Search found 429 matches

by Bill Jurens
Wed Mar 07, 2007 2:31 pm
Forum: Naval Technology
Topic: Hood explosion
Replies: 10
Views: 4751

Forward Magazine Explosion?

There was no forward magazine explosion on Hood. The forward hull failure was due to hydrostatic implosion.

Bill Jurens.
by Bill Jurens
Thu Mar 01, 2007 5:17 am
Forum: Naval Technology
Topic: Bismarck and Titanic
Replies: 10
Views: 7207

Titanic displacment

It is quite easy to get confused with displacements, as they are often defined in unusual ways, both in merchant ships and warships. If one takes the product of Titanic's length, beam, and draft, one gets the displacement of an equivalent prism in cubic feet. Dividing this by 35 gives displacement i...
by Bill Jurens
Thu Feb 08, 2007 4:42 am
Forum: Bismarck General Discussion
Topic: Bismarck and her contemporaries
Replies: 1293
Views: 133674

hits on armor belt, etc.

There has been some discussion here regarding the number of large caliber hits on Bismarck's armor belt(s). As someone who has spent about sixty hours actually looking at the wreck, often with particular reference to the issues in question, I feel confident in commenting as follows: 1) Someone sugge...
by Bill Jurens
Tue Feb 06, 2007 11:57 pm
Forum: Naval Weapons
Topic: Bismarck's Vo measuring system.
Replies: 12
Views: 4982

Instrumented barrels

Instrumented barrels would be of very little use shipboard, as all of the information which they can deliver, e.g. loss of velocity vs Effective Service Rounds, etc., is much better obtained at the proving ground. There would be no point -- or almost no point -- in feeding I.V. information obtained ...
by Bill Jurens
Tue Feb 06, 2007 2:47 am
Forum: Naval Weapons
Topic: Bismarck's Vo measuring system.
Replies: 12
Views: 4982

Instrumented barrel

The reference in the AKVS test is evidently to what is normally called an 'instrumented barrel', i.e. a gun tube that has been drilled at intervals in order to allow the insertion of pressure gages that can give pressure vs time and pressure vs position along the bore and/or contacts that can detect...
by Bill Jurens
Sat Nov 11, 2006 5:17 pm
Forum: Naval Technology
Topic: Effective battle ranges
Replies: 18
Views: 7417

"As I recall, some of the people at Dahlgren figured it was when the angle of depature exceeded approximately 15* ... in the case of the German 38cm, this is also the range of angle of departure (15-20*), with the least possibility of scatter. " I would be interested in finding out where this 15* a...
by Bill Jurens
Fri Nov 10, 2006 6:10 am
Forum: Naval Technology
Topic: Effective battle ranges
Replies: 18
Views: 7417

Danger Space/range

For what it is worth, the USN considered 'long range' to be where the angle of fall exceeded 30 degrees, and/or less than one hit could be assumed per salvo. This, incidentally, was one reason why the 12-gun BBs were seen to have a longer effective range than the 8-gun BBs...

Bill Jurens.
by Bill Jurens
Thu Nov 09, 2006 5:41 am
Forum: Bismarck General Discussion
Topic: Re: "If 15" shell had exploded in POW Bridge"
Replies: 32
Views: 10286

Effects of Single Hits...

George Elder wrote this on this thread some time ago, and I just stumbled upon it now, more or less by accident. My reply is at the very bottom, after asterisks... Bill Jurens Hi Bill: I am having a bit of trouble with this notion: "In general, a single hit forward (or, for that matter, anywhere) on...
by Bill Jurens
Sat Oct 21, 2006 3:42 am
Forum: Naval Technology
Topic: Bismarck class turret protection
Replies: 74
Views: 35137

Hoyer Document

I've seen a number of references to "Hoyer", etc. on this thread. Can I get more information on the name and availability of the original document?

Bill Jurens
by Bill Jurens
Tue Oct 17, 2006 10:28 pm
Forum: Bismarck General Discussion
Topic: Who really sank the Hood? Bismarck or Prinz Eugen?
Replies: 45
Views: 61167

Magazine explosion

I don't understand why such a programme would have you involved if they ignore your expert opinion - what would they have to gain? Whether the forward magazine exploded or not is surely academic to the fact that Hood sank." Well, frankly that somwhat baffles me, too. I have expressed opinions on th...
by Bill Jurens
Fri Oct 13, 2006 5:24 pm
Forum: Naval Technology
Topic: Iowa Class real performance
Replies: 67
Views: 27399

Homogeneous armor

Dave Saxton wrote: "I'm finding the homogenous predictions for penetration fall short of predictions for face hardened armour. For example striking at 460 mps at nearly right angles the amount of homogenous armour penetrated (my curves included) is predicted to be about 13% less than the curves for ...
by Bill Jurens
Fri Oct 13, 2006 5:43 am
Forum: Naval Technology
Topic: Iowa Class real performance
Replies: 67
Views: 27399

More penetration

Your results match my calcs almost exactly. A range around 14600 meters would seem to be near the optimum situation. ORD SK 78841 predicts a limit velocity of 1942 f/s, i.e. c. 591 m/s, and the impact velocity is at that range, picked quickly off a graph -- is about 575 or 580. About 98% as you note...
by Bill Jurens
Fri Oct 13, 2006 2:43 am
Forum: Naval Technology
Topic: Iowa Class real performance
Replies: 67
Views: 27399

Faceplate penetration

Well, you sure know how to flatter a guy... I am working on a number of other things now, but your kind comment enticed me to do a quick 'back of the envelope' calculation using the USN's official ORD SK78841 as a guide. This suggests that penetration of an Iowa faceplate by a 15" bullet was improba...
by Bill Jurens
Thu Oct 12, 2006 6:19 pm
Forum: Naval History (1922-1945)
Topic: South Dakota´s barbette impact
Replies: 9
Views: 2680

Barbette impact

The hit on South Dakota is unlikely to have been from an armor-piercing round. The steel doesn't lie; an impact from an a.p. round would have caused much more damage at the impact point, and the amount of damaged and removed decking is much too large to have been removed by the relatively small char...
by Bill Jurens
Thu Oct 12, 2006 4:34 pm
Forum: Naval Technology
Topic: Iowa Class real performance
Replies: 67
Views: 27399

Armor impacts

The hit on South Dakota is unlikely to have been from an armor-piercing round. The steel doesn't lie; an impact from an a.p. round would have caused much more damage at the impact point, and the amount of damaged and removed decking is much too large to have been removed by the relatively small char...