Manual TDC
From Wolves at War
To new recruits:
I wanted to save these articles and discussions from the old site -- makes for good reading while you're waiting for your boat assignment. These references were originally in the "Officer's Club" area, but this is probably a better place for them where new recruits can view the material.
First was an message from Kaleun Andreas Schmitt, which included a reference to an article on long-range intercepts of convoys and targets. This is an excellent article and may be useful when performing your final training patrol.
http://www.communitymanuals.com/shiii/index.php?title=Intercepting_Targets
The second message was from Kaleun Franz Saar, which included a reference that goes into extensive details on ways to perform close-in intercepts and Manual TDC.
[1]http://www.paulwasserman.net/SHIII/
If you find manual targeting hard, here are some hints on what I do that might help you. [color=red][i]Keep in mind there is no one way to do Manual TDC -- this is just mine.[/i][/color] Practice will determine what's best for you.
Manual TDC can be frustrating at first, but as many others have said, once you start using Manual TDC successfully, you'll probably never go back to automatic -- even with the occasional misses. After all, the goal of W@W is realism, not just high tonnage. That said, here's how I approach Manual TDC --
First, set your speed and angle off bow once and leave them alone.
I find the notepad pretty useless most of the time for speed. I find the 3.5 minute rule discussed in the second article above more useful. Actually, any time distance measurements will work if you use the analog time-distance-speed chart on the right side of your maps. Get a time and distance -- draw a straight line through your time (sec) and distance (km) on the chart -- where the line intersects the speed -- that’s your estimate.
You can also use sighting reports from BdU as an initial estimate. If you're told a convoy is going 6 kts, why not start with that?
Once I establish a speed, I go to the TDC, select MANUAL, enter the speed, and reselect AUTO. As long as you don’t enter a speed on the notepad, entering the other data from the notepad will not change your manual speed entry.
For angle off target bow, I initially set it close to 90 off, but make sure you get the correct side. Remember, this is how the target sees you in relation to it’s bow. Selecting the wrong side will ruin your day and your shot.
I select 90 degrees because this is where I want to shoot -- why make things harder -- and I will make every effort to position my boat here for shooting. You know you’re abeam when you just lose sight of the forward portion of the target’s bridge. If I can’t make the abeam position, I’ll change AOB once in step 6 below.
Second, ID your ship.
You’re not going to get good range information without a proper ID. You can ID multiple ships and the notepad will remember each ship Identified for quite a long time -- even if you unlock the ship and relock later. But keep that recognition book handy and set to your primary target just in case -- the notepad can forget after long periods of time.
Third, select your torpedoes.
Even at range you can usually tell whether the target is big or small -- BdU recommends a minimum of two torpedoes per target -- it’s a pretty safe selection.
Select them (usually two), set depth, set speed, set spread -- the greater the range, the less spread angle you want to use (unless you’re going for the shotgun effect against a convoy). Remember, every 1 degree of spread at 1000 meters is 17.5 meters (approx. 55 feet) of separation between torpedoes. My rule of thumb against a small single target is:
300 - 999 meter shot -- 5 degree spread 1000 - 1499 meter shot -- 4 degrees 1500 - 1999 meter shot -- 3 degrees 2000 - 2500 meter shot -- 2 degrees > 2500 meters -- why bother?!
I’ll usually do this in between range/bearing estimates when trying to get speed in the first step above, but the positive ID will influence your depth setting.
Fourth, now that you have ID, speed and AOB set, you can concentrate on Range and Positioning your boat.
You need good range for two reasons: (1) to assess how you’re doing relative to positioning your boat; and (2) the final shot. Remember, the TDC is computing the lead the torpedo must pull to intercept the target. AOB and speed are important, but a good range is critical.
If you use 100% realism, then periscope stabilization will be turned off, which makes range a bear in rough seas; especially when looking to the side. This is because the wave action against the side of the boat causes it to roll back and forth, and if you’re looking sideways, the net effect is an up and down pitch. In these cases, unlock the target -- set the horizontal crosshair on the ship’s waterline -- and put the target’s highest point under the vertical ticks on the left hand side of the scope and count them off. Now that you know how many ticks, relock the target -- select notepad range -- click the range icon -- move the variable range bar to the correct tick -- and click the mouse. You don’t have to worry about positioning the horizontal crosshair directly under the ship -- if you’ve counted the correct number of ticks, you have what you need).
Fifth, OPEN your torpedo doors (“Q” on the keyboard)
You’re torpedoes will come out a lot faster with the doors already open, and you want torpedoes on their way as soon as possible after you make you final range calculation.
Sixth, time for the final shot --
Lock the target. If you're not going to shoot abeam, adjust your AOB now.
You really want your nose (or tail for stern shots) on the target to get a final range calculation -- the least amount of scope stabilization roll occurs within 20 degrees of your nose (or tail for stern tubes). But don’t be maneuvering all over the place when getting ready for the shot -- get positioned ahead of time.
Now everything should be preset except for the current range. This really has to be done with the scope locked on the target -- to get the rest of your notepad data for final download to the TDC. I perform these steps as quickly as I can as the target gets close to where I want to shoot:
1.) Select notepad range 2.) Get the horizontal crosshair on the target waterline 3.) Click the range compute icon 4.) Move the variable range line to the highest point on the target and left click the mouse
If you get a sudden pitch during steps 2, 3 and 4 -- do them again -- get a good range.
5.) If the range is good, click the checkmark to SAVE 6.) Click the checkmark again to DOWNLOAD the notepad data to the TDC -- [b]don’t forget this step[/b] 7.) Fire torpedoes
This was really step by step, I typically shorten it to:
Range -- Save -- Download -- Shoot
Lastly, what Olaf and others have said is absolutely true. You’re best chance of a kill is in close and personal. The closer you are (but not inside 300M minimum range), the less any minor errors in you calculations will have on the final outcome -- the greater the range, the greater the impact of your cumulative errors.
The Snap Shot
The snap shot was a viable technique of shooting when in the "thick of things" where you either don't like your solution or just don't have time to get one. In a snap shot, you are not using the TDC, but aiming the torpedo's path using the periscope or UZO. Range shouldn't matter, but I don't recommend this outside 1000 meters. Snap shots should also be performed close to the bow (or stern for rear shots) unless you really understand how a torpedo travels -- a subject I'll address in a separate post later. To perform a snap shot, you do the following:
1.) Lock the target and note the bearing
2.) Compute the gyro angle by adjusting for lead from the table below. Add lead to the bearing if target is moving left to right; subtract lead from bearing if target is moving right to left.
3.) Break lock and move the periscope to lead the target by the angle computed in step 2. Remember, you are NOT setting the periscope look angle, you are setting the GYRO ANGLE located directly under the notepad. The two may be very close in value depending on what legacy data is in the TDC, but it is the GYRO ANGLE you want to set ...
4.) ... and shoot.
This is best used in the abeam position against a medium or large target. You have to knock degrees off as your AOB increases from abeam position. For example, firing 45 degrees from abeam, you may want to cut the lead almost in half. Clearly, how much lead you pull is dependent on the speed of the target. Most often, you will probably be shooting SLOW (30 kts) torpedoes, but here's my rule of thumb for lead in degrees against various convoy speeds and different torpedo speeds. These also assume your torpedo doors are already open.
Lead for Abeam Snap Shots Convoy Spd \ Torpedo Spd 30 kts 40 kts 45 kts -------------------------------------------------------- 6 kts \ 11 deg 8 deg 7 deg 10 kts \ 20 deg 15 deg 13 deg 14 kts \ 28 deg 21 deg 18 deg
Example. I have a target bearing 280 moving right to left and estimate it's speed at 6 kts. Firing a 30 kt torpedo, the lead is 11 degrees from the table. I want to shoot when the target bears 270. Because the target is moving right to left, I must subtract the lead. 270 bearing - 11 lead = 259 gyro angle. My torpedo doors are already open. As the target approaches 270, I break lock; move the scope to the left until my Gyro Angle reads 259; and shoot.
One last thing if you haven't already noticed -- in NYGM, the ENTER key will NOT launch you're torpedoes -- I think this is a good thing personally -- you must hit the FIRE button on the torpedo control panel to launch torpedoes.
Hope this information is useful. Happy Hunting with Manual Targeting.
