# Why were PT boats not more dangerous to big warships? **URL:** \ **Category:** Factual Questions\ **Created:** [January 31, 2012, 9:15am UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286 "2012-01-31T09:15:53Z")\ **Posts on this page:** 17\ **Page:** 3
**Author:** ![The\_Second\_Stone](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@The\_Second\_Stone](https://boards.straightdope.com/u/The_Second_Stone)\ **Post date:** [June 25, 2013, 4:36pm UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/41 "2013-06-25T16:36:37Z")
And they were only fast when in tip top condition. Which was rare. The boat that evacuated MacArthur from the Philippines was actually much slower than rated. ---
**Author:** ![Sailboat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sailboat/32/461_2.png) [@Sailboat](https://boards.straightdope.com/u/Sailboat)\ **Post date:** [June 25, 2013, 4:47pm UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/42 "2013-06-25T16:47:10Z")
> [@Lumpy](#): > > And while this would need better analysis, I can’t help but think that Japan’s cultural attitudes toward war hindered their following a dispassionate cost/benefit strategy. Also a factor, IMHO, is that any dispassionate cost/benefit analysis would have been so demoralizingly terrifying to Japanese leadership it’s no wonder they chose to believe the war could be decided by more ephemeral things like “spirit” and morale. According to John Keegan, the index of war production showed American output of war materiel exceeding that of the Japanese by 20:1. Given that the US _also_ had technological advantages (torpedo design being a notable exception, but American fleet submarines were better designed than their Japanese counterparts, and radar gave them a huge edge), increasingly so as the war progressed, that’s intimidating. When the enemy _starts_ with more ships and weapons and resources than you do, _outproduces_ you 20:1, and that equipment is _better_ in most categories, irrationality may be the only way to persuade yourself to carry on. > [@TokyoBayer](#): > > …but a weapon they failed to utilize its advantages fully in that they did not attempt to direct their submarines against US supply ships. Another example, of course, of their heroic mindset – to the mid-century Japanese, war was about meeting enemy warriors and besting your equals, not about interdicting lowly commerce, or watching charts and graphs. ---
**Author:** ![Quercus](https://avatars.discourse-cdn.com/v4/letter/q/7ab992/32.png) [@Quercus](https://boards.straightdope.com/u/Quercus)\ **Post date:** [June 25, 2013, 5:29pm UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/43 "2013-06-25T17:29:16Z")
**lisiate** ’s post seems to have sunk without a trace, so to repeat: The ships called [Destroyers](https://en.wikipedia.org/wiki/Destroyer) that we’re all familiar with were originally called “Torpedo Boat Destroyers”, because they were designed to, uh, destroy torpedo boats. So the big reason PT boats weren’t used to attack battleships and aircraft carriers in open battle is that they would have been shot to pieces by destroyers (fighter planes would also probably be pretty effective). Without looking anything up, I wonder if by WWII battleships had enough medium-caliber guns to defend themselves against quite a few PT boats anyway. ---
**Author:** ![smiling\_bandit](https://avatars.discourse-cdn.com/v4/letter/s/e9a140/32.png) [@smiling\_bandit](https://boards.straightdope.com/u/smiling_bandit)\ **Post date:** [June 25, 2013, 6:23pm UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/44 "2013-06-25T18:23:04Z")
> [@Sailboat](#): > > Another example, of course, of their heroic mindset – to the mid-century Japanese, war was about meeting enemy warriors and besting your equals, not about interdicting lowly commerce, or watching charts and graphs. Well, that and a battlefield victory was almost their only hope. If they could deal enough damage quickly, they might be able to force war-victory as well. They failed to understand that this was essentially impossible barring extreme fortune, and simply failed to comprehend how the American public would view the results even if they succeeded beyond their wildest dreams at Pearl Harbor. Yamamoto, of course, did understand quite well, but the top naval officers were effectively pushed into the decision by the JO’s, who had more balls and pride than sense. ---
**Author:** ![Sailboat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sailboat/32/461_2.png) [@Sailboat](https://boards.straightdope.com/u/Sailboat)\ **Post date:** [June 25, 2013, 6:38pm UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/45 "2013-06-25T18:38:55Z")
> [@smiling\_bandit](#): > > simply failed to comprehend how the American public would view the results even if they succeeded beyond their wildest dreams at Pearl Harbor. If you read enough military history, eventually you see that particular error over and over and over again. Those “decadent Americans/ oppressed Soviets/ primitive Vietnamese/ (nation of [British]) shopkeepers/ peasant longbowmen/ yellow-bellied Yankees/ short Japanese/ barbarians/ what-have-you” will never stand up to OUR mighty legions, motivated by our moral cause! That aspect of their thinking, at least, was not unique to Japan, sadly. ---
**Author:** ![Dissonance](https://avatars.discourse-cdn.com/v4/letter/d/85f322/32.png) [@Dissonance](https://boards.straightdope.com/u/Dissonance)\ **Post date:** [June 25, 2013, 6:50pm UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/46 "2013-06-25T18:50:43Z")
> [@Quercus](#): > > **lisiate** ’s post seems to have sunk without a trace, so to repeat: > The ships called [Destroyers](https://en.wikipedia.org/wiki/Destroyer) that we’re all familiar with were originally called “Torpedo Boat Destroyers”, because they were designed to, uh, destroy torpedo boats. The torpedo boats that torpedo boat destroyers were designed initially to counter during the end of the 19th and beginning of the 20th century were not the same thing as PT boats. The destroyer essentially evolved from the torpedo boat by the size of torpedo boats becoming larger and placing a greater emphasis on gun armament. From here, [torpedo boats of the German Navy, 1885-WW1](http://www.german-navy.de/hochseeflotte/ships/torpedoboats/): > [@](#): > > The concept of the German Torpedo Boats in World War I was to execute torpedo attacks on bigger warships. While other nations like Britain started to increase the size and gun armament of their torpedo boats - or torpedo boat destroyers - and designed a ship that would later just be called “destroyer”, the German Navy stayed with the idea of small crafts that were focus on their torpedo weapons. > > Compared to the \*\*1000t ships with 10,2 cm guns that were used in the Royal Navy \*\*at the outbreak of World War I, the biggest German torpedo boats were only **about half the size and equipped with 8,8 cm guns** as a secondary armamment to defend themselves against the British torpedo boat destroyers. > > During the war, it got obvious that the artillery component of those boats had to be increased, therefore all torpedo boat classes laid down during wartime got more and larger guns - the climax were the large torpedo boats (“Große Torpedoboote”) of the Design 1916 - with their four 15 cm guns and over 2000t in size they were the biggest and most powerful ships of their kind at the end of the war. > > Its quite interesting that even those late designs officially never were called “destroyers”, they were still labeled with the name “Torpedoboot”. Bolding mine, these were ocean worthy if short legged vessels of 500 tons displacement or more and lengths up to 300 feet, not the 50 ton or so under 100 foot length PT/MTB/E-Boat type of boats. Torpedo boats were expected to operate with the main fleet, engage in fleet actions and deliver torpedo runs against capital ships, 61 torpedo boats were at the [Battle of Jutland](http://en.wikipedia.org/wiki/Battle_of_Jutland). The exact distinction of where torpedo boats end and destroyers begin is a bit blurry; the German torpedo boats that fought at Jutland are sometimes referred to as destroyers, sometimes as large torpedo boats, but the Germans themselves still referred to them as torpedo boats. Vessels falling into this category were also built during the interwar period such as the [Italian _Spica_-class](http://en.wikipedia.org/wiki/Spica-class_torpedo_boat) torpedo boats. With changing terminology they would also be referred to both as destroyer escorts and frigates. ---
**Author:** ![smiling\_bandit](https://avatars.discourse-cdn.com/v4/letter/s/e9a140/32.png) [@smiling\_bandit](https://boards.straightdope.com/u/smiling_bandit)\ **Post date:** [June 25, 2013, 9:45pm UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/47 "2013-06-25T21:45:15Z")
> [@Sailboat](#): > > If you read enough military history, eventually you see that particular error over and over and over again. > > [snip] > > That aspect of their thinking, at least, was not unique to Japan, sadly. Not quite. This was not a comparison of who believed their soldiers were superior; rather, the Japanese leadership utterly failed to properly judge the overall political will in America if motivated to fight. It’s common, or even quite normal, to overestimate the ability of one’s fighting men when morale is riding high. It is not normal to assume the enemy will simply give up and surrender without fighting. It is also not normal To some degree, tyrannies (of various stripes) and republics (of various stripes) have believed this of each other, partly because they have a hard time understanding the tools each side has to motivate support. However, the Japanese fell into an even more devious trap, which they baited and set _themselves_. Their action would not - could not - have dealt sufficient damage as to remove the United States from the ensuing war, a war in which both sides knew the United States possessed nearly-unlimited might. Both sides knew that Japan was therefore at a tremendous disadvantage, and its major angle was that Americans were not interested in war. Simply put, most people would probably not have considered the Pacific region worth fighting for, even though they felt sympathy for the Philippines\* and Chinese. While not concerned with European colonies definitely felt more kindly-disposed towards them than towards Japan. But, by launching the all-out attack on Pearl Harbor, Japan both physically and psychologically intruded into American space. Even had the declaration of war been delivered just before the attack instead of just after, Americans would have still felt it was a dishonorable attack. (Admittedly one may argue over what in specially dishonorable in warfare, but Americans in general have always been hastier in declaring war than in attacking, and seem to feel others ought to do the same.) Beyond any question of legitimacy, Japan made itself the aggressor, forced itself into our collective consciousness as an immediate and murderous threat, and in essence made itself a gigantic target. Although war fever was hardly unanimous, both Japan and Nazi Germany demonstrated themselves (at least in the eyes of 1941’s America) as the lowest of the low, and unworthy of mercy. Japan in particular simply _must_ be crushed and broken until it was incapable of launching another attack, although as it turned out Germany fell first with the bloody sacrifice of millions of Russian boys. And it’s hard to see what else could have possible happened. Japan staked everything - and I do mean everything - on America knuckling under. But it’s completely implausible that we would have done so without a major economic turn in favor of Japan which simply didn’t exist. We not only beat Japan, but we did so with only a portion of our military might focused on them. Their action only made sense if you assumed that we were afraid to fight to the point where we would accept outright attack. Except the Japanese _knew_ we weren’t that spineless and did it anyway. Well, as they say, all politics is local. The voices in favor of war were the JO’s who saw glory and power stemming from it; the grand strategies were in the hands of the old men who resisted. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [June 25, 2013, 10:25pm UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/48 "2013-06-25T22:25:50Z")
I just want to point out that for their small cost the PT boats were very effective at destroying shallow-water Japanese supply boats & troop transports. So, altho they were not really dangerous to IJN Capital Ships, they did their part in the war very effectively. A/C could perform the sort of attacks the OP is thinking about. They were cheaper, faster and had pretty good range. One thing A/C weren’t very good at was night flying (until the last year or so of the War0 so the niche of the PT boat was night patrols for small craft sneaking in under cover of darkness. ---
**Author:** ![BMalion](https://avatars.discourse-cdn.com/v4/letter/b/e274bd/32.png) [@BMalion](https://boards.straightdope.com/u/BMalion)\ **Post date:** [June 25, 2013, 10:27pm UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/49 "2013-06-25T22:27:39Z")
> [@smiling\_bandit](#): > > Zombie. > > I’d like to see a movie about zombie PT crewman arising form the dead to wreak havoc on an unsuspecting shipfull of Japanese tourists. McHale! ---
**Author:** ![the\_diego](https://avatars.discourse-cdn.com/v4/letter/t/7bcc69/32.png) [@the\_diego](https://boards.straightdope.com/u/the_diego)\ **Post date:** [June 26, 2013, 12:17am UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/50 "2013-06-26T00:17:51Z")
PT boats were basically a danger to unarmed merchantmen needing to pass through a specific route. In the Mediterranean and English channel during ww2, some portions of the shore on either side were dotted with numerous PT boat bases because of their limited combat radius. Against warships in the open sea, there’s hardly a chance. Around islands and inland seas like in Surigao Strait, Gudalcanal and the Med, there’s a chance but PTs have limited search and spotting capabilities. An alert look out can spot them coming in. A warship’s secondary and AA batteries will wipe them out before they come within torpedo range. And face it, the only way you can intercept a cruiser or destroyer, or battleship going 30 knots is to meet it near its vector, and either turn to cross the ‘T’ so you can use long-rqange guns, or close in and met it parallel to use torpedoes or gunfire. Either way, a PT boat doesn’t have the right weapons. ---
**Author:** ![SpyOne](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@SpyOne](https://boards.straightdope.com/u/SpyOne)\ **Post date:** [June 26, 2013, 3:00am UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/51 "2013-06-26T03:00:03Z")
Perhaps what you are missing is that the full name of the vessels now called “destroyers” is “_torpedo boat_ destroyers”: they were developed to defend capitol ships against exactly what you envision. ---
**Author:** ![the\_diego](https://avatars.discourse-cdn.com/v4/letter/t/7bcc69/32.png) [@the\_diego](https://boards.straightdope.com/u/the_diego)\ **Post date:** [June 26, 2013, 3:06am UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/52 "2013-06-26T03:06:31Z")
What mystifies me is the “Patrol” part of the name. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [June 26, 2013, 4:20am UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/53 "2013-06-26T04:20:08Z")
> [@SpyOne](#): > > Perhaps what you are missing is that the full name of the vessels now called “destroyers” is “_torpedo boat_ destroyers”: they were developed to defend capitol ships against exactly what you envision. Not quite. As Dissonance pointed out, the earlyTorpedo Boats very more like very small destroyers. The very very first, were actually supposed to ram enemy warships with an explosive charge on the end of a spar. That didn;t last long. The first destroyers were made to defend against craft that weighed 100-200 tons or even more. The PT boat weighed in at less than half that. > **[Torpedo boat](https://en.wikipedia.org/wiki/Torpedo_boat)** > > A torpedo boat is a relatively small and fast naval ship designed to carry torpedoes into battle. The first designs were steam-powered craft dedicated to ramming enemy ships with explosive spar torpedoes. Later evolutions launched variants of self-propelled Whitehead torpedoes. > These were inshore craft created to counter both the threat of battleships and other slow and heavily armed ships by using speed, agility, and powerful torpedoes, and the overwhelming expense of building a like number of... Mind you there was some overlap. The early Torpedo boats were quickly dumped to a large extent and replaced by Destroyers, which indeed were originaly envisioned to kill what was then a “Torpedo boat”. Turns out the early TB’s were unseaworthy and more or less useless. By the time the first TB sank a Capital ship, the TB weighed about 700 tons and the line between a Destroyers and Torpedo boat was almost non-existant. > **[Chilean torpedo gunboat Almirante Lynch](https://en.wikipedia.org/wiki/Chilean_ship_Almirante_Lynch_(1891))** > > The torpedo gunboat Almirante Lynch and her sister ship Almirante Condell, were purchased in England and launched in 1890. > The vessels had a high forecastle and poop, and a ram on the bow. the hulls were steel. The principal armament was five Whitehead torpedo tubes, one in the bow and two in each broadside. They also had two 76.2 mm (3.00 in) 12-pounder guns in echelon on the forecastle and one on the poop, four 3-pounder guns, and two machine guns. > Almirante Lynch was part of the small force ... The last hurrah of the original style of TB was in the Russo-Japanese war. After that (and even during that) the difference was small, a TB was just a small Destroyer. ---
**Author:** ![Dissonance](https://avatars.discourse-cdn.com/v4/letter/d/85f322/32.png) [@Dissonance](https://boards.straightdope.com/u/Dissonance)\ **Post date:** [June 26, 2013, 6:05am UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/54 "2013-06-26T06:05:11Z")
> [@DrDeth](#): > > By the time the first TB sank a Capital ship, the TB weighed about 700 tons and the line between a Destroyers and Torpedo boat was almost non-existant. > [Chilean torpedo gunboat Almirante Lynch - Wikipedia](http://en.wikipedia.org/wiki/Chilean_ship_Almirante_Lynch_(1891)) Indeed, as I said the line between where torpedo boats ended and ‘torpedo boat destroyers’ or simply ‘destroyers’ begins is very blurry. At the start of WW1 German torpedo boats were mostly in the range of ~500 tons while British torpedo boat destroyers or destroyers were about twice that displacement averaging ~1,000 tons. Yet paradoxically the British destroyers (which the British called destroyers) had scarcely grown in size to ~1,100-1,500 tons in the [V and W-classes](http://en.wikipedia.org/wiki/V_and_W-class_destroyer) at the end of the war, while the final torpedo boats built by the Germans in WW1, the [Großes Torpedoboot 1916-class](http://en.wikipedia.org/wiki/SMS_S113), which the Germans still called torpedo boats weighed in at 2,400 tons or roughly twice the displacement of the end war British destroyers. ---
**Author:** ![slaphead](https://avatars.discourse-cdn.com/v4/letter/s/e9bcb4/32.png) [@slaphead](https://boards.straightdope.com/u/slaphead)\ **Post date:** [June 26, 2013, 7:06pm UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/55 "2013-06-26T19:06:44Z")
If anyone is interested in finding out the details, the official history of PT Boats in the USN is available [here](http://www.ibiblio.org/hyperwar/USN/CloseQuarters/) and is a pretty good read. I actually have it in ebook format but I have no idea where I downloaded it from. I think a big block quote from the beginning of part 2 may be helpful since it highlights that they tried to sneak about in the dark if possible, and that the operating environment was not kind to the equipment. > [@](#): > > At first glance, it may seem paradoxical that high speed would not be used in a perfect torpedo attack. Ideally, a PT sneaks in slowly with muffled engines to firing range, launches its torpedoes, turns and idles silently away. This is seldom possible. Usually, by the time the torpedoes are launched, the enemy has been alerted and his guns are blazing away at the PT. Then speed, maneuverability, and a smokescreen are the PT’s only protection. Speed also permits PT’s to leave their base at dusk, thrust deep into enemy territory and return to base by dawn. It is imprudent to be out in daylight where the enemy controls the air. In a daylight contest between 1 or 2 PT’s and 1 or 2 planes, the PT’s have the advantage; but where 15 or 20 planes may attack 2 PT’s, the advantage is the other way. > > Good as it is, the speed of PT’s frequently has been exaggerated. PT’s do not make 70 knots – or even 60. They were designed to make better than 40 knots at full war load. And that, over the water, is fast – more than 45 land-miles per hour. With proper maintenance – a clean bottom, engines tuned, everything just right – a PT can be expected to turn up 40 knots without difficulty. But after long periods of operating in advanced areas, without proper maintenance and repair facilities, speed deteriorates. The men of the New Guinea squadrons sang a song which began: > > “Oh, some PT’s do seventy-five, > And some do sixty-nine; > When we get ours to run at all > We think we’re doing fine . . .” ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [June 26, 2013, 8:08pm UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/56 "2013-06-26T20:08:27Z")
> [@Sailboat](#): > > If you read enough military history, eventually you see that particular error over and over and over again. Those “decadent Americans/ oppressed Soviets/ primitive Vietnamese/ (nation of [British]) shopkeepers/ peasant longbowmen/ yellow-bellied Yankees/ short Japanese/ barbarians/ what-have-you” will never stand up to OUR mighty legions, motivated by our moral cause!.. And we’ll have the boys home by Christmas / Hanukkah / Kwanzaa / the Emperor’s birthday! > [@smiling\_bandit](#): > > I’d like to see a movie about zombie PT crewman arising form the dead to wreak havoc on an unsuspecting shipfull of Japanese tourists. > [@BMalion](#): > > McHale! And Borgnine’s dead now, so it’s perfect casting. ---
**Author:** ![SCAdian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scadian/32/3292_2.png) [@SCAdian](https://boards.straightdope.com/u/SCAdian)\ **Post date:** [June 27, 2013, 4:04am UTC](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286/57 "2013-06-27T04:04:28Z")
> [@TriPolar](#): > > Good question. Someone once told me the PT boats had to be towed across the Pacific. There were [12 PTs](http://www.ptboats.org/20-07-05-reports-002.html) at Pearl Harbor on 7 Dec 41. Six were moored at the sub base; the others were being loaded aboard the oiler USS Ramapo (AO 12) to be carried to the Philippines. (Four were already loaded; the other two were in cradles on the dock.) As far as I know, all the boats that crossed the Pacific were carried aboard oilers like this. [Previous page](https://boards.straightdope.com/t/why-were-pt-boats-not-more-dangerous-to-big-warships/611286.md?page=2)