Technology and Operations
This forum is for discussing technological & operational matters pertaining to U-boats.
Re: Shinano sinking
Posted by:
J.T. McDaniel
()
Date: March 29, 2006 02:06AM
What I posted was manually typed, but the scans on the DVD are jpg images of the originals or, possibly, positive images scanned from the microfilm copies, so they're exactly what was turned in after the patrol. Despite somehow missing those two lines the first time, I tried to duplicate the original as exactly as possible, including typos, spacing errors, and any other fluffs.
The TDC would continue to update between shots, so technically it might not be a new setup. A couple of years ago I got to hang around in COD's conning tower while the TDC worked on a solution. We manually programmed in an initial bearing, target speed, angle on the bow, and own ship course and speed, then just let it run.
The solution light came on fairly quickly, and it was fascinating to watch the dials and readouts turning as it kept the notional target lined up in the boat's sights. At one point the solution light went out as the "target" passed too close down one side, getting inside the safety range of a Mark 14, and then shifting the "target" to the stern nest and getting a solution for those fish. It was, of course, a somewhat more ideal setup than you'd normally encounter in combat, where the target would be zig zagging instead of steaming a straight course, and the sub would be maneuvering to insure an optimal attack.
In any case, if you fired three torpedoes at the same 8 second interval and then waited three times that long to fire the next one, you'd probably get the same sort of difference in track and gyro angles as the TDC adjusted the setup for the changing relationship between submarine and target. SHINANO was moving fairly fast, and the range was only 1400 yards, so the relationship between the two vessels would have changed pretty rapidly.
As far as I know, there are only two places where you can do this sort of thing, Cleveland and San Francisco, as COD and PAMPANITO have the only two functional TDCs. Different Marks, so both get to be unique. Most of the time you can't even do it in those places, as the TDC is located in the conning tower and submarine museums don't normally allow casual visitors up there.
J.T. McDaniel
The TDC would continue to update between shots, so technically it might not be a new setup. A couple of years ago I got to hang around in COD's conning tower while the TDC worked on a solution. We manually programmed in an initial bearing, target speed, angle on the bow, and own ship course and speed, then just let it run.
The solution light came on fairly quickly, and it was fascinating to watch the dials and readouts turning as it kept the notional target lined up in the boat's sights. At one point the solution light went out as the "target" passed too close down one side, getting inside the safety range of a Mark 14, and then shifting the "target" to the stern nest and getting a solution for those fish. It was, of course, a somewhat more ideal setup than you'd normally encounter in combat, where the target would be zig zagging instead of steaming a straight course, and the sub would be maneuvering to insure an optimal attack.
In any case, if you fired three torpedoes at the same 8 second interval and then waited three times that long to fire the next one, you'd probably get the same sort of difference in track and gyro angles as the TDC adjusted the setup for the changing relationship between submarine and target. SHINANO was moving fairly fast, and the range was only 1400 yards, so the relationship between the two vessels would have changed pretty rapidly.
As far as I know, there are only two places where you can do this sort of thing, Cleveland and San Francisco, as COD and PAMPANITO have the only two functional TDCs. Different Marks, so both get to be unique. Most of the time you can't even do it in those places, as the TDC is located in the conning tower and submarine museums don't normally allow casual visitors up there.
J.T. McDaniel
