Quote:
Originally Posted by ColonelSandersLite
Good catch, you're certainly right on that. The stabilization must have used an assumed submarine speed. Whether it was 0 knots or some other number, I see no indication of. I sort of doubt it was 0 as if this is the case, the entire system is sorta pointless as you could just use the centerline of the periscope instead.
It seems that the 89KA40/1.414 was replaced by the 91KA40T/1.414HA sometime during the war. Looking at the maintenance manual for the new model, I notice that the stabilized azimuth line function is completely omitted. No mention as to why, but I would think it was either regarded as mechanically unreliable or just not useful. That might (or just as easily might not) tie into the above uselessness of a stabilized line that does not in any way account for submarine speed.
I'm not sure when exactly these replacements where made but looking at a few periscopes in surviving boats (no, I didn't check them all, just a few) the ones I saw where all the 91. I had been thinking that maybe the groups in charge of one of the surviving boats would be willing to provide a picture but I suspect that there are probably no surviving model 89s left.
|
Well, I think the same. Taking into account correction for own speed would require the knowledge of the target AoB and target bearing (you don't need correction if the target is just ahead, but you need if it is abeam). All this would require small calculating device. I think, that such device was not developed because it would be complicated, its input depended on estimated value of AoB, so it would not give any advantage over plotting or even estimating. I suppose, stabilized line was abandoned because it just impractical. The absence of such device in U-Boats periscopes (despite the fact that Zeiss manufactured periscopes with "Feste Linie im Raum") would confirm such assumption.
--
Regards
Maciek