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washishu · 03-01-15, 05:56 AM

I wasn’t questioning the real-world physics of torpedoes; I understand that with a small, curved surface striking a large, curved surface it would be surprising if the torpedo wasn’t deflected when hitting at a shallow angle. The purpose of my idle, Saturday morning experiment was to see if/how that was modelled in SHIII and it seems that it is modelled but how accurately I’m not sure. (I should maybe say here that on that particular Saturday morning I had nothing better to do and it was raining hard outside. I had thought to carry out a number of experiments at differing angles to see if there might be a span within which detonation was certain, another span beyond the first where probability of deflection increased and another span beyond both of these where deflection was certain. But after two or three trials I got bored and gave up thinking surely you can find something better to do with what remains of your life).

I also understand the reasons for the zero gyro-angle shot sublynx; the fewer variables there are, the greater the chance of success and so I also almost always try to get into that perfect position. The crux of my post—maybe I didn’t explain it well—was that, in reading the accounts in the books (on the occasion that prompted this it was Drumbeat but it applies to the other books too), the attack position appears to be a long way from perfect even when the attack was not a forced snatch-shot. Eg. “At 1244 Hoffmann had Malay where he wanted her: speed a surprising eleven knots, range 400, angle on the bow Green 21. Los! The last G7e left for a twenty-eight second voyage. . . “ and so on. My point is that I would have thought that an AOB of 21º at 400 metres was a far from perfect solution, but the preamble to this and the “. . . had Malay where he wanted her . . .” suggests that this was not a snatch-shot under difficult circumstances.

I hadn’t considered Nemo66, your very pertinent observations on the magnetic detonator characteristics, but I’d still maintain that, with all the uncertainties that you outline, it’s easy to be daring in a game when, if it goes wrong you can just shrug and have another cup of tea; it’s another thing entirely when your life depends on getting it right.

Towards the end of the book Gannon details an attack by U-123. Hardegen has only two torpedoes left, he’s stern-chasing a tanker but it’s fast and he struggling to catch it. So he takes a stern shot (“. . . U-boat’s speed at time of launch nine knots; own course 307 degrees; target’s course 350.5 degrees; torpedo’s course 318 degrees . . “) The expected explosion doesn’t come . . . but then, “. . . just as he bent to give a new course to the pipe the western sky suddenly erupted in a blinding red-and-yellow explosion”. Quite possibly this was just such a case as you outline sublynx (the set depth of the torpedo is given as only three metres but given the uncertainties . . .) Also, a course of 307º and torpedo course 318º suggests a gyro angle of around 10º and I wonder why, after over an hour of pursuit he didn’t come to 318º and have a zero gyro-angle to further minimise the variables of what he recognises is a risky shot. As much of the detail of these attacks is claimed to be taken from logs and war-diaries, it can’t easily be dismissed as author’s error or artistic license.

03-01-15, 05:56 AM	#4
washishu Mate Join Date: Apr 2010 Location: England Posts: 54 Downloads: 2 Uploads: 0	I wasn’t questioning the real-world physics of torpedoes; I understand that with a small, curved surface striking a large, curved surface it would be surprising if the torpedo wasn’t deflected when hitting at a shallow angle. The purpose of my idle, Saturday morning experiment was to see if/how that was modelled in SHIII and it seems that it is modelled but how accurately I’m not sure. (I should maybe say here that on that particular Saturday morning I had nothing better to do and it was raining hard outside. I had thought to carry out a number of experiments at differing angles to see if there might be a span within which detonation was certain, another span beyond the first where probability of deflection increased and another span beyond both of these where deflection was certain. But after two or three trials I got bored and gave up thinking surely you can find something better to do with what remains of your life). I also understand the reasons for the zero gyro-angle shot sublynx; the fewer variables there are, the greater the chance of success and so I also almost always try to get into that perfect position. The crux of my post—maybe I didn’t explain it well—was that, in reading the accounts in the books (on the occasion that prompted this it was Drumbeat but it applies to the other books too), the attack position appears to be a long way from perfect even when the attack was not a forced snatch-shot. Eg. “At 1244 Hoffmann had Malay where he wanted her: speed a surprising eleven knots, range 400, angle on the bow Green 21. Los! The last G7e left for a twenty-eight second voyage. . . “ and so on. My point is that I would have thought that an AOB of 21º at 400 metres was a far from perfect solution, but the preamble to this and the “. . . had Malay where he wanted her . . .” suggests that this was not a snatch-shot under difficult circumstances. I hadn’t considered Nemo66, your very pertinent observations on the magnetic detonator characteristics, but I’d still maintain that, with all the uncertainties that you outline, it’s easy to be daring in a game when, if it goes wrong you can just shrug and have another cup of tea; it’s another thing entirely when your life depends on getting it right. Towards the end of the book Gannon details an attack by U-123. Hardegen has only two torpedoes left, he’s stern-chasing a tanker but it’s fast and he struggling to catch it. So he takes a stern shot (“. . . U-boat’s speed at time of launch nine knots; own course 307 degrees; target’s course 350.5 degrees; torpedo’s course 318 degrees . . “) The expected explosion doesn’t come . . . but then, “. . . just as he bent to give a new course to the pipe the western sky suddenly erupted in a blinding red-and-yellow explosion”. Quite possibly this was just such a case as you outline sublynx (the set depth of the torpedo is given as only three metres but given the uncertainties . . .) Also, a course of 307º and torpedo course 318º suggests a gyro angle of around 10º and I wonder why, after over an hour of pursuit he didn’t come to 318º and have a zero gyro-angle to further minimise the variables of what he recognises is a risky shot. As much of the detail of these attacks is claimed to be taken from logs and war-diaries, it can’t easily be dismissed as author’s error or artistic license.