas XTB2D-1 Skypirate was designed to carry four torpedoes, it could carry a maximum bomb load of 8,400lb. On the downside it had a 70ft wingspan and weighed 34,760lb loaded. Probably not a practical proposition for most US carriers at that time, but impressive nonetheless.

 

[merlin]

The Spec for the new medium bomber that was fulfilled by the Halifax and Manchester was initially to be capable of carrying two 18" torpedoes. And that is a large aircraft but still two not four.
In practice even the Beaufort was vulnerable to flak in daylight - imagine what a larger aircraft would have to endure.
OTOH the RAF did use a variant of the Wellington to carry two torpedoes, used on operations in the Med., however these took place at nighttime.
The Bristol design for the Halifax/Manchester spec was the smallest of the designs, rather the a circa 99' wingspan it had 79'. So if that had been ordered as a medium bomber replacement (no more Blenheims or Hampdens), then a two-torpedo attack option might have been used more often.

 

[PMN1]

The Spec for the new medium bomber that was fulfilled by the Halifax and Manchester was initially to be capable of carrying two 18" torpedoes. And that is a large aircraft but still two not four.

I did read that the spec was originally for 4 torpdoes then someway along the timeline, it was realised that torpedoes were quite large things.

 

[Archibald]

Couldn't the Skyraider or Martin Mauler carry four torpedoes ?

 

[royabulgaf]

I've seen pictures of the Mauler carrying four torpedos.

 

[royabulgaf]

Look before you write. The pictures show the Mauler carrying three torps. One centerline hardpoint and one inner hardpoint on each wing could carry a one ton torpedo. Keep in mind also the Mauler was larger.

 

[Kevin Renner]

To reduce AA vunerability you need loner ranged weapons. The Long Lance might fill the bill. But once you are facing carrier groups and radar the aircraft are meat one the table

 

[T. A. Gardner]

https://www.secretprojects.co.uk/threads/us-carrier-torpedo-and-bomber-aircraft.4302/

Down thread is the TBD, among others with 3 + torpedoes.