The US Artillery would open with the biggest guns first which happened to be the furthest away. The 280mm (8"), then the 6" (155 mm),
Then the medium artillery would chime in afterward.  The 105mm and then the 3" (76mm)
Finally the local regimental and finally company mortars. (120mm, 81 mm and finally the 60 mm)

The idea was to shell an area such that all shells impacted the target zone simultaneously.  The effect was thought to be devastating.

Did any other nation do this during WW II?

We did TOT at summer camp in the Texas ARNG. 8 inch SP.

Our 120mm mortars are immediate suppression.  The big guns (155mm) will follow if you're the priority, but I don't count on them.  Counter-battery is a real threat, and no one wants to move the guns if they don't have to...

280mm /= 8"

I hadn't heard it was combined batteries.  Think it was based on IBM technology at the time, and I don't think any other nation had that advantage during the 2nd WW.

I think we did.  A Finnish forward observer, using a manual fire correction circle, could focus the fire of different batteries and different artillery types into one target without knowing the coordinates of the firing unit. The calculations for corrections as well as the time on target were calculated at the battery level.  

Nenonen's fire correction tool

Edit: Also wikipedia credits the development of TOT to the British

thanks Backbender.  I haven't read about the Germans or Russians doing it.


Opps.  You're right.  280 = 11" like on the Graf Spee & Scharnhorst. It should be 203 mm like the guns on the Prinz Eugen.

But, back to ToT.

U.S. would've been using 4.2" (107mm) mortars in WWII, not 120mm.

BTW, I learned that the British invented time-on-target and the Americans learned it from the British.

From the time I was a kid I heard about this from the old man and his WWII experience in the artillery.  It sounded like it must be awesome on the other end when everything lands and your little world comes completely unglued.

The Crusader Howitzer was capable of Multiple Rounds Simultaneous Impact (MRSI) fires from one cannon, by firing at different elevations and charges.  Alas, it was never built.

I was one of the OPFOR interactors in the simulations used for the Crusader CEP exercises.

"Time on Target" is simply what we now call a method of control (of engaging a target).  It can be used for pre-planned fires or requested in a call for fire. Any competent cannon battery fire direction center can perform the calculations needed to place fires on a specific target at a specific time, just requires some good accurate arithmetic.  The sort of TOT you're referring to needs a great many things accomplished along the way if the idea is to mass fires of multiple firing batteries of multiple weapon types onto a target or group or series of targets simultaneously.  Sound planning and solid communications foremost among them.  Sometimes we could pull it off, sometimes not.  Murphy always got a vote.  Could other countries do it?  I don't see why not.