Saturday, October 29, 2016

The best Carrier based Torpedo Bomber of World War Two?

Having recently re-read the many comments on an old article in which I discussed the relative strengths and weaknesses of carrier aircraft in WWII, 

(and having reviewed some of the discussion groups that insist on misquoting me), I though it might be useful to make a couple of reflections that show just how silly these debates can get.

First lets make the key point – in the battle between offense and defence, the pendulum keeps swinging.

When I do a discussion with a school group about medieval weapons and armour, I point out that the fanciest sword is no good, if it can’t defeat a new style of armour; and the fanciest armour is no good, if offensive weapons can defeat it. It is always about ‘does this weapon defeat the defence, or does the defence defeat the weapon’.

In WWII this means two things.

First: that even spectacularly effective offensive aircraft from 1939 or 1942 are usually hopeless in the same circumstances against improved defences two years later.

Second: that technological change will require adapting new methods.

Third: that the 'best' aircraft at a given time, is not necessarily going to do the job best at that time, if other elements of the offence vs defence balance need to be considered!

There were many torpedo bombers of course – from bad carrier versions, like the Devestator and the Barracuda, to good land versions, like the Beaufort and the Condor, but for the sake of the argument, I will stick to the two contrasting torpedo bombers that make the most interesting point about what worked best when, and why…

To put that in perspective, lets start with the significant point that the most successful (in terms of tonnage sunk), torpedo bomber of the war – the Fairey Swordfish – was a technological relict even before the war began; while the most successful (in terms of being technologically advanced and impressive to crews) torpedo bomber of the war – the TBM Avenger – was a complete failure in its first actions!

The Fairey Swordfish is possibly the most amazing/amusing aircraft of the war. An old style biplane, with a ridiculously slow attack speed (only 138mph for early versions): it was nonetheless the only allied combat aircraft to remain in production, and in front line combat squadrons, throughout the entire war.

Known as the ‘Stringbag’ not because of its old fashioned wire and fabric construction, but because – like an old ladies string shopping bag – it could be adapted to an incredible range of loads and tasks: the Swordfish was as success mainly because it could keep changing its functions.

Operating as a conventional torpedo bomber for the first half of the war, the Swordfish – despite its antiquated appearance – had innumerable successes. From sinking the first U-boat sunk, to manning the first escort carriers, to rocket strikes on miniature submarines in river mouths in the last days of the war. From disabling the Bismarck and the Italian cruiser Zara in day actions to allow British battleships to catch them; to the first radar guided night attacks on ships and submarines of the war. From the spectacular success in daylight against the anchored French Fleet at Mers El Kebir, to that at night against the anchored Italian fleet at Taranto. (Where a mere 21 obsolescent Stringbags sunk or disabled 3 battleships, 2 cruisers, 2 destroyers, several other ships, a dozen seaplanes AND did the sort of damage to oil an port facilities against a well defended and prepared base during wartime that the Imperial Japanese Navy conspicuously failed to achieve with multiple strikes by ten times the number of much more advanced aircraft at an unprepared and practically defenceless Pearl Harbour during peacetime).

Of course the Swordfish had many failures too… failures that point to the fact that it HAD to change its role to survive.

The incredible manoeuvrability of the Swordfish meant that it was probably the only combat aircraft that could have slipped between the barrage balloons defending the Italian fleet at Taranto, but the appallingly slow speed meant it often couldn’t catch fast moving ships (like the French Dunkerque escaping at Mers El Kebir). It’s success against the Bismarck was partly due to the fact that it flew so incredibly slowly that the Bismarck’s anti aircraft predictors could not slow down enough, and constantly fired shells far in advance of the aircraft. Which was fine if there was no fighter cover! But a few months later the 6 Swordfish that tried to strike the German battle-cruisers and cruiser running up the Channel in daylight were sitting ducks to German fighters in daylight (despite some inadequate attempts at fighter escort). Both the British and German admirals commented very admiringly of their amazing courage and determination, but very much along the lines of the French general who witnessed the charge of the Light Brigade at Balaclava…”it’s magnificent, but it’s not war!”

By 1942 the Swordfish, or its successor the Albacore (which it outlasted in service in the end), simply could not operate in daylight if the enemy had any sort of air cover. But the fact that they had Air–Surface search radar from mid 1941 meant that they remained effective strike aircraft at night, when the enemy COULDN’T intercept them.

This is where the TBM Avenger must be considered. Certainly technically the best torpedo bomber of the war, and one that served well into the 1950’s, it was nonetheless a failure at its first actions. At Midway for instance, 5 of the 6 available were smashed out of the sky (a much higher loss percentage than that of the slow and obsolete Devestator torpedo bombers they were replacing).  This is for the simple reason that even the best and fastest and most advanced torpedo bombers could not survive against fighter cover in daylight at this stage of the war. (Only much later in the war when the allies achieved overwhelming superiority could the Avenger’s operate safely…. But that same circumstance would have mead the Swordfish or Albacore or Devestator completely successful day torpedo bombers again, so that is not saying much).

So the Swordfish and Albacore could be considered more dangerous and unstoppable torpedo aircraft than the much more advanced Avenger for the two years it took until the Avenger could also operate as a night bomber. (Or for the 3 years until the Avenger had overwhelming fighter cover to get it through in daylight.)

Meanwhile of course, the Royal Navy had also adopted the Avenger, and also fitted it for night strikes. But still found jobs a plenty that the Swordfish could do, and the Avenger couldn’t.

First and foremost, was escort carriers. They were so small and slow, that a loaded Avenger usually needed them to be sailing full speed into the wind for a successful take-off, whereas a loaded Swordfish could often take off from one at anchor in harbour if there was even a moderate breeze over the deck. More importantly, if the convoys in the north Atlantic faced rough weather that tossed the ships up and down dramatically, the Swordfish was slow and manouvrable enough to continue the flying operations and landings that were inconceivable to faster more modern aircraft.

Next is flexibility. Swordfish operated successfully as seaplanes, floatplanes, ski-planes, land planes, and carrier planes. They operated from land bases too short for other aircraft; from fields too rough for other aircraft; and from frozen fjords too exposed to the elements for other aircraft. They flew from catapults on battleships and cruisers, from Merchant Catapult Ships, from Escort carriers and Fleet carriers. They operated as torpedo bombers, dive bombers, level bombers, rocket bombers, depth charge bombers; and in conditions ranging from arctic to desert airstrips, and from tropical cyclones to Atlantic sleet storms. They operated successfully both day and night (at a time when few other aircraft could), and continued to be successfully deployed to new tasks when many younger designs (including some specifically designed to replace them) failed to adapt to new needs.

After that comes survivability. Everyone was astonished how much damage a Swordfish could absorb and still come home. Rents, tears, holes in every surface, the Swordfish would just soldier on. (And could often be repaired with a few canvas patches hastily glued in place, and sent straight back into action.) The Swordfish was to aircraft what the USS Yorktown was to ships!

Finally, the Swordfish was simply the most successful torpedo bomber of the war. It damaged and sank more warships (German, Italian, Japanese and French!), more submarines, more merchant ships, more torpedo boats, more midget subs, more just about anything, than any other single type of plane in the inventory of either Axis or Allies. On one occasion in Libya, just three torpedoes from three land based Swordfish sank four ships (2 U-boats, a destroyer and a supply ship). In fact a single Swordfish group varying between 12 - 27 aircraft operating from Malta sank about half a million tons of Axis shipping in nine months – pretty much equivalent to the wartime totals of the Condor, or Judy, or Kate, or Beaufort, or B25, or Dauntless or Helldiver; and not much short of the total for the Avenger.

So, although there is no doubt that the Avenger was a much better aircraft; or that the Kate had a much more dramatic impact in its few short months of effectiveness; or the Beaufighter was incredibly more accurate: the simple fact is that – in so many ways – the best carrier torpedo bomber of WWII was a slow, lightly armed, almost completely obsolescent biplane, that just kept on finding new ways to do things no other aircraft could…