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Re: Bismarck firing procedures at DS

Posted: Tue Feb 23, 2016 7:53 pm
by tommy303
Alberto
One last question: are Germans ALWAYS firing together the guns in a single turret or are you aware of special circumstances when only 1 gun in a turret can be ordered to fire ?

Thanks in advance for your help here.....

Bye, Alberto
Generally speaking, the two guns in a turret would be fired together as the ammunition hoists for the right and left guns traveled up and down together and were not independent of eachother. There was, I believe a delay built into the firing circuit to slightly delay one gun from firing at precisely the same time as its mate in the turret when the circuit closed. This was intended to prevent muzzle blast and shell wave interference which could increase dispersion rates.

Re: Bismarck firing procedures at DS

Posted: Tue Feb 23, 2016 8:14 pm
by alecsandros
@Thomas

Could it be... could it be... that Luetjens's message was reffering... only to the expenditure of projectiles fired against HMS Hood ? [I know it is improbable, but it would reconcile the rapid fire procedure with the number of shells fired at the target. 93 in 4-5 minutes is acctualy pretty close to what one woudl expect from Bismarck rapid fire (2.58 shots per minute per gun with 4min30sec taken as rapid firing base)]

Re: Bismarck firing procedures at DS

Posted: Tue Feb 23, 2016 8:59 pm
by Alberto Virtuani
Alecsandros wrote: "could it be... that Luetjens's message was reffering... only to the expenditure of projectiles fired against HMS Hood ?"
Hi Alec,
in case 93 has to be referred only to Hood, it would mean BS fired more than 200 shells during the whole battle..... a machine gun more than a battleship..... More seriously, needing to replenish her magazines once in Brest, I don't think Lutjens would have omitted the total number of shells expended by his ship. Also, almost everybody said it was the fifth salvo to sink Hood.

I think the explanation is more simple: the theoretical RoF of a gun in itself cannot be assumed as the practical RoF of a ship in a real battle situation . Half this RoF would be a better estimation IMHO. PoW should have fired 2 full salvos per minute, based on the theoretical RoF of the British 14" gun, she fired just 0.94.

Bye, Alberto

Re: Bismarck firing procedures at DS

Posted: Tue Feb 23, 2016 9:38 pm
by alecsandros
Alberto Virtuani wrote: I think the explanation is more simple: the theoretical RoF of a gun in itself cannot be assumed as the practical RoF of a ship in a real battle situation . Half this RoF would be a better estimation IMHO. PoW should have fired 2 full salvos per minute, based on the theoretical RoF of the British 14" gun, she fired just 0.94.

Bye, Alberto
... But Prince of Wales did not go into rapid fire mode... They were doing ranging salvos and waiting for fall of shot all the time...

Re: Bismarck firing procedures at DS

Posted: Tue Feb 23, 2016 9:41 pm
by alecsandros
Alberto Virtuani wrote:
in case 93 has to be referred only to Hood, it would mean BS fired more than 200 shells during the whole battle..... a machine gun more than a battleship.....
... I know it's improbable... But still..
Consider this: Prince of Wales had 74 ordered shots in 9 minutes of ranging salvos, with 6 guns bearing initialy, while Bismarck barely had 40 (or 48) ordered in 5 minutes on 8 available guns, on rapid fire mode.

It shows that Bismarck in rapid fire was ordering shots slower than Prince of Wales was ordering ranging shots !

Re: Bismarck firing procedures at DS

Posted: Tue Feb 23, 2016 9:54 pm
by Antonio Bonomi
Hello everybody,

@ Alecsandros,

on August 1941 there was the interrogation of the Bismarck survivors, they obviously did not know about Adm Lutjens radio message to Berlin.

We have in there another confirmation of the 40 shells needed to sink the Hood directly from the Bismarck survivor interrogation, from the Baron :
Meanwhile "Bismarck" had opened fire on "Hood" from her main armament turrets and her port secondary armament, with armour-piercing shells, firing salvoes of four guns with the 38-cm. armament. The opening range was stated by prisoners to have been 23,000 metres (25,152 yards). According to one prisoner, Fregattenkapitän Schneider, the 1st Gunnery Officer failed to recognise his target as "Hood," believing that he was firing at a British cruiser.

He was corrected by the 2nd Gunnery Officer, Korvettenkapitän Albrecht, who said: "Herr Schneider, observe the superstructure, you know well which ship in the British fleet has that superstructure. That is no other than the battle-cruiser 'Hood'!" The prisoner who recounted this incident also added: "Who of us ever thought we should be engaged in a sea battle! We had merely thought of commerce raiding and sunning ourselves on deck."

Kapitänleutnant Burkhardt von Müllenheim-Rechberg, 3rd Gunnery Officer in "Bismarck," stated during interrogation, that no officer recognised "Hood" at first, and did not do so until "Hood" turned to port, disclosing the long, low sweep of her decks. They had not bargained with coming into contact with "Hood" and for a time they were extremely anxious about the outcome.

The Germans, however, fired with great accuracy, and "Norfolk," who was in a position to witness the duel, states that the first salvo was 100 yards short, but that the second salvo straddled and hit. The third salvo again straddled and hit and a fire broke out in "Hood's" port battery, which spread rapidly to the mainmast.

At 0600, just after "Hood" and "Prince of Wales" had turned together to open "A" arcs, "Hood" was straddled again. There was a huge explosion between the after funnel and the mainmast and the ship sank in three or four minutes. Kapitänleutnant von Müllenheim-Rechberg stated, when interrogated aboard H.M.S. "Dorsetshire," that "Hood" closed the range rapidly, made smoke, and was hit as she turned to port, the smoke possibly assisting ranging.

He added then that "Hood" blew up on "Bismarck's" fifth salvo and cost Germany forty shells in all.
From here :

http://www.uboatarchive.net/BismarckINT.htm
C.B. 4051 (24) - GERMAN BATTLESHIP BISMARCK - Interrogation of Survivors - August, 1941
Bye Antonio :D

Re: Bismarck firing procedures at DS

Posted: Wed Feb 24, 2016 12:57 am
by tommy303
Bismarck's fire control system was highly automated in some respects, particularly when operating in central fire control mode, and I suspect that with a fairly new crew and without the usual intensive gunnery training while steaming underway, Schneider may have preferred to let the automated gyro system do the actual firing. However, this is slower as the system has to compute trunnion tilt and roll. Firing from director by the director layer would have been faster, but required a great deal more skill and judgement--ie learned only through experience--to by pass the main gyro and fire at the optimum time.

Battleships rarely fire at their most rapid or theoretical rate of fire, even when they have highly trained and veteran crews. Discounting problems in drill or mechanical breakdowns which might lead to some guns missing salvos, such rapid fire would frequently be less accurate and with higher dispersion rates than a slower, methodical rate of fire.

Re: Bismarck firing procedures at DS

Posted: Wed Feb 24, 2016 5:16 am
by dunmunro
alecsandros wrote:
Alberto Virtuani wrote:
in case 93 has to be referred only to Hood, it would mean BS fired more than 200 shells during the whole battle..... a machine gun more than a battleship.....
... I know it's improbable... But still..
Consider this: Prince of Wales had 74 ordered shots in 9 minutes of ranging salvos, with 6 guns bearing initialy, while Bismarck barely had 40 (or 48) ordered in 5 minutes on 8 available guns, on rapid fire mode.

It shows that Bismarck in rapid fire was ordering shots slower than Prince of Wales was ordering ranging shots !
40/48 rnds in 5mins = actual output of 8/9.8 rnds/min but these figures would be ~10% higher if we assume that Bismarck had a ~90% output.

74rnds/9 minutes = potential 8.2 rnds/min but actual output = 6.1 rnds/min. Even with A arcs open maximum output would equal 10 rnds/min with probable actual of ~7.4 rds/min.

PoW wasn't ordering ranging shots. She was firing at regular salvo intervals as per RN doctrine.

Re: Bismarck firing procedures at DS

Posted: Wed Feb 24, 2016 6:38 am
by alecsandros
dunmunro wrote: [
40/48 rnds in 5mins = actual output of 8/9.8 rnds/min but these figures would be ~10% higher if we assume that Bismarck had a ~90% output.
No, 40 ordered shots would imply 36 fired shots at 90% efficiency. In 5 minutes that translates to 0.90 shots per minute per gun.

Doesn't seem like rapid fire at all... :think:

Re: Bismarck firing procedures at DS

Posted: Wed Feb 24, 2016 6:44 am
by alecsandros
Antonio,
I know the Baron's number. I do not think he was naming effective shells fired, but ordered shots... It's difficult to accept 100% efficiency. The Baron is an excellent source.. but not perfect, as we know.. I still have many uncertainties..

I know it's unlikely the 93 number was fired only at Hood... I know... But... in such an engagement... with so much at stake... Why fire so slowly when Bismarck was under continous heavy gun fire ?

Thomas mentioned a very interesting automatic fire control. However, IIRC that automated fire control was designed to output at least 2 rounds per minute per gun at up to 15* elevation... AND... we have the Prinz Eugen movie showing us 23 seconds salvo intervals for Bismarck... So it could be done... And WAS done in that morning...

Re: Bismarck firing procedures at DS

Posted: Wed Feb 24, 2016 6:49 am
by alecsandros
dunmunro wrote: PoW wasn't ordering ranging shots. She was firing at regular salvo intervals as per RN doctrine.
... Duncan, Prince of Wales ordered 74 shots for guns bearing on the enemy. There were no ordered shots for Y turret in the first 5 minutes, IIRC.

The average number of guns to which the firing order was sent was 7.7... 74 / 7.7 / 9 = 1.07 spmpg ordered.

Re: Bismarck firing procedures at DS

Posted: Wed Feb 24, 2016 6:51 am
by alecsandros
dunmunro wrote: PoW wasn't ordering ranging shots. She was firing at regular salvo intervals as per RN doctrine.
Ok,
But I assume there was some sort of "rapid fire" command for Royal Navy also. King George Vth and Rodney fired much faster on May 27th in the opening phase, after finding the enemy range...

Re: Bismarck firing procedures at DS

Posted: Wed Feb 24, 2016 7:40 am
by Antonio Bonomi
Hello everybody,

@ Alecsandros,

I see what you mean, ... but I have learned on the many years of discussion about this battle to rely only on the evidence I have, ... not to be accused to intentionally depict and draft a battle I imagine personally.

This is the reason why I underlined the reference I have used as evidence and the supporting reasoning done on the timing thru that Excel table to read the film sequence and the photos and associate them to the battle time on both sides.

In this case, talking Bismarck fire, ...we have 40 ( 5 full salvos ) shells to sink Hood in less than 5 minutes, by the Baron and Capt Leach ... and 93 total shells fired by Adm Lutjens ... on the total around 14 minutes battle time.

The film and photo analysis seems to confirm the slow rate Tommy303 refers to, ... in fact we can divide in section and Group of salvoes ( of 4 guns ordered to fire ) the events :

From 05.55 until 06.00 --> 10 salvos ( 40/44 shells ) to sink Hood with 2 hits

From 06.00 until 06.03 --> 6 salvos ( 20/24 shells ) to damage PoW with 3 hits

Prinz Eugen torpedo ALARM, Bismarck turning to starboard on 270°

From 06.03 until 06.05/6 --> 5 salvos ( 20 shells) showed on the film sequences ( 1+2)

Bismarck turns back to port on 220° ( ? )

From 06.06 until 06.09 ---> 5 salvos ( 20 shells ) showed on the available photos

This is what I have ... if somebody has something more or different ... lets evaluate it ... :think:

@ Tommy 303,

thanks for your precious information ... :wink:

Bye Antonio :D

Re: Bismarck firing procedures at DS

Posted: Wed Feb 24, 2016 7:49 am
by alecsandros
... Dear Antonio,
My suggestion is to be only a paranthesis, and not a new theory. As I said, it's hard to imagine 93 vs Hood... But ... I am not convinced by the evidence available that Bismarck fired THAT slow.

The movie shows much rapid firing intervals ... I see 23sec once, 25 sec once, 31 seconds once... NOt 60... NOt 70...

Between minute 5:41 and 6:36, we have 55 seconds of film (supposedly continous). In those 55 seconds Bismarck fires 20 shots.
This translates to 22 shots per minute , or 2.73 shots per minute per gun

[5:41 - A+B, 5:42 - C+D; 6:03 - A+B; 6:05 - C+D; 6:36 - C+D]
https://www.youtube.com/watch?v=pPmkOtSveXY
====

I consider your work to be excellent with the available info. However, I have doubts over the solidity of the primary documents available to us .

Re: Bismarck firing procedures at DS

Posted: Wed Feb 24, 2016 8:53 am
by Alberto Virtuani
Alecsandros wrote: "King George Vth and Rodney fired much faster on May 27th in the opening phase, after finding the enemy range..."
Hi Alec,
we are still waiting for the final analysis from Duncan of KGV salvos on May 27, but I doubt she fired faster than PoW at ANY stage of battle..... In the first minutes KGV fired at a rate of 1.7 salvos per minute, lower than PoW on May 24 (1,9), please see KGV GAR......

Again, IMHO the explanation for BS slow firing is, as Tommy confirmed, that no ship fires at her theoretical RoF when in a real combat situation.
Regarding the film (and assuming all guns in a turret are actually fired....), it just mean that after the turn they had all guns already loaded and used a "gabelgruppe" fast firing method the get the range again (forgetting precision), but when in effective fire mode this rate could not be maintained (for Schneider's choice or other reasons, as Tommy explained).

Bye, Alberto