Mr. Tittles

He would have trouble using a SF14ZGi with that patch.

So, I disagree that what is being discussed is a RANGEFINDER. Rather, I think the reticle is part of the SIGHT. Because it is well-designed, it can assist in RANGEFINDING. So, perhaps we're both being pedantic. Well I partly agree. That is, you are certainly being pedantic. The triangle is both used for estimating range (while not a digital readout, its sure nice to have) and the actual pointing of the weapon itself. But not at the same time or even not without positioning the triangle differently. Supposedly the Germans aimed at the bottom of the target vehcile. The triangle had to have its base lined up with the target vehicle. In any case, is it really that big a deal to you? Ill drop it if you do and I agree that it probably needs attention for future projects. I think there are other uses for the triangle. It can help in finding the center of the target. Especially ones at longer ranges where the width of the triangle is larger than the base of the target vehcile. [ September 03, 2004, 01:32 PM: Message edited by: Mr. Tittles ]

Heres an experiment. take your cursor and try to point at the middle of the area of this tank. Try to do it 10 times in a row. A training trick is to first move the mouse back and forth along the length, find the middle, then do the same for the vertical. Depending on your monitor and the German sight, lets say a 5X (later model StuGIIIL48 and other panzers with 5X). You can move your seat or head back and use your thumb at arms length to guage it in (3m width tank at 1000m is 3 mil x 5 =15mil). Use a small diameter tube to look through and move the mouse. Next, try to point at a particular feature that you can make out. It can be the bow MG or gun travel lock, etc. Inspect your work after each trial by releasing the mouse (without moving it) and moving very close to the screen. Now point at the bow MG. Try to adjust to the right so that you now are aiming at the right side of the gun travel lock (its that upside down V shaped thing in the front upper hull between the radio operator and driver). Did you adjust that 1 meter interval 1m +/-0.5m? If you did, then you are one lousy gunner! You should find that while trying to center about an area. You would have a spread or scatter. But while aiming at a point, you would have much less error. Do you really buy this pointing error? [ September 03, 2004, 10:29 AM: Message edited by: Mr. Tittles ]

The Tigerfibel actually says that the 3 man technique be used 'if they have time'. I doubt it was used at anything but very long range shots where and there is no enemy counter fire going on. Even then its debateable. In any case, I have never read of any instance where it is used. I have come across references to a TZR1 rangefinder for Tiger tanks. This seems to be something different than a SF14ZGi scissorscope. Using a battlesight technique may have been used when advancing into terrain. But it would not be used while in a defensive position. A tiger tank with time to set up a range card would be better off firing with precision fire (ie entering range and actually aiming at target). Your own experiments show that guaging range with the triangle is actually quite accurate. I would not accept 50% odds on a enemy tank (first shot chance) if I could do better.

I think you have to stop golfing and start bowling.

I think you just do not have much experience with precision systems. I am fully aware of the guns scattering and also the Germans expectations of gun crews to pass a course. If anyone has been following the threads at CMBB lately, they would know that. You are misapplying this pointing error. Perhaps you think its something that needs to be applied every time the guns controls are touched. It is not true. It is only a 'buy-in' first chance factor. It will be nulled out over time. In the example I used with the 88mm at 1000m, the lateral spread is less than the width of the tank (well 99% will be in 0.6m (thats 0.3m L or R) of where the gun's pointing). Your initial pointing error could be +/- 0.5m Even the worst case of adding them together is less than half the width of the tank (3m width). The point is that missing laterally IS correctable on the next shot (under these circumstances)! Why? Because the precision of the firing system (as far as lateral is concerned) makes it so! A miss to the left should be corrected by moving the crosshairs to the right. Not 'pointing' the crosshairs but adjusting the crosshairs over by traversing the gun. How much? Depends on the observed offline amount. I think its well within human perception, aided by binocs, to percieve a relationship between the targets width and how much the shot was off laterally. Wind is not going to make such a large lateral error occur at 1000m. Most likely a out of zero gun would (either through battle damage or road bumps). The point is that with any system, when trying to use precision, the precision must be within the size of the acceptable limits (width of the tank in this example). Adjustments must have a resolution capability smaller than the 'scatter' of the precision (that is, you should be able to make adjustments that are smaller than the shot spread). Typically 1/10 would be nice. Note that gun elevation and traverse are not firehoses. They can still have repeatable (well backlash..) precision and should have it They are not smearing anything. I will bring this up with rexford. [ September 02, 2004, 05:23 PM: Message edited by: Mr. Tittles ]

I think a basic oversight (no pun intended) is that the gunner is watching the fall of shot. Usually he can't. This was brought out in the other thread also. The TC is the one who observes fall of shot and calls corrections to the gunner. The TC is usually using some form of stereocopic equipment (binoculars or scissorscopes) and has superior depth of percetion that is needed to observe the fall of shot. Carius makes this quite clear (Tiger I) in his book. Do you really believe that someone with 10X binocs could not observe fall of shot at 1000m? Observation of fall of shot can be related to the width of the target vehicle for shots that go R or L. There is no recentering when adjusting lateral misses. That is, the adjustment is dialed in and the crosshairs move accordingly. The resolution of the guns traverse sets the amount of adjustment that can be made. There is no smear. The pointing error is misunderstood by Jason. He may have a case about initial pointing trying to find the center of a target. But he can not apply the same amount of error to any other motion of the gun system after that. The resolution of the gun system traverse and elevation is not a fire hose. I think the hearrt of the matter is that Jason is making doubts about human perception, confusion about system precision and the actual method of firing a WWII main gun with a 3 man weapon crew (TC, gunner and loader).

What is being discussed is actually a rangefinder. It is not a sight. But something altogether different. Its function, as rexford agrees, is highly dependant on having good optics also. The clarity, magnification, etc. all being part of its proper function. And Germany had some decent optics AND sights AND a built in range finder feature to boot.

My question would be..Who has a superior method of guaging range..The gunner with a monosight w/triangles or a TC with binoculars with reticles? The TC has a stereoscopic enhancement typically with binoculars. This increases his depth perception. Did German binoculars have some sort of triangle built in? I was thinking of a range measuring aid the other day. Imagine a flat stick, like a ruler, that has a sliding device that can run its length. The sliding device has a small clear square with a outline of a tank engraved in the clear material. You sight a tank in the distance. You then put the end of the stick against your face under you eye. You then slide the tank outline till it overlaps the distant tank (you are lining up your eye, the tank outline and the target tank). The stick has ticks on it that designate range. Could accuracy be read to 100m or less? I would want something that could get ranges between 300m and perhaps 1000m. Basically for ATGs in fixed positions. [ September 02, 2004, 09:15 AM: Message edited by: Mr. Tittles ]

One thing that isnt modeled is atmospheric effects like dust, smoke, mist, heat shimmer that might throw off the triangle method.

Sights are Optics. German sights were excellent optics at that. his test bears out the value of a triangle with precision being built into the optics. Having excellent optical qualities only enhances the ability to read the 'triangle'. [ September 01, 2004, 07:02 PM: Message edited by: Mr. Tittles ]

The noise, unfamiliarity and stress of the gym setting through off the accuracy, which suggests that crew experience and calmness would be important. But the crew would be under this even during training. Being in a AFV is such a noisy uncomfortable thing that it is the norm. You are secluded from the world (gunner anyway) by the walls of the armor. You are much better off than a PAK40 gunner who would be subjected to the atmospheric disturbances of HE and supersonic bullets as well as clods of dirt raining down/dust/etc. You also want to survive and the adrenalized intensity of concentration IS focused through the sight. Its a unique isolation by noise and headphones (your only source of information in a noise storm). Hits on the external armor might not even be percieved unless close to your station. An AFV like a tank is very unique in the level of control by a commander (TC) that takes place. They are level to his morale in most cases. The concentration of training, firepower, will, effort and ability is such a close mesh that they are truly a team in effort. For the gunner, seeing an enemy directly target his vehicle has to be the greatest shock. Especially when you know your own armor is inferior. [ September 01, 2004, 05:13 PM: Message edited by: Mr. Tittles ]

Yeah and stop playing with these F_Knives and go do your homework.

My main thought would be that that while the earlier 88mm AP rounds may not have had the accuracy of the later Tiger I 88mm rounds, they may have made up for it with very accurate range/heading readings and vast amounts of rapid fire.

About the pointing error... Supposedly the Germans aimed at the bottom of the tank with the triangular 'pointer' in their sights. Aiming at center of mass is different in that you must judge the middle point of two dimensions (Length and Width). It is actually easier to estimate the middle of a line than the middle of an area. The trick with the German 'strich' triangle is to slide it up the bottom length of the tank; ie bring the triangle up so it 'pierces' the bottom line of the tank. When the width of the triangle meets the width of the target, then one bottom of the triangle will touch the outer edge of the target before the other! Then correct right or left, so that the width of the triangle fits neatly between the width of the tank, and you have a very neat way to find the center of the width of the target. The one drawback of this is that actual aiming at known weak spots means offset aiming. [ September 01, 2004, 11:17 AM: Message edited by: Mr. Tittles ]

PzBeobWg. Used by artillary observers, this one is mounted on a Panther chassis, note the cupola. The dummy gun is quite obvious. This OP tank was used by FOO’s (Forward Observation Officers), for directing artillery fire. Unlike the command tank, it required more major modification, and only 40 were built. The first prototype was built on the Ausf D chassis in mid-1943. Production began early in 1944and from then on, the remainder were mounted on Ausf A and G chassis. The hulls were as the standard tank, with the modifications being made to the turret. The main gun was removed, this being replaced with a dummy gun made of sheet metal, which was bolted to the front of the turret. Instead of the normal co-axial MG 34, there was a ball mount for the same weapon. This had a traverse of 5° left and right, and elevation range from -10° to +15°. For communications, the vehicle carried three radios. A FuG8, FuG4 and a Funksprechgerät f. There was also a range of observation equipment with which to direct artillery fire. In the turret roof, there was a TBF2 periscope in a ball mounting with 360° traverse. In an adjustable bracket in front of the commanders cupola was a SF142 scissors periscope. This bracket was also used for the TSR1 spotting telescope. On the front wall of the turret was a Zeiss built EM1.25m range finder. There were slots with hinged armoured covers in the front of the turret. Finally, there was a KZF2 telescopic gun sight. In front of the commander, there was a plotting board. This allowed him to accurately plot the position of a target, before directing the guns to fire. There were also several dials in the turret, which assisted the commander with bearings for the target. As these vehicles were so rear, they only went to the premier Pz Div’s, both army and SS. They were used to direct the self-propelled artillery batteries using Wespe and Hummel SP guns. There were four crewmembers in these vehicles, and the weight was reduced to 41.6 tonnes. [ August 31, 2004, 02:21 PM: Message edited by: Mr. Tittles ]

88L56 APCBC 100m....0.1m/0.1m 300m....0.2m/0.1m 500m....0.2m/0.2m 800m....0.3m/0.2m 1000m..0.4m/0.2m Heres a sample of vertical/lateral 50% data for the 88mmL56 APCBC round (TigerI round). Notice at 1000m the rather narrow spread of lateral rounds. If one were to do the stats, then about 95% of them would fall in a lateral spread of 0.58m. Or about 2 feet right or left. Jason claims that a pointing error could add up to another 0.5m R or L. But this should be viewed as an initial 'buy-in' type error and not a scattering type error itself. If firing at a Sherman tank target, the width is approx 3m. So we could have a pointing error of 0.5m left and another 0.3 m left. This is sort of a worst case but certainly could happen. We are still within the width of a sherman tank at 3m. It would take quite a range error then to bring this round to a 'lateral' miss at a 1000m (I dont care abount being long or short for now). This is due to the simple geometry of the situation. The vertical sensitivity to range is due to the sensitivity to effects of gravity. Its a square function and the longer the flight time, the greater the drop, the narrower the 'forgiveness' band where the forward moving rapidly dropping projectile will cross the target's area. The lateral sensitivity to range errors is many times more forgiving. Bringing rounds inline for a 88mL56 at 1000m would take at most one adjustment round (shame on you for missing R or L at this range). Since the so called pointing error is actually larger than the 95% lateral spread, this will be 'nulled-out' by adjusting to the right. Be aware that the rounds are still a scattering variable at this time but the adjustment to the right is not. Once the next round is fired, it will either be a short, long or a hit. Adjustments will only be in the vertical direction now. If its a miss, and at the same height as the previous round, then odds are that you have a case to adjust the vertical. Lets say the round that went wide to the left was about 3m off the grund. The next adjusted round just missed the top of the sherman by 0.5m (sherman about 2.7m tall). It would certainly be worthwhile to adjust the next shot downward about a 1m. Note that the vertical spread is greater and the vehicle shorter. Here is where you would need to trust the gun since it has already given you two vertical samples while adjusting the lateral spread. The 95% vertical spread will be about 1.164 m. Odds are that those two rounds have 'bracketed' the vertical scatter and a downward correction is advisable. Again, the vertical correction is not subject to this pointing error. Note that if this stationary sherman decided to move, its best bet is not to move directly backwards but rather at an angle and backwards. This is due to the fact that varying its range at this point does not effect the firer as much as changing its lateral position. Note how much tighter the vertical 50% zone is at 500m. Since the initial pointing error and range estimates are also reduced (and penetration is up), firing at this close a range at stationary targets is quite deadly.

http://onwar.com/tanks/ussr/profiles/fpt3476m43.htm An interesting thing about T34s is that the upper left corner of the drivers hatch is nearly dead center. If the Germans used the top of the triangle and lined it up on this upper left corner, then they could have a point of reference of repeatability in aiming to reduce this 'pointers-error'. The greater the magnification/clarity of the sight, the more easily it is to point repeatably at a single point also. I believe it is range dependant but still a small error that may effect the initial shot(s). If the sight is not adjusted during those initial shots AND the gun is repeatable as far as coming back to a common initial starting angle, then it is not scattering but staying constant. Its basically a 'buy-in' error. In many cases the shot scatter is larger in vertical than lateral. One might then say that immediate corrections to bring the shots in line are worthwhile. Being left or right should be 'fixed' before long or short is what I am saying. Since tanks are generally wider than tall, this further supports 'fixing' the left or right error first. In fact, being left or right is somewhat independant of range estimation errors! This is actually quite important. Notice that Jasons pointing error is not applicable to adjustments to fire. That is, the firer does not decide to swivel the turret away so that the target needs to be reaquired and a new pointing error created. He could be left of the targets width 1-3mil with the first two shots and adjust the sight to the right 2mil to compensate. This correction would not be subject to his +/-1mil error for 'new' pointing, or does he think it is? Basically he is turning a device to get the effect. He is no longer 'pointing' but rather adjusting. He is no longer striving to get a majical centering on the strangely shaped area target but moving in one plane a percieved amount. There is a difference. Another related topic is the fine resolution that is needed to make adjustments. It is not infinitely variable. I would imagine the finely geared raising of the gun could be better than the turret traverse used as a method to rotate left and right onto a target. Most tanks appear to have a fixed trunion that the gun can raise and lower about but theres no additional refinement for right and left besides the big gears around the turret. [ August 30, 2004, 09:45 PM: Message edited by: Mr. Tittles ]

In Tankerschool (end 1943) the crews had to fulfill the following: 1st Exercise: Using HE on a target at unknown range but less than 1200 meters. Own tank stationary target stationary (size of AT-Gun) Criterion to pass: 1 Hit out of 4 rounds 2nd Exercise: HE on a target at range greater 1200m, six HE rounds authorized (target the same as in 1) Criterion to pass: 1 Hit 3rd Exercise: AT round on a (stationary, frontal) tank target at greater than 1200m. 4 rounds authorized Criterion to pass: 1 Hit 4th Exercise: AT round on a moving (ca. 20km/h) tank target across the field of vision at 800 - 1200m. 3 (!!!) rounds authorized Time: 30 sec. Firing time, target moves 150 m Criterion to pass: 1 Hit Notice: No Examination on tanktarget stationary below 1200 m !!

http://afvinteriors.hobbyvista.com/ This valuable website is closing down unfortunately. The author says that people should copy pages if they feel like it. You have just a day or two.

Sherman 76mm had other problems also. Its debut as the next great thing didnt pan out. From Mycenius website... Addendum - Blast effect of 76mm gun M1, in Medium Tank, M4A1, during firing tests. A total of four (4) rounds were observed from the tank commander's position. Blast obscuration timed in observing a target at 1000 yards varied between 3.1 and 5.8 seconds. It is not believed that tracer could have been picked up by a tank commander with field glasses under 1500 yards. Firing was conducted in a 5 to 10 mile, 12 o'clock wind, in a grassy field. There was absolutely no dust encountered. All obscuration resulted from muzzle smoke. (Note: Many accounts say that the TC must be either heads out or have a ranging scope to observe fall of shot. Gunners are often not able to pick up the flight of the round. But the Sherman 76mm seems to produce such a smoke blast that even a exposed TC can not see the round) The US AT capability was marginally improved by the 76mm shermans till they got HVAP ammo. The 75mm shermans were never improved with HVAP. The 90mm guns had better results with early shot against Panthers but an 'improved' M82 round with a larger HE content seemed to have problems also. The 90mm HVAP was probably the best answer to any Panther/Tiger head to head confrontation.

"Zeroing is firing the gun to ascertain the point of projectile impact, then all instrument crosshairs should be aligned with the center of the shot group on the target." "The gun is said to zeroed if the check round hits within 2 feet of the aiming point at 1500 meters" (for the M41 90mm gun) The major flaw here is that a check ROUND (singular) is used as a final check. It would have to be a shot group of rounds really. One round does not tell much unless the target is very close. I strongly suggest that reading the APCR thread would help in understanding the concepts here. The fact is that gun scatter, if modeled according to a normal distribution, will place many rounds with acceptable precision but quite a few rounds with marginal precision. 1 out of 20 will be wild in all but the closest ranges. So correcting aim based on observed shots needs to take that into account. [ August 30, 2004, 08:40 AM: Message edited by: Mr. Tittles ]

Range estimation is almost certainly the TC's call at greater than 1000m or so. He is the one that has the best ability to do this when he is using any binoculars (with reticles). The gunner has a monocular sight. He is also the one to call corrections. His stereoscopic perception is increased with binoculars and many gunners can not sense the tracer or depth with a monocular sight. German sights had a means of estimating range directly by the gunner but this would be best used for short to medium ranges and have a component of guestimation also. Since firing at these ranges is somewhat forgiving, it wasn't a bad system. But at longer ranges, the task was best accomplished by the TC and his experience and the quality of his binoculars would have a direct bearing. having to face an enemy that conveniently had a homogenous tank mix (like the Russian T34), certainly helps.

I think Jason makes the point that range errors (for any weapon system without a means of actually measuring range to +/- 50m lets say), is the greatest cause loss of accuracy. It is itself range dependant in that longer ranges make larger errors. But gun scatter is much larger than this pointing error he brings up. To give an example, a 75mmL48 has about 1.0m by 0.9m 50% zone at 1500m. This means that typically 5 out of 10 rounds will fall within an area of 0.9 sq m. The next 5 will fall within 7.6 sq m. Most of the 10 will be within the size of a typical tank target in late WWII. The pointing error he claims is smaller than this area and a neccessary component of adjusting for range. So the relative size of each and its function needs to be taken into account. I would 'trust' the gun only for 2-3 shots and then make corrections at long ranges. The precsion of the gun at shorter ranges would enable the gunner to make corrections after one shot. The Germans certainly thought so and the British certainly changed their style to the Germans during the war. Its like trying to throw a ball through a tire. A hard baseball or a still larger softball might not be that much different given a short range and a 16 inch rim type tire. Trying to throw a basketball through it gets much harder. If the precision of the shot scatter is small in relation to the size of the target, then precision can be achieved. Lets say we are firing a Tiger I at a Pershing at 100m. The shot scatter is actually so small that the offset of the gun in relation to the sight is larger.

Until the beginning of 1942 British anti-tank gunnery used a 'false range', they aimed low and added a few hundred yards depending on the actual range. From the beginning of 1942 they adopted zeroing of anti-tank guns, usually using a tank sized target at 500 yard with the aim point being centre of mass. This meant the actual range could be set on the range drum, part of the drill for coming into action was to prepare a range card for recognisable objects in the zone of fire. They also issued simple tables for lead depending on range and speed and whether the target was a 'direct crosser' (45- 90 degree approach angle) or 'diagonal crosser' (15 - 45 degrees). This was related the lead graticules ('lead units') in the anti-tank telescopes. Of course the time of flight of the shot from high velocity anti-tank guns at normal battle ranges was under 1 second, and a tank moving at about 15 mph covered about 7 yards in this time. A 'direct crosser' at 15 mph required a lead of 1 and a 'diagonal crosser' a half, the smallest lead order was a quarter. Anti-tank engagements were conducted by the No 1 giving initial orders to identify the target relative to the centre of arc, describing it, ordering the range and lead, and ordering fire. He then ordered corrections using 'Add' or 'Drop' for range (these were cumulative) and a new lead (not cumulative). These corrections were judged by observing the tracer to see where the shot went relative to its target. By 1943 ranges and correction were always ordered to the nearest 200 yards unless the target was hull down in which case 100 yards was used. The following table, based on firing table probable errors, shows the inherent direct fire accuracy of anti-tank guns when their MPI was on the target centre (ie no human errors). In operations worn guns and other mis-alignments could reduce the chance by up to half at shorter ranges and to a quarter at longer ranges. In the first years of the war training material was issued detailing the most vulnerable areas of enemy tanks. This may have had some use for very short range engagements with infantry anti-tank weapons. It was unrealistic at longer ranges and the 1942 doctrine of 'centre of mass' ended it as far as anti-tank artillery was concerned. Trials also established that a 2 or 6-pdr at the end of its barrel wear life would hit only 18 inches low at 1000 yards. Table 2 - Chance of Hitting a Vertical 6ft × 6 ft Target Gun 1000 yds 2000 yds 5000 yds 2-pdr 90% 40% 1% 6-pdr 96% 55% 3% 17-pdr 98% 80% 15% 25-pdr (Chg super) 80% 45% 7% http://members.tripod.com/~nigelef/anti-tank.htm