Ace destroyers in 1939?

[johnm]

GWX. I am in dec 1939 sailing around north of scapa flow when I get radio warning of a fast task force coming through. Try to get into position, got scared by a destroyer popping and submerged. hydrophones show task force passing south of me between 4 and 6 kilometres. Identify at least one Dido. In desperation try a salvo but foul it up and miss.

Decide to reload from a save off Dundee and attempt to get them again. Not really cricket but it's the first task force I've ever been near.

When I get to same area, no task force. Consulation prize - large merchant, one torpedo, finish off with gun.

Just sailing away when reports of warship closing, fast. Check with hydrophone - about 20 kilometres and after laying off his bearing I see he'll pass about 3k behind me. By this time, I'm submerged -order 60 metres and dead slow.

The little pervert charges up and turns directly onto my stern and starts dropping DCs like their going out of fashion. Three attacks, all exactly over me, all DCs right on me, even though I go flank as soon as they drop, going to 2 knots as soon as they'd exploded and twist and turn.

In he comes again

I order 80 metres but hit the bottom and have to come up a metre or so because of damage. In he comes again, 2 attacks right on the button. The second one causing damage in 4 compartments including Flooding. Full damage control included damage qualified officer and petty officer and half a dozen qualified sailors (thanks to SH3 Commander) and a qualified sailor in every compartment.

Repaired forward quarters, just fixed stern quarters when SH3 announces I'm sunk due to flooding! 53 ex-sailors - no redundancy pay! ah well DiD. Sob.

question 1 - surely if I'm on bottom I can't sink any further and the two compartments still affected would be sealed off from the rest of the sub. After all they were being repaired anyway.

question 2 - destroyers in 1939 surely couldn't have nailed me so quickly or so repeatly accurately. They had little detection equipment and poor sonar then surely? Ignoring the fact that they were still learning the business!

however I'll grit my teeth and say that I do like GWX even though I'm only using about 43% realism and I spend all my time chasing ships and then finding they are neutrals!

I prefer a deck gun attack on Pyros - what a bang!

[Abd_von_Mumit]

If I'm not mistaken about the name, Erich Topp reported that he was spotted by a destroyer and his boat damaged heavily while being submerged at 20 metres, or so, and not doing anything for quite a long time - no shooting, sailing, surfacing. They just rested under the waves and then suddenly... DD. They were DC almost to death, after three days spent on the seafloor managed to repair the boat and surface, ti find a trawler left there... just in case the submarine would surface again.

So... what did you say about their efficiency?

[bigboywooly]

Sonar Timeline
1916: Approx. The Allied Anti-Submarine Detection Investigation Committee (ASDIC) develops the first version...a hydrophone hanging over the side of a ship.
1921: Asdic installed on the HMS Antrim was able to detect a shutdown submarine on the bottom at 2000 yards (under optimal conditions).
1931: The U.S. Navy Underwater Sound Group produces the QB echo-ranging SOund Navigation and Ranging (SONAR) effective below 6 knots.
1934: First echo-ranging equipment installed in the American destroyers of DesDiv 20.
1939: West Coast Sound School opened at San Diego Destroyer Base.
1939: Over 165 British destroyers, sloops and trawlers are carrying asdic equipment that can be used at 15 knots. Adopted by the United States, the "Searchlight" operated at 14-22 kilohertz and was effective up to 2,500 yards. This range was reduced by rough or high-salinity seas, underwater temperature inversions and thermo clines. Although sonar was responsible for 68 of the 104 submarine kills in '39 and '40, it was found to be an ineffective area sweep tool.

[Mooncatt]

however impressive that is surley it would be higher unlikely to get detected sat there doing nothing

[bigboywooly]

Originally Posted by mooncatt

however impressive that is surley it would be higher unlikely to get detected sat there doing nothing

1921: Asdic installed on the HMS Antrim was able to detect a shutdown submarine on the bottom at 2000 yards (under optimal conditions).

[Mooncatt]

ummmm ok. i didnt know that. so how come uboats were so sucessful then in the early years of the war???

[danlisa]

Ha, there you go. They're not 'Uber' they're 'Realistic'.

so how come uboats were so sucessful then in the early years of the war???

I would think that it was a mixture of - lack of training, lack of supply/installation of equipment & the fact that tactics had to be developed to counter U-Boat attacks.

It's still a big ocean/sea. The U-boat has a fairly large target, while the escorts had a small target.

[bigboywooly]

Because not every RN vessel has asdic and not all conditions are optimal
Plus with the rapid growth of the navy there wouldnt have been trained personnel for every ship

And 104 uboats sunk in 3 months of 39 and all of 1940 would say not every sub was succesfull
Add that to the fact the RN didnt have enough ships to protect every convoy out into the atlantic

[Brag]

I just returned from a patrol (June '40--GWX) where 80 percent of the hydrophone contacts were warships. Saw a number of Flower class corvettes. When spotted by aircraft, soon a Flower would show up. It seemed like the waters off northern Scotland had more Flowers than bedbugs in a flop house. With heavy damage I was creeping home not doing much. In each instance got away by running silent at 2 knots, showing minimum profile and not making sharp turns. If the DDs know where to ping, they'll find you.

My only question: Did the RN have that many Flowers in 1940?

Originally Posted by johnm

question 1 - surely if I'm on bottom I can't sink any further and the two compartments still affected would be sealed off from the rest of the sub. After all they were being repaired anyway.

You don't mention which compartments were flooded but it really doesn't matter, especially with two of them fully flooded.

First off, IIRC it's not as if every section of the boat was compartmentalized and bulkheaded with watertight doors.

Also, the sheer weight of having any one compartment flooded would make surfacing impossible. That's even assuming you've workable electric engines still and full compressed air tanks to blow your ballasts.

Worse is that any major flooding of the bow or stern compartments wound up flooding the batteries as well. This not only shorted them out (and so you've no power to the electric engines) but generated huge amounts of chlorine gas. So now you've a small enclosed steel cylinder rapidly filling with a highly toxic gas.

As a good example of what the result is from having your forward torpedo compartment abruptly flood, read here: ww.navy.mil/navydata/cno/n87/usw/issue_23/s5.htm

The crew were very lucky to escape. And it was only due to the combined luck of the length of their boat and the shallow depth of the water that enabled them to manage the manuever they did that resulted in their rescue.

And here is a second example; one, unfortunately, not as lucky. http://homepage.eircom.net/~navalassociation/thetis.htm