Whats with the aft tubes?

[deamyont]

What are the aft tubes for? And four of them? Why did they chose to have them historicaly?

If it was my chose, 6 bow tubes, no aft, and use bigger/more batteries, bigger engine or more fuel instead. Maybee even a shorter hull. Anything but all those aft tubes...

[TDK1044]

For large Convoy's, they're very useful. Last night I fired my six main torpedoes, and then while those tubes were being reloaded I turned and fired my 4 aft torps. This allowed me to fire ten torpedoes in under two minutes. I sank 6 ships.

[Chock]

I sometimes use my aft tubes first, if it is a slow-moving convoy, which leaves my forward tubes ready for when things heat up a bit. Try it some time, you might like it.

They are also good when you get in a convoy, allowing you to engage in two directions, which (historically at least) would help to disguise your position a bit.

And if none of that appeals, try popping some at a pursuing destroyer in a spread, that occasionally works too, and is funny as hell when it does.

[perisher]

Historically, WW1 and just after, as subs got larger they had tubes facing all directions, including beam tubes (these could not be reloaded at sea). Pretty soon the beam tubes were dropped as a bad idea. (Difficult to use and took up a lot of space). Many navies kept the stern tubes, they could be useful but they were much more difficult to use than the bow tubes. The problem was getting a good angle while moving away from your target. Eventually everyone dropped the idea. First to lose it were the British, although the S and T class boats retained an external stern tube. That is, of course, a one shot only tube. As built the T class also had two rearward firing external tubes mounted one either side of the conning tower. These were turned around in a field mod and made to shoot forward, giving the T boats an initial bow salvo of 10 fish. That was six in the bow tubes, plus two external bow tubes in the casing directly above the normal tubes and the two amidships externals.

Between the wars the French experimented with destroyer style rotating tubes on the decks of their larger "cruiser" submarines.

Today, computer aided aiming systems would make stern tubes as easy to use as bow tubes but the stern tubes would seriously interfere with modern streamlining.

[Mudrik]

I quite often use my aft tubes, both in the ways that TDK1044 & Chock describe but also I like to engage a convoy with bow tubes, dive underneath the convoy and once past engage again with aft tubes. This then leaves me with open water ahead to make my escape.

Must admit though that I've never managed to sink a persuing destroyer. Their senses seem too sharp so I now don't even bother trying to engage and save my ammo for merchants.

[7Enigma]

From a theoretical and safety (of the ship and crew) standpoint, it would actually be beneficial to have ALL tubes AFT. This would allow you to lay and wait for your prey, fire off a salvo, then immediately be able to leave as directly as possible.

Having tubes foreward requires a sub to fire at their target, then evade by first moving CLOSER to the target while turning away. I know if it was my arse on the line, I would prefer to have the immediate exit rather then having to turn away as my ship is being hunted....

[SteamWake]

I have tried unsuccessfully to attack pursuing destroyers from astern and from the bow. Typically using a beneath the keel shot with zero success.

The DD usually veers out of the torpedos path or the torpedo fails to detonate.

In fact the only DD's I have claimed never new what hit them.

But the stern tubes are usefull they just take a little more planning to set up a shot.

[perisher]

Originally Posted by 7Enigma

From a theoretical and safety (of the ship and crew) standpoint, it would actually be beneficial to have ALL tubes AFT. This would allow you to lay and wait for your prey, fire off a salvo, then immediately be able to leave as directly as possible.
...

Not so easy in real life, submarines are not humming birds, to quote the guys at NYGM Tonnage War. You cannot get ahead of a convoy, go to periscope depth and just hover there waiting for your prey to cross your sights. You have to keep the boat moving or it will not maintain depth, it will either go up or go down but it will not stay at a constant depth. The game will let you do this, but a real submarine could not.

[7Enigma]

Originally Posted by perisher

Not so easy in real life, submarines are not humming birds, to quote the guys at NYGM Tonnage War. You cannot get ahead of a convoy, go to periscope depth and just hover there waiting for your prey to cross your sights. You have to keep the boat moving or it will not maintain depth, it will either go up or go down but it will not stay at a constant depth. The game will let you do this, but a real submarine could not.

So how about this then :p :

Do your typical 90-degree attack with foreward tubes at very low speed (say 1kt just to keep your depth), then go back 1/3'rd and dive to escape. I'm curious at how inefficient reverse is as opposed to normal foreward movement, and also if there was a significant increase in noise as compared to normal operation. And obviously the aft dive planes would be less effective, but the tradeoff might be worth it to get distance between your target and escorts quicker?

[perisher]

I seriously doubt that a submarine ever went astern except when manoeuvring in harbour, all ships are difficult to handle going astern and I would imagine that depth keeping going astern was next to impossible. I read something abourt this recently but I can't find it right now.

When I use my stern tubes, I approach on a parallel track to my target(s), when I am ready I turn sharply away and increase speed, as my firing angle comes on I slow the boat, centre the rudder and fire. If I want to evade I put the rudder back on, go to flank and dive, once under 200 ft I cut to 1/3, rig for silent and make a 90 degree turn.

Having said that, on my last patrol I got target fixation and ended up too close for the bow shot, so I went under my target and took him with the stern tubes.

[SteamWake]

Youd be better off flooding the ballast tanks and charge foward.

[AhhhFresh]

It's because convoy's zig-zag, and any competent zig-zag pattern should be very difficult to predict exactly even after plotting their course for hours. They could get their base course and be pretty certain where they were going to pass, but to set up to ensure a forward torpedo shot meant that you were risking getting "caught in left field" if they zigged away from you on your firing leg.

Subs got into position so that regardless of the final zig they would have a minimum range shot from either from the bow or stern. That is, that if that zig was to port or starboard it wouldn't make much of a difference.

EDIT: I should note that I've never seen anything other than a very basic zig zag pattern in SHIV, so it's somewhat moot... unless it gets sophisticated in the latter part of the war, which I have yet to play.

[7Enigma]

So can anyone comment on the noise issue with moving in reverse compared to foreward? (ie things like cavitation, increased turbulence, etc.)

[jetthelooter]

reverse was typically used on the surface for maneuvering not for underwater use as it used a LOT more energy to move the sub than moving forward and battery conservation was paramount. stern tubes were typically used for OMG!! WTF!! type of shot on destroyers that sneak up on the sub. they were also used for finishing shots on stubborn targets to save the bow shots. they were also used in nite surface attacks where the more powerful diesel engines could be employed for reverse maneuvering.

[Sailor Steve]

Why aft tubes? Ten is better than six.