Thursday, May 30, 2019

WWI Torpedo Boat Tactics

This attack may look somewhat crazy...

...but it was successful! [link]

[Sorry for hiatus of several months! Have been pursuing Franco-Prussian War and a few other things, plus real life keeps getting in the way! But, have a couple of quick, interesting posts to make...]

Here are some great posts on WWI DD Tactics and Torpedo Runs, etc. Altho it may be between your interests, say Pre-Dreadnoughts and WWII, it should inform both discussions to some degree. After all, if they are having difficulty in WWI, they must be having more difficulties in 1898 or earlier, right?

Anyway, the info is from this TMP Post: 
http://theminiaturespage.com/boards/msg.mv?id=443552

I haven't found any good reference material for DD tactics in the first World War. Would they have attacked as a group? If so, would they have launched a massive number of torpedoes against a single ship or cluster of ships? If one out of five takes a rudder critical, or a bridge critical, would it just drop out and the remainder of the flotilla continue moving together?

Yellow Admiral: They did attack in swarms, by flotilla or half-flotilla. I don't think they had sufficient inter-ship C3 to concentrate torpedoes on a single ship in a line, but could almost certainly concentrate on a single ship alone (e.g. Warspite circling helplessly between battlelines…).

German and British DD captains certainly seemed to have the élan to press home attacks at great odds (not so sure about other navies), but real-life DDs tended to abort and retreat more often than gamers do. In WWI naval games, DD complements are frequently wiped out or reduced to paltry numbers, whereas in real life they tended to suffer some losses and then limp home. The morale rules in GQ3/FAI help defuse the suicidal devotion demanded by gamer admirals quite a bit, if the GM and/or players are paying attention.

There is this RN paper expressing an opinion on how DD should perform a torpedo attack
>>>It is therefore necessary, at long ranges, to take the whole of an enemy's line as the target, and, since the centre of spread should be near the point of aim, it is desirable to fire at the centre of the line. The spread of the torpedoes if a number are fired, may then be expected to cover a considerable area, and, provided the enemy are within range and maintain the same course and speed during the time of flight, not only the centre ship, but a part of the line on either side of the centre will be in danger, the length of line endangered depending on the actual spread of the torpedoes. Moreover, even if the enemy alters course after they are fired, he will probably not be able to keep entirely clear of the dangerous area unless he turns at least eight points, or, if at a range near to the extreme running range of the torpedoes, turns to such less extent as will admit of his ships outranging them. Nothing less than an eight point turn is likely to keep the whole line clear of their angular spread, but a smaller turn may suffice to take the line outside their range before the torpedoes can reach it.>>>>
gwpda.org/naval/nr191402.htm

+1 re Buckeye Bob's post. I have employed just such a minor (20-30deg?) turn away in war games to counter over-enthusiastic torpedo attacks launched at too distant a range. It's simple geometry and works as well on the table top as it did on the North Sea.
My books are still not fully unpacked, so can't cite chapter and verse, but my recollection of readings on WW1 DD tactics is as follows -

In tactical actions, the functions of the destroyers were two-fold: (a) to defend against any enemy torpedo attacks upon the battle line; (b) to attack the the enemy battle line should the opportunity present itself. Whereas the most dangerous torpedo attacks would originate from forward of the head of the battle line, friendly destroyer flotillas were typically positioned well ahead of the battle line on the disengaged side where their smoke would not interfere with gunnery; a certain proportion of destroyers (if available) would positioned at the rear of the battle line to provide protection in case of a course reversal by the battle line.
In a flotilla vs flotilla gunnery fight, British doctrine was to attack in line ahead and concentrate the gunfire by division upon a single enemy destroyer (preferably an opposing division leader) at an effective/decisive range within 3,000 yards or so in hope of quickly crippling it and disrupting the enemy division. The track chart of the destroyer action between Hipper's and Beatty's battle cruiser forces during the "Run to the South" will give an excellent nuts and bolts example.

Torpedo attacks against individual ship targets during daylight (for example, the torpedo attack made upon SEYDLITZ at Jutland) were very much the exception, rarely being undertaken unless said enemy ship was an isolated cripple. Torpedo attacks were intended to be delivered against the enemy battle line by a destroyer flotilla, whose respective divisions would successively launch their torpedoes en masse in a "browning" attack designed to fill with torpedoes a particular zone of ocean through which the enemy formation was projected to pass through. Hit expectations were based upon the relationship of number of torpedoes fired versus the number of enemy ships within the zone and the interval between them. 

British doctrine recommended that such attacks not close nearer than 5,000 yards, as any improvement in the odds of hitting was felt to be greatly outweighed by the increased risk of loss/damage from defensive fire.

The recommended approach to such an attack was from ahead and to windward on a reciprocal course to that of the enemy line, with launch point about 4 to 6 point off the enemy bow; this promised the maximum closure rate between attacker and defender, the shortest practical torpedo running time, the best net angle of attack for the torpedo vis-a-vis enemy base course, restricted the number of secondary guns and the length of time that they could be brought to bear upon the attacker, limited the evasive options open to the targeted line and provided the attacker an opportunity to rapidly disengage under cover of smoke. Simultaneous attacks upon both enemy bows ("anvil" attack) was extremely advantageous, but highly difficult to coordinate and carry out. Attacks from abaft the enemy's beam were highly discouraged, as they largely negated all the afore-mentioned advantages cited in connection with attack from ahead.

The number of torpedoes fired by each destroyer in such an attack depended upon the number of tubes that would bear and the number of torpedoes with the correct range/speed setting. WW1 era torpedo gyros were unreliable and imprecise; torpedo mounts were therefore typically trained over the side (broadly speaking – C/L mounts @ +/- 30deg of abeam on each side; Beam mounts @ +/- 60deg on that side) and fired only when the sight on the torpedo mount or director came onto the nominated target (say, the fourth ship in the enemy battle line). Torpedoes of WW1 were capable of multiple range/speed settings; generally and approximately speaking: 4,000 yds @ 45 kts; 10,000 yds @ 30 kts; 15,000+ yds @ 18-20 kts. However (IIRC) 

British destroyer torpedo settings had to be performed prior to being loaded into their deck mount tubes; settings could not be altered on the fly. Hence, to cover all tactical eventualities, a destroyer might carry two set for medium range, one for short range and one for extended range. Only torpedoes of the same setting could be effectively used in a given attack.

The results of such torpedo attacks in terms of actual hits upon the enemy were dramatically lower than pre-war predictions had suggested. There were several reasons for this. 
*First, the threat of mass torpedo attack was (quite rightly IMO) taken extremely seriously by all navies; even the appearance of an impending attack might well provoke evasive maneuver by the battle line. 
*Second, the technical performance of torpedoes (direction keeping, depth keeping, speed, charge fuzes) under actual war conditions proved considerably less efficient than theoretical pre-war assumptions. British 1916 estimates were that, for one reason or another, only about half of torpedoes launched actually arrived within the target's danger zone. 

That having been said, even an attack that scored zero hits might still yield benefit if it provoked the opponent to turn away at an important tactical moment. The multiple flotilla torpedo attack ordered by Scheer against the British battle line at Jutland scored no hits whatsoever but disordered the British as various ships were forced to evade oncoming torpedoes and compelled Jellicoe to turn his line away and, in the course of doing so, lose sight of Scheer's battle line at a vital moment.

Lots of typing here, LOL. Hope it proves of some interest and use.
Blutarski
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The only bit of Blutarski's post I'd differ from is this bit:
In tactical actions, the functions of the destroyers were two-fold: (a) to defend against any enemy torpedo attacks upon the battle line; (b) to attack the the enemy battle line should the opportunity present itself.
My impression is that this describes the British destroyer mission priorities, whereas the German priority was b/ over a/, which is supported to an extent by design differences observable between the two navies' ships (size, weapon type, etc). That said, this could be a gamer's over-simplification that I'm remembering.

Sailor Steve: I do remember reading somewhere, it may have been John Campbell's 'Jutland: An Analysis of the Fighting':  The Germans tended to go in line abreast, then do a group turn and all six fire one torpedo each, then turn again and run away line abreast. The British habit was to go in line astern. The lead boat would turn and fire, then the second, third etc.

The source I read noted that the Germans thought the British tactics were suicidal, whereas their own were much better.

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