Archive for the ‘WWI’ Category

Risikoflotte Risked – 1914 Naval AAR

May 5, 2018

This weekend the local HMGS-South group played a fictitious naval battle set in the North Sea in May 1914. The British attempt to destroy the German fleet in the North Sea bases. The German fleet sails to fight in the Heligoland Bight. The scenario is based on the British strategy of destroying fleets which may become a threat (Copenhagen) (also), and the German concept of the Risikoflotte (risk fleet).

Player briefings: Copenhagen 1914

Visibility 14,000 yards, improving gradually. Wind westerly at 8 knots. Sea state 3.

Status at the end of the game: Cope IO

Damage output file: Cope Short output

Player reports:
Cope British
Cope German

Plots of ship movements:
0-30 minutes Cope plot 0-30
30-50 minutes Cope plot 30-50
50-60 minutes Cope plot 50-60
All Cope plot all

Computer code (described here)

After more than four hours of play and 60 minutes of game time we called it a day. 5 British dreadnoughts were sunk and 2 were in a sinking condition. 2 German dreadnoughts were sunk and 1 was heavily damaged. The Germans could claim a tactical victory at this point but not a strategic victory.

This battle was played some years ago with an earlier version of the code.

Canadian Autocar Armored Car in 1/144 Scale

April 16, 2018

Shapeways Canadian Autocar armored cars in 1/144 scale. These required very little cleanup. The only oddity is that two of the four have the steering wheels on the right and two have them on the left. I can’t tell from the photos of the real vehicles which is correct.

Blue Max AAR

April 14, 2018

This weekend the local HMGS-South group played a game of GDW’s Blue Max (first edition 1983) using 1/144 scale planes from the Wings of War series. The scenario was an Allied advance in the spring of 1918. A few rules were added to cover attacks on ground units and anti-aircraft fire. Five players (two German, three Allied) each flew one plane, and got a replacement if they were downed or left the table.

Both German and one Allied plane left the table damaged and low on fuel and were replaced. One S.E.5a exploded. We played 28 turns in about 3.25 hours.

 

1/6000 Naval – Armored and Protected Cruisers

March 6, 2018

Some earlier British, French and German armored and protected cruisers completed between 1892 and 1905, using Figurehead 1/6000 scale models.

WW1 Naval – Brindisi 1915

February 10, 2018

This weekend the local HMGS-South group played a fictitious naval battle set in the Adriatic in WW1. On June 15, 1915, a few weeks after the Italian declaration of war on Austria-Hungary, the Austro-Hungarian fleet sails to attack Brindisi and to lure out Italian fleet. The Italians are alerted and hope to avenge Lissa.

Visibility 14,000 yards. Wind WSW at 10 knots. Seastate 2.

Status at the end of the game: Brin IO

Damage output file: Brin output report

Player reports:
Brin Italian reports
Brin A-H reports

Plots of ship movements:
0-20 minutes brin-plot 0-20
20-45 minutes brin-plot 20-45
All brin-plot

Computer code (described here)

After four hours of play we ended the game with the Austro-Hungarians having lost 2 battleships and all their destroyers and the Italians having lost most of their destroyers. Several cruisers on both sides were badly shot up.

 

Course Calculation for Constant Range – 1913

December 22, 2017

In October 1913, Chatfield (Beatty’s flag captain) wrote a memorandum entitled “Fast Division Work from a Gunnery Standpoint” (The Beatty Papers Vol I, Item 49, page 90). This memorandum included the following statements about changes in gunnery range:

“… the attempt to obtain a tactical, or rather a gunnery advantage, usually results in a high and frequently changing rate due to constant change of course. This must affect the gun fire, possibly … to such an extent as to entirely neutralize the value of the position gained.”

“… it is quite easy, with superior speed, to calculate suitable courses which will keep the range constant and the rate nil …”

“The T must never be crossed at too broad an angle as this is unnecessary and causes a big and difficult rate.”

Two examples are given in the memorandum for a fast division speed 5 knots greater than the enemy. Both are apparently wrong and were corrected in notes added by Beatty. Also, specifying only the difference in speed is insufficient. The solution for 10 knots and 15 knots (for example) would be significantly different from the solution for 20 knots and 25 knots.

The following diagram shows the problem in a general form, where:

Ao Angle before the beam of the enemy
De Distance traveled by the enemy unit over the time interval
Df  Distance traveled by your unit over the time interval
R   Range to the enemy unit
A   Angle to steer toward enemy

Although Chatfield says he can calculate ‘perfect gunnery courses’, the range is not precisely constant over the time interval. It is only the same at the start and end points. Line Df would need to be a curve (implying a continuous change of course) to keep the range constant at all times.

A general solution to the problem can be developed by using the Law of Cosines. The area swept by the fire range is divided into two triangles:

To keep the formulas to a manageable size, intermediate terms are calculated:

Tables for various combinations of speeds, ranges and angles can be created:

Seekrieg 5 – Gulf of Finland 1916

December 9, 2017

This weekend the local HMGS-South group played a WWI naval game using the Seekrieg 5 rules.

May 15 1916,  07:30 Western Gulf of Finland
The Russians launch a heavy raid against the German patrols/ blockade of St Petersburg. The Russians sail from St Petersburg just before dusk on the 14th. At dawn both sides are sighted. Clear good weather. Visability starts ar 18,000 yards, increases to 24,000 yards by turn 5 as the morning haze lifts.

Russian:
BB Petropavlovsk
BB Gangut
CA Bayan (II)
CA Rurik
CL Jemtchug
Speed 14 knots. Course 270.

Germans:
BB Helgoland
PBB Deutschland
PBB Schlesien
PBB Hannover
CL Berlin
CA Roon
Speed 8 knots. Course 090. Initial direction to the Russians determined randomly.

Victory is based mostly on damage inflected. The Russians need to avoid a lot of damage. They cannot replace their ships, and badly damaged ships will find no safe harbor for repair. The Russians would like to “run” the Blockade to get into the German merchant shipping, but have to be only lightly damaged for that.

Mines: The Gulf of Finland has been mined by the Russians, but the Germans have prevented the Russians from maintaining the minefields. Some mines have broken loose and wandered. The mines have a low chance of contact (<5% / column of ships / turn). Slower ships can better avoid them. Only the lead ship of a column is at risk. The Russians have out of date maps, giving them some knowledge of where the mines are. Mines should influence tactics but not dominate the game. If ships stay in column there is about a 48% chance of one mine explosion in an 8 turn game.

 

Both sides led with light cruiser to take any mine hits. None occurred. Both sides turned to the north to bring their batteries to bear. With the rear ships out of range, the early turns pitted the two Russian dreadnoughts against the dreadnought Helgoland, while the armored cruiser Roon targeted the light cruiser Jemtchug. After 8 turns the Helgoland was a wreck (8 tiers of damage, two fires and only one remaining damage control team). No other ships had been significantly damaged. We called the game as a Russian victory.

 

1/6000 Naval – Various Late WW1 or Never

November 24, 2017

Filling in some of the gaps in the 1/6000 naval fleets.

[EDIT] Added some Austro-Hungarian protected cruisers and Russian seaplane carriers.

Seekrieg 5 – Dreadnought 1906

July 8, 2017

This weekend the local HMGS-South group played a WWI naval game using the Seekrieg 5 rules. The year is 1906. The British have just completed a new battleship. Navel experts claim it makes every other battleship obsolete. HMS Dreadnought and two British pre-dreadnoughts take on six German pre-dreadnoughts.

After about 4 hours of play and 20 game turns (40 minutes) we called the game. Damage results:

Pommern, 3 tiers, 12 knots
Schlesien, no damage
Braunschweig, 1 tier, boiler damage repaired
Schleswig-Holstein, light damage
Deutschland, 4 tiers, 15 knots
Hannover, 1 tier, 6 knots

Dreadnought, 4 tiers, 17 knots, both wing turrets out
Hindustan, light damage
Prince of Wales, light damage

 

Bay of Algiers, 1914, Again

April 15, 2017

This weekend the local HMGS-South group played a WWI naval game using a modified version of a scenario tested previously.

This fleet action is based on the Triple Alliance naval convention of 1913, as described in “The Great War at Sea” by Sondhaus. The plan was for the Italian and Austro-Hungarian fleets and any German ships in the Mediterranean to engage the French Fleet and block the Algerian troop transports. This scenario assumes that the war starts in February 1914, and that the British Mediterranean squadron joins the French.

The confrontation occurs north of the Bay of Algiers.

Visibility 18,000 yards. Wind NNW at 3 knots. Seastate 1

Status at the end of the game: alg2 io

Damage output file: alg2-output

Plot of ship movements:
0 to 20 minutes alg plot 0-20
20 to 40 minutes alg plot 20-40
40 to 55 minutes alg plot 40-55
55 to 70 minutes alg plot 55-70
full plot alg plot all

Computer code (described here)

The French had more undamaged ships when we quit, so the troop transports should be safe.