Next sets of tests were conducted, this time the type VIIC boat was put to the limit.
All tests were conducted in the same weather conditions, with wind at 4 km/h. Results follow.
VIIC type, no engine upgrades, with deck and flak guns mounted.
Crash dive time
- [speed], [depth] - [result, i.e. time in seconds to reach 15 m depth]
- 0 knots, surfaced - 34 s
- 0 knots, 6.1 metres - 22-24 s
- 0 knots, 7.0 metres - 21 s
- 0 knots, 7.9 metres - 20-21 s
- 8 knots, surfaced - 33-34 s
- 8 knots, 6.1 metres - 22-23 s
- 8 knots, 7.0 metres - 19-21 s
- 8 knots, 7.9 metres - 20-21 s
- flank speed, surfaced - 32 s
- flank speed, 6.1 metres - 21 s
- flank speed, 7.0 metres - 17-19 s
- flank speed, 7.9 metres - 20-21 s
As with the type VIIB, speed doesn't matter a lot. Initial depth is the main factor. The optimum cruise depth is 7.0 metres (reduces diving time by ~40%). Remember though, that not only diving speed is important when patrolling enemy territories - fuel efficiency is also a very important factor (the deeper you go, the more fuel you burn), as well as keeping your above water profile as low as possible. I think a depth of 6 m would be more useful for cruising, as it's quite economic with fuel and it still reduces diving time by as much as 30-35%.
Optimal speed regarding fuel efficiency
8.1 knots, not even 0.1 more or less.
VIIC type, all available '40 upgrades: GW Kapselgeblase engine upgrade, and 800 bttery; deck and flak guns mounted.
Crash dive time
- [speed], [depth] - [result, i.e. time in seconds to reach 15 m depth]
- 0 knots, surfaced - 33 s
- 0 knots, 6.1 metres - 23 s
- 0 knots, 7.0 metres - 19-20 s
- 0 knots, 7.9 metres - 19-20 s
- 8 knots, surfaced - 33 s
- 8 knots, 6.1 metres - 22-23 s
- 8 knots, 7.0 metres - 19 s
- 8 knots, 7.9 metres - 20 s
- flank speed, surfaced - 32 s
- flank speed, 6.1 metres - 21-22 s
- flank speed, 7.0 metres - 18 s
- flank speed, 7.9 metres - 18 s
Here the results vary a bit frm the previous - there is almost no difference between 7.0 m and 7.9 metres diving time. I don't know why. It could be possibly caused by higher power electric engines that propell the boat efficiently even underwater.
Optimal speed regarding fuel efficiency
8.3-8.4, less than upgraded VIIB type, slightly more than no-upgrade VIIC.
And the last test: a user claimed on these Forums, that there IS a difference in boat performance between sailing "surfaced" and sailing "at 0 meters" depth (i.e. after you point 0 m on the depth gauge). No test proved this to be true, not even a slightest difference was noticed in any aspect of U-Boot's performance. "Surfaced" is totally equal to any depth between 0 and 4.5 metres (possibly even 5.0 metres).
I'm not going to do IX nor II type tests, as I don't use these types. If anyone is interested, feel free to post your results in this thread, so that all the info is stored in one place.
Thank you.
