Maximum range on TDC

[nomad_delta]

Has anyone else noticed that the TDC has a maximum range of about 8990 yards? I've spotted a merchant about 20k yards away (according to my cheating WO) on a very clear night and was trying to ballpark guess its actual range with the stadimeter, but it keeps entering "8990" for the range.

What's odd is that the 'range' field on the TDC has FIVE digits, so it seems like it should be able to accept numbers higher than this.

I guess it doesn't matter terribly much, but it pretty well eliminates the use of the stadimeter to make range estimates from far away when trying to plot a target's course and figure out an intercept.

How do you guys plot courses on very-far-away targets and determine your intercept paths? (Assuming you don't have radar, which I currently do not)

nomad_delta

[SteamWake]

Id make a note of his heading and speed and plot an intercept course.

I have never used the TDC as an aid. Usually I start planning from much much further out.

[nomad_delta]

But how do you get heading and speed when all you can see is a blur on the horizon? (I guess I also should have specified that I'm playing with map contact updates turned off...)

nomad_delta

[Puster Bill]

Originally Posted by nomad_delta

But how do you get heading and speed when all you can see is a blur on the horizon? (I guess I also should have specified that I'm playing with map contact updates turned off...)

nomad_delta

Using the Watch Officer isn't cheating: It's his friggin' job to tell you bearings and distances.

What you need to do is build yourself a Submarine Attack Course Finder/IS-WAS. Here is the link where you can download it, along with the instructions:
http://www.subsim.com/radioroom/showthread.php?t=106923
Print it off on cardstock and inkjet transparencies, then put it together.

Here is what mine looks like:

Front:


Back:



Once you've done that, you can use the SACF/IS-WAS to find the true course and speed of a target given two range/bearing observations. You can also use it to plot an intercept course, and you can use it to find the AOB of the target once you are getting ready to shoot.

I *HIGHLY* recommend using it. It works just as well as doing the calculations manually, and much better than just 'guesstimating'. It's also pretty cheap, less than $10 or $15 US in materials to make several of them.

It also has the advantage of being authentic: It is what real US sub commanders (actually, probably someone in the tracking party) used to determine things like course, speed, and AOB of an enemy vessel.

[SteamWake]

Nice job on that Puster Mine looks like a 5 year old put it together LOL.

BTW who the hell still uses a straight key ? I bet you only use it to tune the rig :p

[Puster Bill]

Originally Posted by SteamWake

Nice job on that Puster Mine looks like a 5 year old put it together LOL.

BTW who the hell still uses a straight key ? I bet you only use it to tune the rig :p

BZZZT! Wrong answer. I do 95% CW, and I've only ever used a straight key. Straight keys are the best, because it allows your natural fist to shine through.

I love having a QSO with someone using a vibroplex or a keyer at 20 wpm, then casually mentioning that I'm using a Chinese Army straight key. I can do between 18 and 20 wpm comfortably for a ragchew, and probably 25 or so for a contest type exchange.

Of course, I learned Morse in the Army, and spent 8 hours a day for 4 years copying it (ex 05H10 EW/SIGINT/Morse Interceptor), so I sometimes actually have dreams in CW.

[nomad_delta]

Originally Posted by Puster Bill

Using the Watch Officer isn't cheating: It's his friggin' job to tell you bearings and distances.

Agreed, but how on earth does the WO figure out exact distance to a target that we haven't even identified yet (and which is too far away for me to have any hope of identifying...)

I guess I also don't like relying upon the WO as my only means of determining distances, 'cause he'll only tell me the range and bearing to the closest target... which means if there happens to be a life boat or something sitting closer he'll keep telling me about that instead. :p

I don't mind having the WO do his job, but I'd at least like to know how he does it so I can do the same myself if I have to.

____

The SACF/IS-WAS looks mighty cool, have been thinking 'bout trying to put together one of those. I don't have an inkjet printer handy though so the transparencies might be a bit of trouble.

For now I've just been using the Nav Map to plot my range/bearing sightings, and then drawing a line through the marks on the map to estimate target course and speed. Only problem with that is that I can't get range values until I'm within stadimeter range, which is apparently ~9000 yards.

nomad_delta

[Puster Bill]

Originally Posted by nomad_delta

Agreed, but how on earth does the WO figure out exact distance to a target that we haven't even identified yet (and which is too far away for me to have any hope of identifying...)

I guess I also don't like relying upon the WO as my only means of determining distances, 'cause he'll only tell me the range and bearing to the closest target... which means if there happens to be a life boat or something sitting closer he'll keep telling me about that instead. :p

I don't mind having the WO do his job, but I'd at least like to know how he does it so I can do the same myself if I have to.

____

The SACF/IS-WAS looks mighty cool, have been thinking 'bout trying to put together one of those. I don't have an inkjet printer handy though so the transparencies might be a bit of trouble.

For now I've just been using the Nav Map to plot my range/bearing sightings, and then drawing a line through the marks on the map to estimate target course and speed. Only problem with that is that I can't get range values until I'm within stadimeter range, which is apparently ~9000 yards.

nomad_delta

How my WO gets the range isn't my problem, as long as he gets it. Also, I know this is true in SHIII, not sure about SHIV, but the range the WO gives you isn't exact, it is in 100 meter increments, so there is always some 'slop' in those measurements.

If you need a rational, consider that the guy is an experienced officer, and remember that the human eye in real life can probably resolve details better than you could put on a computer screen.

If you only build the backside of the SACF, you don't need the transparencies. However, if you take the files on a memory stick or diskette to the local Staples or other office supply place, they can print them there on cardstock, transparency, or whatever, and even laminate them for you (which I recommend that you do).

Since I have a printer at home, and had cardstock already to print my QSL cards, all I had to get were some transparencies and some self-stick lamination.

I recommend that you build one as soon as you can. It makes interception and actually hitting the target much easier.

[XLjedi]

Originally Posted by nomad_delta

I guess it doesn't matter terribly much, but it pretty well eliminates the use of the stadimeter to make range estimates from far away when trying to plot a target's course and figure out an intercept.

How do you guys plot courses on very-far-away targets and determine your intercept paths? (Assuming you don't have radar, which I currently do not)

nomad_delta

How does range estimate influence your intercept course calculation?

I would understand if you were saying you need distance to estimate speed... but if target speed and heading are known, distance can be anything you want and it won't effect the result of your constant bearing intercept formula.