Roger wrote:I never said it played a role at Midway.ladajo wrote: Radar gunnery was still being worked out by the time of Midway, the primary use of Radar was early warning.
Though on the other hand the use of optical sightings were pretty much obsolete, or going to be.
The Mark 8 came out in late 1942. Both Mark 3 and 4 were introduced in late 1941.
By the time the Iowas were out they used a Mark 13 3cm radar, Mark 41 Stable Vertical(gyro), two Mark 38 Gun Fire Control Systems, Mark 8 rangekeeper.
Unfortunately the debate you wish to have cannot include many citations of actual ship of the line exchanges, there just weren't that many. Certainly no Iowa vs Yamato scenarios. The Washington and West Virginia each were involved in firing at night to good effect. The Iowa class beat on cruisers and destroyers.
So you wouldn't aim at the bridge?
...that is what were talking about, no?
What I am saying is if you hit the bridge, it is luck, not planned.
Spotting fall of shot is easy even with a crappy radar, and 5 Meter/Yard accuracy is crappy by today's standards. Fall of shot is a function of splash size verses height of eye for the radar.
Radar precision comes as a function of three things: pulse rate (PRR), pulse width (PW), and scan speed. Normally scan speed is not so much an issue given the high pulse rates, and in relative terms, short pulse widths. The issue really tells when you go long range with low pulse rates, and long pulse widths. This is typically found in long range air search or older generic search radars.
PRR determines for one, the theoretical range of a radar. The time between each pulse divided by two, times the speed of light gives you the max range. In practice, there are methods to differentiate between a primary return, and a second or higher zone return, especially on A-scope, but this is difficult, and not widely practiced.
PW determines the the actual range precision the most. If the leading edge of the pulse is nice sharp and clean (not so common on older radars), then you get a nice clean sharp return that is more accurate. The problem is with a wider pulse, you get less resolution. So if you have a wide pulse, you may paint a smaller target, as it gets more energy (or duty cycle) to reflect, but if there are several small targets together, you will only see one big smudge for video. And if they are reflective complex targets like ships tend to be, then you get a even more smeared return.
Scan rate, obviously determines the lateral smearing of a pulse across the target, slow scans mean clean pulse hits, fast scans give more smearing.
Fire control radars employ different types of scan patterns to maintain locks, unlike search radars which mostly employ a classic radial sweep. One of the more common is a spiral or raster pattern. What this actually does is smear your target video even more when in lock.
What I am saying is that given even modern radar technology employed, be it CW Firecontrol or a hybrid track while scan type, such as the widely used Mk92 CAS and its various versions, you do not get so much choice in where you hit the target. As I said before, using radar, you can use the offset functions to "bias" you fall of shot left/right or short/long, and hope for the best. And we have much better stuff today than then.
If you want to selectively target, you are going to use optical, period. I can track a large bug with SPY, but that certainly does not mean I can hit it with a main battery mount.
Modern fire control calculates and tracks Many (with a capital M) variables that it then number crunches for a solution for each round tossed. We do this, because back in the day, you could have a good lock, good solution, and really cool massive fire control gyros, but still miss entirely.
In the Battle of Leyte Gulf, during the Suriago Straits engagement, you had 6 BB's, 4 CA's and 4 CL's along with a 28 DD's. They entered the battle with a chosen limit of firing Main Guns (14 & 16 inch) at 17K to 20K yards due to ammo shortages. The Japanese capitol units were picked up by radar at about 40K. When they reached about 33K the order was given to open up at 26K. All cruisers were ordered to open up when Louisville ranged about 15.6K. Then Main Battel Line opened up at about 22.8K (for the record, 5 of the 6 BB's had been hit or sunk at Pearl, but were now in the game). They were facing Yamashiro and Mogami (of Midway fame). Fuso had already been knocked out of the line by the DD's. West Virginia, Tennessee and California all mounted the Mk8 Fire Control. WV fired 93 rounds of 16inch, Tennessee 69 14inch, and CA 63 rounds of 14inch. Maryland, Mississippi and Pennsylvania mounted the Mk3 fire control. They had difficulty targeting the Japs. Maryland used WV fall of shot splashes as targets, firing 48 rounds of 16inch. MS fired only one full salvo (one glimpse of radar target at 19,790 yds), and PA fired nothing (no radar target). The Cruisers fired over 4200 8inch rounds. Mogami was hit once in the bridge, Yamashiro was not hit in the bridge.