Search found 733 matches

by Thorsten Wahl
Mon Nov 18, 2019 12:47 pm
Forum: Naval Weapons
Topic: American SH shells - Famed or Folly
Replies: 25
Views: 5825

Re: American SH shells - Famed or Folly

british comment in SUPP 6/481
SUPP 6-481 _section_Effect of weight.jpg
SUPP 6-481 _section_Effect of weight.jpg (37.21 KiB) Viewed 26 times
by Thorsten Wahl
Tue Nov 12, 2019 2:35 pm
Forum: Naval Weapons
Topic: Fuze delay in aerial antiship bombs
Replies: 5
Views: 189

Re: Fuze delay in aerial antiship bombs

Instructions for the use of bombs against ship targets ZahlentafelBomben.jpg penetration capabilities dive attack =500 km/h, throwing height 1,2 km, impact angle 60° (90° = perpedicular to plate) impact speed about 280 m/s for all (RS =rocketdriven) PC 500 RS 190 mm PC 1000 RS 180 mm PC 1800 RS 180 ...
by Thorsten Wahl
Mon Nov 11, 2019 8:03 am
Forum: Naval Weapons
Topic: Fuze delay in aerial antiship bombs
Replies: 5
Views: 189

Re: Fuze delay in aerial antiship bombs

german bombs many different types depending on type of target . throwing height, underwater detonation.... SC and SD types delay 0,12 s if the armor stops the bomb nondelay at 800g(SC 800) - 6000g(SD 1700) deceleration depending on type of bomb armor piercing PD 1000 two settings a) "non delay" = 0,...
by Thorsten Wahl
Fri Nov 08, 2019 1:10 pm
Forum: Naval Weapons
Topic: American SH shells - Famed or Folly
Replies: 25
Views: 5825

Re: American SH shells - Famed or Folly

Am I correct that you are referencing that 60deg obliquity angle to the plane of the plate? i.e. - addressing the issue of penetration of horizontal armor? yes. ------------------------------------------------------------------------------------------------------------------------------------------...
by Thorsten Wahl
Wed Oct 30, 2019 10:07 am
Forum: Naval Weapons
Topic: American SH shells - Famed or Folly
Replies: 25
Views: 5825

Re: American SH shells - Famed or Folly

a question does someone know the CRH of the windscreen of the 2240 lb and 2700 lb US AP-shells
sample german L/3,7 Psgr had 8,5 cal
by Thorsten Wahl
Tue Oct 29, 2019 2:47 pm
Forum: Naval Weapons
Topic: American SH shells - Famed or Folly
Replies: 25
Views: 5825

Re: American SH shells - Famed or Folly

addition to the previously said
Headshape dependend angular performance.jpg
Headshape dependend angular performance.jpg (55.54 KiB) Viewed 254 times
additionally the heavy armor-piercing-cap used supports penetration at high obliquities compared to no cap or relatively lighter caps.
by Thorsten Wahl
Tue Oct 29, 2019 8:14 am
Forum: Naval Weapons
Topic: American SH shells - Famed or Folly
Replies: 25
Views: 5825

Re: American SH shells - Famed or Folly

A superheavy projectile held some outer ballistics advantages but, U.S. Navy F-function wich was used for prediction of penetration in american fireeffect tables(Ordnance Sketch 78841) tend to predict a too low critical velocity for penetration at all impact angles above 20 degrees. The error was in...
by Thorsten Wahl
Mon Sep 02, 2019 9:03 am
Forum: Naval Technology
Topic: Discuss
Replies: 1
Views: 226

Re: Discuss

by Thorsten Wahl
Mon Aug 26, 2019 4:16 pm
Forum: Bismarck General Discussion
Topic: FYI: meaning of the notation of the draft measurements during Bismarck’s trial runs, fall 1940
Replies: 28
Views: 1200

Re: FYI: meaning of the notation of the draft measurements during Bismarck’s trial runs, fall 1940

One thing being ignored here, or at least minimized, is the rather dramatic effect of propeller efficiency. Especially if one is running close to the cavitation limit, which Bismarck would almost certainly have been during high-speed trials, even a small defect in blade geometry can affect the spee...
by Thorsten Wahl
Mon Aug 26, 2019 3:50 pm
Forum: Bismarck General Discussion
Topic: Battleship Bismarck: A Design and Operational History
Replies: 59
Views: 9685

Re: Battleship Bismarck: A Design and Operational History

All distances in page 211 map look too great to be correct (BS open fire is reported by Lutjens at 20800 meters while is 21500 in the map at pag.211 An aside note: 20.800 m distance seem the calculated distance for firecontrol purposes. The Germans use true gun distance as distance when discussing ...
by Thorsten Wahl
Wed Aug 14, 2019 8:33 am
Forum: Bismarck General Discussion
Topic: 3-shaft propulsion
Replies: 115
Views: 3904

Re: 3-shaft propulsion

i made a spreadsheet based on development of RPM to achieve certain speed normalised with RPM required to achieve 15 kn beeing 100% -Data according source mentioned -For the US data i used the average RPM number from the FTP 218 spreadsheets -I interpolated RPM numbers for uneven speeds for Howe -Th...
by Thorsten Wahl
Wed Aug 14, 2019 8:19 am
Forum: Bismarck General Discussion
Topic: 3-shaft propulsion
Replies: 115
Views: 3904

Re: 3-shaft propulsion

the advantage was denominated by the Germans 3 Welleneffiziens1.jpg with ~48% screw-efficiency compared to ~42% screw-efficiency for a 4 screw ship. As i wrote earlier this advantage is in line with british publications to the same theme in "The engineeer" That means a 3 screw ship requires about 6 ...
by Thorsten Wahl
Fri Aug 09, 2019 12:27 pm
Forum: Bismarck General Discussion
Topic: 3-shaft propulsion
Replies: 115
Views: 3904

Re: 3-shaft propulsion

KGV recorded .715 lb/shp during trials and 111700shp = 35.65 tons/hr. Just for the record, where is this data from? Regards The Design and Construction of British Warships, 1939-1945: The Official Records : Major Surface Warships by DK Brown. Hello Duncan did DK Brown mentioned the heating value/ d...
by Thorsten Wahl
Thu Aug 08, 2019 8:41 am
Forum: Bismarck General Discussion
Topic: 3-shaft propulsion
Replies: 115
Views: 3904

Re: 3-shaft propulsion

some data for Gneisenau
Gneisenau Fahrleistunga.jpg
Gneisenau Fahrleistunga.jpg (23.45 KiB) Viewed 449 times
by Thorsten Wahl
Thu Aug 08, 2019 7:53 am
Forum: Bismarck General Discussion
Topic: 3-shaft propulsion
Replies: 115
Views: 3904

Re: 3-shaft propulsion

please dont derail this thread.