GENERAL Mar-Apr 1975, Vol.11 No. 6
THE
By Mark Saha
The Kettering aerial torpedo was developed and built for the U.S. Army
Signal Corps by, the Dayton Wright Company in 1917‑1918 and was the
world's first guided missile – though science fiction terminology of the day
would probably have labelled it a "robot bomb." But to the Signal
Corps it was known simply and affectionately as the "bug." It had a
speed of 55 mph and a range of 40 miles, and weighed 560 pounds – including 180
pounds of explosives.
The following Richthofen's War game variant assumes that the "bug” was
in mass production in late 1917 or early 1918, and generous quantities were
sent to
The Situation: It's a blustery, cold day between winter and spring
somewhere in
The Allies are also in desperate straits after four years of war, and so –
knowing full well what's up – are unwrapping every new weapon they have.
Including the
Admittedly, used in this manner, the "bugs" can do little or no
practical damage. Nonetheless, like the buzz bombs over
Therefore, YOU, lucky fellow, have been sent up on patrol to shoot down as
many of the little rascals as you can. Your commanding officer tells you it
ought to be quite easy, really. A sport. A quail shoot. After all, the little
beasts only travel 55 mph ‑ and in a straight line at that – except as
shifted by the wind. So go on pull on your gloves and set your goggles
comfortably in place, and count your lucky stars that you've drawn this dream
of a solo assignment rather than out dog fighting and intercepting missions
with the boys.
But be careful. You are likely to comeback the laughing stock of the
squadron – having been made a complete fool of by the "bugs" – and
you may not even come back at all!
Kettering Aerial Torpedo is a solitaire game
variant for Richthofen’s War. All
Advanced Game RW rules are in effect except as qualified here because of'
special problems posed by shooting down the aerial torpedo. The optional
Prevailing Wind rule is also in effect, and the chart for this rule has been
reproduced on the aerial torpedo's ASP for convenience of the player.
The game assumes the player to be a lone German pilot, not an ace, on
patrol. He has been assigned to intercept and shoot down as many as possible of
the new aerial torpedoes or "bugs" launched from dispersed sites
behind Allied lines, entering the game board from random directions at random
altitudes. While such use of torpedoes by the Allies does little practical
damage, their appearance behind German lines in the final weeks of preparation
for Hindenburg's big 1918 offensive is wreaking havoc with morale of German
troops who have never seen this frightening new weapon before. Thus, the player
has been pulled from regular combat duty and assigned to patrol this sector to
let through as few "bugs" as possible.
He may choose any German plane he wishes for this assignment, though in the
course of' the Campaign Game (a series of twelve "bugs" in one day)
he may never change planes and accumulated damage may thus eventually affect
his aircraft's performance.
(1) Select any German aircraft you wish, including the Fokker DR.I, but do
NOT designate yourself an ace. Set the aircraft anywhere on the south edge of
the game board and face it as you desire. Then choose your current altitude and
speed and set them on your ASP sheet. You are now on patrol and ready to
intercept a "bug.”
(2) Roll a single die and consult the "bug" Starting Hex chart on
the aerial torpedo ASP sheet. The numbers and letters on this chart refer to
six possible entry hexes behind Allied lines. Thus, hex “34” is the specific
hex bearing that number on the west edge of the game board, and "KK"
refers to the specific hex bearing that notation on the eastern edge of the
board. Notice that while both "5" and "21” are north edge hexes,
"bugs" entering on these two
hexes have different facings – Southwest and Southeast, respectively.
Place the "bug" on the game board on the hex indicated by the die
roll, and face it either Southeast or Southwest as indicated by the brackets on
the Starting Hex chart. These are the only two facings a "bug" may
ever have.
(3) Roll a single die to determine the entering altitude of the “bug”.
Consult the Starting Altitude chart on the torpedo ASP sheet and set the
altitude accordingly.
(4) The average speed of the "bug" is "4," so roll the
die to determine whether it is entering at average speed. If the die cast is
even, it is – set the Speed Track on its ASP at "4." If the number is
odd, it is travelling at either faster or slower than average, so you must roll
the die again to determine which; if the number is odd, it enters at
"3" if even at "5". Set the ASP Speed track with the
correct reading.
This is the only time you have to roll the die twice to determine the
torpedo's speed. Hereafter a single die roll moves the Speed indicator one way
or the other as indicated, though it may, never read faster than "5"
or slower than "3" on the Track.
(5) You do not roll the wind chart on the first game turn. Both aircraft
and torpedo are assume to have been already "shifted*' to these star
positions by, the wind.
(6) You are now ready to play. The "bug” moves first, in strict
accordance with rules which are given below. You may move your aircraft a will,
in compliance with usual Advanced Game rules.
(1) Roll die for wind and consult the Wind Chart on the aerial torpedo ASP
sheet. "Shift" both torpedo and aircraft as applicable according to
wind rules. (Notice you do NOT roll on the Wind Chart on the First Game Turn
ONLY!!!)
(2) Roll die to see whether the "bug" will increase, decrease, or
maintain speed this turn. (Again, only, one die roll is required on each AFTER
the First Game Turn.)
(3) Move the "bug" its full movement allowance according to
current ASP Speed Track reading. This is in addition to any forward or backward
"shifting" due to a headwind or tailwind. Also, remember to add or
subtract on movement point from the Speed Track reading is the bug has climbed
or dived this turn (Climbing and Diving rules are given below.)
(4) The German aircraft may now move according to usual Advanced Game
rules. However, special combat rules for attacking the "bug" must he
observed.
That is a Complete Game Turn: this sequence is followed until the “bug”
successfully crosses the game board or is shot down by the aircraft.
(1) FACING: The aerial torpedo
is always placed on the board on one of the six starting hexes given on the
Starting Hex Chart. It is then faced either Southeast or Southwest, according
to the Starting Hex Chart designation for that specific hex. Thus a torpedo
placed on hex “21” on the north edge MUST face southeast.
Once placed on the game board, a torpedo may NEVER change its facing. It
proceeds directly across the board along the hex grain line upon which it has
been placed. Thus a torpedo placed on hex “21” would travel Southeast and
theoretically exit the south (German) edge at hex A‑21.
However, during the course of the game the torpedo will be constantly
"shifted" by the wind front one grain fine to another. Nonetheless,
it will simply continue Southeast along the new grain line, always at its full
current movement capacity, until it either exits the board or is shot down.
(2) WIND EFFECTS: All aircraft
in this game are affected by wind according to the Optional RW Prevailing Wind
rule. However, the "bug," being much lighter, is always shifted ONE
HEX FARTHER than an aircraft within the same altitude bracket. Thus, aircraft
above 2,000 meters are shifted TWO hexes and the bug THREE hexes; aircraft
between 2,000 and 850 meters inclusive shift ONE hex and the bug TWO hexes;
aircraft below 850 meters are shifted NOT AT ALL and the bug ONE hex.
(3) CLIMBING AND DIVING: Whenever
the bug encounters a direct headwind (i.e., it is heading Southeast and
encounters a Northwest wind) it CLIMBS 50 meters and LOSES one movement point
on that turn. This is in addition to being "shifted" backwards by the
wind according to its altitude bracket. When this happens, change the altitude
reading on the ASP but DO NOT change the Speed Track reading: simply remember
to subtract one movement point from whatever that reading is when the bug
executes movement.
Whenever the bug encounters a direct tailwind (i.e. it is heading Southeast
and encounters a Southeast wind) it DIVES 50 meters and GAINS one movement
point that turn. Again, adjust the altitude reading on the ASP but NOT the
Speed I Track; simply, add one movement point to the Speed Track reading at
time of execution of movement.
Thus, it may be seen from this that a “bug” could theoretically, spurt
forward an incredible 9 hexes in one turn. This would happen if it were hit by
a tailwind while travelling at 2,050 meters at a speed of "5." It
would be "shifted" forward three hexes by the wind, dive 50 meters
and gain one movement point, to move six hexes in its movement phase.
Finally, notice that "bugs" usually enter the board very near
Prevailing Winds altitude brackets. Thus, diving or climbing may easily put
them in a new bracket and increase or decrease the degree to which they are
"shifted" by wind. The example just given is a case in point: having
dived 50 meters from 2,050 to 2,000, the bug will now be shifted only two hexes
rather than three by the wind on subsequent ruins. Unless it's hit by a
headwind and climbs again to 2,050 meters
If, due to a constant tailwind, a torpedo at low altitude should descend to
zero altitude – i.e., crashes not due to combat – the consequence is determined
by the hex of impact. A crash in German territory is an Allied success. A crash
in Allied territory or in "no man's land” is an Allied failure, and may
count as a German success. Notice that torpedoes which exit the board over “no
man's land" still count as Allied successes.
(4) LOCAL WINDS & GROUND SPEED:
The above rules are complete Prevailing Wind rules as regards the wind chart on
the ASP. However, remember, we have said that the game takes place on an
unusually blustery day with very unstable and choppy atmospheric conditions.
These more immediate “local conditions" have no effect on aircraft on this
game scale, However, they do affect the much lighter aerial torpedo, as its
smaller engine must attempt to pull its payload through this turbulent air in
what amounts to a series of random sputters and sudden forward jolts.
This is simulated by Step 2 of the Game Turn Sequence and is quite simple.
During this step you roll a single die; if the number is ODD, you decrease the bug's
ASP Speed Track by one movement point; if EVEN, increase the reading by one
movement point. Notice that the Speed Track can NEVER read lower than “3” or
greater than "5". If the Track is at three and an odd number is
rolled, the Track reading simply remains at three, Moreover, notice, it would
take two consecutive even rolls to increase the speed from "3" to
"5" –where it would again remain, no matter how many more even rolls,
until decreased again by an odd numbered roll.
All the RW Advanced Game rules of combat, especially those of range and
“sighting” apply, except as further modified here by special problems presented
by stalking this unique target on a blustery spring day. At first glance, it
might seem that the aerial torpedo is "a piece of cake”; it's travelling
at a fairly, low rate of speed – 55 mph – and on a fixed course. However, it
also happens to be a tiny little devil and is bouncing around a lot in the
wind. Moreover, even its slow speed can catch experienced combat pilots by
surprise – because the more quickly you overtake it, the less time you have to
properly “line a shot." So you have problems, and they are incorporated in
the following combat restrictions:
(a) No deflection shots are allowed. You must either strike a tail shot or
head‑on for a forward shot. You must expend the usual last 2 movement
points to “sight” in either case.
(b) You must be at the EXACT same altitude as the “bug” to “sight” and
"fire" on it. Not 50 meters higher or lower.
(c) You must be within 50 meters range (one hex) of your target to fire at
it without penalty. A head‑on shot may not be attempted at all from
greater than 50 meters. A tail shot may, be attempted from 100 meters but a
penalty subtraction is made from the roll of the dice.
(d) The faster you are travelling relative to speed of the bug, the more
difficult it is to line your shot – and the greater the subtraction penalty to
the dice.
While rules for attacking an aerial torpedo may seem a little complex at
first, in fact they are simpler than Advanced Game dogfights. Remember, you may
only make head or tail shots, and at the exact same attitude as your target. If
you have properly, sighted your target and are entitled to fire according to
range and altitude, here is how to factor any penalties:
(a) RANGE: No head‑on attacks are allowed at greater than 50 meters.
(b) Tail shots are allowed at 50 or 100 meters: but if at 100 meters you
must subtract three (‑3) from the dice.
(c) SPEED: If your Speed Track reading at the time of firing exceeds the
Speed rack of the "bug" by two movement points subtract one (A) from
the dice. If you exceed the Speed Track of the bug by TWICE its current reading
(e.g. he's going “4” and you're going "8"), subtract two (‑2)
from the dice. If you are travelling at TRIPLE the bug's Speed Track (he's at
“3” and you're at "9"), subtract three (‑3) from the dice.
If you have DIVED the turn of your attack, you must add any dive bonus
hexes to your Speed Track reading before comparing it to that of the “bug”.
A head‑on attack is also a special case; in this event, you must ADD
your Speed Track Reading (including any dive hexes) to the Bug's Track reading
– and compare this TOTAL (since you an
approaching the bug at this velocity) to the bug's Track reading to assess your
speed penalty. While this is not quite accurate, it's a reasonably close
approximation to what you're doing and what penalty you should incur.
We warned you that the aerial torpedo was hard to hit, both because Of its
size and hem bounced around by the wind. Nonetheless, if you do hit it you're
likely to knock such a small object right out of' the sky there is no such
thing a "accumulated damage" to the torpedo. Thus:
(a) Only a CRITICAL HIT destroys the aerial torpedo anything else, no
matter how marry hit are counted as misses and have no effect.
(b) However, a critical hit destroys the torpedo instantly. It is not
necessary to roll the Critical Hi 'fable.
(c) However, the torpedo carries 180 pounds of explosives, which may
detonate if your critical hit has penetrated the payload. Thus, when you
destroy, a torpedo it "attacks" you as follows:
If you are at 100 meters distance, it has no effect on your aircraft.
If you are 50 meters distant on a tail shot destruction of the torpedo
results in an "attack" on your aircraft on the B‑6 CRT table
with it modification of the dice.
If yon have destroyed the torpedo with ahead on shot, you are
"attacked" on the A‑1 CRT chart with no modification of dice.
If you receive a critical hit in either case, you must immediately roll the
Critical Hit Table against yourself.
During the Campaign Game of twelve bugs, a certain amount of emergency
repair may be made between interceptions. "Fuel Line Severed, Aileron
Cables Fouled, Controls Jammed, and Gas Tank Punctured" results may all be
repaired at the cost of letting one "bug" pass free overhead.
Elevator cables severed may be repaired by letting two "bugs" pass
overhead. Struts shattered are permanent and affect performance for the
remainder of the day as does engine damage. Pilot killed or wounded and you
lose everything.
Also, "accumulated damage" is permanent and when it exceeds 50%
begins to effect aircraft performance as per standard Accumulated Damage rules.
The Campaign Game is simply a series twelve individual encounters with a
"bug" by your aircraft which is assigned to patrol this particular
sector for the entire day.
After each encounter, you are assumed to have landed and may reload your
machine guns to ammunition capacity without penalty. You may also make any
emergency repairs b, paying the penalty in "bugs" passed overhead as
indicated. Accumulated damage, as you have noted, is permanent for the day.
At the start of each new encounter, you may place your plane on a different
start hex wit different altitude and speed in accordance with set-up rules.
Then, of course, you roll for random entry hex, attitude, and speed of
"bug" intruder.
The odds of shooting down any one "bug" are given on the odds
breakdown chart, although they are based on somewhat ideal range and sighting
figures and disregard problems you may have with wind. Nonetheless, depending
on the aircraft you have selected, you may judge from that the expectations of
your commanding officer and whether you have pleased him or not.
Incidentally, he will certainly not be pleased if you've done damage to his
fine, beautiful new aircraft he's "loaned" you for the day, So a
critical hit not subject to emergency repair or accumulated damage greater than
50% will each "trade off (i.e., delete) one "bug" killing, and
75% damage deletes two "bug" killings, So be nice to your aircraft!
A "bug" must exit the game board over No Man's Land or German
territory to be considered an Allied success. If the wind blows it off course
so that it exits over Allied territory, you may credit yourself a
"win" even though you don't deserve it. But don't place your hopes
too high as I've never seen it happen yet. (Please notice that, as in standard
Prevailing Winds rules, an aircraft or “bug" can never be
"shifted" off the map board; such results are ignored.)
There is a minor exception to standard RW Advanced Game rules which should
be noted here. The "bug" – but not the aircraft – is exempt from the
rule that you may not end your movement on a hex occupied by another aircraft.
Thus, it is not uncommon in the course of a game that the "bug"
will encounter a headwind with an aircraft 50 meters (one hex) on its tail
Since the *'bug" is "shifted" back one hex further than the
aircraft, they will both end upon the same hex. This is allowed, and no
collision occurs.
Moreover, the "bug" always expends its full forward movement
allowance, even if this would place it on a hex occupied by the aircraft.
The aircraft is NOT exempt in this fashion. It may never end its movement
on the same hex as the “bug”
WIND CHART*
Between 50 and 800 meters alt wind shifts bug one hex; between 850 to 2,000
inclusive shifts bug two hexes; above 2,000 shifts bug 3 hexes. Aircraft use
standard wind rules.
|
|
||||
|
Starting Hex |
Starting Altitude |
|||
|
SE |
1 |
21 |
1 |
1,000 |
|
2 |
28 |
2 |
950 |
|
|
3 |
34 |
3 |
850 |
|
|
SW |
4 |
KK |
4 |
2,050 |
|
5 |
OO |
5 |
2,000 |
|
|
6 |
5 |
6 |
2,100 |
|
*Also see HEADWIND AND TAILWIND special rules.
By Richard
J. Plock
This variant presents a very interesting version of the Random Walk problem,
worth a deep and detailed analysis (which I have not given it). I present here a rough approach (hopefully
sufficient for readers to apply for themselves), and its application to two of
the German planes. I realise that most will only be interested in the final
answer, but some may wish to see how well they are doing with planes other than
those I have selected.
My basic assumptions are that you, being the hotshot flier you are, will
make no errors in manoeuvring and will enter at a reasonably optimum altitude
and position; likewise you have been able to convince your commander that you
want one of his better planes. (If you think a clunker will do, wait until you
see what happens with a good plane.) This, then, represents the best average
you can hope for with the two planes I have chosen. If you are lucky, you may
do better; but you cannot expect to average much better,
The first thing we need to know is the behaviour of the torpedo. I will not
give the methods by which I arrived at these numbers, but the table below gives
the average speed after the first turn:
|
ALTITUDE |
HEADING |
|
|
Southeast |
Southwest |
|
|
Low |
4.90 |
4.66 |
|
High |
5.15 |
4.89 |
Speed is perhaps a poor term in this case; what I am referring to is the mean
displacement per turn towards the southern edge of the board. There is in
addition an Eastward displacement that I had to use, but it is not necessary
for your purposes. There is also an average drop of 17 meters per turn for
torpedoes headed southeast. Using this, we can arrive at the following for the
average number of turns the bug remains on the board:
|
ALTITUDE |
ENTRY
HEX |
|||||
|
5 |
OO |
KK |
21 |
28 |
34 |
|
|
Low |
9.16 |
8.94 |
8.08 |
7.90 |
8.80 |
7.92 |
|
High |
8.77 |
8.57 |
7.75 |
7.20 |
8.40 |
7.60 |
For the remainder, it is necessary to handle each aircraft in an individual
fashion. I have chosen to examine the Fokker D‑7 and the Albatros D‑3.
The Fokker is the best in the German arsenal; it has a maximum speed of 10, a dive
speed of 8, a dive limit of 500 meters/turn, and a manoeuvre chart D. For the
Albatros (the workhorse of "Bloody April”) these are respectively 9. 6,
350, and C; this is still pretty good. I assume the Fokker to enter at about
2200 meters; the Albatros at about 1900 meters. Both fly at maximum speed until
they reach the torpedo.
Going by the averages, the Fokker may expect to reach the torpedo on turn
#3 no matter where it has entered. Approximately 67% of the time it will have a
tail shot, 33% a head shot. By taking the manoeuvre chart D and considering
every possible combination of wind directions and torpedo velocities, it is
possible to conclude that the Fokker can maintain a position on the torpedo
tail (distance of one hex) and continue to shoot to all cases of a SE directed
torpedo, and 95% of the turns for a SW directed one. Thus we get the following
mean number of shots using the Fokker:
|
ALTITUDE |
ENTRY
HEX |
|||||
|
5 |
OO |
KK |
21 |
28 |
34 |
|
|
Low |
6.9 |
6.7 |
5.8 |
5.9 |
6.8 |
5.9 |
|
High |
6.5 |
6.3 |
5.5 |
5.2 |
6.4 |
5.6 |
This gives an overall average of 6.1 shots. The mean probability of a shot
being successful is about 0.125. Our expectation of destroying the torpedo
therefore comes out to be 56%.
The Albatros does not do as well. It may get head shot on the torpedo on
turn #3 if it enters low but expects a tail shot on turn #4 for high
entries. Furthermore using chart C (and
once again looking at all possible combinations), the probability of an immediate
follow‑up shot is only 67% if the current shot is head‑on, and 75% ‑
80% the current shot is a tail shot. Our
overall average number of shots in this case is only 4.5; and the expectation
of' destroying the torpedo 45%.
Keep in mind that all of the above assumes there has been no loss in the
airworthiness of the plane from damage by a previous torpedo. Should that
occur, you can expect much poorer results. If you undergo no significant
damage, you may expect to get 6‑7 bugs with the Fokker out of a sequence
of 12, and about 5 with the Albatros. Still think you want to use a
Halberstadt?
For those of you that want to extend this to the other planes. I obtained
the figure of 12.5% probability of a successful shot by estimating the 15% of
the shots have no subtraction, 50% subtract 1, 20% subtract 2, and 15% subtract
3. Remember also that you do not add the probability of hits, but multiply the
probability of misses. Hence, for the Albatros and Fokker, I used the
following:
|
Number of Shots |
3 |
4 |
5 |
6 |
7 |
8 |
|
Probability of Success |
0.33 |
0.41 |
0.49 |
0.55 |
0.61 |
0.66 |
In trying to do you own calculations, keep in mind the fact that you must
not "guess I'll get 4 shots in turns," but set up every combination
of wind directions and bug speeds, find its final location and see what
restrictions exist for the plane to get shot this next turn. If it is possible,
then take new speed required for the shot and see whether possibilities are
still covered (or, rather which ones, are not – you will find few cases of 100%
coverage). You will find that manoeuvre charts A and B start to impose severe
limits on the probability of successive shots, hence seriously reduce the total
number of shots you can take. Here is a sample part of my tables:
|
Bug Heading SW |
Albatros |
Current Shot |
||||
|
Current Bug Speed |
Wind |
Altitude Change |
New Speed |
Probability |
Tail |
Head |
|
4 |
SW |
-50 |
3 |
1/12 |
6 |
NO |
|
SW |
-50 |
5 |
1/12 |
8 |
NO |
|
|
SE |
0 |
5 |
1/6 |
6 |
7 |
|
|
E |
0 |
5 |
1/6 |
5 |
6 |
|
|
SE |
0 |
3 |
1/6 |
ANY |
5 |
|
|
E |
0 |
3 |
1/6 |
6 |
5 |
|
|
NE |
50 |
3 |
1/12 |
NO |
NO |
|
|
NE |
50 |
5 |
1/12 |
6 |
7 |
|
The last two columns give the restrictions on the current speed of the plane
to get a shot this coming turn (keeping in mind the speed limits). (NO means no
shot possible; ANY means shot always possible.)