Brigade XO wrote:WW II sub pack tactics were primarily a German tactic and was designed along with a screening force of subs to attack convoys. You maneuver to put your wolfpack if front of an expected convoy and adjust the position based on any sightings your screen &/or air assets pick up. The WP attacks- from submerged positions- and many of the subs attempt to infiltrate the escort screen to close on as many targets as possible and shoot the up before escaping. Escaping usualy meant having to go deep and slow (or stop) and attempt to stay out of either contact with or getting depthchagged by bad luck by ending up where an escrort dropped a string of charges based on best-guess of where the U-Boat might be. Keeping a U-Boat submerged (and unable to see to fire a torpedo) and unable to get head of a convoy was almost as good as a kill. If they don't sink your cargo ships you are way ahead of the game.
Much of the other submarine warfare was not in pack tactics. A lot of the US boats were doing solo patrols of given hunting areas and the travel lanes they were assigned going out and comming back. There was general knowlege or intelegence of where Japanese shipping was moving but nothing like the convoys of the North Atlantic. So you essentialy sent stalking where ships needed to travel to get between given points and intercept them. Freightes, oilers, warships, whatever, find it and sink it----and make it home.
A variation on tactics was to deploy a screen of subs in a long line against known or anticipated movement. The opening round of the US side of the Battle of the Atlantic as faced on the Eastern Seaboard was like that. U-Boats were strung along the coastal shipping route and then all started engaging after a set time against primarily civilian traffic, not transatlantic convoys. The net effect was the same, slaugher amoung the coastal traffic until enough anti-submarine ships and aircraft (including blimps) were brought against the U-boats and either forced them much further off shore or killed them.
On the other hand, late in the war a destroyer, USS England, ended up steaming up along a line of Japanese subs deployed somewhere in the western Pacific and, with the subs well out of visual range of each other and apparently hearing of underwater blasts, managed to kill at least three of them. It wasn't an intentional, planned, attack. The DD ended up comming on each sub in sequence and did what DD's are supposed to do- Kill them.
I suspect that if the Sharks or LennyDetts or any other spider drive ships are deployed as ambush hunters to catch either freighers or warships transitioning to or from hyperspace outside of systems, the reactions is ultimatly going to be attempting to flood the areas with ships hunting them which will probably end up getting a lot of information on the spyder drives and discovering ways to kill those ships. Almost nothing remains static in that kind of Darwinian enviornment.
The US used some smaller patrol lines of their subs later in WWII. But that was usually a short term thing in response to intel suggesting a worthwhile target - the patrol line would sweep back down the extected patch and have a higher change of one of the subs spotting it. But in direct contrast to German tactics a US sub spotting the target was expected to attack solo, then only after that breaking radio silence to announce the find.
Of course part of the reason the US didn't go full German style wolfpack was they realized the coordinating radio traffic back from the subs put them at risk of shore based radio direction finding (which the Allies used to try to route convoys around wolfpacks even when the actual transmitted messages couldn't be decoded). But the other reason was that Japan never went in for the kinds of convoys or escort levels that would justify large concentrations of subs. The bigger problem, especially as the war went on, was simply finding a worthwhile target. Having subs concentrated simply means less ocean gets searched - but doesn't raise the changes of successful attack enough to make up for fewer targets found.
Anyway, the LennyDets may be used occasionally to ambush freighters. But there's no reason to build something bigger than an SD and designed around pods and graser torps just to kill freighters. A much smaller ship, even smaller than the Sharks, could do that. The only reason you need a LennyDet is to have a survivable way to lay down a lot of firepower quite quickly. Which implies tangling with warships, and warships that may well be able to counter-battery you. So yeah, Germany tried using Bismark and Tirpitz as commerce raiders - but that's not why they build those battleships. If they just wanted to kill freighers, even freighters in convoys, it would have been far more cost effective to build more cruisers. Fast enough to run away if the convoy had a BB hanging around, powerful enough to shoot through sloops or corvettes, or even a few destroyers, and unlike the BBs numerous enough you could afford to risk them tangling with the escorts to get a shot at the convoy (plus more ships hunting is more chances to actually find a convoy)