Bismarck analysis

Discussions about the history of the ship, technical details, etc.

Moderator: Bill Jurens

alecsandros
Senior Member
Posts: 4344
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania

Re: Bismarck analysis

Post by alecsandros » Tue May 14, 2019 10:23 am

dunmunro wrote:
Tue May 14, 2019 10:01 am
I gave you direct quotes from Rodney's GAR
How many salvoes did Rodney fire between 8:47 and 9:02, and how many salvos did KGV fire within the same time frame ?

dunmunro
Senior Member
Posts: 3908
Joined: Sat Oct 22, 2005 1:25 am
Location: Langley BC Canada

Re: Bismarck analysis

Post by dunmunro » Tue May 14, 2019 4:37 pm

alecsandros wrote:
Tue May 14, 2019 10:23 am
dunmunro wrote:
Tue May 14, 2019 10:01 am
I gave you direct quotes from Rodney's GAR
How many salvoes did Rodney fire between 8:47 and 9:02, and how many salvos did KGV fire within the same time frame ?
Up to ~0902:00 Rodney had fired 22 salvos according to her salvo chart. KGV fired 22-24 salvos up to (0848-0902) ~0902:00.

alecsandros
Senior Member
Posts: 4344
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania

Re: Bismarck analysis

Post by alecsandros » Tue May 14, 2019 4:59 pm

dunmunro wrote:
Tue May 14, 2019 4:37 pm
Up to ~0902:00 Rodney had fired 22 salvos according to her salvo chart. KGV fired 22-24 salvos up to (0848-0902) ~0902:00.
Your own material posted here viewtopic.php?f=1&t=6834#p67414

writes that KGV fired 18 salvos up to 9:00.

Now you say KGV fired 22-24 salvos up to 9:02.

Are you suggesting KGV fired 4 to 6 salvoes in 2 minutes, or have you revised your material above ?

===

By the way, with what turrets was KGV actually firing between 8:48 - 9:02 ? And how many shells did KGV actually outputted in that time interval ?

dunmunro
Senior Member
Posts: 3908
Joined: Sat Oct 22, 2005 1:25 am
Location: Langley BC Canada

Re: Bismarck analysis

Post by dunmunro » Tue May 14, 2019 5:16 pm

alecsandros wrote:
Tue May 14, 2019 4:59 pm
dunmunro wrote:
Tue May 14, 2019 4:37 pm
Up to ~0902:00 Rodney had fired 22 salvos according to her salvo chart. KGV fired 22-24 salvos up to (0848-0902) ~0902:00.
Your own material posted here viewtopic.php?f=1&t=6834#p67414

writes that KGV fired 18 salvos up to 9:00.

Now you say KGV fired 22-24 salvos up to 9:02.

Are you suggesting KGV fired 4 to 6 salvoes in 2 minutes, or have you revised your material above ?

===

By the way, with what turrets was KGV actually firing between 8:48 - 9:02 ? And how many shells did KGV actually outputted in that time interval ?
KGV's salvo rate is known from 0853-0913 but during other periods I have to approximate it based upon Rodney's salvo chart, comments in KGV's GAR and the tactical plot. That is why I have placed ~ in front of the numbers. As I've explained and as we've discussed, KGV opened her A arcs at ~0900, according to her GAR. I have already provided an estimate of output from both KGV and Rodney, earlier in the thread, for the first 25 salvos from each ship.

alecsandros
Senior Member
Posts: 4344
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania

Re: Bismarck analysis

Post by alecsandros » Tue May 14, 2019 5:27 pm

dunmunro wrote:
Tue May 14, 2019 5:16 pm

KGV's salvo rate is known from 0853-0913 but during other periods I have to approximate it based upon Rodney's salvo chart, comments in KGV's GAR and the tactical plot. That is why I have placed ~ in front of the numbers.
In other words, you do not know.
As I've explained and as we've discussed, KGV opened her A arcs at ~0900, according to her GAR. I have already provided an estimate of output from both KGV and Rodney, earlier in the thread.
The estimate you provided is wrong, because Rodney was alternating between 4 and 5 gun salvos from salvo 4.
As she used turret X for only 6 salvos (of the first 25) , it is logical to assume 6 salvos were fired with alternating guns (4.. 5 guns), with the other 19 salvos (of the initial 25) being fired with 3+3 guns (3 guns salvo1, 3 guns salvo2... same as KGV was doing).

Therefore, my opinion is that HMS Rodney ordered about 9 more shells between 8:47 and 9:02 then KGV did, of which I don't know how many were actually fired.

In shell numbers ordered, that would translate to , probably, 16x3 + 6x4,5 = 75 shells ordered by Rodney for the first 22 salvos, and 20-22 x 3 = 60-66 shells ordered by KGV within the same time frame.

dunmunro
Senior Member
Posts: 3908
Joined: Sat Oct 22, 2005 1:25 am
Location: Langley BC Canada

Re: Bismarck analysis

Post by dunmunro » Tue May 14, 2019 5:40 pm

alecsandros wrote:
Tue May 14, 2019 5:27 pm


The estimate you provided is wrong, because Rodney was alternating between 4 and 5 gun salvos from salvo 4.
I've provided you with the exact number of salvos fired by Rodney with her A arcs open (all 3 turrets bearing on the target) and at salvo 25 it was 6:
In the action with the BISMARCK "X" turret could only bear on the target on 6 out of the first 25 salvoes.
http://www.kbismarck.com/rodney-gunnery-report.html
Rodney (From Robert's The Final Action) at ~0852 fired 2 salvos with A arcs open and 3 more from 0858 until opening them continuously from ~0904 and salvo 25.
Again, is there something in my quoted statements that you don't understand?

alecsandros
Senior Member
Posts: 4344
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania

Re: Bismarck analysis

Post by alecsandros » Tue May 14, 2019 5:47 pm

There is confusion in the quotes you provided between turret X and turret A.

If you interpolate the 2 quotes, you end up with Rodney firing most of the original 25 salvos with turret Y alone, which means with 3 guns out of 9.

dunmunro
Senior Member
Posts: 3908
Joined: Sat Oct 22, 2005 1:25 am
Location: Langley BC Canada

Re: Bismarck analysis

Post by dunmunro » Tue May 14, 2019 5:58 pm

alecsandros wrote:
Tue May 14, 2019 5:27 pm
dunmunro wrote:
Tue May 14, 2019 5:16 pm

KGV's salvo rate is known from 0853-0913 but during other periods I have to approximate it based upon Rodney's salvo chart, comments in KGV's GAR and the tactical plot. That is why I have placed ~ in front of the numbers.
In other words, you do not know.
As I've explained and as we've discussed, KGV opened her A arcs at ~0900, according to her GAR. I have already provided an estimate of output from both KGV and Rodney, earlier in the thread.
The estimate you provided is wrong, because Rodney was alternating between 4 and 5 gun salvos from salvo 4.
As she used turret X for only 6 salvos (of the first 25) , it is logical to assume 6 salvos were fired with alternating guns (4.. 5 guns), with the other 19 salvos (of the initial 25) being fired with 3+3 guns (3 guns salvo1, 3 guns salvo2... same as KGV was doing).


Therefore, my opinion is that HMS Rodney ordered about 9 more shells between 8:47 and 9:02 then KGV did, of which I don't know how many were actually fired.

In shell numbers ordered, that would translate to , probably, 16x3 + 6x4,5 = 75 shells ordered by Rodney for the first 22 salvos, and 20-22 x 3 = 60-66 shells ordered by KGV within the same time frame.
Rodney fired salvo 25 at ~0904:10 (according to her salvo chart) so I don't know why you are talking about 0902.

Rodney fired 5 salvos with her A arcs open at from 0848-0901:59 and 17 salvos with A arcs closed. Therefore 17 x 3 + 3 x 5 and 2 x 4 (or possibly the reverse) for 51 + 15 + 8 = 74 rnds (with 100% output). KGV fired ~18 x 3 gun salvos and ~4 x 5 gun salvos, for 74 rnds fired at 0902.

At 904 when Rodney has fired 25 salvos, KGV has also fired at least 25 salvos.
Last edited by dunmunro on Tue May 14, 2019 6:05 pm, edited 1 time in total.

dunmunro
Senior Member
Posts: 3908
Joined: Sat Oct 22, 2005 1:25 am
Location: Langley BC Canada

Re: Bismarck analysis

Post by dunmunro » Tue May 14, 2019 6:03 pm

alecsandros wrote:
Tue May 14, 2019 5:47 pm
There is confusion in the quotes you provided between turret X and turret A.

If you interpolate the 2 quotes, you end up with Rodney firing most of the original 25 salvos with turret Y alone, which means with 3 guns out of 9.

A arcs open, means that all three turrets can bear on the target. A arcs closed, means only the forward turrets can bear on the target. A arcs, does not refer to A turret but to the orientation of the ship with respect to the target.

When Rodney's A arcs are closed, she will fire 3 gun salvos (2 + 1) and when A arcs are open she will fire 4 or 5 gun salvos (2+1+1 or 2+1+2)

alecsandros
Senior Member
Posts: 4344
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania

Re: Bismarck analysis

Post by alecsandros » Tue May 14, 2019 6:13 pm

dunmunro wrote:
Tue May 14, 2019 5:58 pm

Rodney fired 5 salvos with her A arcs open at from 0848-0901:59 and 17 salvos with A arcs closed. Therefore 17 x 3 + 3 x 5 and 2 x 4 (or possibly the reverse) for 51 + 15 + 8 = 74 rnds (with 100% output). KGV fired ~18 x 3 gun salvos and ~4 x 5 gun salvos, for 74 rnds fired at 0902.

At 904 when Rodney has fired 25 salvos, KGV has also fired at least 25 salvos.
A, ok.
I estimate roughly the same output for Rodney at 9:02, but I do not think KGV had the same total output, because she fired 1 minute later (then Rodney did), and she was initially hindered by Rodney's smoke , and by the uncertainty over the provenance of the shell splashes.

dunmunro
Senior Member
Posts: 3908
Joined: Sat Oct 22, 2005 1:25 am
Location: Langley BC Canada

Re: Bismarck analysis

Post by dunmunro » Tue May 14, 2019 6:26 pm

alecsandros wrote:
Tue May 14, 2019 6:13 pm
dunmunro wrote:
Tue May 14, 2019 5:58 pm

Rodney fired 5 salvos with her A arcs open at from 0848-0901:59 and 17 salvos with A arcs closed. Therefore 17 x 3 + 3 x 5 and 2 x 4 (or possibly the reverse) for 51 + 15 + 8 = 74 rnds (with 100% output). KGV fired ~18 x 3 gun salvos and ~4 x 5 gun salvos, for 74 rnds fired at 0902.

At 904 when Rodney has fired 25 salvos, KGV has also fired at least 25 salvos.
A, ok.
I estimate roughly the same output for Rodney at 9:02, but I do not think KGV had the same total output, because she fired 1 minute later (then Rodney did), and she was initially hindered by Rodney's smoke , and by the uncertainty over the provenance of the shell splashes.
KGV had the advantage of radar FC and from 0853 onward KGV had overcome the confusion with Rodney's salvos. From 0853 to 0913 KGV fired at 1.7 salvos per minute (34 salvos according to her GAR) versus 1.3 salvos per minute for Rodney (26 salvos according to her salvo chart). After 0913 when her FC radar failed KGV's RoF fell considerably, due to visibility issues.

alecsandros
Senior Member
Posts: 4344
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania

Re: Bismarck analysis

Post by alecsandros » Tue May 14, 2019 6:35 pm

dunmunro wrote:
Tue May 14, 2019 6:26 pm
KGV had the advantage of radar FC and from 0853 onward KGV had overcome the confusion with Rodney's salvos. From 0853 to 0913 KGV fired at 1.7 salvos per minute (34 salvos according to her GAR) versus 1.3 salvos per minute for Rodney (26 salvos according to her salvo chart). After 0913 when her FC radar failed KGV's RoF fell considerably, due to visibility issues.
Between 8:53 and 9:02 there are 9 minutes, and at 1.7salvos/minute it means 9 x 1,7 = 15,3 salvos fired.
Between 8:48 and 8:53 there are 5 minutes, in which I do not know how many salvos KGV fired. I presume about 1 salvo/minute, due to the initial problems, but it's just a guess.

dunmunro
Senior Member
Posts: 3908
Joined: Sat Oct 22, 2005 1:25 am
Location: Langley BC Canada

Re: Bismarck analysis

Post by dunmunro » Tue May 14, 2019 7:21 pm

alecsandros wrote:
Tue May 14, 2019 6:35 pm
dunmunro wrote:
Tue May 14, 2019 6:26 pm
KGV had the advantage of radar FC and from 0853 onward KGV had overcome the confusion with Rodney's salvos. From 0853 to 0913 KGV fired at 1.7 salvos per minute (34 salvos according to her GAR) versus 1.3 salvos per minute for Rodney (26 salvos according to her salvo chart). After 0913 when her FC radar failed KGV's RoF fell considerably, due to visibility issues.
Between 8:53 and 9:02 there are 9 minutes, and at 1.7salvos/minute it means 9 x 1,7 = 15,3 salvos fired.
Between 8:48 and 8:53 there are 5 minutes, in which I do not know how many salvos KGV fired. I presume about 1 salvo/minute, due to the initial problems, but it's just a guess.
The initial spotting problems didn't slow the RoF, but it did effect accuracy after the first two salvos, as the KGV spotting corrections were being made on Rodney's salvos because the fall of shot warning buzzer had incorrect timing. At 0849 at salvo 4 and 0853, at salvo 10 Rodney ceased fire for one minute each and the mistake was found and corrected. Even with the brief ceasefires Rodney fired 10 salvos up to 0854 or about 1.5 salvos/min or 2 salvos minute excluding the ceasefires and I would expect that KGV would have fired about 7-10 salvos up to 0853.

Ata
Junior Member
Posts: 4
Joined: Fri Jun 21, 2019 6:52 pm

Re: Bismarck analysis

Post by Ata » Sat Jun 22, 2019 10:04 am

alecsandros wrote:
Thu May 31, 2018 6:53 am
Given the storm, and ranges of the observations, no definitive answer can be given.

Also to be considered is that in the early phase of the battle, KGV was behind Rodney, and her observations were further hindered by Rodney's funnel smoke and main battery gun smoke.
Armor piercing hits are very difficult to spot (remember that during the first battle of May 24th, Prince of Wales did not spot any hits on Bismarck at all, although 3 had been obtained)
Not so! The spotting officer on Prince of Wales stationed in the Standby 14" Director recorded all hits, starting with the third salvo, the previous two having gone over. He did say that it was diifficult to establish whether the first exploded as it had penetrated the hull.

alecsandros
Senior Member
Posts: 4344
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania

Re: Bismarck analysis

Post by alecsandros » Tue Jun 25, 2019 10:08 am

Ata wrote:
Sat Jun 22, 2019 10:04 am
alecsandros wrote:
Thu May 31, 2018 6:53 am
Given the storm, and ranges of the observations, no definitive answer can be given.

Also to be considered is that in the early phase of the battle, KGV was behind Rodney, and her observations were further hindered by Rodney's funnel smoke and main battery gun smoke.
Armor piercing hits are very difficult to spot (remember that during the first battle of May 24th, Prince of Wales did not spot any hits on Bismarck at all, although 3 had been obtained)
Not so! The spotting officer on Prince of Wales stationed in the Standby 14" Director recorded all hits, starting with the third salvo, the previous two having gone over. He did say that it was diifficult to establish whether the first exploded as it had penetrated the hull.
At "salvo 3", KGV was still ranging on Rodney's salvos.

Post Reply