Matching Course and Speed

derstosstrupp · 05-14-20, 11:57 AM

Here’s a simple reference for performing “Ausdampfen” as found in the Kriegstagebücher (KTBs). A simple method that provides great results!

https://docs.google.com/presentation...gGw2f3Eow/edit

Description in “U-977” by Heinz Schäffer:
“Mast tip off the starboard bow!” The lookout had paid attention. It can just be faintly made out in the sharp binoculars. The commander comes to the bridge. He sees it right away.....

.......The commander tells the watch officer that he’ll direct the boat from here. “Hard to port, both engines half speed ahead!”

.......We had a speed of six knots before. In a few seconds we are at twelve. The boat turns until the mast tip is directly aft. “Good right there!” says the commander to the helmsman.

An especially heavy and large set of binoculars is placed on the targeting column (UZO). It is used for surface attacks and is connected to the computer just like the periscope........The commander is standing at it. The mast is in the crosshairs, it gets smaller and moves to port. “Aha, course for North America......” “Both engines two times half speed ahead!” 14 knots......Now the mast tip can only be seen in the UZO, the surface targeting column. “Hard to starboard!” We are running exactly perpendicular to the first course. The mast tip disappears. “20 degrees to starboard!” Very slowly it comes back in sight and gets bigger. “Both engines great speed ahead!” 16 knots. “10 degrees to port!” Now the mast tip stays the same size, we are on the same course as the ship. But apparently it is faster than us, since the mast tip is moving forward. “Damned fast ship. Hopefully we’ll get it.”
We are still aft and for an attack we have to be forward of the enemy. Even if you are only one knot faster than the enemy, you need many hours, often days to get in front. A lot of luck is involved in torpedoing a fast ship if find yourself in an aft position upon sighting. “Both engines two times great speed ahead!” Almost 17 knots. The engines are warmed up, their exhaust is barely visible. The engine room personnel work excellently. The mast tip stay in the same spot; so the ship is traveling around 17 knots. Damned fast. “Both engines full speed ahead!”

FUBAR295 · 05-14-20, 03:06 PM

Quote:

Originally Posted by derstosstrupp

Here’s a simple reference for performing “Ausdampfen” as found in the Kriegstagebücher (KTBs). A simple method that provides great results!

https://docs.google.com/presentation...gGw2f3Eow/edit

Good stuff. Thank You.

Good hunting,
FUBAR295

derstosstrupp · 05-14-20, 03:43 PM

Original post updated to include an excerpt from U-977 describing the procedure.

John Pancoast · 05-15-20, 06:59 AM

Yep, after intercepting a convoy the first thing I do is match it's speed from either the port or starboard side.
Easy to do and always gives good results. I do one last manual check before attacking and that's it for speed work and the two methods rarely produce different results from one another.
Simple is good, even more so when it was an actual method.

05-14-20, 11:57 AM	#1
derstosstrupp Grey Wolf Join Date: Aug 2008 Posts: 883 Downloads: 489 Uploads: 0	Matching Course and Speed Here’s a simple reference for performing “Ausdampfen” as found in the Kriegstagebücher (KTBs). A simple method that provides great results! https://docs.google.com/presentation...gGw2f3Eow/edit Description in “U-977” by Heinz Schäffer: “Mast tip off the starboard bow!” The lookout had paid attention. It can just be faintly made out in the sharp binoculars. The commander comes to the bridge. He sees it right away..... .......The commander tells the watch officer that he’ll direct the boat from here. “Hard to port, both engines half speed ahead!” .......We had a speed of six knots before. In a few seconds we are at twelve. The boat turns until the mast tip is directly aft. “Good right there!” says the commander to the helmsman. An especially heavy and large set of binoculars is placed on the targeting column (UZO). It is used for surface attacks and is connected to the computer just like the periscope........The commander is standing at it. The mast is in the crosshairs, it gets smaller and moves to port. “Aha, course for North America......” “Both engines two times half speed ahead!” 14 knots......Now the mast tip can only be seen in the UZO, the surface targeting column. “Hard to starboard!” We are running exactly perpendicular to the first course. The mast tip disappears. “20 degrees to starboard!” Very slowly it comes back in sight and gets bigger. “Both engines great speed ahead!” 16 knots. “10 degrees to port!” Now the mast tip stays the same size, we are on the same course as the ship. But apparently it is faster than us, since the mast tip is moving forward. “Damned fast ship. Hopefully we’ll get it.” We are still aft and for an attack we have to be forward of the enemy. Even if you are only one knot faster than the enemy, you need many hours, often days to get in front. A lot of luck is involved in torpedoing a fast ship if find yourself in an aft position upon sighting. “Both engines two times great speed ahead!” Almost 17 knots. The engines are warmed up, their exhaust is barely visible. The engine room personnel work excellently. The mast tip stay in the same spot; so the ship is traveling around 17 knots. Damned fast. “Both engines full speed ahead!” __________________ Ask me anything about the Type VII or IX! One-Stop Targeting Shop: https://drive.google.com/drive/folde...WwBt-1vjW28JbO My YT Channel: https://www.youtube.com/channel/UCIJ...9FXbD3S2kgwdPQ Last edited by derstosstrupp; 05-14-20 at 03:42 PM.

05-14-20, 03:43 PM	#3
derstosstrupp Grey Wolf Join Date: Aug 2008 Posts: 883 Downloads: 489 Uploads: 0	Original post updated to include an excerpt from U-977 describing the procedure. __________________ Ask me anything about the Type VII or IX! One-Stop Targeting Shop: https://drive.google.com/drive/folde...WwBt-1vjW28JbO My YT Channel: https://www.youtube.com/channel/UCIJ...9FXbD3S2kgwdPQ

05-15-20, 06:59 AM	#4
John Pancoast Ocean Warrior Join Date: Apr 2002 Location: Minnysoda Posts: 3,183 Downloads: 490 Uploads: 4	Yep, after intercepting a convoy the first thing I do is match it's speed from either the port or starboard side. Easy to do and always gives good results. I do one last manual check before attacking and that's it for speed work and the two methods rarely produce different results from one another. Simple is good, even more so when it was an actual method. __________________ "Realistic" is not always GAME-GOOD." - Wave Skipper