DW makes me wonder: How did WW2 subs find anything?

Wisq · 05-07-15, 12:15 AM

Hi all,

I was playing some DW again today, taking on some of the missions for the first time. In the San Diego Breakout mission, I was happily TMAing the FFG via its active pings. Easy peasy when they give you such a regular, crisp signal, eh? But aside from the actives, I wasn't picking anything up whatsoever on passive, even the towed array, for the entire mission.

(I don't know how close we got, but the truth layer says we started at 8 NM apart. That's a tiny tiny portion of the whole US West Coast map, which is basically just California anyway. Oh, and there was no layer to speak of.)

Now, I've also played a lot of Silent Hunter, particularly SH4. And while some of my intercepts were convoy reports supplied by HQ, a lot of them were just "hey, I'm puttering along and I pick up a ship on the hydrophone". I don't recall the exact distances I could hear them at (and I don't have a truth layer to check), but it always seemed pretty darn far. Plus, the ocean is a huge place, so for me to be picking up ships on a regular basis, the detection distance must be pretty high.

So, long story short, this got me wondering — if modern, high-tech, computer-aided super-multi-frequency passive sonar can't pick up a surface ship chugging along at 5 to 8 knots only 8 NM away, how the heck did anyone ever find anyone else in WW2 (and in SH3/4)?

I've got a bunch of theories — and I imagine it's some combination of these — but I'm curious if anyone happens to know what exact combination it is:

1. Maybe detection range is just unrealistically long in SH. (But I've played with lots of realism-enhancing mods, and I can't imagine they would let this slide, unless the gameplay was just broken without it.)

1(b). Maybe it's the thermal layer — I know there are situations where you can hear things at huge distances due to thermocline refraction. I believe this would be a transient thing and would come and go, which is not what actually happens in SH, but maybe SH can't model that and so they just gave the hydrophones longer ranges to emulate it.

2. Maybe surface ships, particularly military ones, are just a lot quieter now. This certainly makes some sense to me — it always seemed like I was mostly picking up ships by their engine and propeller noises, and we have much better engine and propeller designs today.

3. Maybe it was just that everything was so shallow. Most of the mission, I was cruising in depths of only 50m or less. I seem to recall that shallow water makes sonar trickier, mainly because of its acoustic properties but also because you can't stream the array very far.

4. Maybe it's just time compression — with DW only doing a few levels of it, whereas SH goes up to 8192x compression and missions span months of travelling at max speed, it's just inevitable that I would encounter something on a regular basis, even if it takes days between encounters. Whereas my DW missions take a few hours, max.

5. Maybe there's just a ton of traffic in SH, or they intentionally spawn stuff near you. I think I recall someone (Ubisoft?) mentioning that the campaigns were reasonably realistic except that you would see a lot more action than was truly realistic. But I might be thinking of Falcon 4.0 instead …

6. Maybe it's all in my head. Maybe the SH distances just seem longer because the subs are so bloody slow. Maybe the DW distances just seem shorter because I'm looking at the entire US west coast. (But, I pulled up Japan on Google Maps, and the distances I seem to recall detecting ships at are still pretty large.)

7. Shipping lanes. If they're used heavily and I pass through them regularly, maybe there's just a good chance of inevitably encountering something on a semi-regular basis.

8. Maybe there was just a heck of a lot more shipping back then. I mean, nowadays so much stuff goes by plane, and shipping is just for bulk cargo. (But then, there's so much economy today that I would imagine this balances out and then some …)

… and possibly more aspects I haven't thought of.

So. Any insights? Just curious. I'm actually thinking it's probably mostly #4, time compression — just the sheer luck of running into things when your missions span months of travel, rather than hours.

05-07-15, 12:15 AM	#1
Wisq Watch Join Date: Feb 2009 Posts: 18 Downloads: 57 Uploads: 0	DW makes me wonder: How did WW2 subs find anything? Hi all, I was playing some DW again today, taking on some of the missions for the first time. In the San Diego Breakout mission, I was happily TMAing the FFG via its active pings. Easy peasy when they give you such a regular, crisp signal, eh? But aside from the actives, I wasn't picking anything up whatsoever on passive, even the towed array, for the entire mission. (I don't know how close we got, but the truth layer says we started at 8 NM apart. That's a tiny tiny portion of the whole US West Coast map, which is basically just California anyway. Oh, and there was no layer to speak of.) Now, I've also played a lot of Silent Hunter, particularly SH4. And while some of my intercepts were convoy reports supplied by HQ, a lot of them were just "hey, I'm puttering along and I pick up a ship on the hydrophone". I don't recall the exact distances I could hear them at (and I don't have a truth layer to check), but it always seemed pretty darn far. Plus, the ocean is a huge place, so for me to be picking up ships on a regular basis, the detection distance must be pretty high. So, long story short, this got me wondering — if modern, high-tech, computer-aided super-multi-frequency passive sonar can't pick up a surface ship chugging along at 5 to 8 knots only 8 NM away, how the heck did anyone ever find anyone else in WW2 (and in SH3/4)? I've got a bunch of theories — and I imagine it's some combination of these — but I'm curious if anyone happens to know what exact combination it is: 1. Maybe detection range is just unrealistically long in SH. (But I've played with lots of realism-enhancing mods, and I can't imagine they would let this slide, unless the gameplay was just broken without it.) 1(b). Maybe it's the thermal layer — I know there are situations where you can hear things at huge distances due to thermocline refraction. I believe this would be a transient thing and would come and go, which is not what actually happens in SH, but maybe SH can't model that and so they just gave the hydrophones longer ranges to emulate it. 2. Maybe surface ships, particularly military ones, are just a lot quieter now. This certainly makes some sense to me — it always seemed like I was mostly picking up ships by their engine and propeller noises, and we have much better engine and propeller designs today. 3. Maybe it was just that everything was so shallow. Most of the mission, I was cruising in depths of only 50m or less. I seem to recall that shallow water makes sonar trickier, mainly because of its acoustic properties but also because you can't stream the array very far. 4. Maybe it's just time compression — with DW only doing a few levels of it, whereas SH goes up to 8192x compression and missions span months of travelling at max speed, it's just inevitable that I would encounter something on a regular basis, even if it takes days between encounters. Whereas my DW missions take a few hours, max. 5. Maybe there's just a ton of traffic in SH, or they intentionally spawn stuff near you. I think I recall someone (Ubisoft?) mentioning that the campaigns were reasonably realistic except that you would see a lot more action than was truly realistic. But I might be thinking of Falcon 4.0 instead … 6. Maybe it's all in my head. Maybe the SH distances just seem longer because the subs are so bloody slow. Maybe the DW distances just seem shorter because I'm looking at the entire US west coast. (But, I pulled up Japan on Google Maps, and the distances I seem to recall detecting ships at are still pretty large.) 7. Shipping lanes. If they're used heavily and I pass through them regularly, maybe there's just a good chance of inevitably encountering something on a semi-regular basis. 8. Maybe there was just a heck of a lot more shipping back then. I mean, nowadays so much stuff goes by plane, and shipping is just for bulk cargo. (But then, there's so much economy today that I would imagine this balances out and then some …) … and possibly more aspects I haven't thought of. So. Any insights? Just curious. I'm actually thinking it's probably mostly #4, time compression — just the sheer luck of running into things when your missions span months of travel, rather than hours.