Search found 275 matches

by northcape
Sat Dec 01, 2018 12:01 am
Forum: Bismarck General Discussion
Topic: Bismarck at DS after the second turn
Replies: 212
Views: 5635

Re: Bismarck at DS after the second turn

I might comment that one thing must not be forgotten: Any sudden change of course at high speed will throw off the gyrocompass - so the bearings (if any) taken after initiation of the hard turns should be taken very cautiously, or at least they should be assumed to be much more inaccurate then the b...
by northcape
Wed Nov 28, 2018 5:51 pm
Forum: Bismarck General Discussion
Topic: Bismarck at DS after the second turn
Replies: 212
Views: 5635

Re: Bismarck at DS after the second turn

Hello everybody, I wrote: "PoW was already some 200 meters on HOOD starboard side" Having redone a more precise calculation, I have to correct my approx statement above. Pow was stationed at 4 cables (= 740 meters, the dotted line in Antonio's proposed "starting point" at 6:00 from Rowell map http:...
by northcape
Tue Nov 27, 2018 4:44 am
Forum: Bismarck General Discussion
Topic: Bismarck at DS after the second turn
Replies: 212
Views: 5635

Re: Bismarck at DS after the second turn

Regarding bearings, I still think that the current discussion misses one essential point: The superposition of systematic instrument error (poor calibration due to limited number of astronomical fixes) and random reading errors (as in Bill Juren's example). Even if the reading is perfectly accurate ...
by northcape
Sun Nov 25, 2018 6:22 pm
Forum: Bismarck General Discussion
Topic: Bismarck at DS after the second turn
Replies: 212
Views: 5635

Re: Bismarck at DS after the second turn

No, we cannot assume +/-1 degree accuracy. The scale under the binoculars appears to be graduated at 5 degrees per marking and there is the issue of taking bearings on a ship at sea via unstablized sights . If this is the case then indeed the reading accuracy cannot be expected less than 2.5 degree...
by northcape
Sun Nov 25, 2018 6:15 pm
Forum: Bismarck General Discussion
Topic: Bismarck at DS after the second turn
Replies: 212
Views: 5635

Re: Bismarck at DS after the second turn

However, if we are really interested in reconstructing the battle, then we must realize that we often have reciprocal bearings (or timings) taken from both sides and these bearings (timings) match perfectly. Thus we can logically assume that there is no error at all in these cases and that we can l...
by northcape
Sun Nov 25, 2018 5:25 am
Forum: Bismarck General Discussion
Topic: Bismarck at DS after the second turn
Replies: 212
Views: 5635

Re: Bismarck at DS after the second turn

Coming back to the tolerances of bearings, I think there is still the misconception that the only error is a reading error. This is not correct. Even if your reading error would be zero, your bearing would still be wrong (or not perfectly accurate). Why? Because the instrument where you take the bea...
by northcape
Sat Nov 24, 2018 6:48 am
Forum: Bismarck General Discussion
Topic: Bismarck at DS after the second turn
Replies: 212
Views: 5635

Re: Bismarck at DS after the second turn

First I think we need to agree about the fact that talking about bearings and distances, ... the difference between navigational range and gun range in this case will be, ... given speed, course and relative distances, ... in the range of 0,5 degrees, … so well below the +/- 1 degree tolerance as f...
by northcape
Mon Nov 19, 2018 7:22 pm
Forum: Bismarck General Discussion
Topic: Bismarck at DS after the second turn
Replies: 212
Views: 5635

Re: Bismarck at DS after the second turn

The optical reading accuracy is just one part. I still think that +/- 1 deg is feasible for reading (depending on the optical instrument). However, I also still think that the limited calibration of the instrument introduces a much higher inaccuracy such that the effective bearing tolerance is much ...
by northcape
Mon Nov 19, 2018 6:17 am
Forum: Bismarck General Discussion
Topic: Bismarck at DS after the second turn
Replies: 212
Views: 5635

Re: Bismarck at DS after the second turn

Strictly speaking, the true vs. grid north exists for all projections, since the grid north always is parallel to the vertical edge of the map. However, if I am not mistaken the large-scale nautical charts were mostly gnonomical projections where meridians plot as straight lines, do. the true north ...
by northcape
Sun Nov 18, 2018 10:15 pm
Forum: Bismarck General Discussion
Topic: Bismarck at DS after the second turn
Replies: 212
Views: 5635

Re: Bismarck at DS after the second turn

Hello everybody, regarding the north maps reference, it is my assumption that they were using the geographical north they had on their maps. But if the difference among the 3 type of north and probably on the type of maps used has been a crucial factor on the night of the 23rd for the Suffolk, it i...
by northcape
Sun Nov 18, 2018 12:31 am
Forum: Bismarck General Discussion
Topic: Bismarck at DS after the second turn
Replies: 212
Views: 5635

Re: Bismarck at DS after the second turn

Regarding maps and north directions, if existing POW and PG tracks should be synchronized: Is it actually known to which north the original battlemaps are referenced? For navigation and localization, there are three north references: 1) Magnetic North - I doubt that this will be a reference to any o...
by northcape
Thu Nov 15, 2018 6:26 am
Forum: Bismarck General Discussion
Topic: Bismarck at DS after the second turn
Replies: 212
Views: 5635

Re: Bismarck at DS after the second turn

I would support having a moderated forum. It is a pity, but this seems to be needed to maintain a minimum level of maturity and seriousness. Constantly demonstrating the emotional maturity of a toddler and the intellectual / logical capability of a preschooler is not beneficial for a meaningful disc...
by northcape
Thu Nov 15, 2018 1:12 am
Forum: Bismarck General Discussion
Topic: Bismarck at DS after the second turn
Replies: 212
Views: 5635

Re: Bismarck at DS after the second turn

Instead I will keep on asking him what does he have to try ( surely unsuccesfully as more than obvious ) to challenge Paul Schmalenbach 1978 reconstruction of the Bismarck track based on the photos, the PG map and the PG film analysis : This challenge is a quite simple exercise: This map (as any ot...
by northcape
Sun Nov 11, 2018 4:41 am
Forum: Bismarck General Discussion
Topic: Bismarck at DS after the second turn
Replies: 212
Views: 5635

Re: Bismarck at DS after the second turn

For the time being, despite all the "philosophic" considerations about methodology, NOBODY has been able to propose a better (=more precise and respectful of the evidences) battle reconstruction that Antonio's one: " in essence, in one sentence: The theory can not be " COUNTERED and this is a FACT ...
by northcape
Fri Nov 09, 2018 8:35 pm
Forum: Bismarck General Discussion
Topic: Bismarck at DS after the second turn
Replies: 212
Views: 5635

Re: Bismarck at DS after the second turn

Mathematics, geometry and trigonometry are scientific laws and are more than enough independent proof. .......... As simple as that, ... and always with the due tolerances. Bye Antonio Mathematics, and its sub-disciplines geometry and trigonometry are scientific tools, not laws. By themselves, they...