Thermal layers are built into SH3 Commander, if you use it. If not, they are not in the stock SH3 AFAIK.

In NYGM, it seems that there is almost always one escort trolling at low speed (or even stopped, the treacherous buggers!) whenever there are 2 or more escorts.

So which ones right then? Should I be able to do 0 knots at 220m without my pumps running or do i have to have enough revolutions with silent running to maintain my depth and therefore make some noise either way. Ive just done my usual start of patrol depth test to 225m after leaving Thalia (24/21940)and went to All Stop. Didnt sink even on TCx8.

So will I start to sink if I rigged for silent running because of no pumps....?

What are the symbols that appear when you are rfsr? One is no reloading but the other 3?
Its all a learning curve.... :D
Cheers for helping me out chaps?

Riccardo

The reality is when you are running silent the pumps still operate. There are merely operated by hand rather than by noisy machinery. It may not be as efficient, but it's a lot quieter.

From a number of first-person accounts, including Werner's, AFAIK. Why would he bottom the boat if it could hover? You can hold trim for a while, but the boat does continuously take on water. As long as water is coming in, water must go out or the boat will settle. How can trim be maintained without running the pumps? How can neutral buyancy be maintained without running the pumps? Technical manuals and first-person accounts all indicate that the submarine could not "hummingbird" for an indefinite period.. It could maintain trim and bouyancy for a while, but not indefinitely. Sooner or later, either pumps or motors would have to be operated to maintain depth.

Yes, the pumps could be operated by hand. Everything on the boat except the propulsion could.But do you have a source that says that neutral bouyancy could be maintained indefinitely with hand-operated pumps? And that operating the pumps by hand was silent? Less noisy, sure, but a continuous noise source was all the escorts were listeing for. And sound travels a long way in water.

Does anyone have a published source that says that a WW2 submarine could mainatin constant depth indefinitely without operating electric motor-driven equipment? There are certainly first-person accounts (and technical documents) that indicate they couldn't.

Was that the "Hold down" invented by Johnny Walker?

Hopefully wont happen in GWX....

Thanks for the info. I'll have another Test Dive when I go back to Wilhelmshaven above the Shetlands. If I sink at low revolutions rigged for silent running then sh3 is accurate?

Right? :confused:

Riccardo U-111
Somewhere near Rosyth.....

Will only happen if you have Stiebler's Silent Running Fix enabled. And for Stiebler, you must also use h.sie's patches. Get a lot of enha ncements. Worth having.

V

No one is saying that the boat will hover indefinitely underwater. Yes, under normal operation the pumps are used to evacuate any accumulated water. However, under silent running, compressed air and hand pumps are used to maintain trim. Sure, one cannot vigorously operate a hand pump without making too much noise. Similarly even vigorous operation of a hand pump is not as efficient as just turning on a motor and letting it run. Compressed air will need to be used, and eventually it will run out.

However, even if the boat seems to be settling, maintaining depth is just as simple as angling the boat up slightly. Yes, this will result in a certain loss of forward motion, and yes, the boat will eventually fill up with so much water that the angle will end up being too extreme to maintain. Nevertheless the amount of water that a submarine takes on at periscope depth is negligible. The water just doesn't have that much pressure. On the other hand, at 100 meters under, the water will have 10 times the pressure and the amount of water entering will be substantially greater.

So no, I'm not saying that a boat can hover indefinitely at all stop 220 meters under the surface without running pumps. However, I don't see why someone would be all stop at that depth. If you really have run into a hunter-killer group, you need to make tracks. My boat can go 20 hours under before the CO2 hits 3. During that time I would hope to be at least 20 nautical miles away from the initial point of discovery and 30-40 would be better for my survival. So don't call all stop. Run silent, run deep, and run for your life.

Please explain how your boat maintains forward motion indefinitely with the elctric motors off. Pitching the boat while hovering - with NO forward motion - won't accomplish much.

Of course, it is perfectly possible to hold depth without running pumps, provided the boat has way on. The planes can hold it. But hovering implies no motion. No motion + no pumps = no depth control.

Surely they could hand-crank the pumps, or couldn't they?

Please explain how you graduated from grammar school with no reading comprehension skills.

I specifically said that the ship would be moving forward, at perhaps 1 knot. This is so slow that the ship's noise is minimal and will not be heard except at very close range.

Second, even assuming that the boat is not moving at all, the boat can be handled by adjusting its buoyancy. Compressed air can be released into the ballast tanks. If the boat seems to be pitching down, compressed air can be released into the fore ballast tank. If the boat seems to be pitching up, compressed air can be released into the aft ballast tank. Conversely air can be released and water taken in to adjust its pitch.

Will the compressed air eventually run out? Of course. However, U-boats did not sink like stones every time they stopped moving. U-boats contained sophisticated controls and had a crew of about two score to keep it working as the captain wanted.

A far more realistic adjustment to the reality of U-boat life would be to have the compressed air used up more quickly when the boat is at all stop rather than having the boat sink.

First, for what reason did you choose to address an insulting personal remark? I don't recall that I or anyone else on this thread directed personal insults your way.

Second, if you will review some of the previous posts, you will see that the question under discussion was whether a submarine could maintain depth control while hovering - that is, with no way on. No one was disputing the ability of a submarine to maintain a constant depth while moving. For mistakenly thinking that your comments were intended to be relevant to the question at hand, I apologize.

http://www.uboataces.com/uboat-type-work.shtml

"Thus, a U-boat [was] able to rise or sink to the depths solely by manipulating its buoyancy. Buoyancy had to be kept in check often as it varies according to the amount of fuel [on board], ammunition expended, ocean depth and salinity of water. Buoyancy can change rapidly when torpedoes are launched. A ton of positive buoyancy is created when a torpedo leaves its tube, and [it] has to be offset immediately with ballast water to prevent the U-boat from popping to the surface.

"When at rest or moving slowly underwater, a U-boat has to be handled carefully as it has a tendency to tip up or down into a vertical position. In shallow water, it can rest on the sea bed. When moving forward, a pair of hydroplanes controls the vessel’s depth. U-boat commanders prefer to keep their boat at neutral buoyancy. In this condition, the boat can dive or surface rapidly without constant dependence on the limited compressed air."

http://jtmcdaniel.com/diving.html

"Submarines are designed so that, with the main ballast tanks fulls, the weight of water displaced will be as close as possible to the weight of the boat. That is, there should be a balance between displacement and buoyancy, referred to as neutral buoyancy. If true neutral buoyancy is achieved the boat will float at whatever depth it presently is, unless something acts on it to make it rise or sink. In practice, submariners prefer to maintain a very slight positive buoyancy, so that if power if lost the boat may be expected to slowly rise to the surface.

"In addition to the main ballast tanks, which are normally kept either empty or completely filled with water, there are also several variable ballast tanks located inside and outside the pressure hull. These include bow and stern buoyancy tanks, various trim tanks, and the negative and safety tanks....

"Buoyancy and trim tanks are used to adjust the center of balance of the submerged submarine. By pumping air and water back and forth between the trim tanks the diving officer can balance the boat."