Barr & Stroud Dreyer vs. German Zeiss

[Karl Heidenreich]

Hood´s rangefinder was a Barr & Stroud which, at least in WWI, was clearly inferior to the German Zeiss. To this handicap we must add the use of the Dreyer Fire Director which was, again by WWI, inferior to the Argo Clock of Arthur Hungerford Pollen that was not adopted by the Royal Navy due to Admiralty politics.
At Jutland these elements play it´s share in the evolution of events, specially in the Battlecruiser action.
But, did the Germans at Jutland used a Dreyer FC equivalent or something more close to the Argo?
On the other hand, Hood retain her Barr & Stroud to her final day in addition to her Dreyer. But PoW as the Nelson Class were equipped with the "new" systems which might be Pollen´s Argos. So, when the Hood began firing at DS she did with obsolete Fire Direction systems using an inferior rangefinder than those on her enemy: Bismarck and PE. That´s, maybe, the reason Hood didn´t score a single hit against the two German ships while PoW did. And that´s why Schneider´s fire was so accurate.
Which were the specifications of Bismarck´s Fire Control?
Repulse was refitted in several ocassion prior to WWII. Was her Fire Direction optimized?
Best regards.

[mike1880]

I recommend "Dreadnought Gunnery and the Battle of Jutland" by John Brooks for a more up to date view of fire control capabilities and the degree to which Admiralty FC systems were influenced by Pollen.

There's also some discussion of the Argo's capabilities at "The Dreadnought Project" which adds further technical detail to some of Brooks' comments.

Mike

[marcelo_malara]

Nelson class used the Mk I Admiralty Fire Control Table. This was an evolution of the Dreyer, for example the plotting of the ranges from each rangefinder was automatic. The only components that had been influenced by the Argo Clock were the variable-speed drives (John Brooks, Admiralty Fire Control Tables, Warship 2002-3).
KGV used the Mk IX AFCT, futher enhancements, but always the same principle.

[tommy303]

The Germans, during the battle of Jutland, used a system inferior to the Dreyer system in use in Britain. It was in fact a manually operated system based on a Range Clock and a German version of the Dumaresq calculator, and a director pointer, whereas the Dreyer fire control table combined the range clock, Dumaresq and continuous plot. In addition control of the guns was exercised from a director fire control tower which both aimed and fired the guns. The German system relied upon a director pointer to track the target for the fire control system, but it was the responsibility of the gunlayers turret trainers to set their sights from data supplied via follow the pointer and to track the target and fire on the uproll.

That the German gunners did so well in the openning phase of the battle was due to visibility which favored them at the time, better rangefinders, and superior training and reaction times.

As to Brooks work, he is a little onesided and his narrative has a number of faults. It would be well to take a look at a critique of his book:

http://muse.jhu.edu/journals/journal_of ... umida.html

[mike1880]

There's not much point posting a link that has restricted access. Perhaps you could summarise the principle arguments.

(It should also be pointed out that the author of the critique cannot by any stretch of the imagination be considered impartial in the debate.)

Mike

[Karl Heidenreich]

Marcelo:

Nelson class used the Mk I Admiralty Fire Control Table. This was an evolution of the Dreyer, for example the plotting of the ranges from each rangefinder was automatic. The only components that had been influenced by the Argo Clock were the variable-speed drives (John Brooks, Admiralty Fire Control Tables, Warship 2002-3).
KGV used the Mk IX AFCT, futher enhancements, but always the same principle.

No Argo Clock in both of them? Why was the RN still using a Dreyer evolution if it was a fact that it plagiarized, with some important flaws, the Pollen´s desgin?

tommy303:

That the German gunners did so well in the openning phase of the battle was due to visibility which favored them at the time, better rangefinders, and superior training and reaction times.

Campbell in his book about Jutland dismisses that the visibility played so great a protagonism in the opening stages of Jutland (but he acknowledge it was a factor to considerate) but speaks of the rangefinders (Zeiss) and the superior training.

tommy303:

The Germans, during the battle of Jutland, used a system inferior to the Dreyer system in use in Britain. It was in fact a manually operated system based on a Range Clock and a German version of the Dumaresq calculator, and a director pointer, whereas the Dreyer fire control table combined the range clock, Dumaresq and continuous plot. In addition control of the guns was exercised from a director fire control tower which both aimed and fired the guns. The German system relied upon a director pointer to track the target for the fire control system, but it was the responsibility of the gunlayers turret trainers to set their sights from data supplied via follow the pointer and to track the target and fire on the uproll.

So , no superior Fire Director, as a matter of fact, an inferior one.

But the question still goes: the Germans got a new system for Bismarck and it was used in Denmarck Straits? Was it better than that used by Hood during their battle?

[Tiornu]

It's best if you can get a copy of the Brooks book. Fortunately, it has been issued as a paperback which, though still expensive, is not as outrageously priced as the hardcover. You may have to order it from Britain, though.
Brooks does a good job of handling the plagiarism allegation and overturns many mistaken claims forwarded in Sumida's work.

[Karl Heidenreich]

Thanks Tiornu, I´ll look forward for the book. But from searching to ordering to getting the book delivered we are talking about a month (Costa Rica is hardly London). In that time, is there an answer to the Bismarck´s system question?

[Tiornu]

Apparently German FC is most difficult to research. In researching his upcoming book on FC systems, Norman Friedman had the most trouble tracking down German sources.

[marcelo_malara]

To Karl:

In fact the little bibliography I have on fire control (the mentioned article plus three numbers of WI) doesn´t agree that the Pollen Argo clock was copied by Dreyer. They recognize that the Pollen was better but that the Dreyer was adopted because he was a Navy man.

To Tiornu:

Did you say that Friedman is wtiting a book about fire control? When will it be released?

[Karl Heidenreich]

Bruce Taylor is enfatical in that respect about the Dreyer being a copy of Pollen´s Argo. Where does this came from?
And what about Bismarck own fire control?

[marcelo_malara]

Who is Bruce Taylor?

[mike1880]

The reasons why they bought the Dreyer are complex but can be boiled down to the fact that he was prepared to work with the navy and work within the standard framework of naval procurement, and Pollen wasn't.

Mike

[Karl Heidenreich]

Bruce Taylor is the lad who wrote the book battlecruiser HMS Hood: An illustrated biography.

[Tiornu]

As I understand, Friedman completed his manuscript just a short time ago. Publication is a certainty, so maybe we'll see the book within a year.
Sumida is a great researcher. Unfortunately he seems to have accepted rather uncritically Pollen's version of British FC developments. From this, we have seen many misconceptions, hard to uproot because they rest on such a credible source as Sumida. Brooks wrote his book largely to correct these errors. Brooks has the advantage of actually knowing engineering, which enables him to assess the gizmos themselves rather than relying on partisan opinions. His book is not a general account of the battle--in fact, it assumes the reader's knowledge of the events at Jutland and focuses on the factors affecting gunnery there.