RFB, Accurate Manual Targeting and Realism

[Munchausen]

Originally Posted by Nisgeis

From a static point, a ship steaming East at 5 knots at a range of 5,000 yards will have the same bearing change rate as a ship steaming East at 10 knots, at a range of 10,000 yards. This is a problem if you spend some time observing your target whilst running a parallel course.

:hmm: I think that's the point of adjusting speed.

Say you judged your target to be 5,000 yards away. But it's a bigger ship and actually 10,000 yards away. Your approach officer plots the correct bearing but at the estimated range of 5,000 yards ... then a second plot gives him a speed of 5 knots.

Plugging the data into the TDC and engaging PK, the actual target will cross each successive bearing sooner than indicated on the TDC. So you increase target speed. Eventually, you'll cancel out the error generated by incorrect target distance ... although the geometry in the TDC won't necessarily look anything like the real approach.

A good way to test this is by plotting sonar. With map contacts on, mark the tip of one sonar line ... then do it again after about three minutes. Measure length of the sonar line and take an educated guess at target speed. Then insert range, bearing, AOB (target heading) and speed into the TDC. Turn on PK and track target bearing via sonar. If the target runs ahead of PK bearing, increase target speed. If it runs behind, decrease speed.

One good thing about this technique is that you can change target speed on the TDC without messing up any of the other data (changing range and bearing always changes target heading ... setting it to whatever heading corresponds to last-set AOB).

The bad thing is you can find yourself chasing the speed dial. If your target bearing is advancing slower than the TDC, you need to memorize a good speed, then dial down to near-zero and wait for the target to catch up ... then set the new speed. If your target bearing is advancing faster than the TDC, you need to insert a speed higher than required and let the TDC catch up ... then set the correct target speed. (Instead, you could, of course, adjust bearing directly ... but that would then throw off your estimated range and target heading.)

[pragr]

I'm noob and maybe I'm discovering the wheel only, but after I read this thread, I begun use this method (at least during submerged attacks).

As soon as the ship reachs the range where I can use the stadimeter for estimate the distance, I use the reco manual and set the distance to the target with it's data. When I have the distance this way, I switch to the sonar and use it for the accurate measurement of the range. So now, I have three numbers. Two for distance, one for the mast/funnel/deck high. All the other things are easy. The ratio between the "sonar"(most accurated I can get) distance and the "stadimeter" distance is the same as the ratio between the real high of mast/funnel/deck and the one I used.

e.g. I used 90ft for the mast in stadimeter. So I got 7000yards as the distance through the stadimeter, but sonar distance is only 5000yards. It means I overrated the high of the mast about 30% (5000/7000). So I reset the high of the mast to the 63ft (0.7*90) and any next measurement through periscope will be accurate.

The best thing on this method is, that you don't need to use the pre-set reference point. If you want, you can use the high of the funnel for merchents or bridge for the warships. You not even need the recognition manual.

I haven't had enough time to test it, but these several encounters I used it, it worked great. At least enough I could hit the targets even from 3000yards.

Pragr.

[kstanb]

Sorry for really newbie questions:

- Playing with RFB 1.52 and noticed that for some ship picture there are 2 models (e.g. medium oiler, medium tanker), both with identical pictures, but with different mast heights. Is this WAD?

- How far away from a DD is it safe to use the active sonar for range finding?

- Is RFB 1.52 compatible with any optic magnification MOD?

thanks a lot

[Bilge_Rat]

I found this thread while searching for something else, but while relooking at RFB 2, I still have problem with this whole issue.

When I play the "torpedo tutorial" in RFB 2.0, the recognition manual and the 1.52 manual tells me to use the funnel height to determine the range of a heavy warship. If I use that standard, the range to the CA Mogami is way off, around 2700 yds instead of around 1500 yds actual.

On the other hand, if I use the top of the tallest mast, the range is always within 10% of the actual range.

So what is the proper method, always use tallest mast or do we have to guess with each ship?

[TorpX]

My understanding, is that the tallest funnel is the proper point for warships. But, as CapnScurvy says, the numbers are dubious. I encountered a Chitose seaplane tender, and I didn't know if the reference pt. should be the flight deck (for aircraft carriers), or tallest funnel (other warships).