Search found 765 matches

by Bill Jurens
Thu Sep 03, 2020 2:15 am
Forum: Naval Weapons
Topic: Turret weight vs calibre length
Replies: 14
Views: 720

Re: Turret weight vs calibre length

That's true. The relationship between wear rate and initial velocity is extremely complex, depending upon the design of the driving band(s), projectile seating, gun caliber, propellant chemistry, and rate-of-fire, and usually must be treated on a case-by-case basis. In VERY rough terms, the followin...
by Bill Jurens
Wed Sep 02, 2020 5:52 pm
Forum: Naval Weapons
Topic: Turret weight vs calibre length
Replies: 14
Views: 720

Re: Turret weight vs calibre length

Another good question. Probably because the additional wear and tear on the gun and mounting didn't justify the advantage except in unusual circumstances. To begin with, it's more difficult to design supercharges as they tend to be smaller in size than regular bag loads, i.e. for a five bag load, go...
by Bill Jurens
Tue Sep 01, 2020 7:26 pm
Forum: Naval Weapons
Topic: Turret weight vs calibre length
Replies: 14
Views: 720

Re: Turret weight vs calibre length

Good questions. Generally, the chamber is not filled completely. Even if one crammed the bags in by force, there would still be considerable 'empty' volume left, as (for example) single perforated grains -- basically thick tubes -- still leave the entire internal volume of the grain, and the space b...
by Bill Jurens
Thu Aug 27, 2020 9:08 pm
Forum: Naval Weapons
Topic: Turret weight vs calibre length
Replies: 14
Views: 720

Re: Turret weight vs calibre length

A few quick observations: There is little advantage to improved tube stiffness except at very short ranges. At longer ranges, it hardly matters at all. So far as weight vs caliber is concerned, it's safe -- as a rule of thumb -- to assume that weight is proportional to the cube of the caliber. It's ...
by Bill Jurens
Fri Aug 21, 2020 5:03 am
Forum: The Wreck of the Bismarck
Topic: Bismarck's port rudder
Replies: 49
Views: 41449

Re: Bismarck's port rudder

It's very difficult to say. I am skeptical that any convincing case can be made regarding the detailed effects of the explosion re venting, etc., as such phenomena are rarely, if ever, tested full size, and we actually know quite little about the precise explosion point, etc. It is very difficult to...
by Bill Jurens
Wed Aug 05, 2020 7:14 pm
Forum: Bismarck General Discussion
Topic: Was the battleship Bismarck really the best of its time?
Replies: 34
Views: 1663

Re: Was the battleship Bismarck really the best of its time?

The continued references, by a variety of parties, to relatively light high-velocity projectiles vs relatively heavy low velocity projectiles is interesting to me insofar as simple ballistic analysis will quickly show that at ANY range for equivalent initial energies delivered at the muzzle, the res...
by Bill Jurens
Thu Jul 30, 2020 11:40 pm
Forum: Naval Weapons
Topic: Who won?
Replies: 33
Views: 2239

Re: Who won?

My thanks to Wadinga for his kind comments re INRO and Warship International. Paul Mercer wrote: "[Regarding the relative effects of a one ton bomb against a one ton shell, if I am correct in my understanding of the replies [to a previous question] the answer being that a shell would be falling at a...
by Bill Jurens
Wed Jul 29, 2020 5:30 pm
Forum: Naval Weapons
Topic: Who won?
Replies: 33
Views: 2239

Re: Who won?

There are a number of rule-of-thumb formulas for this. At normal battle ranges, these allow doing the problem in one's head. For 9 guns and U.S. guns, expected pattern size is range is typically around 1.8-2.0% of range. At long ranges where gun alignment doesn't really matter much, provided the int...
by Bill Jurens
Wed Jul 29, 2020 12:10 am
Forum: Naval Propulsion
Topic: Ships boilers
Replies: 6
Views: 1156

Re: Ships boilers

Yes. Bill Garzke is a close friend of mine, so I have had a copy of this book for years now. It is a nice treatment, and it's likely that I actually helped in completing parts of it. Memory fails...

Bill Jurens
by Bill Jurens
Wed Jul 29, 2020 12:07 am
Forum: Naval Weapons
Topic: Who won?
Replies: 33
Views: 2239

Re: Who won?

Often, small salvos were used because it made spotting more difficult -- it's harder to accurately spot a four-gun pattern than a nine-gun pattern, and the target practices were often for training purposes. Sometimes shorter ranges were employed with reduced charges, which essentially made a 24000 y...
by Bill Jurens
Mon Jul 27, 2020 2:03 am
Forum: Naval Weapons
Topic: Who won?
Replies: 33
Views: 2239

Re: Who won?

Thanks, Thorsten. I remain, very respectfully, skeptical...

Bill Jurens
by Bill Jurens
Sun Jul 26, 2020 5:49 pm
Forum: Naval Weapons
Topic: Who won?
Replies: 33
Views: 2239

Re: Who won?

A few posts ago, Wadinga wrote: "... those very few, unusually-long range hits you cited were only possible in the stern chase situation, ie small rate of change of both azimuth and distance and easily-estimated inclination." I'd have to disagree. Actually, until very late in the fire control develo...
by Bill Jurens
Thu Jul 23, 2020 4:57 pm
Forum: Bismarck General Discussion
Topic: Robert J. Winklareth +
Replies: 5
Views: 821

Re: Robert J. Winklareth +

Although he and I often disagreed on various points, I invariably found him to be a cooperative, honest, reasonable, and knowledgeable opponent when we disagreed, and a patient and generous source of information when we did not. I tip my hat to a man who made some fine and useful contributions to th...
by Bill Jurens
Wed Jul 22, 2020 8:17 pm
Forum: Naval Propulsion
Topic: Ships boilers
Replies: 6
Views: 1156

Re: Ships boilers

The situation depends upon the type of boiler in use. Fire-tube boilers, which were not used much in warships after about 1905 or so, contain a good deal of superheated water that can flash into steam if the pressure vessel complex is breached. But, in practical terms, this rarely happens because in...
by Bill Jurens
Mon Jul 13, 2020 4:30 am
Forum: Hypothetical Naval Scenarios
Topic: Vanguard vs. Iowa?
Replies: 28
Views: 10451

Re: Vanguard vs. Iowa?

Steve Crandall wrote: "Bill: What percentage chance do you think an Iowa class battleship would have to hit a battleship size target at 30,000 yds? 35,000 yds?" For a battleship-sized target, at 30,000 yards, estimates were 2.7% for Top Spot, 3.5% for Plane Spot, and 3.4% for Radar Spot. There are, ...